Wednesday, April 26, 2006

DAN and SSS Issue Joint Press Release

We received an email from Dan Orr, President of DAN concerning a joint news release from DAN and SSS located on DAN's web site. This is a most welcome note indicating that the impasse between the two entities has been resolved and settled. Here is the note from DAN:

"Divers Alert Network (DAN) and SSS Network of Recompression Chambers (SSS) Joint Press Release

Divers Alert Network (DAN America) and clinic members of the SSS Network of Recompression Chambers (SSS) announce that they have reached a settlement in the recent legal action. Representatives of SSS announce that DAN America insurance is once again accepted as a result of the resolution of the outstanding claims that were the basis for the lawsuit. The terms of the settlement remain confidential. The SSS Network of Recompression Chambers and DAN America pledge to work closely together to ensure that injured divers will receive the most appropriate and effective medical care."

Decompression illness presenting as breast pain.

There is an interesting article in the Undersea and Hyperbaric Medical Journal relating two reports of decompression illness presenting as painful breasts. This is in Volume 33, #2 by A.J. Trevett, C. Sheehan, Y. Forbes.

They present two cases of decompression illness in women in whom the initial symptom causing distress after completion of the dives was breast pain. Both women were also subsequently found to have a patent foramen ovale. They postulate that breast pain may be an unusual under-recognized manifestation of decompression illness.

This is more interesting because of a discussion that took place on our Scuba Clinic Forum back last year concerning several women divers with similar complaints and responses provided by consultants and other divers. Two of these divers anecdotally had PFOs. This thread can be seen on our forum at this location:

More about women divers at

2nd Congress of the Alps-Adria Working Community on Maritime, Undersea, and Hyperbaric Medicine

The Croatian Maritime, Undersea, and Hyperbaric Medical Society Naval Medical Institute is sponsoring a meeting to be held at Zadar from 18th to 21st October 2006. Capt. Nadan Petri writes requesting that we post information about this meeting, the 2nd such held since 2001.

Dear Dr. Campbell,
please be so kind and put the web site

as a link on Scubadoc portal.

It is the official web site of the 2nd Congress of the Alps-Adria Working Community on Maritime, Undersea, and Hyperbaric Medicine.

You might remember that you did the same for us in 2000/2001, on the occasion of the 1st Congress, held in April 2001.

Hope your visitors might be also interested in knowing the info about our Congress.

Thank you so much for your concern in this matter and your most kind support.

Best wishes,

CAPT Nadan M.Petri, MD, PhD
President of the Croatian Maritime, Undersea, and Hyperbaric Medical Society
Naval Medical Institute

21000 Split, p/o box 196

fax 00385-21-381-716

MedWatch Warning: Risk of Oxygen Regulator Fires from Poor Gasket Use

April 25, 2006 — Healthcare professionals and the public have been warned by The US Food and Drug Administration (FDA) and the National Institute for Occupational Safety and Health (NIOSH) of the risk for fires from the cylinder valves and regulators of oxygen tanks.

MedWatch, the FDA's safety information and adverse event reporting program reports today that fires have been linked to the incorrect use of CGA 870 seals.

The FDA has received 12 reports in which the regulators burned or exploded, in some cases during emergency medical or routine equipment use. Although there may have been other contributing factors, improper use of the nylon crush gasket variety of CGA 870 seals is believed to have played a major role in both fire ignition and severity.

The FDA notes that these single-use gaskets require higher torque than the elastomeric multiple-use sealing washers, and they require more torque with each successive use to seal the cylinder valve/regulator interface. Wrenches or other hand tools used to achieve this torque can deform the crush gasket and damage the cylinder valve and regulator, resulting in oxygen leaking across the gasket. This apparently causes "flow friction" from O2 leaking across the gasket surface and producing thermal energy igniting the nylon material.

The FDA and NIOSH advise against reuse of plastic crush gaskets. Other recommended precautions include "cracking" cylinder valves to allow expulsion of foreign matter from the foreign port prior to regulator attachment; use of manufacturer-recommended sealing gaskets; and visually verifying that the regulator and seal are in good condition prior to connecting the valve.

Hand-tightening the T-handle is also advised to reduce the risk for damage associated with wrenches and other hand tools. The post valve should then be opened slowly while maintaining a grip on the valve wrench to allow rapid closure if gas escapes at the junction.

Additional information regarding the proper use of CGA 870 seals may be obtained by contacting April Stubbs-Smith, Office of Surveillance and Biometrics (HFZ-510), 1350 Piccard Drive, Rockville, Maryland 20850. Questions may also be submitted by fax to 1-301-594-2968 or by e-mail at, and voicemail messages left at 1-301-594-0650 will be returned as soon as possible.

Healthcare professionals are encouraged to report adverse events related to use of CGA 870 seals to the FDA's MedWatch reporting program by phone at 1-800-FDA-1088, by fax at 1-800-FDA-0178, online at, or by mail to 5600 Fishers Lane, Rockville, MD 20852-9787.

University of Auckland Graduates First Physician as a Specialist in the field of Diving and Hyperbaric medicine.

Dr Dives To Medical History

University of Auckland, from Tower

The newspaper 'Scoop' reports from the University of Auckland that it has graduated it's first physician as a specialist in the field of Diving and Hyperbaric medicine.

Christchurch emergency physician Dr Sandy Inglis will make New Zealand medical history on April 27th when he becomes the first doctor to graduate with a Postgraduate Diploma in Diving and Hyperbaric Medicine from The University of Auckland.

The diploma programme and a Master of Science specialisation in the field are run by Associate Professor Michael Davis, Medical Director of Christchurch Hospital's Hyperbaric Medicine Unit, which is one of only two units in the country equipped to treat scuba divers suffering from "the bends".

Professor Des Gorman, Head of the School of Medicine at Auckland's Faculty of Medical and Health Sciences, congratulated Dr Inglis on becoming the first to graduate from the programme, which was introduced in 2004.

See the entire article at this web site.

More about New Zealand dive accident facilities at this site:

Tuesday, April 25, 2006

DDRC Investigates HBOT Effect on QoL on Diabetic Neuropathy

The DDRC (Diving Diseases Research Center), always in the forefront studying hyperbarics, is investigating the long term effect of HBOT on the quality of life of patients with diabetic neuropathy. The condition can be devastating, causing loss of use as well as incapacitating pain. Read about this study (and others) at this site:

DDRC - investigation into the impact of Hyperbaric Oxygen Therapy (HBO2)
on Quality of Life (QoL) in patients with Diabetic Neuropathy

5th International Symposium for Hyperbaric Oxygenation and the Recoverable Brain

Please remind your readers that we are fast approaching the deadline for early bird reduced rate for delegates – May 1st.

Thanks very much.

Sharon Phillips

Saturday, April 22, 2006

UK Coast Guard Diving Accidents

UK Diving fatalities down, but accidents up (From the

The 2005 figures for open water diving accidents reported by HM Coastguard reveal that while fatalities are down from 2004, the overall number of accidents has risen slightly. During 2005, HM Coastguard Maritime Rescue Coordination Centres reported a total of 254 open water diving related accidents, and these incidents ranged from cases of decompression illness and medical emergencies to broken down vessels.

Thirteen fatalities have been recorded, with one case reported 'previously missing' (body found of a previously missing person). The greatest single incident category remains decompression illness (DCI) which accounts for 70 incidents alone, with a further 45 attributed to rapid ascent, which may have developed into DCI. Medical emergencies also accounted for 27 which may not have been diving related but arose from a pre-supposing medical conditions.

These statistics relate to only those in which HM Coastguard coordinated Search & Rescue or was involved. National Diving statistics including both open water and inland diving together with detailed analysis, are available from the BSAC ( who is the National Governing body for UK Sport Diving.

The south coast of the UK again saw the highest number of accidents reported reflecting its popularity and accessibility as one of the premier diving areas in the country.

More about UK Dive Accident Facilities and contacts at

Friday, April 21, 2006

Are There Risks for Diving while on Dialysis?

Dialysis and diving

Hemodialysis being done

A recent question prompted an effort to find the risks of scuba diving while on renal dialysis.

I am a librarian in a French hospital and I am looking for articles or other documents about diving and dialysis. I have found the following link on your website : but I can't find anything else.

Could you help me ?

There are no studies or references to dialysis and diving, that I can find. Of course, I have had several questions over the years from persons with renal failure who want to dive, have dived or who have questions or comments about the problem. The material below summarizes my recommendations to a question from a diver.

Main problems seem to be associated with immersion effects, dehydration and/or diving "wet" (in the case of peritoneal dialysis, with an abdomen full of fluid or diving just before the need to dialyze.). The study linked below indicates some of the cardiovascular changes that can occur.

