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Contrast medium-induced nephrotoxicity (CMN) is a common form of iatrogenic acute renal failure. Typically, patients experience changes in serum creatinine or creatinine clearance between 1 and 5 days after exposure to a contrast medium, but they rarely require dialysis. The mechanism for CMN is not understood, but renal insufficiency, dehydration, and congestive heart failure are risk factors. The frequency of CMN with high-osmolality versus low-osmolality media is controversial. Prophylaxis can reduce CMN. Of many different strategies, hydration with normal saline before and after exposure offers the best protection with the fewest adverse effects.

Amphibians absorb water osmotically across their skins and rely on chemosensory information from the skin to assess the suitability of hydration sources. The time spent with skin in contact with a moist surface provides a quantitative measure of their ability to perceive the ionic and osmotic properties of aqueous solutions. Dehydrated toads given hyperosmotic (250 mM) solutions of NaCl or Na-gluconate showed significantly longer periods of hydration behavior on the gluconate solution, but they lost water osmotically when immersed in either solution. Similarly, dehydrated toads given 250 mM solutions of NaCl, Na-acetate, Na-phosphate or Na-gluconate showed a progressively greater length of hydration time on solutions with the larger mol. wt anions. These results are consistent with the chemosensory phenomenon previously described in mammalian tongue as 'anion paradox'. On dilute (50 mM) solutions of NaCl or Na-gluconate, the hydration time was not different between anions, despite toads gaining water more rapidly when immersed in dilute NaCl than in Na-gluconate solutions. The differing behavioral results with hyperosmotic and hypoosmotic salt solutions suggest that chemosensory transduction through toad skin involves both transcellular and paracellular pathways.

This review highlights characteristics of extracellular fluid (ECF) that are often overlooked. ECF has, in addition to plasma and interstitial fluid (ISF) surrounding cells, a third large compartment, the ISF of skin and connective tissue. This acts as a reservoir that gives up ECF to plasma volume (PV) in order to sustain circulation in the event of either shock or dehydration. While Starling forces drive filtration, ECF is returned to PV more by lymph and less by Starling forces than previously appreciated. Lymph return to PV is dependent on physical activity and muscle contraction to overcome gravity. Regional change in metabolic rate alters the need for oxygen and nutrients that is met by a regional increase in capillary blood flow. Blood flow is controlled by vasoactive compounds released in response to a drop in PO(2); these relax capillary smooth muscle to increase blood flow and delivery of oxygen and nutrients. Plasma proteins, including albumin, are filtered into the interstitium through larger pores than those filtering ECF. The rate of protein filtration is set by size and charge of these larger endothelial pores and by size and charge of proteins. Charge of these pores, hence albumin permeability, is regulated by many of the same vasoactive compounds that control capillary flow. As a consequence, in response to gravitational stress and other forms of shock that reduce effective circulation, albumin as well as ECF is rapidly shifted from plasma and sequestered in ISF. When this has occurred, as in burn shock, restoration is better effected by generous expansion of ECF with Ringer's solution alone, rather than with Ringer's solution supplemented with human serum albumin or other colloid. Restoring both PV and ISF volume restores lymph circulation and returns sequestered albumin to PV.

The water-seeking behavior (WR) of toads (Bufo viridis) was investigated. Fully hydrated toads that are allowed free choice of wet or dry filter paper voluntarily and spontaneously select to sit on water-soaked paper at a regular frequency during trials. Dehydration of bladder-emptied toads by 14% elicits WR in all animals. Injection of aldosterone or angiotensin-I reduced the dehydration threshold to 7% weight loss. WR frequency increased when plasma osmolality was elevated by injection of NaCl or other solutes (both ionic and non-ionic). Only urea, to which cell membranes are highly permeable, was the exception that did not produce this response. The increase in WR frequency induced by elevated plasma osmolality was augmented by injection of aldosterone or angiotensin-I. In vivo water uptake, measured in a water bath, was increased by an NaCl or oxytocin injection, but not by aldosterone. It is concluded that elevated plasma osmolality induces an increase in WR frequency that is separate and prior to the water uptake process. Different hormones are involved in each step.

