A typical pattern of daily water exchange was determined in 10 medical students during three different seasons: summer, autumn and winter. The daily water intake was averaged to 3,810ml of which 1,256ml was from liquids, 2,055ml from the water contained in food and 500ml from the water of oxidation. On the other hand, the daily water output was 1,844ml by urinary loss, 144ml by fecal loss and 1,819ml by evaporative loss. The above quantitative pattern of daily water exchange in the Korean remained unchanged throughout the year. The daily urinary output of NaCl and urea-nitrogen was in the order of 20gm and 10gm, respectively. Furthermore, the magnitude of daily water intake was well correlated to the daily urinary output of NaCl but little correlated to that of urea-nitrogen. A comparison of these data with the corresponding figures obtained from the occidental indicates that the daily water intake and the daily urinary output of NaCl were significant1y greater in the Korean than those in the occidental. On the basis of these results, the greater water intake in the Korean was attributed to their high salt intake.
Adult ; Asian Continental Ancestry Group ; *Diuresis ; Human ; Kidney/*physiology ; Korea ; Male ; *Water ; Water-Electrolyte Balance

INTRODUCTION: A physiological profiling study was conducted to evaluate thermal strain as well as fluid and electrolyte balances on heat-acclimatised men performing a 72-km route march in a field setting. METHODS: 38 male soldiers (age range 18-23 years) participated in the study, as part of a cohort that marched for 72 km, with loads for about 26 hours. Core temperature and heart rate sensors were used for the duration of the march. Fluid and food intake and output were monitored for the duration of the march. Blood samples were taken one day before the march (pre-march), immediately after the march (Post 1) and on the 15^th day after the march to ascertain recovery (Post 2) to assess fluid and electrolyte profiles. RESULTS: Mean core temperature was within safe limits, ranging from 37.1 to 38.1°C throughout the march. There was an overall decrease in serum sodium levels, a decline in serum sodium concentration in 28 participants and three instances of hyponatraemia (serum sodium concentration <135 mmol/L). CONCLUSION Our study found low thermal strain heat-acclimatised individuals during a 72-km route march. However, there was an overall decrease in serum sodium levels, even when the participants were allowed to drink ad libitum. Challenges of exercise-associated hyponatraemia during prolonged activities remain to be addressed.
Humans ; Male ; Adolescent ; Young Adult ; Adult ; Military Personnel ; Hyponatremia ; Water-Electrolyte Balance/physiology* ; Exercise/physiology* ; Sodium

Water balance is one of the basic regulation mechanisms of homeostasis. There are 13 subtypes of aquaporins in mammals (AQP0-AQP12). In neural system, the AQP4 is mainly distributed in astrocytes. Phosphorylation and expression regulation of AQP4 is involved in the formation of brain edema, particularly in the clearance of vasogenic edema and the formation of cytotoxic edema. This article reviews regulations and functions of AQP4 in vasogenic edema and cytotoxic edema.
Animals ; Aquaporin 4 ; metabolism ; physiology ; Brain ; metabolism ; physiopathology ; Brain Edema ; metabolism ; physiopathology ; Homeostasis ; Humans ; Water-Electrolyte Balance ; physiology

OBJECTIVETo explore the effect of seawater immersion on serum osmotic pressure and electrolytes balance following chest trauma in dogs.

METHODSTwenty-five healthy adult dogs were used in the experiment. A canine model of right open pneumothorax was established by chest puncturing on all animals. Animals were divided into three groups: a control group (n=10) with chest trauma without any immersion; a seawater group (n=10) immersed in seawater after chest trauma and a normal saline group (n=5) immersed in normal saline solution following chest trauma. Blood samples were taken at different time intervals to determine plasma osmotic pressure and electrolytes. The hemodynamic changes were also recorded.

RESULTSMortality in the seawater group was much higher than that of the control group and the normal saline group. The mean survival time in the seawater group lasted only 45 minutes, while in the control group and the normal saline group the average survival time was more than 4 hours (P<0.01). One of the most important causes of death was hypernatremia and high osmolality. Severe electrolytes imbalance was observed in seawater group. Hypernatremia and high osmolality were the most significant factors of high mortality in the seawater group.

CONCLUSIONSSeawater immersion after chest trauma appears to be associated with severe electrolyte imbalance as well as high osmotic pressure. These may be the risk factors leading to fatal outcome.

Animals ; Dogs ; Hemodynamics ; Osmotic Pressure ; Risk Factors ; Seawater ; adverse effects ; Thoracic Injuries ; physiopathology ; Water-Electrolyte Balance ; physiology

INTRODUCTIONThe aim of this study is to investigate the amount of water loss and percentage dehydration experienced during 1 hour of paddling on the kayak ergometer so as to help coaches and athletes tailor a suitable and adequate rehydration regime. Also, rehydration efficacy between water and a well established, commercially available sports drink (Gatorade, Quaker Oats company, USA) was investigated in this cross-over study.

MATERIALS AND METHODSTen national flatwater kayakers were monitored in a controlled setting while paddling the kayak ergometer for 1 hour at an intensity sustainable for long distance marathon. They rehydrated themselves ad libitum with provided beverage. Post-void towel-dried body mass was measured before and after the exercise with percentage dehydration calculated. Body core temperature (tympanic temperatures), ratings of perceived exertion and thirst index were monitored every 15 minutes. The amount of fluid consumed, urine output and urine specific gravity were obtained after exercise.