Renal disease can cause changes in the sensorium due to obtundation from elevations in byproducts of metabolism (BUN, creatinine). Whether or not this is additive to the effects of elevated partial pressures of nitrogen at depth is not known but should be assumed. In addition, there might be some cerebral alteration in the response to stress and decision-making abilities from accumulations of blood nitrogen (metabolic, as well as gaseous).

There would be no problems related to the depth/pressure changes that take place in air-containing body cavities and there probably would not be any increased risk from a decompression accident due to the renal disease, unless there was associated dehydration. Peritoneal access sites should be well healed or sealed due to the possibility of marine infection and there should be no air containing equipment on the diver. The diver should not dive while "wet" - that is with a fluid load of the dialysate intra abdominal.

Simple immersion causes a central shift in the body fluids, which would increase the GFR (glomerular filtration rate) in the normal individual. This factor, plus the decrease in the anti-diuretic hormone, causes normal kidneys to excrete more urine (pee factor with diving). If the kidneys could not manage this increased load, there would be the possibility of increased cardiac pre-load with the possibility of heart failure and pulmonary edema.

If there are no secondary changes associated with the renal failure (eye, heart, brain), one can be certified as fit to dive. However, there are other factors that must be taken into consideration - one of which is the anemia that is usually associated with renal failure. Diving should not be done if the Hgb is below 12 Gm/dl. This is usually managed by using Procrit (Erythropoitin) injections and oral iron replacement. The patient can also be on many other medications which might be inimical to scuba diving, such as anticoagulants, sedatives, blood pressure medications and antihistamines.

The person on dialysis walks a fine line between diving dehydrated, right after a treatment and diving wet, just before a treatment. Each of these situations has it's risks.
Here is a citation in Medline about cardiovascular changes in dialysates during diving.

Evaluation of cardiovascular autonomic function tests in dialysis patients.
Chu TS, Tsai TJ, Lee SH, Yen TS.
J Formos Med Assoc. 1993 Mar;92(3):237-40.

Standard Diving Medicine textbooks do not discuss diving and dialysis, nor is it addressed by the UKSDMC or DAN.


Cuba Moves Ahead in Hyperbaric Medicine

Cuba Moves Ahead in Hyperbaric Medicine

There is a conference about hyperbaric medicine that is going on in Cuba at this time. In the province of Sancti Spiritus the Cuban Society of Hyperbaric Medicine and Undersea Activities (SCMHBAS)is closing a meeting today (April 21, 2006) attended by experts from Spain, Costa Rica, Panama, Mexico and Peru.

Every hospital on the island is provided with hyperbaric oxygen services. In several of these facilities, hyperbaric chambers are indeed multipurpose units in which patients in critical conditions have been treated.

Participants in the conference are analyzing the use of hyperbaric techniques in the treatment of ulcers, graftings, diabetes, herpes zoster, chronic arterial deficiency and other illnesses.

Cuba is well supplied with hyperbaric facilities - there being a chamber in every hospital in the country.

Information about Cuban chambers can be seen on our web site at .

Wednesday, April 19, 2006

Bermuda Hospital Board is Looking for Hyperbarics Safety Officer


We require a qualified and experienced Hyperbaric Safety Officer to manage and supervise the operation of the hyperbaric chamber and equipment and maintain safe operating procedures, emergency procedures and maintain routines. The Hyperbaric Safety Officer is to ensure that all personnel operating hyperbarics equipment and attending patients in the facility are appropriately qualified to perform their duties.

Responsibilities include:

· Ensures compliance with all applicable codes and standards and in particular National fire Protection Association 99 (NFPA99) compressed Gases Association (CGA) standards for hyperbaric medicine

· Reviews and monitors all department safety standards, compiles and submits reports to departmental staff and to the Quality Improvement Department

· Works closely with Medical Staff, Critical Care Programme Management Team, and Faculties Management to develop and review polices and procedures, operational and maintenance strategies

· Develops positive relationships with jurisdictions having authority including: Emergency Measures Organization, Bermuda Fire Services, Pressure Vessel Inspectors, and others.

· Works closely with the Medical Director, Clinical Coordinator and Facilities Management for all chamber upgrades and equipment maintenance to ensure that all applicable standards are net, conducts tests of all modifications prior to manner pressurization

· Evaluates hyperbaric chamber equipment/ supplies used in the chamber and ensure that they meet safety requirements before they are permitted in the chamber

· Maintain a safe environment in the hyperbaric in the hyperbaric facility for patients and staff and utilizes approved and recognized decompressure procedures for all persons with hyperbaric exposure to inert gases

· Serves as one of the hyperbaric facilities technical trainers for staff, and provides in-services related to the various aspects of hyperbaric physiology, decompression requirements, equipment operations, and safety and treatment protocols

· Generates and supervises hyperbaric chamber safely drills which are tailored to improve staff response to emergency situations

· Conducts an annual review of safety related events in order to identify trends and monitor improvement.


· Minimum of (3 –5) three to five years experience in clinical hyperbaric chamber operations

· May be a registered Nurse or Respiratory Therapist or Electrical / Mechanical Technologist

· National Board of Diving and Hyperbaric Medicine Technology (NBDHMT) or recognized equivalent Hyperbarics Safety Course

· B.C.L.S. and Computer Literate

Professional Affiliation:

· Membership in professional organization such as: Undersea and Hyperbaric Medical Society (UHMS) Associates of HHMA, etc.


U.S. Clinical Trial to Explore Link between Common Heart Defect and

St. Jude Medical Announces First Implant in Its Migraine Headache Study;
U.S. Clinical Trial to Explore Link between Common Heart Defect and
Migraine Headache

More about PFO at

Cardiocerebral Resuscitation

Cardiocerebral Resuscitation: An Interview with Gordon A. Ewy, MD

The mortality rate with cardiorespiratory resuscitation is miserable and now it's time to do away with the "giving breathes" aspect of rescuscitation - just using chest compression. This good study shows the way.

Cardiocerebral Resuscitation on Medline - Related Articles

Monday, April 17, 2006

"Pressure", publication of the UHMS, March/April, 2006

The UHMS has sent out it's publication, "Pressure" for March/April, 2006.

MESSAGE FROM OUR PRESIDENT .............................. 1
DON’S PERSPECTIVES ................................................... 2
QUALITY ASSURANCE CORNER ................................. 3
ASSOCIATES NEWS ....................................................... 4

Even if you are not a member of the UHMS, this information is valuable for your scuba diving and hyperbaric related activities. It is an excellent organization for physicians and non-physician professionals to consider joining.


2006 Annual Meeting of the EUBS (European Underwater and Baromedical Society)

Dr. Olivier SIMON sends us the following information about the upcoming EUBS meeting to be held in August in Bergen, Norway.

"May I suggest you to publish the following announcement on (and blog)
In case you didn't write about it (or maybe I didn't watch carefully enough....)
This conference might seem a little bit too far away from your country, but I think it is worthwhile. (beside the fact that english is the official language ;-)

It is the 2006 Annual Meeting of the EUBS (European Underwater and Baromedical Society) that will take place this year in Bergen,Norway on the 23rd-26th of August.

Here's the link for more information and registration:

Olivier SIMON, MD
Member of Medsubhyp
Member of EUBS"

DAN Tip of the Month

DAN Tip of the Month: Eco-friendly Diving
As we prepare to celebrate Earth Day on April 22, think about what it means to be an eco-friendly diver.
There are lots of things you can do to show your love of the underwater world.
---Streamline your gear so it doesn't drag and damage the site
---practice good buoyancy control and don't touch—anything
---If you must touch as you spearfish or collect lobster, be aware of local game laws and make sure you adhere to them.
---Finally, participate in the many cleanup days planned in your area; divers as a whole contribute greatly to helping keep oceans and beaches clean.

---collectively divers can make a huge difference. For more information, visit

Sunday, April 16, 2006



Dr. David Elliott writes us about an advanced course to be presented in association with the medical subcommittee of the European Diving Technology Committee (EDTC) and the North Sea Diving Medical Advisory Committee (DMAC). He comments that this is for people who already have a good basic knowledge of the subject (eg preferably recognised as medical examiners of divers or as HBO doctors): 20 hours theory and 20 hours practical.

The functional objectives of this advanced course are directed towards the medical management of all types of diving illnesses and accidents at all depths. It is for doctors who have a duty of care for divers and will be an intensive 40-hour course at Level IIa of the ECHM and EDTC requirements towards competence in diving medicine. It will be recognised by the International Marine Contractors Association as appropriate worldwide for doctors with responsibilities for working divers. It is also advanced training for military medical officers.