Objective: To observe the therapeutic effect of Zhixie Buye mixture (ZXBYM) on infantile diarrhea patient with mild and middle degree of dehydration., Methods: The controlled observation method was adopted in the clinical and experimental study., Results: There was no significant difference in the treatment of dehydration between the ZXBYM group and ORS group (P > 0.05), while it was more effective for ZXBYM to eliminate the symptoms such as vomiting and abdominal distension (P < 0.01). In addition, it was confirmed that the ion concentration of sodium, potassium, chlorine, glucose and osmotic pressure in the mixture was similar to those in ORS. Animal experiment showed that it has the effect of rat intestine peristalsis suppression and water absorption promotion in colon for ZXBYM. And there was statistical difference in antidiarrhea effect between the mixture and ORS (P < 0.01)., Conclusion: The ZXBYM is an effective mixture in the treatment of diarrhea with dehydration. It has a good prospect of development and application.

Rice gruels have been used as home remedies to treat dehydration associated with diarrheal illness in developing countries. These preparations have produced conflicting results, most likely due to the heterogeneity of starch used. We investigated whether the modified tapioca starch, Textra (TX), at 5.0 or 10.0 g/L added to a 90 mmol/L Na+-111 mmol glucose oral rehydration solution (ORS) enhanced water and electrolyte absorption in two models of diarrhea. To induce a secretory state (model A), the jejunum of juvenile rats was perfused with 10 mmol/L theophylline (THEO) under anesthesia and then perfused with the solutions indicated above. To produce chronic osmotic-secretory diarrhea (model B), rats had a magnesium citrate-phenolphthalein solution as the sole fluid source for 1 wk, and then were perfused as the THEO-treated rats. Water, electrolyte, and glucose absorption were measured during both perfusions. As an extension of the perfusion studies, we compared how fast rats recovered from chronic osmotic diarrhea by offering them either water, ORS, or ORS containing 5.0 g/L TX along with solid food. Recovery rate markers were measured after 24 h and included weight gain, food and fluid intake, and stool output. In model A, addition of 5.0 g/L TX to ORS reversed Na+ secretion and improved net water as well as K+ and glucose absorption, compared with THEO-treated rats perfused with ORS without TX. In model B, addition of TX to ORS increased water, Na+, K+, and glucose absorption, compared with rats perfused without TX. Increasing TX from 5.0 to 10.0 g/L had no additional benefit. In recovery experiments, animals with free access to ORS with TX had significantly greater weight gain and decreased stool output compared with animals recovering with water or ORS without TX. Our experiments suggest that TX may be a useful additive to standard ORS to promote fluid and electrolyte absorption and may provide additional energy without increasing ORS osmotic load.

Background: The influence of non-ionic osmols on thermoregulation is unclear., Hypothesis: Hyperglycemia will attenuate the rise in exercise core temperature., Methods: Dehydrated by 4-h of water immersion (34.5 degrees C) to the neck, 6 men, (35+/-SD 7 yr) participated in each of three trials where 2.0 g x kg(-1) body wt of oral glucose (33.8% weight per volume) was consumed followed by 80 min supine rest (Glu/Rest), or 70 min supine cycle exercise at 62.8%+/-SE 0.5% (1.97+/-0.02 L x min(-1)) peak O2 uptake, followed by 10 min supine recovery with prior (Glu/Ex) or without glucose (No Glu/Ex) ingestion. Blood samples were taken periodically for measurement of Hb, Hct, Na+, K+, Osm, and glucose; mean skin (Tsk) and rectal (Tre) temperatures, and sweating rate (resistance hygrometry) and skin blood velocity (laser Doppler) were measured intermittently., Results: Mean percent changes in plasma volume (p<0.05) for the exercise trials were not different: -12.3+/-2.2% (No Glu/Ex) and -12.1+/-2.1% (Glu/Ex). Mean (+/-SE) pre-exercise plasma [glucose] for Glu/Ex was higher than that of No Glu/Ex (108.4+/-3.9 vs. 85.6+/-1.6 mg x dL(-1), respectively, p<0.05). Glu/Ex vs. No Glu/Ex data, respectively, at the end of exercise indicated that: Tre was lower by 0.4 degrees C (38.2+/-0.2 vs. 38.6+/-0.1 degrees C, p<0.05), Tsk was lower (32.0+/-0.3 vs. 32.4+/-0.2 degrees C, p<0.05), forearm sweating rate was lower (0.94+/-0.09 vs. 1.05+/-0.07 mg x cm(-2) x min(-1), p<0.05); and head (temporal) skin blood velocity was not different (1.67+/-0.21 vs. 1.51+/-0.24 Hz x 10(3), NS)., Conclusions: Elevation of plasma [glucose] prior to supine submaximal exercise in dehydrated men attenuates the increase of Tre without alteration of heat production, total body sweating, serum electrolytes and osmolality, or exercise-induced hypoglycemia: the mechanism may be enhanced peripheral blood flow that could enhance body heat loss.

