Effective treatment of diarrhoeal dehydration with an oral rehydration solution containing citrate

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.     

Can village mothers prepare oral rehydration solution?

Both the prepackaged glucose-electrolyte powder and the domestic rehydration solution have received wide publicity, yet there has been little evaluation of how accurate the mother can be in preparing the mixture. The 2 studies described here attempted to measure this human factor in actual field situations in India and Trinidad. The 1st study attempted to quantify the variability in the size of the 2-finger and thumb pinch of salt. The 2nd study measured the different concentrations when mothers diluted a standard packet of glucose and electrolytes in domestic vessels. In India and Trinidad, mothers of children with diarrhea were instructed about making up local salt-sugar-water mixtures for home treatment. They were shown how to take a 2-finger and thumb pinch of salt in a way which had previously been agreed upon. Multiple pinches--5 in Trinidad and 10 in India--were then weighed on standard laboratory scales to find the average salt picked up. The fingers of the mothers were measured to see if the weight of salt picked up correlated with hand size. Other factors which could influence the pinch size were also considered: type and quality of salt available and the relative humidity. In the packet dilution study, mothers in rural India were instructed in the local language by an indigenous nurse who used diagrams in the teaching. The glucose concentrations of the mixture made up by 66 village mothers were analyzed in the field by a pocket refractometer. The finger-pinch method of measuring salt was very inaccurate in field tests. At least 1 mother in 20 would pick up double the amount of salt intended. There was no statistical correlation between finger size and the weight of a pinch of salt. In the packet dilution study there was a wide range of concentrations, but over 83% of the mothers mixed the solution to within 40 mmol/liter of the "correct" value.     

Evaluation of home-made salt-sugar oral rehydration solution in a rural Nigerian population

Standardized local measures for preparing oral rehydration solution (ORS) in Nigeria were re-evaluated under laboratory conditions. Our results confirm those of the standardization team in respect of granulated and cube sugar. However, our mean weight of one salt measure (2.8155 +/- 0.292 g) is about 20% greater than their value. Consequently, correct use of the measures in our study gave solutions of 211-297 mmol-1 total concentration and 60-80 mmol-1, Na+ as against their values of 173-251 mmol 1-1 and 45-70 mmol-1, respectively. This discrepancy is most likely due to differences in salt type. Analysis of home-made solutions prepared by 40 illiterate mothers showed that 60% of them made accurately composed solutions. All the rest made hypertonic solutions. Salt type, spoon size and levelling technique are all possible causes of their error. The tendency to err only on the side of greater rather than lower salt concentration may be culture based or simply due to natural maternal instinct. To combat this trend, health education programmes in Nigeria should emphasize the danger in feeding a hypernatremic solution to a dehydrated child.     

How much oral rehydration solution is actually administered during home-based therapy?

In some parts of the world up to one-half of all deaths in young children are attributable to dehydration associated with diarrhoea. As a countermeasure, mothers in underdeveloped countries are being successfully taught to give oral rehydration solution at home. There are, however, serious doubts as to whether mothers give their children enough. The focus of our investigation was a methodology capable of establishing the exact quantity of fluid administered by unsupervised mothers at home. Accurate quantitative data are essential for programme planning and evaluation. In our sample of 44 cases, only two children received more than 90 ml kg-1 day-1. The mean observed value was 44 ml kg-1 day-1 (SD 28.4); well below the recommended dosage. Preliminary data were also gathered on natural consequences which may discourage use of ORS such as vomiting, increased frequency of watery stools, and distaste for the solution.     

Search for the ideal oral rehydration solution: studies in a model of secretory diarrhoea.

In situ perfusion of whole rat small intestine was used to compare the efficacy of five oral rehydration solutions in promoting water and sodium absorption in normal intestine and secreting intestine after exposure to cholera toxin. Solutions varied in their sodium (35-90 mmol/l) and glucose (111-200 mmol/l) concentrations, molar ratio of glucose:sodium (1.2-5.8), and osmolality (281-331 mOsmol/kg), and contained either bicarbonate (18-30 mmol/l) or citrate (10 mmol/l). In normal intestine all solutions promoted net water absorption. Cholera toxin induced reproducible water secretion but all solutions reversed this to absorption. Water absorption was greatest with solutions containing sodium 60 mmol/l and glucose 111 or 140 mmol/l, and with a glucose:sodium ratio approximately 2, in both normal and secreting intestine. All solutions promoted net glucose absorption in both normal and secreting intestine. Net sodium absorption occurred with solutions containing greater than or equal to 60 mmol/l sodium in normal intestine but sodium secretion occurred from all solutions in secreting intestine. Sodium movement was directly related to the sodium concentration of the solution and sodium secretion occurred despite net water and glucose absorption. We consider that these studies may guide future development of oral rehydration solutions.     