The week will be recognised towards meeting essential requirements leading towards the degree of BScMedScHons (Underwater Medicine), a distance learning course of the University of Stellenbosch: details from <>.

Application for CME/CPD is being made to the Royal College of Physicians. This is recognised for professional development in occupational medicine and in all hospital specialties and has also been sufficient for equivalent recognition in many other countries.

Candidates need to have a prior understanding of the basic principles, should have attended an introductory course equivalent to EDTC Level I (medical examiners of divers). Some personal experience of diving is an advantage but not obligatory. The course will include practical sessions in diving and with recompression chamber, so candidates should meet the fitness requirements

Rob van Hulst, the Senior Diving Medical Officer of the Royal Netherlands Navy will be the Course Director supported by naval divers and diving officers and with a teaching faculty including Hans Ornhagen, lately Director of Research, Swedish Defence Research Agency, and David Elliott, Civilian Consultant to the Royal Navy.

The Tuition Fee will be €1,500 if paid by before 10 September 2006, and after that date €2,000. Candidates are responsible for their own travel and living expenses.

Full details on the course and accommodation are available from:

Diving Medical Centre, Royal Netherlands Navy
PO Box 10.000, 1780 CA Den Helder
The Netherlands
Tel: 00-31-223-653214; Fax: 00-31-223-653148

Friday, April 14, 2006



June 11-16 August 6-11 October 1-6


The objective of this course is to promote the advancement of knowledge of hyperbaric oxygen therapy and problem wound management for physicians and allied health professionals based on a thorough understanding of decompression tables, hyperbaric chamber safety, treatment indications for hyperbaric oxygen, normal wound healing, patient assessment techniques, and wound treatment modalities. Complete goals and objectives in advance available upon request.

Who Should Attend:

· Physicians, Nurses, Technicians and Allied Health Care Providers specializing in hyperbaric medicine and wound care.

Limited Space Available: Enrollment limited to 45


This activity has been planned and implemented in accordance with the Essential Areas and Policies of the Accreditation Council for Continuing Medical Education (ACCME) through the joint sponsorship of the Undersea & Hyperbaric Medical Society (UHMS) and Praxis Clinical Services. The UHMS is accredited by the ACCME to provide continuing medical education for physicians. The UHMS designates this educational activity for a maximum of 53 Category 1 credits toward the American Medical Association Physician’s Recognition Award. Each physician should claim only those credits that he/she actually spent in the activity. One credit hour may be claimed for each hour of participation by the individual physician. The AAFP designates this educational activity for a maximum of 51.50 Prescribed Category 1 credits. This continuing education offering is approved for 53 Nursing CEU’s through Praxis Clinical Services by being “Provider approved by the California Board of Registered Nursing, Provider Number CEP12817”. This program has been reviewed and is acceptable for 53 Category A credit hours by the National Board of Diving and Hyperbaric Medical Technology.


Day 1: 0800 - 1830 (8.5 hours) Day 4: 0800 – 2100 (10.5 hours)

Day 2: 0800 - 1845 (9.25 hours) Day 5: 0800 – 2045 (10.25 hours)

Day 3: 0800 - 1800 (8.5 hours) Day 6: 0800 – 1700 (7.5 hours)

Topics to Be Presented:

Physics and physiology of hyperbaric exposure

Mechanisms of hyperbaric oxygen

Air decompression procedures

UHMS accepted indications

Patient assessment and management

Selection of patients for hyperbaric oxygen treatment

Side effects and contraindications

Hyperbaric chamber systems

Hyperbaric safety and emergency procedures

Hands-On Practicums Covering: Wound VAC, Apligraf, Compression Wraps, PadNet, Venous Doppler, Semmes-Weinstein and ABI’s, Total Contact Casting, Debridement Lab, Wound Assessment/Documentation

Assessment of problem wound patients

Technical aspects of Transcutaneous PO2 measurement and Practicum

Topical wound dressings and practicum

Treatment of problem wound patients

New technology in wound care

Documentation and Reimbursement for nurses and physicians

Faculty Disclosure:

All faculty participating in continuing medical education activities sponsored by Praxis Clinical Services are expected to disclose to the participants any real or apparent conflict of interest related to the content of their presentation. Full disclosure of faculty relationships will be made at the activity.

Commercial Support Disclosure:

This course receives commercial support in the form of unrestricted educational grants from the following vendors: Organogenesis, KCI, and Johnson & Johnson


Robert A. Warriner, III, MD, FCCP, ABPM/UHM, CWS
Chief Medical Officer, Praxis Clinical Services

Medical Director, Southeast Texas Center for Wound Care and Hyperbaric Medicine

Caroline E. Fife, MD, CWS
Medical Director, Memorial Hermann Center for Hyperbaric Medicine

Patricia Pasceri, RNC, ET
Vice President, Clinical Services, Praxis Clinical Services

Pat Hudson, RN, CWOCN
Regional Director of Operations, Praxis Clinical Services

Michael J. Crouch, CHT
Director of Reimbursement, Praxis Clinical Services

Terry Beard, CHT, ACHRN
Regional Director of Operations, Praxis Clinical Services

Jerry Geiger, CHT
Safety Director and Senior Technician, Southeast Texas Center for Wound Care and Hyperbaric Medicine

Others as Invited!!!

Program Location:

The program will be conducted at The Woodlands Waterway Marriott Hotel, The Woodlands, Texas 77380.


$1,200 tuition includes all seminar materials, chamber pressurization, training manuals, continental breakfast and lunch. A service charge of $50 per enrollment will be withheld from all cancellations received in writing 2 weeks prior to conference date. For cancellations received after that date, a service charge of $100 will be withheld.


Participants are responsible for their own travel and lodging. A block of rooms has been reserved for our attendees at The Woodlands Waterway Marriott Hotel. Hotel room rates are $144.00 for a double room. Reservations will be made through the course coordinator. If you require special arrangements, (ie. smoking vs. nonsmoking room, etc.), please advise Sherrill White when you submit your registration form. It is approximately 40 miles from Bush Intercontinental Airport (IAH) to the hotel; therefore, it is recommended that you rent a car for your visit; however, there is a shuttle available for a $40 round trip fee.

Registration Information:

For additional information and registration form, please call Sherrill White, Program Coordinator, at (281) 298-1400. Registration forms may be faxed to (281) 298-1570 or emailed to

Sherrill A. White,
Education Coordinator
Praxis Clinical Services
1610 Woodstead Court, Suite 460
The Woodlands, Texas 77380
(281) 298-1400
(281) 298-1570 FAX

See on our web site:

HBO...Indications, contraindications, links references

Pressure-equalizing earplugs do not prevent barotrauma on descent from 8000 ft cabin altitude.

We get repeated queries about the use of vented ear plugs for the relief and prevention of middle ear barotrauma.(Doc's Proplugs, Earplanes, JetEar). Although there is no conceivable reason why they should work across an intact tympanic membrane - there are many who swear by it's benefits. I have often thought that this is more of a placebo effect than anything else and have not promoted or recommended them as beneficial. Now, I have some experimental work and observations to back up my position. In the Aviation, Space and Environmental Medicine Journal, there is report of a good study showing no benefit from the use of JetEar plugs in preventing middle ear barotrauma. As a matter of fact, the ears using the plugs were worse. The abstract of the article is shown below. Whether od not this ear plug translates to the Doc's Proplugs is not known for sure but is highly likely.

Pressure-equalizing earplugs do not prevent barotrauma on descent from 8000 ft cabin altitude.
Klokker M, Vesterhauge S, Jansen EC.
Aviat Space Environ Med. 2005 Nov;76(11):1079-82.

Aviation Medical Center & Dept. of Otorhinolaryngology, Head & Neck Surgery, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, DK-2100 Copenhagen, Denmark.

INTRODUCTION: The aim of this study was to evaluate the effect of pressure-equalizing earplugs available in major airports and drugstores. No previous study has focused on preventing barotrauma using these earplugs. METHODS: Blinded and double-blinded, one type of pressure-equalizing earplugs (JetEars) was studied in 27 volunteers disposed to ear barotrauma. They acted as their own controls with an active earplug in one ear and a placebo earplug in the other ear at random. All were exposed to the same well-defined pressure profile for 1 h at 8000 ft, comparable to the environment in civil commercial air travel in a pressurized cabin. Satisfaction was assessed by questionnaire and objective results were evaluated prior to and after the pressure exposure by tympanometry and otoscopy using the Teed classification. RESULTS: The majority of the volunteers (78%) reported a pleasant noise-reducing feeling using the earplugs. However, 75% also experienced ear pain during descent. In comparing the middle ear pressure before and after pressurization, a decrease was found in ears with both active earplugs and placebo earplugs. No difference between the active and the placebo earplugs were found. Furthermore, after evaluation of the two groups of ears using otoscopy, no prevention of barotrauma was found. In fact, the ears using an active pressure-equalizing earplug scored significantly worse (p = 0.033). CONCLUSIONS: Feelings of noise reduction were reported, but no prevention of barotrauma could be demonstrated with the use of pressure-equalizing earplugs. Pressure-equalizing earplugs cannot be recommended in air travel for preventing ear barotrauma.