Background: The mechanism for reduction and restoration of total body water and plasma volume (PV) during initial exposure to acute altitude (ALT) is not clear but may involve involuntary dehydration; i.e., delayed voluntary fluid intake., Method: Ten men (24 +/- SD 3 yr, 180.8 +/- 8.1 cm height, 78.8 +/- 12.8 kg weight, 1.99 +/- 0.19 m2 surface area, and 12.2 +/- 4.0% body fat) were in a semi-reclining position for 12 h in a chamber at 2800 m (539 mmHg) ALT or at 321 m (732 mmHg; ground). They ate a controlled breakfast (450 kcal + 3 ml x kg(-1) H2O) on the ground, and lunch and dinner at ALT (or on the ground) for a total daily intake of 2850 kcal (14% PRO, 67% CHO, 16% fat, 2.6g NaCl). At hour 10 they consumed fluid-electrolyte beverages or water (12 ml x kg(-1), 948 ml x d(-1)) in 4 sessions at weekly intervals. Beverage compositions were: a) 185 mEq x L(-1) Na+, 283 mOsm x kg(-1); b) 21.6 mEq x L(-1) Na+, 365 mOsm x kg(-1); c) water at ALT; and d) water on the ground., Results: After 10 h at ALT % deltaPV (Hb-Hct) decreased (p < 0.05) by: a) 9.0 +/- SE 1.5%; b) 6.2 +/- 1.7%; c) 7.4 +/- 2.2%; and d) by 9.0 +/- 2.4%, respectively. After drinking from 1000-1030 h, PV at 1200 h changed by: a) +8.3 +/- SE 2.0% (p < 0.05); b) +2.8 +/- 2.7% (NS); c) -0.9 +/- 1.5% (NS); and d) by +0.8 +/- 3.5% (NS), respectively. The similar ground-induced hypovolemia suggests a response to confinement rather than an ALT effect and involuntary dehydration does not appear to be implicated., Conclusion: The significant increase in PV after consuming the (a) NaCl-NaCitrate beverage indicates that drink ionic composition appears to be more important than its osmolality for restoring PV in these conditions. Practical considerations: Because this hypovolemia was probably due to the confinement rather that reduced ambient pressure, appropriate countermeasures could be consumption of isotonic beverages, elastic stockings, leg exercise, and leg elevation.

