John Monaco, M.D.
Gastroenteritis is a frequent diagnosis for children admitted to the hospital. Vomiting, diarrhea and dehydration are exceedingly common pediatric complaints both in the outpatient and inpatient setting. Occasionally, these complaints are caused by bacterial infections. Most often, they are due to viruses. Rotavirus, so named because of its wheel like appearance under the electron microscope, is one of the more common ones, and one that can be easily identified in the laboratory.
Our institution is experiencing the final stages of one of the worst rotavirus outbreaks that any of us have seen in years. These epidemics tend to occur during the winter months, and ours reached its peak in mid March when nearly 80% of the kids admitted to our pediatric ward were infected with the virus.
The clinical history of children with this infection has an eerie sameness to it. It almost seems scripted, and we heard the story so many times this winter, we usually could recite it back to the families and referring pediatricians before they finished telling us. Typically, we would receive a call from the ER or a doctor's office. They would have a child of almost any age, from several months, up to seven or eight years, who experienced a high fever (often in excess of 103ƒF) three or four days earlier. Two days earlier, seemingly out of nowhere, the child would vomit. Then, when the vomiting seemed to be subsiding, but the child was quite lethargic, then diarrhea would begin. And it would be profuse, very watery, and accompanied by very severe cramps. The child often refused to drink, appeared quite dehydrated, and hadn't urinated in many hours ‚ sometimes 12 to 18. Invariably, with this story, when the stool was checked for rotavirus, it was positive.
Sometimes a child will be sent to us before the diarrhea stage had begun. When we tell the parents of a child who has been vomiting, complaining of abdominal cramping and experiencing high fever that their child will soon begin having very watery diarrhea, they often appear suspicious of our apparent clairvoyance. Invariably, we are right, and they think we are brilliant diagnosticians. If only this were true! It has happened that an explosive stool occurs even while we are having this conversation. This makes a powerful diagnostic statement!
There is no specific treatment for rotavirus. Several years ago a vaccine was released, marketed and administered in pediatricians' offices. The incidence of significant side effects was so high, however, that the preparation was taken off the market. Worldwide, where gastroenteritis and dehydration are the leading cause of infant mortality, this has had huge implications. In the US, where access to IV fluids is much greater, the mortality remains low even without the vaccination. However, children can still die from this infection if the signs of dehydration are misinterpreted or the degree of dehydration is underestimated.
So how does a parent know if their child is becoming dehydrated? It is important, first of all, to understand the basic pathophysiology of this virus, as well as most gastrointestinal viruses. They infect the mucosal lining of the intestinal tract, creating inflammation and swelling. Electrolyte "pumps" in the cells lining the gut are disabled causing the intestinal lining to secrete huge amounts of water, as well as potassium and bicarbonate. Sodium can be affected as well, and laboratory blood tests will often demonstrate abnormalities in these blood chemicals. The fluid loss can be extremely large, and for children, who can tolerate far less fluid depletion than adults, this can quickly lead to dehydration. Sometimes, only two or three large, watery stools can be enough to dehydrate a small child. If children with severe diarrhea can tolerate fluids by mouth, they can keep up with fluid losses by replacing them with what they drink. Unfortunately, the diarrhea is often accompanied by vomiting or loss of appetite. In this case, fluid loss can quickly exceed fluid intake, and dehydration results.
The signs and symptoms of dehydration are well known by most parents. Dry lips, dry skin, sunken eyes and lack of tears are obvious evidence. Lethargy and other behavior changes can be more subtle. Lack of urine output is clear evidence that fluids are needed quickly. It is important to remember that any of these signs can be gradual in onset, and so may not be readily apparent to the parent who is hovering at the bedside of a sick child. When in doubt, call the doctor.
The treatment? Fluids. If the child can tolerate fluids by mouth, an electrolyte containing fluid like Gatorade, or even flat soda is preferable. Fruit juices may make diarrhea worse, and too much plain water can result in electrolyte problems. If oral fluids are not an option, then IV fluids are the mainstay of therapy. Never use over the counter anti-diarrhea drugs in children. They simply mask the symptoms and do not affect the disease process, and can, in some cases, be dangerous.
As for prevention, this is a difficult virus to avoid during certain times of the year. Hand washing is extremely important in preventing spread in families, day care centers and schools. And just as our Moms taught us, kids should never share drinks!
John E. Monaco, M.D., is board certified in both Pediatrics and Pediatric Critical Care. He lives and works in Tampa, Florida. He welcomes your comments, suggestions, and thoughts on his observations.
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