See also on our web site:

ENT Problems in SCUBA Diving

Dehydration and Diving - Does It Really Increase the Risk for DCS?

Dehydration is often listed as one of the main factors that are thought to increase the risk of decompression illness, it having been suggested that hydration may enhance inert gas removal or increase surface tension of the blood. There is usually a caveat stating that this has not been studied. Now, in the Journal "Aviation, Space and Environmental Medicine", Fahlman and Dromsky at the Naval Medical Research Center have studied pigs and have shown that yes, there is an increased risk for DCS due to dehydration.

In an article titled "Dehydration effects on the risk of severe decompression sickness in a swine model", they showed that dehydration significantly increased the overall risk of severe DCS and death. Specifically, it increased the risk of cardiopulmonary DCS, and showed a trend toward increased CNS DCS. In addition, dehydrated subjects manifested cardiopulmonary DCS sooner and showed a trend toward more rapid death (p < 0.1).

Here is a portion of the abstract of the article published in the February 2006 issue of Aviat Space Environ Med. (2006 Feb;77(2):102-6.)
BACKGROUND: Several physiological factors have been suspected of affecting the risk of decompression sickness (DCS), but few have been thoroughly studied during controlled conditions. Dehydration is a potential factor that could increase the risk of DCS. It has been suggested that hydration may enhance inert gas removal or increase surface tension of the blood.

HYPOTHESIS: Dehydration increases DCS risk.

METHODS: Littermate pairs of male Yorkshire swine (n=57, mean +/- 1 SD 20.6 +/- 1.7 kg) were randomized into two groups. The hydrated group received no medication and was allowed ad lib access to water during a simulated saturation dive. The dehydrated group received intravenous 2 mg x kg(-1) Lasix (a diuretic medication) without access to water throughout the dive. Animals were then compressed on air to 110 ft of seawater (fsw, 4.33 ATA) for 22 h and brought directly to the surface at a rate of 30 fsw x min(-1) (0.91 ATA x min(-1)). Outcomes of death and non-fatal central nervous system (CNS) or cardiopulmonary DCS were recorded.

RESULTS: In the hydrated group (n=31): DCS=10, cardiopulmonary DCS=9, CNS DCS=2, Death=4. In the dehydrated group (n=26): DCS=19, cardiopulmonary DCS=19, CNS DCS=6, Death=9.

CONCLUSION: Hydration status at the time of decompression significantly influences the incidence and time to onset of DCS in this model.

Mentions of Dehydration on Diving Medicine Online

An Elegant Article: What Really Happens to Neurons When Exposed to CO2, Oxygen and Nitrogen at depth?

Neuronal sensitivity to hyperoxia, hypercapnia, and inert gases at hyperbaric pressures.

Dean JB, Mulkey DK, Garcia AJ 3rd, Putnam RW, Henderson RA 3rd.
Department of Anatomy and Physiology, Wright State University, Dayton, OH 45435, USA.

Free Full Article can be seen at

As ambient pressure increases, hydrostatic compression of the central nervous system, combined with increasing levels of inspired PO2, PCO2, and N2 partial pressure, has deleterious effects on neuronal function, resulting in O2 toxicity, CO2 toxicity, N2 narcosis, and high-pressure nervous syndrome. The cellular mechanisms responsible for each disorder have been difficult to study by using classic in vitro electrophysiological methods, due to the physical barrier imposed by the sealed pressure chamber and mechanical disturbances during tissue compression. Improved chamber designs and methods have made such experiments feasible in mammalian neurons, especially at ambient pressures <5 atmospheres absolute (ATA). Here we summarize these methods, the physiologically relevant test pressures, potential research applications, and results of previous research, focusing on the significance of electrophysiological studies at <5 ATA. Intracellular recordings and tissue PO2 measurements in slices of rat brain demonstrate how to differentiate the neuronal effects of increased gas pressures from pressure per se. Examples also highlight the use of hyperoxia (<=3 ATA O2) as a model for studying the cellular mechanisms of oxidative stress in the mammalian central nervous system.

anesthesia; carbon dioxide toxicity; free radicals; high-pressure nervous syndrome; membrane potential; nitrogen narcosis; oxidative stress; oxygen toxicity; polarographic oxygen electrode


See also on our web site:
Problems Due to Gases and Pressure

Physical Examinations for Divers - should they be regularly required?

DocVikingo wrote an article for the Oct, 2002 issue of Undercurrent . It was printed with permission from the author and Undercurrent Editor,
Ben Davison, in our Ten Foot Stop Newsletter August 31, 2004.

I particularly agree with the article and enjoy DocV's style of writing. "Physical Examinations for Divers should they be regularly required? Major U.S. training agencies mandate diving physicals and medical clearances for divemasters, assistant instructors, and instructors. Entry-level divers only need to fill out a medical

In Australia, however, the Queensland Territory has a legislative requirement for medical clearance for trainees, and nationally major training agencies encourage such medical clearance. Dr. Michael Bennett of the University of New South Wales Department of Diving and Hyperbaric Medicine acknowledges, “To their credit, the major dive training organizations have accepted such examinations as desirable throughout the country. It is standard practice that diving candidates are not accepted without medical clearance.”

The South Pacific Underwater Medicine Society has published a standard medical form to guide physicians through examinations. In 1969, the British Sub-Aqua Club made medical examinations for divers mandatory. They required physicals of all applicants and members, and these became progressively more frequent with age. A diver’s general practitioner (GP) could conduct these.

In 1994, the Sub-Aqua Association and Scottish Sub-Aqua Club joined with BSAC to form the UK Sport Diving Medical Committee (UKSDMC), which sets common standards for all three diving organizations. The UKSDMC found that examination by a GP was largely unhelpful in identifying divers with significant medical conditions, so last year it replaced the routine examination with a health questionnaire the diver completed. If a diver answers “yes” to any question, he or she must contact a medical referee who may pass the diver or, if necessary, refer him or her to a specialist. Dr. Stephen Glen, UKSDMC Chairman, told Undercurrent that the organization will publish three-year safety statistics next year. (PADI UK follows the same guidelines as PADI America, the self-report medical questionnaire with medical clearance required for “yes” answers. (It’s similar to what UKSDMC members do.)

Since 1990 in the United States, applicants for all levels of dive training are required to complete and sign a standard “Diver’s Medical Questionnaire.” Developed by the Undersea and Hyperbaric Medical Society (UHMS) and DAN; the form canvasses medical conditions that may affect safe scuba diving. A “yes” answer to any item means that the applicant must obtain written medical clearance to dive. Even then, not all students are accepted.

PADI’s director of training and quality management, Brad Smith, told Undercurrent that, ultimately, the scuba instructor decides whom they will permit to take a scuba course. He or she may require anyone to secure medical approval from a physician, even if the student has marked “no” on all questions on the medical form. However, once certified, divers may dive forever with no further medical prohibitions unless they indicate problems on predive questionnaires.

Should routine medical clearance be required?
Ernest Campbell, M.D., (a.k.a.“Scubadoc”) told Undercurrent that he feels strongly that “medical aspects of the sport should be more closely regulated by some central, nongovernmental entity possibly similar to the UK Sport Diving Medical Committee. However, this would require the total support of the training agencies and our quasi-official societies, as well as UHMS, DAN, and the recently formulated national boards. Getting physicians trained would be the easy part. Draconian rules would make it difficult by placing monetary, liability, and certification roadblocks.”

UKSDMC medical officer John Betts is not so sure that getting trained physicians would be easy. He told Undercurrent that even if it is tempting to envisage mandatory medical examinations, it would be impossible to provide enough experienced diving doctors to cope with the numbers involved. While these are real issues, the overriding question is, “Would mandatory diving physicals for all recreational scuba significantly decrease morbidity and mortality?” They may not.
A study in the British Journal of Sports Medicine (2000; 34:375-378) suggests that self-certification may be sufficient to keep medically related dive accidents to a minimum. It analyzed the routine physical examinations and self-certification questionnaire findings of 2,962 Scottish divers. No examination finding alone caused a subject to be classified unfit to dive. One hundred and seventy-four subjects reported abnormalities and were referred to physicians. The most common reasons were assessment of asthma, hypertension, and obesity. Upon expert evaluation, they allowed most of the subjects to dive, with only 25 percent not receiving immediate clearance.

