Oral rehydration therapy--a review

Paediatrics: how to manage viral gastroenteritis

Background

Viral gastroenteritis is the most common diarrhoeal disorder seen in general practice and emergency departments. This article aims to provide a narrative updated review on the evaluation and management of viral gastroenteritis in children.

Methods

A PubMed search was performed with Clinical Queries using the key term 'viral gastroenteritis'. The search strategy included clinical trials, meta-analyses, randomized controlled trials, observational studies and reviews. The search was restricted to the English literature and the paediatric population.

Results

Acute viral gastroenteritis is usually self-limiting. However, it can lead to dehydration and electrolyte imbalance if not properly treated. Adequate fluids containing physiological concentrations of glucose and electrolytes should be provided to compensate for gastrointestinal losses and cover maintenance needs. Oral rehydration therapy is as effective as intravenous (IV) fluid therapy for rehydration for children with mild-to-moderate dehydration. Measurements of serum electrolytes, creatinine and glucose are usually not necessary and should only be considered in a subset of children with severe dehydration who require hospitalization and IV therapy. Judicious use of ondansetron can increase the success rate of oral rehydration therapy and minimize the need for IV therapy and hospitalization.

Conclusion

Acute viral gastroenteritis is associated with substantial morbidity in developed countries and significant mortality in developing countries. Physicians should educate caregivers on proper personal hygiene and handwashing to prevent faecal to oral transmission of the pathogen as well as the importance of rotavirus vaccine in the prevention of rotavirus gastroenteritis. Several norovirus vaccines are currently undergoing clinical trials with promising results. It is hoped that development of an effective norovirus vaccine will further reduce the incidence of viral gastroenteritis.

Travelers' Diarrhea: A Clinical Review

BACKGROUND

Travelers' diarrhea is the most common travel-related malady. It affects millions of international travelers to developing countries annually and can significantly disrupt travel plans.

OBJECTIVE

To provide an update on the evaluation, diagnosis, treatment, and prevention of traveler's diarrhea.

METHODS

A PubMed search was completed in Clinical Queries using the key term "traveler's diarrhea". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to English literature. Patents were searched using the key term "traveler's diarrhea" from www.freepatentsonline.com.

RESULTS

Between 10% and 40% of travelers develop diarrhea. The attack rate is highest for travelers from a developed country who visit a developing country. Children are at particular risk. Travelers' diarrhea is usually acquired through ingestion of food and water contaminated by feces. Most cases are due to a bacterial pathogen, commonly, Escherichia coli, and occur within the first few days after arrival in a foreign country. Dehydration is the most common complication. Pretravel education on hygiene and on the safe selection of food items is important in minimizing episodes. For mild travelers' diarrhea, the use of antibiotic is not recommended. The use of bismuth subsalicylate or loperamide may be considered. For moderate travelers' diarrhea, antibiotics such as fluoroquinolones, azithromycin, and rifaximin may be used. Loperamide may be considered as monotherapy or adjunctive therapy. For severe travelers' diarrhea, antibiotics such as azithromycin, fluoroquinolones, and rifaximin should be used. Azithromycin can be used even for the treatment of dysentery whereas fluoroquinolones and rifaximin cannot be used for such purpose. Recent patents related to the management of travelers' diarrhea are discussed.

CONCLUSION

Although travelers' diarrhea is usually self-limited, many travelers prefer expedient relief of diarrhea, especially when they are traveling for extended periods by air or ground. Judicious use of an antimotility agent and antimicrobial therapy reduces the duration and severity of diarrhea.

Acute gastroenteritis in children: role of anti-emetic medication for gastroenteritis-related vomiting

Acute gastroenteritis is associated with significant morbidity in developed countries and each year is the cause of death of several million children in developing countries. Acute gastroenteritis is usually self-limiting. Oral rehydration therapy (ORT) is effective and successful in the majority of patients. Vomiting is common at the outset of viral gastroenteritis and can limit the effectiveness of ORT. Treatment with newer anti-emetic medications has been reported to facilitate ORT and to minimize the risk of dehydration and the need for intravenous hydration and hospitalization. The role of anti-emetic medications in the treatment of gastroenteritis-related vomiting is not clear. Some physicians agree with the use of anti-emetic medications because vomiting is unpleasant and distressing for the child and parents alike, and because vomiting can increase the likelihood of dehydration, electrolyte imbalance, and the need for intravenous hydration or hospitalization. Several surveys have shown that anti-emetic medications are commonly prescribed in the treatment of pediatric gastroenteritis and that adverse events are uncommon. Efficacy studies of the newer anti-emetic medications are now available and reveal that some are effective and help facilitate ORT. Other physicians disagree with the use of anti-emetic medications because acute gastroenteritis is a self-limiting condition, vomiting might help rid the body of toxic substances, there was previously a relative lack of published evidence of clinical benefit, and there are potential adverse events associated with the use of an anti-emetic medication. Anti-emetic medications that are currently available include ondansetron, granisetron, tropisetron, dolasetron, ramosetron, promethazine, dimenhydrinate, metoclopramide, domperidone, droperidol, prochlorperazine, and trimethobenzamide. Randomized, placebo-controlled trials suggest that ondansetron is efficacious and superior to other anti-emetic medications in the treatment of gastroenteritis-related vomiting. A recent double-blind clinical trial showed that a single oral dose of ondansetron reduces gastroenteritis-related vomiting and facilitates ORT without significant adverse events. Ondansetron shows promise as a first-line anti-emetic, and judicious use of this agent might increase the success of ORT, minimize the need for intravenous therapy and hospitalization, and reduce healthcare costs. Ondansetron should be considered in situations where vomiting hinders ORT, but a larger randomized, placebo-controlled trial is necessary before the medication can be routinely recommended for the treatment of gastroenteritis-related vomiting in children.