Absorption of a hypotonic oral rehydration solution in a human model of cholera.

The development of oral rehydration solutions (ORSs) has been one of the important therapeutic advances of this century. The optimal formulation, however, of ORSs for both cholera and other infective diarrhoeas is still debated. Part of the problem in developing ORSs has been the lack of adequate test systems for the assessment of new formulations before clinical trial. We have developed a jejunal perfusion, cholera toxin induced, secretory model in humans and have compared net water and solute absorption from a hypotonic ORS (HYPO-ORS: sodium 60 mmol/l, glucose 90 mmol/l, osmolality 240 mOsm/kg) and the British Pharmacopoeia recommended ORS (UK-ORS: sodium 35 mmol/l, glucose 200 mmol/l, osmolality 310 mOsm/kg) in six healthy volunteers. A plasma electrolyte solution (PES) was also perfused in all subjects to confirm a secretory state. Only HYPO-ORS reversed sodium secretion to absorption (p < 0.01). Both ORSs promoted net water absorption but this was greatest with HYPO-ORS (p < 0.01). Glucose and potassium absorption rates were similar for both ORSs whereas chloride absorption mirrored sodium absorption and was greatest from HYPO-ORS (p < 0.05). These results, in a biologically relevant model of secretory diarrhoea, suggest it may be possible to achieve improved rates of rehydration by the use of hypotonic ORS with mid range sodium concentrations.     

An update on diarrhoeal diseases in Malaysia

Analysis of diarrhoeal disease patterns in Malaysia from 1981-1986 suggested that infectious hepatitis ranked as the most predominant diarrhoeal disease followed by typhoid, food poisoning, dysentery and cholera. Although these five major food and water-borne diseases are still endemic in this country, diarrhoeal diseases per se no longer become an important public health problem in Malaysia. Enforcement of the cholera control program brought the incidence of the disease to a minimal. Unfortunately, this fatal form of diarrhoeal disease caused the greatest mortality compared to the others. Seasonal influence also played a part in controlling the occurrence of the disease. There was a preponderance of diarrhoeal diseases during the rainy season implicating contaminated water as a source of transmission. Although greater than half of the population has been supplied with piped water and sanitary latrines, a lot more has to be done before diarrhoeal diseases could be eliminated from this country.     

Epidemiology of diarrhoeal diseases in Singapore.

Diarrhoeal diseases in the form of bacterial food poisoning are prevalent in Singapore. Common food poisoning organisms implicated were Staphylococcus aureus, non-thypoid Salmonellae and Vibrio parahaemolyticus. El tor cholera, believed to be introduced through intra-regional trade and travel, occurred sporadically with a common source outbreak, probably food-borne, in September 1978. Shigellosis and amoebiasis were mainly confined to areas where poor personal hygiene was prevalent. The incidence of enteric favers (typhoid and paratyphoid) continued to decline with 39.1% of the cases imported in 1978. Non-bacterial diarrhoeal diseases, including rotavirus, constituted 8--90% of the cases. The emergence of multiple antibiotic resistance enterobacteria which gave rise to occasional outbreaks in institutions, is a matter of concern. Control of diarrhoel diseases is directed mainly at food control and legislation and health education, backed by a high standard of environmental sanitation and a well-established system of epidemiological survelliance. The use of oral rehydration solution for the treatment of diarrhoea is being promoted.     

First do no harm: making oral rehydration solution safer in a cholera epidemic.

Oral rehydration solution (ORS) is lifesaving therapy for cholera and pediatric diarrhea. During a cholera epidemic in Guinea-Bissau, we evaluated the microbiologic quality of ORS prepared at a hospital and tested a simple intervention using special vessels for disinfecting tap water with bleach and for preparing, storing, and dispensing ORS. Few coliform bacteria and Escherichia coli were recovered from tap water; however, pre-intervention ORS contained numerous bacteria including E. coli and toxigenic Vibrio cholerae O1. In contrast, ORS samples from intervention vessels had few or no coliform bacteria, no E. coli, and no V. cholerae. Mean pre-intervention counts of coliform bacteria (3.4 x 10(7) colony-forming units [cfu]/100 ml) and E. coli (6.2 x 10(3) cfu) decreased significantly during the intervention period to 3.6 x 10(2) cfu and 0 cfu, respectively (P < 0.001). This simple system using bleach disinfectant and special storage vessels prevents bacterial contamination of ORS and reduces the risk of nosocomial transmission of cholera and other enteric pathogens.