Even physicians trained in dive medicine may not be able to determine fitness to dive. A study reported in the Medical Journal of Australia (1999; 171:595-598) sent fifteen hypothetical clinical scenarios to a group of physicians who had completed approved training in underwater medicine and asked them to declare the prospective scuba diver fit, unfit, fit after investigation, or to offer specialist referral. Seventy percent agreed about unfitness in four cases, and fitness in only two cases. For each case where the guidelines firmly indicated an unfitness to dive, at least one physician passed the hypothetical prospective diver. The study concluded, “There is no consensus among doctors who perform diving medical examinations about what constitutes fitness to dive; current guidelines need to be improved.”

Joel Dovenbarger, vice president of medical services for DAN, says that few young persons entering scuba have worrisome health problems. The older population with longstanding health issues is by far the most problematic. In fact, more than half the diving deaths occur in the 40-to-50-- year-old groups. Cardiovascular disease, which is strongly age related, is the most common medical condition among those who die. Dovenberger maintains, “The responsibility for maintaining personal health remains with the individual, as well as the reassessment of fitness after illness, injury, or the effects of aging.”

Major U.S. training agencies do promote medical prudence in their students and professionals. Without compelling evidence that diving physicals substantially reduce the risk of injuries and death, it is unlikely that the U.S. dive industry, a self-regulating and peer-reviewed entity, will mandate standards that increase the external costs of diving and reduce the pool of potential or active divers. — Doc Vikingo"

More about this on our web site at
Medical Exams
Medical Exam and Physical, Sport Diving
Fitness for Diving

EDTC Introduces new book Medical Assessment of Working Divers

European Diving Technology Committee introduces new book Medical Assessment of Working Divers

A new book from the European Diving Technology Committee (EDTC) ‘Medical Assessment of Working Divers’ is supported by IMCA – the International Marine Contractors Association – who provided a grant towards publication of the manual for the benefit of medical examiners worldwide who are trained to EDTC standards.

Edited by Jürg Wendling, David Elliott and the late Tor Nome, the book provides a desktop guide for those undertaking medical assessments, bringing together the EDTC ‘Fitness-to-Dive Standards’ with an extensive desktop reference for medical examiners of divers.

Sections are devoted to the principles of assessment; general guidelines – assessment of organ systems; an extensive 140-page reference section covering otorhinolaryngology, respiratory system, heart and circulation, nervous system, psychiatry, internal organs, musculoskeletal system, eyes, paediatrics [Hugh/Jane: in the book it is actually called ‘pediatrics’ but as we are English it seems odd to send it out like that in a release!]; the range of activities necessitating fitness; appendices covering reliable tests of physical fitness, guidelines for medical training in diving (and hyperbaric) medicine EDTC/ECHM, and recommendations of the 6th ECHM Consensus Conference on Prevention of dysbaric injuries in diving and hyperbaric work; a bibliography of current literature; national references of authorities and scientific societies; and a full index.
The material can also be seen in a PDF file at this address:

Thursday, April 13, 2006

Hyperoxemic therapy - New Heart Treatment?

I ran across this article about initiating a study of using hyperoxemic blood in order to treat heart muscle threatened by coronary artery disease. The article on the web site of NBC4.TV in Los Angeles writes about the use of a new process called Hyper-Oxemic treatment during a heart catheterization. The blood is run through a "mini-hyperbaric chamber?" hyperoxygenated and then run back through the same catheter into the coronary artery, thereby bypassing stunned blood vessels and save injured heart tissue.

A study is to be done that will enroll 300 patients at over twenty sites in the U.S. In an earlier study, patient's showed a 60-percent improvement in heart wall motion in the area of the original attack.

For information about the trial:

Googled Information Here

Notes from Don Chandler, Exec. Dir. UHMS

To all-

In this email you will find information on the following topics.

1. Our Annual Scientific Meeting in Orlando.
2. The United States/Japan Panel Meeting in Kauai, Hawaii

1. Our Annual Scientific Meeting in Orlando. Well, you have done it again. Our record is clean in not having to pay for our meeting rooms at our host hotel. Our "magic" number was 80% of the contracted room nights in order to get meeting rooms free of charge. We have made it! Thanks to all of you who have registered already for making this happen. For those of you who have not yet made your reservations at the Hilton Hotel at Disney World, I encourage you to do so as soon as you can so you can take advantage of our discounted rate before we fill all the blocked rooms. Telephone (407) 827-4000 or (800) 782-4414 for reservations at the Hilton Disney World and please make sure you mention "Undersea and Hyperbaric Medical Society" in order to get the discounted rate of $148.00 per night.

If you choose, you can make room reservations at our overflow hotel, the Grosvenor, at the discounted rate of $89.00 per night if you mention "Undersea and Hyperbaric Medical Society." The Grosvenor is located just across the street from the Hilton and their telephone number is (800) 624-4109 or (407) 828-4444.

By the way, there is bus service to and from the airport at a cost of $17.00 (a taxi will cost about $50.00). If you drive to our host hotel, there is complimentary parking but if you use a valet it will cost $12.00. A brochure on its way to you as I write this...if it hasn't already been mailed (some have been) it soon will be. The brochure has lots of information about what will be available at the meeting, a tentative program, a registration sheet, and folded within is a ballot for voting for UHMS officer candidates.

If you haven't registered for our meeting as yet, remember you can go to our website at and register on line. Many have done so and I encourage this to everyone because it reduces our work here at the home office and should save you lots of time.

2. The United States/Japan Panel Meeting in Kauai, Hawaii. This panel was born out of the long time U.S. State Department program called "United States/Japan Agreement in Natural Resources" (UJNR). The Diving Physiology/Technology Panel was one of nineteen panels and for at least a quarter century it was one of the, if not the, most active panels of the agreement. About four years ago NOAA, who had been the U.S. sponsor for many years, determined that it no longer fit their mission and declared the panel inactive.

Many of us in both Japan and the U.S. who had been a part of the panel for many years wanted to continue with the meetings every two years, trading locations between Japan and the United States. In organizing a plan to continue the biennial meetings, we determined to open the panel to Aerospace Medicine because in recent years we had Astronaut members from both the U.S. and Japan presenting at each meeting. Our first panel meeting without NOAA sponsorship was held in Tokyo in 2004 at the Tokyo Medical Dental University. Dr.'s Yoshihiro Mano and Mahito Kawashima organized the meeting and to say it was an excellent one would be an understatement. These two notable physicians organized a meeting that went beyond anything that we expected.

The next meeting is in the U.S. and since I am the Chair for the U.S. side, I chose Kauai, Hawaii for the 2006 meeting. We were there for a UJNR meeting many years ago and it proved to be a great place to meet...relaxing and VERY laid back. October 19-21, 2006 will find this important scientific meeting at the Sheraton Kauai Resort, 2440 Ho'oani Road, Koloa, HI 96756. We have negotiated two rates, one for an ocean view and one with a garden view. When you call, tell the reservation clerk you are with the Undersea and Hyperbaric Medical Society UJNR Meeting and want the "EXTEND" order to get the discounted rates.The meeting is open to all interested parties and if you are interested in presenting, please send your abstract to me at I hope to see many of you there.

Consider attending the U.S./Japan Panel meeting in Kauai. You won't be sorry you did.

That's all for now, folks. I will be back with you when I hear of more developments that benefit us as a professional society.


Introductory Course in Hyperbaric Medicine and Wound Care, Long Beach Memorial Medical Center


I am writing to inform you that the Hyperbaric Medicine Department at Long Beach Memorial Medical Center is offering a week-long, 40-hour
Introductory Course in Hyperbaric Medicine and Wound Care.

The primary purpose of this program is to use both didactic and practical chamber-side teaching formats to introduce and educate physicians, with a background in a variety of specialties, in the theory, principles, and practices of hyperbaric medicine and wound care. Additionally, this CME program is designed to educate nursing, allied health professionals, and medical administrators who have educational interests or needs in hyperbaric medicine and wound care.

This course is expected to provide the participant with core knowledge about the theory and practices of hyperbaric medicine and wound care and to be a solid base for which further education and training in hyperbaric medicine and wound care can be built upon.

The faculty at LBMMC Department of Hyperbaric Medicine is uniquely qualified to provide this education. Members of our faculty include leaders in the field of hyperbaric medicine. We take advantage of our multi-specialty background (e.g., orthopedic surgery/wound care, emergency medicine, hematology/oncology, and pulmonary/critical care medicine) to provide a well-rounded perspective of the specialty.

