drug induced dehydration

[susiehouston]

Hi!

We recently had a discussion on the use of medication such as lithium and the effects on diving fitness. For this hypothetical exercise it shall be irrelevant what the underlying condition is and how it may or may not be appropriate to dive.

Lithium causes dehydration and will help deplete another important electrolyte, Sodium. When not in the water, this can easily be remedied with drinking enough and adding NaCl (normal salt) to the diet. A gallon of Gatorade or equivalent isotonic drinks may do the job. This may still be tricky, especially with diuretics or excessive sweating. Adding diving means adding another parameter, and that leads to the question here (as dehydration is a major cause for DSC):

What are the potential effects of lithium in the system on decompression obligation, and the conduct of notably long or deep decompression dives on the electrolytes and a possibly resulting lithium toxicity? Follow up question: what could a diver do to still dive within safe parameters from a toxicity-dehydration-decompression point of view, if there is such a thing?
We are looking for more than the answers on the DAN webpage which resemble the usual non-diving related side effects only.

Thanks for your input!
Susie

 

[jbd]

Interesting question. Its been way too long since I studied pharmocology and even then I seldom administered it. Hopefully one of MD's will have response.

 

[Dr Deco]

Dear Scuba Board Readers:

Lithium

I have never had any experience in the laboratory with DCS risks and lithium. I would be surprised if this ion was to make much of a physiological difference as far as DCS was concerned. The psychiatric effect is a different question.

I would suspect that regard for proper hydration would take care of any problems regarding perfusion and surface tension. I would doubt (but do not know for certain) that any laboratory test would demonstrate a difference in DCS incidence in human subjects with a clinical doses of lithium.

Dehydration

Dehydration does play a role in DCS risk, but it is tissue gas loading that is the primary agent. Since all decompression algorithms will maintain the gas loads at a safe level, the reason one diver has a DCS problem and not another is unclear. In the laboratory, a part of the cause can be found to be workloads. In addition, there are individual differences between divers and these differences have not yet been examined in sufficient detail. Hydration is a portion of that story.

Dr Deco :doctor:

Please note the next class in Decompression Physiology :book3:
http://wrigley.usc.edu/hyperbaric/advdeco.htm

 

[Saturation]

Hi!

We recently had a discussion on the use of medication such as lithium and the effects on diving fitness. For this hypothetical exercise it shall be irrelevant what the underlying condition is and how it may or may not be appropriate to dive.

Lithium causes dehydration and will help deplete another important electrolyte, Sodium. When not in the water, this can easily be remedied with drinking enough and adding NaCl (normal salt) to the diet. A gallon of Gatorade or equivalent isotonic drinks may do the job. This may still be tricky, especially with diuretics or excessive sweating. Adding diving means adding another parameter, and that leads to the question here (as dehydration is a major cause for DSC):

What are the potential effects of lithium in the system on decompression obligation, and the conduct of notably long or deep decompression dives on the electrolytes and a possibly resulting lithium toxicity? Follow up question: what could a diver do to still dive within safe parameters from a toxicity-dehydration-decompression point of view, if there is such a thing?
We are looking for more than the answers on the DAN webpage which resemble the usual non-diving related side effects only.

Thanks for your input!
Susie

Li is removed mostly via renal excretion, and how it effects fluid loss, Na, K and other salt excretion is variable ... both hyper and hypo excretions occur. Thus, the primary issue is monitoring electrolyte balance as key to Li therapy as it reflects impending toxicity more than Li levels, AND monitor of BUN - Cr for renal function. Gatoraide is not necessarily the solution of choice if one suffers a diabetes insipidus like effect [which is common] and causing overall serum hypernatremia. In addition, the diuresis of diving may aggravate a hypernatremia and made worse by Gatoraide .. the treatment is dilute water in this case.

Prolonged immersion causes diuresis and increases the likelihood of Li toxicity... if lost fluid cannot be replaced while in in-water the possibility for a toxic reaction occuring mid-dive, the threshold is not predictable on Li, cannot be eliminated. Li toxicity has wide manifestations, a most important one is that on the CNS. Diminished alertness is common on therapuetic levels alone, toxicity further induces confusion and agitation.