Background: Despite the known potent vasoconstrictor effects of vasopressin, the role of this hormone in the maintenance of blood pressure is incompletely understood. In studies performed in animals with increased plasma vasopressin concentrations, several complex cardiovascular effects have been noted, including decreases in heart rate and cardiac output, which may account for a lack of effect on arterial pressure despite the vasopressin-induced increase in total peripheral resistance. Only a few studies have been done to assess the cardiovascular effects of vasopressin in human subjects, and most of these have been limited to measurement of heart rate and arterial pressure only. The present study was designed to identify more fully the cardiovascular effects of vasopressin when plasma vasopressin concentrations are increased by osmotic stimulation without the superimposition of major nonosmotic stimuli associated with severe volume depletion., Method: Studies were performed on 11 normal human subjects in supine and erect posture before and after 24 hours of fluid deprivation, and following administration of a selective V1 receptor antagonist, [d(CH2)5Tyr(ME)]AVP, after dehydration. Cardiovascular parameters were measured noninvasively by thoracic electrical bioimpedance cardiography and blood samples for measurements of plasma concentrations of vasopressin and other hormones affected by dehydration and differences in posture were collected for subsequent analysis., Results: After 24 hours of fluid restriction, plasma osmolality was increased from 287 +/- 0.9 to 294 +/- 0.7 mosm/kg H20 and plasma vasopressin concentrations (Pavp) were increased in both supine and erect posture. Mean arterial (MAP) and systolic blood pressure (SBP) were reduced by fluid restriction but were higher in erect than in supine posture both before and after fluid restriction. Heart rate (HR), diastolic blood pressure (DBP), and systemic vascular resistance (SVRI) were also higher in erect than in supine posture, while cardiac index (CI), stroke index (SI), end-diastolic index (EDI), and an index of total thoracic fluid content (TFC) were all reduced in erect posture, both before and after dehydration. Plasma renin activity (PRA) and plasma norepinephrine concentrations (Pne) were increased in erect posture, both before and after dehydration, but there was no effect of erect posture on plasma vasopressin concentrations (Pavp), either before or after dehydration. Administration of the V1 receptor antagonist after dehydration had no effect on hemodynamic parameters other than small reductions in DBP and cardiac preload., Conclusion: It is concluded from these studies that small increases in Pavp associated with moderate dehydration do not play a role in the maintenance of arterial pressure in normal human subjects in either supine or erect posture.

Diarrhoeal diseases are a major contributory factor for high infant mortality and morbidity in Pakistan. To overcome this, Government of Pakistan launched a National Programme for Control of Diarrhoeal Disease. A Diarrhoea Training Unit (DTU) was established at the National Institute of Child Health, Karachi, where apart from proper case management, 17 training workshops were held between July, 1989 to July, 1991. Eighty-five doctors from various facilities in Sindh were trained in proper management of diarrhoea and establishment of Oral Rehydration Therapy (ORT) units in their regions. Evaluation of DTU training, assessment of the knowledge of trained doctors, case management and function of ORT Units were done between September, 1992 and October, 1993. Two teams each consisting of a doctor and a lady health visitor, visited 30 such facilities. An observation check list was used for assessing the ORT unit and diarrhoea case management and a test questionnaire for the knowledge of facility physician and paramedic. Of the 29 facilities, 17 had DTU trained doctors. ORT corner had been established in 26, weighing scales were used in 21, record keeping in eight and soap and water was available for hand washing in seven centres. The presence of untrained doctors provided an opportunity to compare the two groups. Dehydration assessment was fairly good, weight was recorded in fewer cases than desirable, case management was similar in the two groups, except for infrequent use of antibiotics by the trained group. Prevention was poorly advised. Physicians' knowledge in both groups was similar but deficient in advising the use of ORS, feeding in diarrhoea and nutritional assessment. The trained ones had significantly better knowledge about drugs and this was reflected in their case management. Paramedic case management were similar to those in doctors. The study thus showed positive and beneficial effects of training.

The main aim of the study was to evaluate the combination of quantitative diffusion, T2 and Magnetisation Transfer Imaging of brain water homeostasis using untreated diabetes as an animal model of brain dehydration. In addition, experimental groups of diabetic rats treated with insulin and insulin-like growth factor (IGF-I) and normal rats treated with IGF-I and growth hormone were studied using the same MR imaging protocol. Untreated diabetes caused weight reduction and an increase in water intake, indicating a general body dehydration linked to chronic blood hyperosmolarity. In the investigated cortical gray matter untreated diabetes caused a significant reduction in the apparent diffusion coefficient of water (ADC) and an increase in T2 relaxtivity (R2) when compared to a control group. No significant changes were observed for the calculated magnetisation transfer parameters Kfor and T1sat. Both ADC and R2 normalized after appropriate insulin treatment whereas only ADC was normalized after IGF-I treatment. IGF-I treatment of normal rats caused significantly higher rate of increase in body weight compared to normal controls. There were, however, no significant changes in ADC, R2 nor the magnetisation transfer parameters measured in the cortical gray matter of the IGF-I treated normal rats. In conclusion, we found that changes in brain water homeostasis during diabetes were detected by quantitative MR imaging, and that the dehydration induced by diabetes was normalized by insulin treatment but not by IGF-I.