The courses are scheduled from: May 8, 2006 – May 12, 2006
November 6, 2006 – November 10, 2006

If you are interested in attending this course or would like more information, please contact:

Department of Hyperbaric Medicine
Long Beach Memorial Medical Center
2801 Atlantic Ave
Long Beach, CA 90806

(562) 933-6950


Stuart Miller, MD
Course Director
Department of Hyperbaric Medicine
Long Beach Memorial Medical Center

Tuesday, April 11, 2006

Suggestions for Review of Fitness to Dive Guidelines: ENT

We have had requests for a repeat of an editorial review of ENT fitness to dive guidelines, in our Ten Foot Stop for April 15, 2005.

Suggestions for Review of Fitness to Dive Guidelines: ENT

In our last newsletter we brought up the suggestion that guidelines placing restrictions on diving in certain conditions and with certain drugs might be too stringent and might possibly be either misapplied or archaic.

The suggestion has also been made that guidelines have been promulgated for military, commercial and professional divers based on conclusions drawn from naval diving medical officers for military personnel and that a different set of rules should be considered for sport and recreational divers. In addition, many recommendations in various guidelines are based on physician judgment and anecdotal experience and not on good clinical evidence. There is not a large body of evidence in support of many of the 'absolute' and 'relative' contraindications usually listed. However, it also can be stated that the same physical forces are acting on the same human body when anyone descends beneath the surface, and that immutable physical laws should apply across the board. This is certainly true but it is the strict application of rules without any 'wiggle room' that is vexing to many people.

In the final analysis for many of the restrictions, it is actually the amount of risk that an individual is willing to take in order to participate in sport diving. After reading my editorial in the last newsletter, Glen Egstrom, PhD wrote this about risk associated with diving:

"Scubadoc- I read your newsletter with the usual amount of stimulation. I feel that an old (1787) Ben Franklinism fits here very well. He observed “Having lived long I have observed many instances of being obliged by better information and for consideration to change opinions even on important subjects which I once thought right but found to be otherwise.” The evolutionary changes in the view of the relative levels of risk associated with diving often have the appearance of lowering levels of concern on the part of the medical and instructional communities of divers. I prefer to view it as a heightened appreciation for the nature of the risk vs. benefit evaluation. Risk assignment should be based upon objective, scientific analysis of a hazardous condition. The benefits, often less quantifiable, should be viewed in terms of physical as well as mental health aspects. The nature of the calculated risk should be clearly explained to the individual on the basis of the objective evidence. Most individuals, armed with specific knowledge about their fitness to dive and the risks placed in perspective, are likely to make good informed decisions. For those who do not pay attention, they will probably continue to let their minds make appointments that their bodies cannot keep. As is their right as an individual.

It has always been easier to be arbitrary and overly restrictive than it has been to get good evidence for a balanced opinion. I personally have always felt that regular doses of hyperbaric “therapy” in the form of diving have provided benefits to my life that make the risks more than acceptable. Good luck on your project, it could be a real challenge! "

Revisiting the "Absolute Contraindications" to diving - as outlined by various organizations such as the RSTC and NOAA and copied by most of the certifying agencies, turns out to be a difficult project, as there are few studies to be found that back up their recommendations. Making the guidelines more lenient turns out to be just as difficult - again because there are few suggestions that can be based on evidence. Expert opinion and anecdotal evidence are generally the substantiating factors in making decisions about fitness to dive.

The obvious reasons why a person should not be allowed to dive are as follows:

* Disorders that lead to altered consciousness
* Disorders that inhibit the "natural evolution of Boyle's Law"
* Disorders that may lead to erratic and irresponsible behavior.

Here is the first system that we looked into, the ear, nose and throat - abnormalities in which can stop a person immediately from diving without any rules having been applied. Reviewed and commented upon by Allen Dekelboum, MD.

RSTC Absolute Contra-indications
• Monomeric TM
• Open TM perforation
• Tube myringotomy
• History of stapedectomy
• History of ossicular chain surgery
• History of inner ear surgery
• History of round window rupture
• Facial nerve paralysis secondary to barotrauma
• Inner ear disease other than presbycusis
• Uncorrected upper airway obstruction
• Laryngectomy or status post partial laryngectomy
• Tracheostomy
• Uncorrected laryngocele
• History of vestibular decompression sickness


NOAA Absolute Contra-indications

Inability to equalize pressure in the middle ear by auto-inflation. This may be due to a correctable problem such as polyps, nasal septal deviation or allergic rhinitis in which case the diver can be reevaluated after correction of the problem. In addition, this may be purely a training problem with technique and altering the clearing method might be all that's necessary. Nevertheless, one cannot and should not dive until this maneuver can be accomplished with ease.

Risks: Damaged middle and inner ear from barotrauma
Hearing loss
Severe balance problems

Perforation of the tympanic membrane. Until fully healed or successfully repaired with good Eustachian tube function, diving is contraindicated. Ease of equalization should never be ignored.
Risks: Water in the middle ear
Vertigo and possible drowning
Infection, middle and inner ear
Hearing loss.
Balance problems

Open, nonhealed perforation of the TM.
Risks: Water in the middle ear
Vertigo and possible drowning
Infection, middle and inner ear
Hearing loss.
Balance problems

Monomeric TM. A thinned out ear drum. Thickness differs in individuals. If the diver has good Eustachian tube function and can equalize easily - diving might be allowed. ENT consultation assessing the amount of pressure sustainable by the tympanic menbrane.
Risks: Perforation of ear drum
Water in middle ear with same risks as above.

Tympanoplasty, other than myringoplasty (Type I)
Tympanoplasty, Types II, III, IV all deal with tympanic membrane perforations as well as damaged ossicles. Goals are to have a dry ear, functioning Eustachian tubes, increased hearing, normal balance. Successful surgery with these factors present would not seem to be adverse to diving if ability to equalize is present. Discussion with surgeon about risk factors. Most chronic middle ear disease and mastoid disease is due to a poorly functioning Eustachian tube (ET). Correcting the middle ear disease, might not correct the ET problem.
Risks: Water in the middle ear
Vertigo and possible drowning
Infection, middle and inner ear
Hearing loss.
Balance problems

History of stapedectomy.
Most recently there have been good studies to show that stapedectomy is not the risk that was once thought. A study in the journal 'Otolaryngology, Head and Neck Surgery' in October, 2001 by Drs. House, Toh and Perez at the House Ear Clinic in Los Angeles concluded that stapedectomy does not appear to increase the risk of inner ear barotrauma in scuba and sky divers. These activities may be pursued with relative safety after stapes surgery, provided adequate eustachian tube function has been established. There had been the fear that the stapes implant would be pushed into the round window, damaging the inner ear. Those that agree with Dr. House are in the minority.

Otolaryngol Head Neck Surg 2001 Oct;125(4):356-60
Diving after stapedectomy: clinical experience and recommendations.
House JW, Toh EH, Perez A.
Clinical Studies Department, House Ear Clinic and Institute, 2100 West Third
Street, Los Angeles, CA 90057, USA.

History of inner ear surgery.
There are those who do not feel that successful inner ear surgery is a contra-indication to diving - given a functioning Eustachian tube and easy clearing of the middle ear. There should be hearing remaining that is normal or near normal. Not all who have repair of labyrinthine fistulae recover their hearing.
Status post laryngectomy or partial laryngectomy
Valid recommendation

History of vestibular decompression sickness - This probably is a valid recommendation. A study showed that only 28-32% of divers with IEDCS completely responded to hyperbaric treatment - indicating possible permanent damage to end organs such as the vestibule and cochlear. Farmer et al have demonstrated a near total return to baseline hearing if recompression is initiated immediately.
Inner Ear Decompression Sickness in Sport Compressed-Air Diving.
Laryngoscope. 111(5):851-856, May 2001.
Nachum, Zohar MD; Shupak, Avi MD; Spitzer, Orna MA; Sharoni, Zohara MA; Doweck, Ilana MD; Gordon, Carlos R. MD, DSc

Farmer JC, Thomas WG, Youngblood DB, et al. Inner ear decompression sickness. Laryngoscope 1976;86:1315-1327.

Radical mastoidectomy (posterior) involving the external canal is disqualifying. (Closed childhood OK). Dr. Dekelboum describes several commercial divers with mastoid cavities who went to work, waited for the vertigo to cease, after a few minutes, and performed their tasks, using prophylactic antibiotic ear drops after leaving the water.

Risks: Water in the middle ear
Vertigo and possible drowning
Infection, middle and inner ear
Hearing loss.
Balance problems

Meniere's disease is disqualifying, as well as surgical procedures designed to treat the condition. I can find no references backing this up except the unsupported statement that pressure worsens the condition. However, pressure is exerted in and on the body equally - not just on the endolymph. Meniere's is known to be initiated by vestibular stimulation and stress - certainly scuba diving can cause both of these - but so can many other things. Although risky, there are many Meniere's sufferers who dive. Diving is not recommended - unless one has a very reliable buddy who understands the risks.

