Dehydration oral rehydration

Worldwide, dehydration is especially problematic for children younger than age 5. However, the highest rate of death in the United States occurs among the elderly.5 Rehydration is the foundation of therapy for GI infections, and oral rehydration therapy (ORT) is usually preferred (Table 73-1). 

Rehydration and maintenance of water and electrolytes are the primary treatment measures until the diarrheal episode ends. If vomiting and dehydration are not severe, enteral feeding is the less costly and preferred method. In the United States, many commercial oral rehydration preparations are available (Table 23-3). 

Magnesium hydroxide is a laxative and is not a constituent of oral rehydration salts, which tend to be recommended for use in diarrhoea, to avoid dehydration. Sodium chloride, glucose, potassium chloride and sodium citrate are required to maintain a proper electrolyte balance and are included in oral rehydration salts. 

Oral rehydration solution (g/L of boiled water NaQ 3.5, glucose 20, NaHCOs 2.5, KQ 1.5). Oral administration of glucose-containing salt solutions enables fluids to be absorbed because toxins do not impair the cotransport of Na+ and glucose (as well as of H2O) through the mucosal epithelium. In this manner, although frequent discharge of stool is not prevented, dehydration is successfully corrected. 

Hahn S, Kim Y, Garner P. Reduced osmolarity oral rehydration solution for treating dehydration caused by acute diarrhoea in children. Cochrane Database Syst Rev 2002. 

Oral rehydration therapy is a simple, cheap and effective treatment for diarrhoea-related dehydration, such as that caused by cholera or rotavirus. It consists of a solution of salt and glucose and is administered orally. It has saved millions of children from diarrhoea, stiU a leading cause of death, particularly in the developing world. The standard manufactured WHO/UNICEF solution contains ... 

Heat Syncope. Heat exposure can cause postural hypotension leading to a syncopal or near-syncopal episode. Heat syncope is believed to result from intense sweating, which leads to dehydration, followed by peripheral vasodilatation. Initial management of the patient with heat syncope involves cooling and rehydration of the patient with oral rehydration solutions (such as commercially available sports drinks). 

Milder forms of volume depletion may be managed in outpatient settings. For example, supplemental fluids can be added to the usual estimated daily requirements of 30 to 35 mL/kg in patients older than 12 years of age with dehydration. Commercially available carbohy-drate/electrolyte drinks generally are more palatable than water and may promote earlier recovery. When the dehydration involves substantial losses of salt as well aswater, additional sodium may need to be added to these drinks because they usually contain 50 mEq/L or less of sodium. This is less than the amounts of sodium (e.g., 90 to 120 mEq/L) generally recommended for rehydration." The additional sodium will increase osmolarity, but this does not appear to delay gastric emptying." Also, guidelines for oral rehydration of children with acute diarrhea are available, which, if used appropriately, may prevent future hospitalization." Intravenous rehydration of... 

Rehydration and maintenance of water and electrolytes are primary treatment goals until the diarrheal episode ends. If the patient is volume depleted, rehydration should be directed at replacing water and electrolytes to normal body composition. Then water and electrolyte composition are maintained by replacing losses. Many patients will not develop volume depletion and therefore will only require maintenance fluid and electrolyte therapy. Parenteral and enteral routes may be used for supplying water and electrolytes. If vomiting and dehydration are not severe, enteral feeding is the less costly and preferred method. In the United States, many commercial oral rehydration preparations are available (Table 36-3). 

Because of concerns about hypernatremia, physicians continue to hospitalize and intravenously correct fluid and electrolyte deficits in severe dehydration. Oral solutions are strongly recommended. In developing countries, the World Health Organization Oral Rehydration Solution (WHO-ORS) saves the lives of millions of children annually. 

Most patients with acute diarrhea experience mild to moderate distress. In the absence of moderate to severe dehydration, high fever, and blood or mucus in the stool, this illness is usually self-limiting within 3 to 7 days. Mild to moderate acute diarrhea is usually managed on an outpatient basis with oral rehydration, symptomatic treatment, and diet. Elderly persons with chronic illness and infants may require hospitalization for parenteral rehydration and close monitoring. 

Molina S, Vettorazzi C, Peerson JM. Clinical trial of glucose-oral rehydration solution (ORS), rice dextrin-ORS, and rice flour-ORS for the management of children with acute diarrhea and mild or moderate dehydration. Pediatrics 1995 95 191-197. 

Faraque ASG, Mahalanabis D, Islam A, et al. Breast-feeding and oral rehydration at home during diarrhoea to prevent dehydration. Arch Dis Child 1992 67 1027-1029. 

The dehydration of cholera is often treated with an oral rehydration solution containing Na+, K+, and glucose or a diet of rice (which contains glucose and amino acids). Glucose is absorbed from the intestinal lumen via the Na+-dependent glucose cotransporters, which cotransport Na into the cells together with glucose. Many amino acids are also absorbed by Na+-dependent cotransport. With the return of Na+ to the cytoplasm, water efflux from the cell into the intestinal lumen decreases. 

Mineral balance Hypernatremia, hypokalemia, and acidosis have been reported after incorrect administration of oral rehydration solutions to two infants [lOS ]. In both cases the parents had diluted 21 g of each oral rehydration solution packet in 200 ml of water. In one case the electrolyte abnormalities were corrected and the losses were replaced with properly reconstituted oral rehydration solution. In the other case there was severe dehydration and the child died. 

Oral rehydration therapy (ORT) is a simple and effective way to treat or prevent dehydration and the accompanying electrolyte loss, especially if the dehydration is caused by diarrhea. Oral rehydration therapy was developed in the 1950s for use in developing countries where diarrhea-producing diseases like cholera, combined with unsanitary water and food, cause the death of an estimated 4 million children annually. The threat to children in developed countries is not nearly as great an estimated 500 children die annually from diarrhea in the United States. 

Every year, oral rehydration therapy (ORT)—the feeding of an electrolyte solution—saves the lives of countless children worldwide who become severely dehydrated as a result of diarrhea. One requirement of the solution used is that it be isotonic with human blood. 

Blood volume. Blood volume has a direct effect on blood pressure. It also has an important effect on VR. A decrease in blood volume resulting from hemorrhage or dehydration causes a decrease in venous pressure and in VR. An increase in blood volume following oral or venous rehydration or a transfusion causes an increase in venous pressure and in VR. 

A mouth that is dry and painful may be due to candidiasis (treat with nystatin), to dehydration (rehydrate the patient judiciously where this can be done orally) the symptom can be managed by frequent small drinks or crushed ice to suck (plus assiduous mouth hygiene to prevent unpleasant infection) if due to antimuscarinic drugs, including some antidepressants, withdraw the drug or adjust its dose. 

Granules Granules are a t5rpe of oral formulation whose use among the elderly is warranted (166,167). This type of dosage form not only circumvents the difficulty in swallowing that may be encountered by older patients, but it also provides the patient with a certain amount of rehydration. As the elderly are often dehydrated, this is a feature that should not be overlooked. More importantly, medications that have been dispersed in a liquid are not likely to be affected by changes in GER that may occur in older patients. 

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