Although dehydration impairs the response to a fixed volume hemorrhage, both 7.5% hypertonic saline/6% dextran 70 (HSD: 4 mL/kg) and standard Ringer's lactate (33 mL/kg) are effective resuscitation fluids. However, the efficacy of resuscitation during continuing hemorrhage remains in question. Using a conscious swine model of continuous pressure-driven hemorrhage, we evaluated the effects of dehydration and HSD resuscitation on survival time, hemorrhage volume, regional blood flows, and central hemodynamics. Three groups of pigs were compared: euhydrated control (EC), dehydrated control (48 h water deprived) (DC); and dehydrated and resuscitated with HSD (D + HSD). All pigs were subjected to an initial 37% blood volume hemorrhage for 60 min followed by a continuous hemorrhage proportional to the instantaneous mean arterial pressure. The D + HSD pigs were resuscitated at the end of the 37% blood volume hemorrhage. Dehydration reduced body weight (-6.5 +/- .3%) and increased hematocrit (8.9 +/- 1.8%), serum osmolality (11.6 +/- .9%), serum sodium (11.9 +/- .9%), and serum total protein (9.4 +/- 1.8%). Compared with the EC group, DC had a greater increase in heart rate and arterial base deficit in response to the pressure-driven hemorrhage and a reduced pH and survival time (159 vs. 107 min). In contrast to the DC group, D + HSD had increased mean arterial pressure, cardiac output, oxygen delivery, and regional blood flows to the gut (superior mesenteric artery), kidneys, liver (hepatic artery), and adrenals at 5 min after HSD resuscitation. The HSD did not increase blood loss but tended to prolong survival (+26 min; p = .1079). thus, dehydration compromises survival time (-33%) and the hemodynamic and metabolic responses to pressure-driven hemorrhage, while treatment with HSD improves the hemodynamic responses.

A small volume of 7.5% NaCl/6% Dextran-70 (HSD) can rapidly expand the plasma volume, but concerns exist regarding its adverse effects on renal function in the dehydrated state. Sheep were thirsted for 4 days (13% plasma volume contraction), and subjected to a fixed-pressure shock model (mean arterial pressure of 50 mmHg for 2 h), followed by resuscitation with either HSD (4 mL/kg) or lactated Ringer's solution (LR; 37 mL/kg). Mean arterial pressure was restored to 90%, cardiac output to 125% and 120%, and plasma volume to 78% and 72% of baseline in LR and HSD groups, respectively. Glomerular filtration rate improved to 100% of baseline following HSD compared with 82% following LR. No significant urinary 70,000 molecular weight dextran was observed, suggesting an intact renal glomerular membrane. These data suggest that small volume HSD resuscitation is effective, even with pre-existing dehydration. In addition, renal function is not compromised by HSD resuscitation of hemorrhaged, dehydrated animals.

One-hundred-and-seventy-seven children with post-measles complications divided into two comparable groups were studied for the effect of Vit.A Supplementation. Eighty-nine children received Vit.A in doses of 200,000 units daily on two consecutive days in addition to antibacterials and other supportive care and 88 did not reveice Vit.A. The case fatality rate was 16 per cent in those who received VIT.A, while the same was 32 per cent in those who did not receive Vit.A (P < 0.02). There was no statistical difference in the mortality rate among two groups when the children were suffering from severe malnutrition or encephalopathy (P > 0.1).

A 34-year-old female presented to our clinic with complaints of hearing loss, tinnitus, and severe rotational vertigo. A test battery including complete audiometric testing, auditory brainstem response (ABR) audiometry, electronystagmography (ENG), electrocochleography (ECoG), and dehydration testing was performed. Monitoring of hearing sensitivity, speech understanding, and ECoG responses following administration of a dehydrating agent were sensitive measures of cochlear function and confirmed the diagnosis of Meniere's disease. The induced changes also contributed to the therapeutic measures recommended.