Labyrinthitis This would be a situation that would not be permanent. Diving should certainly not be allowed in the acute phase.

Inner ear barotrauma and Perilymph fistula. No evidence that returning to diving is contra-indicated. . A repaired, asymptomatic fistula from round window rupture is not an automatic contra-indication to some diving medicine specialists. Parell et al have shown that if proper precautions are taken to maintain proper eustachian tube function, no further deterioration takes place in hearing if a patient returns to diving after experiencing cochlear IEBT.

Parell GJ, Becker GD. Inner ear barotrauma in scuba divers. A long-term follow-up after continued diving. Arch Otolaryngol Head Neck Surg 1993;119:455-457.

Dr. Allen Dekelboum states that he has the same feelings about this as to inner ear surgery. Although not published,he did an informal survey many years ago, involving the two largest series of those who treated inner ear barotrauma. All agreed that if there was usable hearing remaining in the ear and the patient took precautions to adequately equalize, aborting any dive when equalization failed, they would allow their patients to dive. Before I agreed with those surgeons, I always recommended that they not dive. They all did anyway and no one was hurt.

Cholesteatoma is disqualifying.

Cerumen impactions - remove before allowing to dive. This causes barotrauma of the external ear canal between the cerumen plug and the ear drum. Just remove the impactions. There is no need to remove non-impacted cerumen. Being too aggressive could lead to external otitis.

Stenosis or atresia of the ear canal- disqualifying. Narrowing of the external ear canal without blockage would be less risky and probably not adverse to diving.

Facial paralysis secondary to barotrauma. It is assumed that further diving would increase the risk of further barotrauma to the ear (the facial nerve passes through the wall of the ME.). .
This does not seem acceptable that barotrauma will occur every time a person dives. Given ease of equalization this might be a situation that is not absolute and these patients could dive.

Tracheostomy, tracheostoma . Endotracheal tubes can be rigged to accept respirators - so it's possible that a scuba regulator could also be fitted to a tracheostomy. However, this is extremely risky and possibly fatal. It is not recommended that anyone with an external connection to the trachea dive.

Incompetent larynx due to surgery (Cannot close for valsalva maneuver). However, it might be possible to do other maneuvers that will open the ET.

Laryngocoele. This is an extremely rare occurrence and effects of the condition are variable. A large, fluid or pus filled sac obstructing the airway would certainly be a contra indication to scuba diving. An air filled sac with a narrow neck would be risky for obstruction and rupture due to barotrauma. A small asymptomatic laryngocoele would probably not cause a problem.

Congenital or Acquired hearing loss. It is assumed that this is because of the possibility of further hearing loss from a scuba diving accident. Whether or not to dive would depend upon the degree of hearing loss of each case. Total hearing loss in one ear confers the risk of complete deafness should the other ear be damaged due to a diving accident. When the risks are explained to the patient, they will make their own choice.

Saturday, April 08, 2006

Courses from the Undersea and Hyperbaric Medical Society

Here is a regularly updated web page on the UHMS site that offers contact sources for various diving medicine and hyperbaric courses. Located at , the courses are divided into SPONSORED INTRODUCTORY COURSES, SPONSORED COURSES, SPONSORED ENDURING MATERIALS AND NON-SPONSORED COURSES.

See also on our web site: Meetings and Courses

Friday, April 07, 2006

Falsifying medical forms for dive certification lessons

While recently answering a question from a scuba instructor we ascertained that he felt that one of the most dangerous activities that he faced was "lying on medical forms". Failure to report risky preexisting medical problems would certainly be adverse to diving safety, not only to the student but to the instructor and others on a dive excursion. In order to find out more about this problem we asked several of our consultants knowledgeable about diving medicine and who are also instructors. We thought you'd be interested in some comments we received.

Here is a letter from Dr. Martin Quigley who also queried one of the certifying agencies.

"Here are my thoughts:

Obviously the most serious scenario is when the student (or certified diver on a charter or boat trip) conceals medical information and the instructor/dive master/boat captain doesn't learn of the condition until there's an accident (or worse). Not much of anything you can do in that situation.

If the instructor discovers a deliberate omission by a student (for example sees a thoracotomy scar in the pool when the student denied prior surgery or sees a student using an inhaler for asthma) I think there are only two choices. One would be to summarily dismiss the student from the class. The disadvantage of this approach is the student is probably going to try the same approach again with a different instructor and/or dive shop.

I believe that a better choice would be to suspend the student from class and insist that he see a physician (hopefully one with some dive medicine experience) for evaluation and medical clearance. The decision as to whether or not to accept the student back is ultimately the instructors depending, in part, on the medical assessment) but this approach is likely to lead to the safest outcome.

Martin M. Quigley, MD, MBA, MHA
1056 Paseo del Rio Drive, NE Saint Petersburg, FL 33702-1457

When asked the same question, the certifying agency (PADI) had the following answer:

"Thank you for your email. We would advise a member on with the steps that you listed for your second option. That would be to discontinue training until such time the student can get with their physician to sign the medical and get authorization for diving. Once an Instructor is aware of a divers medical condition they need to take the proper steps to make sure that that divers is fit for scuba diving."

Another of my instructor friends had the following comment:

"Ern- I believe this to be serious problem that is rarely dealt with. The "no harm - no foul" mentality works until there is a consequence, then it gets ugly. I have seen over a dozen cases wherein the lie is rationalized to the level of an "oversight" and the defendants recover large sums. The "problem" is so common place that I doubt much will change. Even with the much more lenient medical fitness standards, many divers feel that if they tell the truth they will not be able to dive. Tough problem."

We have placed a query with a poll on our Scuba Clinic forum at . Please visit the thread and poll to give us your opinion of this problem.

See also these web pages on our web site:
Medical Exam and Physical , Sport Diving - PADI Medical Statement Physical Exam Form. -

[PDF] Medical Exams
Medical Exams. q. Family practitioner assists filling out A special form and ... NAUI Medical Exam Forms. ...

Medical Exams - Why A Medical Exam? The only real reason for recreational divers to have an ... Family practitioner assists filling out a special form and suggests referral ... -

New Zealand Police Diving Safety Article

In the New Zealand Police News there is an article that you might find interesting and informative about diving safety. This can be seen at this site:

Even the professionals keep their training up to date - here police dive squad members undertake a surface supply breathing apparatus course.
Copyright 2005 NZ Police

See also our web site about Diving Safety at

Wednesday, April 05, 2006

Last Ten Posts on Scuba Clinic

1 Scuba Clinic / Gastrointestinal problems / Hiatal Hernia on: Today at 10:52:06 AM
Started by Ern Campbell | Last post by Ern Campbell
Posts retrieved from cache

I was looking at contraindicated conditions and noticed that Hiatal Hernia is listed as one of those condiditons. This is kind of surprising because I have had a sliding hiatil hernia for years and have been diving with no problems. I know that there is an exception for every rule but how many of these "contraindicated" medical conditions are supported by actual doc**ented studies and how many guinea pigs did they use before labling a condition "contraindicated"? This is an issue for me me because if I want to pursue further recreational dive training I need a note from my doc because I am over 40 and there is training I want to do. So is it o.k. to dive or do I have to hang up my tanks. Please let me know. Thanks.


Site Admin

Posted: Wed May 04, 2005 3:48 pm Post subject: Hiatal hernia disqualifying?

Hello JohnB:

The answer to your question is that 'not all hiatal hernias are disqualifying'. If there is significant gastroesophageal reflux, then there is the risk of aspiration of gastric contents on ascent due to the effect of Boyle's Law and the 'weightlessness' underwater with loss of the normal mechanisms protecting us from reflux.

Paraesophageal or sliding hiatal hernias are contraindications for diving but the most frequently seen hiatal hernias are usually minimally asymptomatic sliding hernias are not disqualifying.

If there is any air trapping in the part of the stomach above the diaphragm, it must be remembered that swallowed air at depth expands four to five times upon ascent to sea level.

So, whether or not you can continue diving depends to a great extent on whether or not you are symptomatic, whether or not you can belch and rid your self of air and how your physician feels about your specific condition.

Hope this is helpful!
Diving Medicine Online



Posted: Wed May 04, 2005 4:02 pm Post subject: AN IDEA

I do suffer from GERD but don't dive when symptomatic. I was wondering and I just realized this is something that I forgot mention is I do plan my dives to allow for a slower than normal assent and if I experience any discomfort I slow down until I belch or pass gas. So then another idea might be instead of contraindicating diving modify the parameters of the dive profile for persons with certain conditions.
And thank you for your prompt reply.

