Dexa puts a hexa on kids' growth

This corticosteroid could actually be hurting rather then helping infants with respiratory failure

By Katherine Addleman

Baby Sarah Feldman was born under complicated circumstances. She's five weeks premature, underweight and fell into respiratory distress a few hours after her birth. The use of dexamethasone was suggested by a resident but being up on the latest research, the on-call doctor refuses to order the drug because of its questionable safety in preemies. As it turns out, he made the right decision, considering the documented long-term side effects of this steroid.

Dexamethasone was first recommended for respiratory distress syndrome in premature infants in the early 1970s. But in the last few years, this practice has come under fire. In 2002, as more and more studies were reporting links to severe side effects, the Canadian Paediatric Society and the American Academy of Pediatrics announced that the routine use of systemic 'dexa' was "not recommended" for low birth-weight preemies. More recently, a study published in the March 25 issue of the New England Journal of Medicine (NEJM) has banished any doubt docs may have had about the dangers of dexa.

The report presents data from an ongoing followup of 146 middle-class children in Taiwan who'd been treated with the steroid within 12 hours of birth. All had been placed on mechanical ventilation soon after being born because of severe respiratory distress syndrome. After the first week, the drug was tapered from a starting dose of 0.25mg/kg.

The double-blind, placebo-controlled trial, led by Dr Tsu-Fuh Yeh, found that the kids paid heavily for their treatment. By the time they reached school age (about six years old) the treated children � especially the girls � were significantly shorter than controls. Their head circumferences were smaller. Their motor skills and coordination were markedly impaired, and visual-motor (hand-eye) coordination was affected. But worst of all, cognitive deficits were apparent, according to several scoring methods.

Originally, steroids were given to preemies on respirators because they reduced inflammation and the risk of developing chronic lung disease. In fact, only about 15% of babies who got dexamethasone developed chronic lung disease compared with 28% who were given placebos. Even so, doctors have long suspected that the benefits of the drug don't justify the risks. Even short-term adverse effects can be severe. These include gastrointestinal bleeding, hypertrophic cardiomyopathy and greater risk of neonatal infection.

The choice of dexamethasone may have been a mistake to begin with. The steroid, betamethasone, actually seems to be more effective for reducing complications in preemies. Another alternative is hydrocortisone, seen as "kinder and gentler" in an NEJM editorial by Dr Alan Jobe of the Cincinnati Children's Hospital Medical Center, it's probably the best choice for these delicate patients.

According to Dr Yeh, "some doctors use dexamethasone like water." But neonatologist Dr Michael Dunn, of Women's College Hospital Ambulatory Care Centre in Toronto, says that in his experience, Canadian doctors don't use dexa much anymore. "The information from Dr Yeh's study � which has been reporting data regularly from this same group of Taiwanese children � can't really be generalized to our Canadian population, or to the way we've been using dexamethasone," he explains. "For example, Dr Yeh's preemies were much bigger than any babies we would consider for dexa treatment in this country, and they were getting a very big dose very early on. Canadian neonatologists tend to use it much more selectively, at lower doses, and they titrate the dose. In fact," Dr Dunn remarks, "dexamethasone isn't used much at all here anymore, and even without it, chronic lung disease doesn't seem to be much worse." He cautions that if a doctor decides dexamethasone treatment is warranted, he or she must explain the possible risks very clearly and fully to the parents beforehand.