The purpose of our studies was to determine whether hypertonic (7.5%) saline (HTS) resuscitation is effective in the setting of dehydration. We compared the effects of HTS (5 cc/kg) to those of Ringer's lactate (RL; 45 cc/kg) on renal function, following resuscitation from hypovolemia in hydrated (free access to food/water) vs. dehydrated (food/water restricted) rats (300-350 g). Renal failure was produced by hemorrhage (15 cc/kg) plus renal artery occlusion (25 min) followed by fluid resuscitation. Dehydration was confirmed by hemoconcentration and weight loss (8-10%). Renal function was assessed at 24 hr using 14C-inulin clearance (Cin) measurements. In hydrated animals, the Cin of RL-treated rats (625 +/- 54 microliters/min/100 g; n = 12) was no different from the Cin in HTS-treated rats (517 +/- 48 microliters/min/100 g; n = 13). Among dehydrated rats, Cin in HTS-treated rats (n = 6) was significantly lower (P < or = 0.05) than in RL-treated rats (n = 5) (117 +/- 33 microliters/min/100 g vs. 542 +/- 84 microliters/min/100 g, respectively). Cin in dehydrated RL-treated rats was not significantly different from that in hydrated RL-treated rats. Furthermore, in dehydrated animals, nine of nine resuscitated with RL survived, compared to six of 13 resuscitated with HTS. All hydrated animals survived. In summary, renal failure was ameliorated by RL and worsened by HTS resuscitation in dehydrated rats. Furthermore, mortality was increased in dehydrated animals resuscitated with HTS compared to RL.

Sucrose was tested as a possible alternative to glucose in oral diarrhoea therapy. Eighteen patients were given oral sucrose plus electrolytes as a maintenance solution. Fifteen of these patients could be maintained using this solution, but three developed massive increases in net fluid losses with increases in plasma specific gravity, necessitating termination of oral therapy. Twelve patients tested all had significant concentrations of stool reducing sugar. The data contrast with the rarity of treatment failures of oral glucose-electrolyte solutions. Glucose, therefore, is preferable to sucrose for oral therapy of diarrhoeal diseases.

A mathematical model of the adrenal postpituitary system has been used in cases of brain disease in which endocrine disturbances play an aggravating role. A computer simulation has suggested a type of therapy adding vasopressin to corticoids; this association seems to elicit better results than corticoids alone. Posttraumatic disorders of the cerebral hydration, on one hand, and inoperable or recurrent tumors, on the other hand, take advantage of such a systemic, formalized approach.

To verify whether there is a state of phosphate depletion in dehydrated infants with diarrhea and whether phosphate administration affects recovery from metabolic acidosis, two groups of infants were studied. All were males, from 1 to 7 months old, and in good nutritional state. The control group was treated with a standard regimen of I.V. fluids initially, followed by feedings of a diluted milk formula starting on the 2nd day of treatment. The study group, in addition to this standard regimen, received sodium phosphate (Na2HPO4/Na2HPO4, 4:1, pH 7.4), initially by the I.V. route and thereafter orally with the feedings, at the dose of 2mM/kg/day. During the first 6 days of treatment, daily electrolyte (Na, K, Ca, Mg. Cl and P) and nitrogen balances were recorded. Hydrogen ion excretion (NH4 + TA--HCO3) was determined daily. Clinical findings and course were similar in the two groups. No untoward effects were observed with phosphate administration. In the control group, P balance was negative during all the periods and losses were in excess of those expected from nitrogen losses, thus suggesting a state of depletion. In the P-treated group however, P retention was not demonstrated in the first 2 days, finding a not suggestive of a P depleted state. Linear regressions between both daily and cumulative balances of P-nitrogen-free and Ca indicated a close correlation, thus suggesting that these two ions are mobilized concommitantly.

The literature on oral sugar-electrolyte mixtures for treatment of acute diarrhoea is reviewed. Several trials have shown that the solution proposed by the WHO for developing countries containing inter alia 90 mmol/l of sodium and 111 mmol/l of glucose is safe for short term oral rehydration. When used in this manner there is no risk for development of hypernatraemia. The surplus base of the solution is not essential and, furthermore, other anions e.g. acetate may be substitute for bicarbonate. Other modifications of the WHO formula have also been successfully tried, e.g. sucrose 4% (117 mmol/l) instead of glucose 2% (111 mmol/l). A somewhat lower concentration of sucrose may, however, prove to be better. Most acute childhood diarrhoeas are not mediated by enterotoxin and thus not of the secretory type, but temporary malabsorption is common. Therefore, the amount of carbohydrate in oral sugar-electrolyte mixtures should be limited. Osmotic diarrhoea due to carbohydrate malabsorption is a more likely cause of hypernatraemia in dehydrated children than too much dietary sodium. In developed countries prepacked oral sugar-electrolyte mixtures are mainly designed for moderately sick children treated at home. There is no reason to raise the carbohydrate content of these mixtures above that of the WHO formula, but the sodium content must be lower. For most situations in home treatment 50 mmol/l of sodium will be adequate.