2 Scuba Clinic / Gastrointestinal problems / Carbonated beverages and diving? on: Today at 10:43:49 AM

Posts retrieved from cache

Contribution of Carbonated Beverages to DCI


Posted: Mon Jul 26, 2004 12:48 pm Post subject: Contribution of Carbonated Beverages to DCI

hello forum,

QUESTION #1: How many times, and in what publications, has there been a warning that the consumption of carbonated beverages before diving will trigger DCI? (say within 24 hours before a dive) And I'm not inferring the diuretic contribution of caffeine to dehydration here. I am instead referring to the propensity for CO2 to form bubbles upon decompression. I know of only one source. It was a PADI basic certification dive manual vintage 1986. I can't quote you the author and page numbers at this time, though.

It was stated in Buhlman's book on decompression that CO2 is forty times more soluble in olive oil, than is N2. (by either molar or weight) Olive oil is supposed to closely approximate human fat. The ingested CO2 will dissolve under pressure, into the stomach or small intestine, I suppose. The circulatory system is supposed to reject excess cellular CO2 into the lungs, when it is above a certain partial pressure. But can it reject the CO2 from a 12oz can of carbonated beverage, when it is dissolved into the stomach/small intestine?

QUESTION #2: Can the ingestion of carbonated beverages prior (within 24 hours) to hyperbaric treatment (HBOT), in a chamber, be dangerous to the patients and to the staff?

thanks forum, Doug Kemp.


Site Admin

Posted: Mon Jul 26, 2004 4:16 pm Post subject: Carbonated beverages, DCI?
Hello Doug:

We had a similar question a couple of years ago - which I answered in my March 31, 2002 Divemed newsletter.

Here is what was said:

Diving after drinking carbonated beverages?
I hear a rumor that carbonated beverages are a contributing factor to DCI. In fact I think that I confirmed this rumor in the PADI basic diving manual. Is this true? If so, what would be the underlying mechanisms?
It is doubtful that carbonated beverages would increase the gas load to a sufficient level to increase the chance of gas bubble growth in a decompression situation. The lungs would excrete whatever was to enter the venous system.
Carbon dioxide would dissolve into the the fluids in the stomach, and could ultimately be absorbed into the bloodstream. The chemistry would suggest that the CO2 would react with H2O and would be carried into the
bloodstream as a HCO3- bicarbonate ion, but some would remain as CO2. Most CO2 produced by metabolism is carried this way to the lung. There, the equilibrium is upset as the CO2 dissolves across the cell membranes and into the lung airway. This drives the reaction of HCO3- + H+ --> CO2 + H2O and the CO2 continues to be eliminated.

The same thing would apply in a dry chamber dive as in a wet dive. Carbonated beverages that contain caffeine are diuretic and thus may increase the risk of DCI.

Hope this helps!




Posted: Sun Aug 01, 2004 11:19 am

I seem to remember in my hyperbaric training, we were told to have pt.s avoid soda before treatment because gas expansion occurs within the intestines on ascent, and may result in vomiting, flatus, abdominal discomfort and colicky pains. Rarely severe.
The only danger I see to hyberbaric staff might be flatus in a multiplace chamber.


Site Admin

Posted: Wed Aug 11, 2004 3:02 pm Post subject: Swallowed gas

Good point!

Carbonated beverages are taken in at ambient pressures - gas escapes as CO2 in the GI tract. Most is absorbed, some lingers as CO2 in the stomach.

The diver descends - the gas gets smaller and probably is added to by the diver swallowing air during equalizing maneuvers.

It is further compressed as the diver descends. On ascent, what gas is not absorbed enlarges.

If there is significant quantity still left in the stomach - then there will be pain, discomfort and belching. It is the diver who cannot belch [as in people who have hiatus hernia repair] who will be at significant risk for rupture of the stomach.

Gas in the GI tract is discussed on our web site at .


3 Scuba Clinic / Dive Training, Gear and Technical Problems / Re: Stomach gas while diving on: April 04, 2006, 08:07:01 PM
Started by Mantaman | Last post by docvikingo
Hi Mantaman,

The hypothesis that this gentleman is unwittingly swallowing air is a good place to start. It is consistent with his symptoms and air swallowing is not uncommon in new divers. A student with this issue should inform the instructor so that they may take steps to correct the behavior.

Given such a complaint, it also would be prudent to eat a small, bland meal prior to but not in very close proximity to scuba. Avoid drinking too much liquid with this meal.

If the student takes medication to control acid reflux, e.g., Tagamet, Zantac, he should maintain his regular regimen while diving. If he does not, he may wish to consider such a drug. Also, taking a plain antacid tablet or two just prior to a dive may prove helpful

Finally, belching and passing gas freely can bring remarkable relief and should be encouraged.

If the problem continues despite reasonable measures, medical evaluation should be undertaken.

This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual and should not be construed as such.




5 Scuba Clinic / Dive Training, Gear and Technical Problems / Stomach gas while diving on: April 04, 2006, 01:36:31 PM
Started by Mantaman | Last post by Mantaman
I have had a query from a workmate who is keen to begin diving, and wishes to resume an interrupted course in a few weeks time. He was compelled to abort a shallow try/training dive owing to gathering gas pressure in his stomach which he claims grew sufficient to seriously inhibit his breathing, this while at a constant depth. He cites a meal prior to the dive, and a history of gas problems, but I suspect that he was also unwittingly swallowing air as his symptoms seemed acute. Obviously his awareness of various factors affecting him such as regulator performance, stress, etc, are beyond his horizon at this stage. The problem was resolved naturally after the dive, and he felt fine, but is now anxious that he will suffer the problem again. He is considering the usual pharmaceutical solutions. Any advice from other sufferers?

6 Scuba Clinic / Medical and Surgical Problems and the diver / MOVED: Tooth Implant and Diving. on: April 04, 2006, 10:34:20 AM
Started by docvikingo | Last post by docvikingo
This topic has been moved to the Dental Problems forum.


7 Scuba Clinic / Dental Problems / Excess salivation in a new diver on: April 04, 2006, 10:22:34 AM
Started by Ern Campbell | Last post by Ern Campbell
This query was sent to us by email and is posted here for comment by others who may have had similar experiences.

The last time I was diving- this past weekend, I experienced an excess salivation in 3 out of 5 dives that was so much I felt like it was choking me. I would spit it into regulator, but it was quite unpleasant. What makes this happen and how can it be prevented. Could it be that this mouthpiece was too big? I should tell you I am pretty new to diving and this was the certification dive.

Hello diver:

I haven't run into this question before but suspect that it is due to stimulation of the salivary glands from action of the regulator mouthpiece. You may be correct that the mouthpiece is ill fitting or that the simple presence of the object in the mouth is stimulating you to salivate.

Suggestions include wearing the mouthpiece around the house in order to get used to the feeling or to get a mouthpiece that can be heat molded to fit your bite better.

I plan to send your question to one of my dental diving consultants for another opinion.

Best regards:

Ern Campbell, MD


8 Scuba Clinic / Dental Problems / Re: Tooth Implant and Diving. on: April 04, 2006, 07:53:00 AM
Started by newdiver48 | Last post by docvikingo
Hi Scotty,

I have provided you with a copy of Dr. Stein's "Alert Diver" (Mar/Apr '05) article entitled, "Dental Implants & Diving." Based on that, I'd guess the bone grafting will put you off the second stage mouthpiece for at least a couple of months, perhaps more.

But, you need an expert opinion so I'm going to contact Dr. Stein and ask him to respond to your inquiry.

Stay tuned.



9 Scuba Clinic / Dental Problems / Tooth Implant and Diving. on: April 04, 2006, 06:40:54 AM
Started by newdiver48 | Last post by newdiver48
I'm going to have my lower back molar taken out and and they are going to do a bone graph and they told me this would have to heal for 4 months before the new crown or tooth goes on. Question, How will this affect my diving? Will I be able to Dive, etc... would appreicate any info you guys can share...thanks Scott P.S. This is suppose to take place June 1 and the only dives for the first couple of months would be at the ga aquarium in 33' of water at the deepest. Then in August, we are going to Hawaii, will I be able to do this? thanks


10 Scuba Clinic / Dive Training, Gear and Technical Problems / Re: For Dive Instructors: Student Lying on Medical Forms on: April 03, 2006, 06:48:43 PM
Started by Ern Campbell | Last post by mddolson
I am a retired instructor and do not have to deal with this issue anymore.
However, student safety and my liability are the primary concerns.

I would forbid any further water sessions until a doctor (diving doctor) signed a fit-to dive medical declaration.

Mike Dolson
NAUI 4780/PADI 202288 (Retired)

Many Thanks to Patty Dilworth for the great photos of nudibranchs.