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.