Prolonged whole-body cold water immersion: fluid and ion shifts

Abstract

To characterize fluid and ion shifts during prolonged whole-body immersion, 16 divers wearing dry suits completed four whole-body immersions in 5 degrees C water during each of two 5-day air saturation dives at 6.1 msw. One immersion was conducted at 1000 (AM) and one at 2200 (PM) so that diurnal variations could be evaluated. Fifty-four hours separated the immersions, which lasted up to 6 h; 9 days separated each air saturation dive. Blood was collected before and after immersion; urine was collected for 12 h before, during, and after immersion for a total of 24 h. Plasma volume decreased significantly and to the same extent (approximately 17%) during both AM and PM immersions. Urine flow increased by 236.1 +/- 38.7 and 296.3 +/- 52.0%, urinary excretion of Na increased by 290.4 +/- 89.0 and 329.5 +/- 77.0%, K by 245.0 +/- 73.4 and 215.5 +/- 44.6%, Ca by 211.0 +/- 31.4 and 241.1 +/- 50.4%, Mg by 201.4 +/- 45.9 and 165.3 +/- 287%, and Zn by 427.8 +/- 93.7 and 301.9 +/- 75.4% during AM and PM immersions, respectively, compared with preimmersion. Urine flow and K excretion were significantly higher during the AM than PM. In summary, when subjects are immersed in cold water for prolonged periods, combined with a slow rate of body cooling afforded by thermal protection and enforced intermittent exercise, there is diuresis, decreased plasma volume, and increased excretions of Na, K, Ca, Mg, and Zn.

Direct and indirect methods for determining plasma volume during thermoneutral and cold-water immersion

“…This haemodilution is due to an increase in external hydrostatic pressure, relative to capillary hydrostatic pressure, which forces interstitial fluid into the vascular space (Miki et al 1989), and is proportional to immersion depth (Greenleaf 1984). Conversely, haemoconcentration accompanies cold-water immersion (Rochelle and Horvath 1978;Young et al 1987;Deuster et al 1989;Vybı´ral et al 2000) and is believed to be associated with the thermal stress of cold water (Deuster et al 1989), although this has to be established conclusively.…”

Pyridostigmine and Warm Water Diving Protocol 90-05. 4. Physical Performance

“…9 b. The drug did not significantly affect minute ventilation, oxygen consumption, tidal volume, heart rate, or perceived exertion.…”

“…For immersions lasting longer than 2 h this diuresis can result in significant loss of body fluid. 9 " 0 Consequently, any associated decrease in I plasma volume might impair peripheral thermoregulation through circulatory alterations, or compromise the ability to maintain cardiac output during exercise. 8 Second, as water temperature approaches that of the skin the gradient for heat loss from the body is reduced.…”

Effectiveness of Glycerol Ingestion for Enhanced Body Water Retention during Cold Water Immersion

“…Immersion has been shown to significantly increase diuresis (Claybaugh et al 1986;Deuster et al 1989;Epstein 1978;Harrison et al 1986;Rochelle and Horvath 1978). Accompanying the increased urine production is an increased loss of sodium (Na) and potassium (K) ions (natriuresis and kaliuresis) (Epstein et al 1975;Epstein 1978).…”

“…Prolonged immersion diuresis, either with or without supplemental water intake, produces significant plasma volume loss over a range of 8Z to 18% and whole body dehydration (Bmning et al 1972;Deuster et al 1989;Doubt et al 1988;Epstein 1978;Harrison et al 1986;Rochelle and Horvath 1978;Goforth, unpublished data). Dehydration (Buskirk et al 1958;Jacobs 1980), hypohydration (Caterisano et al 1988;Caldwell et al 1984), and plasma volume lois negatively affect work capacity (Coppin et al 1978;Craig and Cummings 1966;53itin 1964).…”