Head‐out Water Immersion: Animal Studies

Krasney, J. A.

doi:10.1002/cphy.cp040238

Cited by 9 publications

(25 citation statements)

References 76 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The major role of the kidney in HOWI is to blunt the expansion of PV and prevent a further increase in PV (see Fig. 4) and CO as seen in Figure 5 (201,256,257). Early in immersion PV increases about 7% (Fig.…”

Section: Circulatory Responses and Fluid Shiftsmentioning

confidence: 95%

“…Plasma oncotic pressure is decreased in HOWI resulting in hemodilution, whereas plasma osmolarity is unchanged. Amino acids and potassium are increased in the plasma suggesting that the majority of the fluid shifted is out of the intracellular compartment (83,201,358). In spite of this, interstitial fluid volume and lymph flow do not change in HOWI.…”

Section: Circulatory Responses and Fluid Shiftsmentioning

confidence: 99%

“…The relative increase in SV exceeds the observed decline of HR such that there is a net increase in CO as shown in Figure 5. MAP is not effected by HOWI and therefore TPR must be decreased (11,201,281). V O 2 is unchanged during HOWI in TN water, thus it is apparent that systemic O 2 delivery quickly exceeds systemic O 2 demands in HOWI.…”

Section: Circulatory Responses and Fluid Shiftsmentioning

confidence: 99%

“…HOWI in thermoneutral (TN) water (34 or 35 • C for 3-6 h) results in a translocation of blood from the dependent limbs to the chest, as well as increased plasma volume (PV) due to transcapillary autotransfusion of fluid from the cells (201,204). These responses augment intrathoracic blood volume (11,109,203) which in turn increases cardiac end-diastolic volume, stroke volume (SV) and cardiac output (CO) due to increased end-diastolic cardiac fiber length (237).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Human Physiology in an Aquatic Environment

Pendergast

Moon

Krasney

et al. 2015

Comprehensive Physiology

134

137

View full text Add to dashboard Cite

Water covers over 70% of the earth, has varying depths and temperatures and contains much of the earth's resources. Head-out water immersion (HOWI) or submersion at various depths (diving) in water of thermoneutral (TN) temperature elicits profound cardiorespiratory, endocrine, and renal responses. The translocation of blood into the thorax and elevation of plasma volume by autotransfusion of fluid from cells to the vascular compartment lead to increased cardiac stroke volume and output and there is a hyperperfusion of some tissues. Pulmonary artery and capillary hydrostatic pressures increase causing a decline in vital capacity with the potential for pulmonary edema. Atrial stretch and increased arterial pressure cause reflex autonomic responses which result in endocrine changes that return plasma volume and arterial pressure to preimmersion levels. Plasma volume is regulated via a reflex diuresis and natriuresis. Hydrostatic pressure also leads to elastic loading of the chest, increasing work of breathing, energy cost, and thus blood flow to respiratory muscles. Decreases in water temperature in HOWI do not affect the cardiac output compared to TN; however, they influence heart rate and the distribution of muscle and fat blood flow. The reduced muscle blood flow results in a reduced maximal oxygen consumption. The properties of water determine the mechanical load and the physiological responses during exercise in water (e.g. swimming and water based activities). Increased hydrostatic pressure caused by submersion does not affect stroke volume; however, progressive bradycardia decreases cardiac output. During submersion, compressed gas must be breathed which introduces the potential for oxygen toxicity, narcosis due to nitrogen, and tissue and vascular gas bubbles during decompression and after may cause pain in joints and the nervous system.

show abstract

Section: Circulatory Responses and Fluid Shiftsmentioning

confidence: 95%

Section: Circulatory Responses and Fluid Shiftsmentioning

confidence: 99%

Section: Circulatory Responses and Fluid Shiftsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Human Physiology in an Aquatic Environment

Pendergast

Moon

Krasney

et al. 2015

Comprehensive Physiology

134

137

View full text Add to dashboard Cite

show abstract

“…This difference might be explained by the partial transfer of albumins (which make up approximately 60% of total protein pool) to interstitial fluid. During immersion, with compression of superficial tissues and continuous transcapillary "autotransfusion" [13], enhanced loss of interstitial fluid occurs. To limit tissue dehydration, plasma albumins might shift to interstitial fluid and increase its oncotic pressure.…”