Shock is to define by clinical symptoms, measurable haemodynamic and metabolic changes, clotting failure and disorders of fluid, electrolyte and acid-base balance. It is essential to remove hypovolemia, acidosis, cardiovascular failure, pulmonary and renal insufficiency. Quite a lot of proved and controversial pharmacological substances are placed at physician's disposal. However, the mortality of cardiogenic shock and gram-negative septic shock is more than 80% respectively 30%, often caused by shock lung or irreversible injury to the kidneys. Shock due to depletion of extracellular fluid, poisoning and acute pancreatitis require specific treatment.

A 40-year-old man with the Verner-Morrison syndrome (refractory watery diarrhoea and hypokalaemia in islet-cell tumour of the pancreas) had an islet-cell carcinoma of the non-B-cell type with metastases to liver and mesenteric lymph nodes. High concentrations of a vasoactive intestinal polypeptide (VIP) were demonstrated in tumour tissue and plasma by radioimmunological tests. After surgical removal of the tumour the plasma VIP concentration fell to normal. Immunohistochemical tests of the tumour for gastrointestinal hormones demonstrated marked fluorescence only for vaso-active intestinal polypeptide. It is assumed that this polypeptide is largely responsible for the clinical signs. In the described case the severe watery diarrhoea ceased after glucocorticoid administration.

Of 57 male children, aged 5 months to 2 1/2 years with rotavirus diarrhoea, 28 were given oral therapy with sucrose electrolyte solution and 29 were given glucose electrolyte solution in a randomised double-blind trial. All were rehydrated and remained so on oral therapy alone. These patients were compared with 44 children, also with rotavirus, who were treated only with intravenous hydration. The oral therapy and intravenous therapy groups did not differ clinically in the rate of rehydration or the rate of purging. Vomiting did not prevent the giving of oral therapy during hospital admission. Bangladeshi children with rotavirus diarrhoea have a defect of carbohydrate digestion but this defect does not prevent the use of a sugar electrolyte solution for oral hydration.

Gangrene of the extremities complicating diarrhoea and severe hypernatraemic dehydration occurred in 6 infants. This is a rare complication of gastroenteritis, and its association with hypernatraemia does not seem to have previously been emphasized. The increased blood viscosity resulting from serum hyperosmolarity may have been responsible for the gangrene, and studies in our patients suggested that disseminated intravascular coagulation was present. In addition to fluid and electrolyte replacement, the infants were treated with heparin with some recovery of the affected extremities.

Oral hydration of diarrhoeal dehydration. Acta Paediatr Scand, 72:167, 1983.--Two groups of infants aged 2 to 20 months with moderate to severe dehydration were randomly assigned to either sucrose high sodium (90 mEq/l) or sucrose low sodium (58 mEq/l) solution in a double blind manner. Rehydration was assessed on clinical grounds and confirmed by serial determination of body weight, hematocrit, total serum protein and blood urea nitrogen. Twenty (80%) of 25 patients on sucrose high sodium solution and 20 (77%) of 26 patients on sucrose low sodium solution were successfully hydrated. Only the assigned sucrose-electrolyte solution was given during the average rehydration period of about 7 hours when the serum electrolytes were remeasured. Three patients on high sodium solution developed mild hypernatremia. Slight hyponatremia was encountered in 2 patients on low sodium solution. Purging rate was significantly higher in patients who failed as compared to those who succeeded. The results of this study suggest that oral sugar electrolyte solution with sodium concentration of 90 mEq/l is safe and effective in the majority of infants with diarrhoeal dehydration of diverse causes. However, intravenous fluids must be available particularly for those with a high purging rate as a significant number of them may fail.