Traveler's diarrhea

Travelers' diarrhea is common. Between 8% and 50% of travelers develop diarrhea; incidence depends on the country visited. The attack rate is highest for travelers from a developed country who visit a developing country. Children are at particular risk. Travelers' diarrhea is usually acquired through ingestion of fecally contaminated food and water. Most cases are due to a bacterial pathogen, commonly, Escherichia coli, and occur within the first few days after arrival in a foreign country. More than 90% of episodes develop within the first 2 wk of initiation of travel. Dehydration is the most common complication. Water and electrolyte replenishment is important and can usually be accomplished with an oral rehydration solution. Judicious use of an antimotility agent and antimicrobial therapy reduces the duration and severity of diarrhea. Pretravel education on hygiene and on the safe selection of food items is important in minimizing episodes. Dukoraltrade mark (Aventis Pharma Ltd., Auckland, New Zealand) vaccine should be considered for travelers who are 2 y of age or older and who will be visiting an area associated with risk of infection due to enterotoxigenic E coli or Vibrio cholerae. Typhoid vaccine is recommended for travelers who will be visiting areas with poor sanitation and hygiene.

Rotavirus gastroenteritis

Rotavirus is the single most important cause of severe, dehydrating gastroenteritis in infants and young children worldwide. Rotavirus gastroenteritis is associated with high morbidity in developed countries and significant mortality in developing countries. Virtually all children are infected with rotavirus by 3 years of age. Fecal-oral transmission is the most likely route of virus spread. Group A serotype strains G1 through G4 account for more than 90% of rotavirus gastroenteritis in humans, with G1 being the predominant serotype. The virus preferentially infects the mature small-intestinal enterocytes. Rotavirus gastroenteritis is characterized by fever, vomiting, and diarrhea, with vomiting particularly prominent. Dehydration is a frequent complication because of the severity of the diarrhea and the associated vomiting. Rehydration and maintenance of proper fluid and electrolyte balance remain the mainstay of treatment. Hygienic measures have little effect on the reduction of rotavirus infection rates. The disease can be effectively controlled by universal rotavirus vaccination.

Acute diarrhea in children. What to do and what not to do

Acute diarrhea is a leading cause of childhood morbidity and mortality. Primary care physicians and pediatricians should be familiar with its clinical features and management. Rehydration and maintenance of proper fluid and electrolyte balance are the most important aspects of treatment. While intravenous rehydration is the best form of treatment for children who are in shock or unable to drink, oral rehydration is the treatment of choice for the majority of children who have mild to moderate dehydration. Oral rehydration therapy is simple, practical, inexpensive, effective, and safe for children in developing as well as developed countries. We recommend the use of commercially available rather than homemade solutions. Antibiotic and antidiarrheal agents are usually not indicated. Early reintroduction of milk, formula, or solid food is important, as is instruction of parents in measures to minimize transmission of infectious agents.

Efficacy and safety of two oral solutions as maintenance therapy for acute diarrhea. A double-blind, randomized, multicenter trial

There is continuing uncertainty about the appropriate level of sodium in oral fluid therapy for children with acute gastroenteritis in developed countries. The present study was undertaken in order to assess whether an oral glucose/electrolyte solution designed for fluid replacement (Na+ concentration 75 mmol/l) and an oral glucose/electrolyte solution designed for maintenance of hydration (Na+ concentration 45 mmol/l) would be safe and effective in the treatment of acute childhood diarrhea in a developed country. Children aged 3-24 months (n = 54) with acute diarrhea and less than 5 percent dehydration were randomized to receive either maintenance (n = 27) or rehydration (n = 27) fluid. Outcome was assessed at 24 and 48 hours after entry to the study. Both solutions were found to be equally effective and safe. The fluid was refused by one child in each group. Analysis of efficacy showed that hydration status was maintained in all patients and 98 percent of children showed significant improvement in diarrheal status at 24 hours. We conclude that for well-nourished ambulatory children aged 3-24 months with acute diarrhea and minimal (less than 5%) or no dehydration, the use of an oral fluid containing 75 mmol/l of sodium is as safe and effective as the use of an oral fluid containing 45 mmol/l of sodium.