Section: Interstitial Volume: Water Redistribution Bymentioning

confidence: 99%

Body Fluid Changes, Cardiovascular Deconditioning and Metabolic Impairment Are Reversed 24 Hours after a 5-Day Dry Immersion

Coupé¹,

Tomilovskaya²,

Larcher³

et al. 2013

OJNeph

View full text Add to dashboard Cite

Dry immersion is an effective and useful model for research in physiology and physiopathology. The focus of this study was to provide integrative insight into renal, endocrine, circulatory, autonomic and metabolic effects of dry immersion. We assessed if the principal changes were restored within 24 h of recovery, and determined which changes were mainly associated with immersion-induced orthostatic intolerance. Five-day dry immersion without countermeasures, and with ad libitum water intake, standardized diet and a permitted short daily rise was performed in a relatively large sample for this experiment type (14 healthy young men). Reduction of total body water derived mostly from extracellular compartment, and stabilized rapidly at the new operating point. Decrease in plasma volume was estimated at 20% -25%. Five-day immersion was sufficient to impair metabolism with a decrease in glucose tolerance and hypercholesterolemia, but was not associated with pronounced autonomic changes. Five-day immersion induced marked cardiovascular impairment. Immediately after immersion, over half of the subjects were unable to accomplish the 20-min 70˚ tilt; during tilt, heart rate and total peripheral resistance were increased, and stroke volume was decreased. However, 24 hours of normal physical activity appeared sufficient to reverse orthostatic tolerance and all signs of cardiovascular impairment, and to restitute plasma volume and extracellular fluid volume. Similarly, metabolic impairment was restored. In our study, the major factor responsible for orthostatic intolerance appeared to be hypovolemia. The absence of pronounced autonomic dysfunction might be explained by relatively short duration of dry immersion and daily short-time orthostatic stimulation.

show abstract

Cold-water acclimation does not modify whole-body fluid regulation during subsequent cold-water immersion

Stocks

Patterson

Hyde³

et al. 2004

European Journal of Applied Physiology

View full text Add to dashboard Cite

We investigated the impact of cold-water acclimation on whole-body fluid regulation using tracer-dilution methods to differentiate between the intracellular and extracellular fluid compartments. Seven euhydrated males [age 24.7 (8.7) years, mass 74.4 (6.4) kg, height 176.8 (7.8) cm, sum of eight skinfolds 107.4 (20.4) mm; mean (SD)] participated in a 14-day cold-water acclimation protocol, with 60-min resting cold-water stress tests [CWST; 18.1 (0.1) degrees C] on days 1, 8 and 15, and 90-min resting cold-water immersions [18.4 (0.4) degrees C] on intervening days. Subjects were immersed to the 4th intercostal space. Intracellular and extracellular fluid compartments, and plasma protein, electrolyte and hormone concentrations were investigated. During the first CWST, the intracellular fluid (5.5%) and plasma volumes were reduced (6.1%), while the interstitial fluid volume was simultaneously expanded (5.4%). This pattern was replicated on days 8 and 15, but did not differ significantly among test days. Acclimation did not produce significant changes in the pre-immersion distribution of total body water, or changes in plasma osmolality, total protein, electrolyte, atrial natriuretic peptide or aldosterone concentrations. Furthermore, a 14-day cold-water acclimation regimen did not elicit significant changes in body-fluid distribution, urine production, or the concentrations of plasma protein, electrolytes or the fluid-regulatory hormones. While acclimation trends were not evident, we have confirmed that fluid from extravascular cells is displaced into the interstitium during acute cold-water immersion, both before and after cold acclimation.

show abstract

Head‐out Water Immersion: Animal Studies

Cited by 9 publications

References 76 publications

Human Physiology in an Aquatic Environment

Human Physiology in an Aquatic Environment

Body Fluid Changes, Cardiovascular Deconditioning and Metabolic Impairment Are Reversed 24 Hours after a 5-Day Dry Immersion

Cold-water acclimation does not modify whole-body fluid regulation during subsequent cold-water immersion

Contact Info

Product

Resources

About