A new analysis of 83 studies of treatments for bronchiolitis found the research flawed and devoid of evidence that any of the treatments worked.
"We just found there wasn't compelling evidence to support any of these treatments," says researcher Meera Viswanathan, a health services research analyst at the nonprofit Research Triangle Institute, based in Research Triangle Park, N.C.. The institute collaborated with the University of North Carolina at Chapel Hill on the project.
"The irony of the situation is that it's hard to make definitive conclusions about these drugs that physicians use all the time," adds Dr. Clay Bordley, who worked on the research while at UNC but is now an associate professor of pediatrics at Duke University Medical Center.
Bronchiolitis, a viral infection of the lower respiratory tract, afflicts more than one in five U.S. infants annually and causes 90,000 hospitalizations and 4,500 deaths a year. The disease is the most common cause of hospitalization in the first year of life, and almost all American babies have it within the first two years, Bordley says.
Viswanathan and her fellow researchers analyzed studies of bronchodilators, which dilate air passages to the lungs; ribavirn, an antiviral medication; and corticosteroids, steroids that also are the primary drugs used to treat asthma. The work was done as an "evidence report" for the Agency for Healthcare Research and Quality, part of U.S. Department of Health and Human Services.
Their analysis found the existing research was flawed for a variety of reasons, including too few patients; widely varying doses of medications, preventing valid comparisons; and tracking of short-term results such as respiratory rates and wheezing 30 to 90 minutes after taking medication, rather than more important barometers.
"What a parent cares about are large outcomes like hospitalization," Bordley says. "I care about whether these kids going to the emergency room need to be admitted or not; then I care about duration and prevention of severe disease."
The disease, which is caused by one of several viruses, obstructs small airways in the lungs. Its symptoms include a runny nose, a slight fever for two to three days, coughing, rapid breathing and wheezing. The disease differs significantly from bronchitis, an inflammation of the bronchi, the main air passages to the lungs.
Most infants and young children get only a mild form of bronchiolitis and are treated as outpatients. More serious cases require hospitalization, and the most severe cases can result in respiratory failure and the need for a ventilator to support breathing.
In their analysis, the researchers said only a large-scale, well-designed study could determine the effectiveness of common bronchiolitis treatments.
Bordley also notes that most of the studies did not report side effects, which he says raises an important question: "Did [side effects] just not occur, or did the researchers just not report them?"
"People have been arguing about the effects of bronchodilators and steroids [in bronchiolitis treatment] for a long time," Bordley says, "and yet we're still stuck with a large number of small studies. If we could just get a slant on a large-scale, well-done study, we could put some of these issues to rest."
The analysis, however, did find evidence supporting the use of palivizumab, an antibody, to prevent bronchiolitis among high-risk infants and children who have a chronic lung disease or were born prematurely and are less than 6 months old.
Dr. Leonard Weiner, a member of the American Academy of Pediatrics' committee on infectious disease, says the study's findings came as no surprise to him.
"There's no evidence [in general]. . . that bronchodilators or steroids make any difference for hospitalized patients or non-hospitalized patients," he says.
"It's important to remind people that sometimes it's OK to let nature take its course and not to use other interventions that are not proven to be useful," adds Weiner, who is also the head of the division of pediatric infectious disease at the State University of New York Upstate Medical University in Syracuse.
In some severe cases of children in pediatric intensive care, though, a bronchodilator might help, Weiner says.
He says what physicians really need is a vaccine to prevent the disease. Developing one, however, could prove difficult, as the immune system response to bronchiolitis is complicated, he says.
The American Academy of Family Physicians recommends you call a doctor immediately about bronchiolitis if your child was born prematurely or has heart disease. You should also call if your child is vomiting and can't keep liquids down, is breathing rapidly, has to sit up to breathe, or if your child's skin pulls between the ribs with each breath.
In other cases, the academy recommends plenty of liquids, a cool-mist vaporizer in the bedroom during sleep, acetaminophen for fever, and hot steam in the bathroom for coughing and breathing difficulty.