To compare the clinical efficacy of oral rehydration salts (ORS) from effervescent tablets containing citrate with the WHO recommended ORS for the treatment of dehydration due to acute diarrhoea, a randomized clinical trial was carried out in 57 adults and 58 children. These patients had mild or moderate degrees of dehydration and acidosis due to acute watery diarrhoea that was caused by enterotoxigenic Escherichia coli in 43-47% of the cases. Efficacies were compared by measuring oral fluid intake, stool output, gain in body weight, decrease in serum specific gravity and correction of acidosis during treatment. Successful rehydration and maintenance of hydration was achieved in 25 adults and 24 children treated with citrate containing ORS and 25 adults and 24 children treated with WHO ORS. The mean intake of ORS/kg body weight in children receiving WHO ORS was greater (p less than 0.05) and correction of acidosis was faster than the citrate group during the initial 24 h of therapy (p less than 0.05). By 48 h, however, both groups showed satisfactory and comparable intake of ORS and correction of acidosis. Thus ORS from effervescent tablets containing sodium citrate base is effective for management of diarrhoea in both adults and children and is a convenient stable form of ORS for use in the home and for travelers.

Plasma volume contraction in pregnancy is diagnosed by an increase of hematocrit above 38%. Hydroxyethylstarch was administered to 30 patients with hemoconcentration alone, to 36 patients with fetal growth weight retardation and to two patients with pre-eclampsia. In the present study the tolerance and effectiveness of middle molecular hydroxyethylstarch as volume replacement was studied. The data presented a significant decrease in the incidence of small for date babies (from 52% to 34%). In addition to these findings, hematocrit, erythrocyte aggregation and plasma viscosity were decreased and cardiac output was increased. By twenty three women we registered a newborn weight below the 10th percentile according to Hohenauer. The impaired rheological properties of blood in this group were associated with a decrease of cardiac output. We conclude that hydroxyethylstarch is a safe (no maternal-fetal transfer and only a small incidence of starch storage (1.4% of patients) in the placenta) and effective colloid substance for plasma volume expansion in pregnancy.

Five standardbred geldings were given 1 mg/kg bodyweight of frusemide by intramuscular injection to induce mild dehydration. After food and water deprivation overnight, the mean weight loss was 24.4 +/- 1.8 kg (5.5 per cent of bodyweight). The horses were then given an equivalent volume of an oral glucose-glycine-electrolyte solution by stomach tube. No more than 10 litres was given every 30 minutes until the calculated bodyweight loss had been replaced. Measurements made before, during and after the fluid administration included bodyweight, arterial blood haematocrit, PCO2, pH, standard bicarbonate, base excess and plasma concentrations of sodium, potassium, chloride, total protein, glucose, urea and creatinine. The final measurement was taken eight hours after the last dose of fluid and no food or water was offered to the horses during this time. Administration of the solution caused a rapid correction of the frusemide-induced dehydration and metabolic alkalosis. Absorption of the fluid from the gastrointestinal tract appeared to be very rapid because by 30 minutes after the last dose of the solution, plasma protein values were not significantly different from those before administration of frusemide. Plasma glucose concentrations became significantly increased for up to three hours after the fluid was given and an increase in creatinine and urea concentrations, which was observed after the administration of frusemide, was still evident at eight hours. The glucose-glycine-electrolyte solution was well retained, there being a mean bodyweight loss of 2.8 kg at three hours and 6.2 kg at eight hours after the last dose of fluid.

Isotonic saline is the fluid most commonly used for treatment of asymptomatic hypotonic dehydration, but as shown in the case presented in this article, rapid increase in serum sodium may follow administration of isotonic saline, leading to the development of central pontine myelinolysis (CPM). Because the necessity of rapid correction is less, whereas the risk of CPM is greater with chronic asymptomatic hyponatremia than with acute hyponatremia, use of a half normal saline might be more appropriate than normal saline for treating certain patients with hypotonic dehydration with asymptomatic hyponatremia. The calculations indicate that half normal saline will expand the extracellular volume quite effectively, but the rate of increase in serum sodium will be considerably slower than that with normal saline.