RESULTSThe results [mean +/- standard deviation (SD)] showed that kayakers underwent 1.10 +/- 0.52% dehydration while rehydrating with water as compared to 0.72 +/- 0.38% while rehydrating with Gatorade. Also, athletes on water rehydration had higher rating of perceived exertion (RPE) at the 30th and 60th minute mark of the exercise. Overall, athletes undergoing water rehydration lost significantly more body mass (0.70 +/- 0.39 kg) as compared to rehydrating with Gatorade (0.46 +/- 0.27).

CONCLUSIONAlthough the hydration efficacy of Gatorade proved superior to that of water, the athletes' hydration habits with either fluids did not provide adequate hydration. It is recommended that specific strategies be developed to address dehydration and rehydration issues of kayakers in Singapore.

Adult ; Beverages ; Competitive Behavior ; Cross-Over Studies ; Dehydration ; metabolism ; physiopathology ; Drinking ; Exercise ; physiology ; Female ; Fluid Therapy ; methods ; Humans ; Male ; Monitoring, Physiologic ; Physical Exertion ; physiology ; Ships ; Sports ; Water-Electrolyte Balance ; physiology

Positive fluid balance is a risk factor for mortality in critically ill patients, especially those requiring continuous renal replacement therapy (CRRT). However, the association between daily fluid balance and various organ impairments remains unclear. This study investigated the impacts of daily fluid balance prior to CRRT on organ dysfunction, as well as mortality in critically ill patients. We identified daily fluid balance between intensive care unit (ICU) admission and CRRT initiation. According to daily fluid balance, the time to CRRT initiation and the rate of organ failure based on the sequential organ failure assessment (SOFA) score were assessed. We recruited 100 patients who experienced CRRT for acute kidney injury. CRRT was initiated within 2 [0, 4] days. The time to CRRT initiation was shortened in proportion to daily fluid balance, even after the adjustment for the renal SOFA score at ICU admission (HR 1.14, P = 0.007). Based on the SOFA score, positive daily fluid balance was associated with respiratory, cardiovascular, nervous, and coagulation failure, independent of each initial SOFA score at ICU admission (HR 1.36, 1.26, 1.24 and 2.26, all P < 0.05). Ultimately, we found that positive fluid balance was related with an increase in the rate of 28-day mortality (HR 1.14, P = 0.012). Positive daily fluid balance may accelerate the requirement for CRRT, moreover, it can be associated with an increased risk of multiple organ failure in critically ill patients.
Acute Kidney Injury/*diagnosis/mortality/therapy ; Aged ; Critical Illness/*mortality ; Female ; Humans ; Intensive Care Units ; Male ; Middle Aged ; Organ Dysfunction Scores ; *Renal Replacement Therapy ; Retrospective Studies ; Risk Factors ; Survival Rate ; Water-Electrolyte Balance/*physiology

Positive fluid balance is a risk factor for mortality in critically ill patients, especially those requiring continuous renal replacement therapy (CRRT). However, the association between daily fluid balance and various organ impairments remains unclear. This study investigated the impacts of daily fluid balance prior to CRRT on organ dysfunction, as well as mortality in critically ill patients. We identified daily fluid balance between intensive care unit (ICU) admission and CRRT initiation. According to daily fluid balance, the time to CRRT initiation and the rate of organ failure based on the sequential organ failure assessment (SOFA) score were assessed. We recruited 100 patients who experienced CRRT for acute kidney injury. CRRT was initiated within 2 [0, 4] days. The time to CRRT initiation was shortened in proportion to daily fluid balance, even after the adjustment for the renal SOFA score at ICU admission (HR 1.14, P = 0.007). Based on the SOFA score, positive daily fluid balance was associated with respiratory, cardiovascular, nervous, and coagulation failure, independent of each initial SOFA score at ICU admission (HR 1.36, 1.26, 1.24 and 2.26, all P < 0.05). Ultimately, we found that positive fluid balance was related with an increase in the rate of 28-day mortality (HR 1.14, P = 0.012). Positive daily fluid balance may accelerate the requirement for CRRT, moreover, it can be associated with an increased risk of multiple organ failure in critically ill patients.
Acute Kidney Injury/*diagnosis/mortality/therapy ; Aged ; Critical Illness/*mortality ; Female ; Humans ; Intensive Care Units ; Male ; Middle Aged ; Organ Dysfunction Scores ; *Renal Replacement Therapy ; Retrospective Studies ; Risk Factors ; Survival Rate ; Water-Electrolyte Balance/*physiology

Most patients with trauma-hemorragic shock, prior to ICU admission, have been resuscitated and stabilized in the emergency room (ER) and/or operation room (OR). Many of them suffer from systemic edema. This extra-vascular fluid is caused by massive infusion of fluid and blood for the maintenance of blood pressure. During the recovery stage, the patients exhibit spontaneous diuresis followed by negative fluid balance. Urine volumes of some patients are more than 10000 ml/d. Do we need to maintain a balance between daily input and output of water at this situation? There are many references in the medical literature and textbooks about fluid resuscitation and the principles in maintaining the balance between input and output of water, but rarely about when and how to restrict it, that is, when and how to permit a negative balance. In this retrospective review, we examined the resuscitation records of 205 patients with systemic edema after trauma-hemorragic shock.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Cause of Death ; Child ; Critical Care ; methods ; Diuresis ; physiology ; Female ; Fluid Therapy ; methods ; Humans ; Injury Severity Score ; Intensive Care Units ; Male ; Middle Aged ; Multiple Trauma ; diagnosis ; mortality ; therapy ; Predictive Value of Tests ; Probability ; Prognosis ; Retrospective Studies ; Risk Assessment ; Shock, Hemorrhagic ; diagnosis ; mortality ; therapy ; Survival Rate ; Water-Electrolyte Balance