Viral bronchiolitis is a common cause of respiratory failure in children. Approximately 10% to 15% of previously healthy children are likely to be admitted to an intensive care unit (ICU) if they become hospitalized by bronchiolitis, and approximately half of these children will need mechanical ventilation. Children with preexisting conditions, such as congenital heart disease and chronic lung disease, and children who are immunocompromised are at a much greater risk of developing bronchiolitis.
The viruses that cause bronchiolitis cause the small airways in the child's lungs to be obstructed; this causes them to cough and wheeze. Bronchiolitis has no definitive treatment. Although many different therapies for bronchiolitis have been identified and studied, there currently is not enough evidence to support the use of any of them, and children with bronchiolitis are often given only supportive care.
Surfactant is a substance made up of proteins and lipids that is required for normal functioning of lungs. Severe bronchiolitis may also cause children to become deficient in surfactant. Surfactant has been suggested as a possible therapy for bronchiolitis as it is able to make the alveoli more stable and helps to improve mechanical properties of lungs. Therefore, it has been suggested that administering surfactant into the lower airways might help children who develop severe bronchiolitis to recover from the disease more quickly.
OBJECTIVES
The aim of this study was to determine the efficacy of surfactant for the treatment of acute bronchiolitis in mechanically ventilated children when compared with placebo, no intervention, or standard care.
METHODS
Jat and Chawla1 searched for clinical trials that looked at the outcomes of children who had been given surfactant after a diagnosis of acute viral bronchiolitis that required them to be intubated and mechanically ventilated. They included both children who had been previously healthy and those who were at high risk (ie, those with congenital heart disease, chronic lung disease, etc). They included all randomized controlled studies, including both those that did and those that did not use a placebo control. The main outcomes looked at were mortality, duration of mechanical ventilation, duration of ICU stay, and reported adverse effects.
RESULTS
Three trials were included in the review, giving a total of 79 patients (39 received surfactant and 40 were controls). One study used a placebo control approach.
Outcomes
Mortality: No mortality was reported in any of the studies.
Duration of mechanical ventilation: All 3 studies showed that surfactant therapy reduced the length of time that a child needed to be mechanically ventilated; in 1 study, this did not reach statistical significance. Combining the 3 studies showed no significant decrease in duration of mechanical ventilation, but a nonsignificant trend (2.6 days shorter).
ICU length of stay: All 3 studies showed that surfactant therapy reduced the length of stay in ICU. In 1 study, this did not reach statistical significance. Combining the 3 studies showed a significant decrease in duration of ICU stay by 3.3 days.
Adverse effects: No study in the review reported any adverse effect caused by taking surfactant.
CONCLUSIONS
Treating children with bronchiolitis who have been mechanically ventilated with surfactant may be effective. These 3 small trials suggest that surfactant therapy for bronchiolitis might shorten the length of ICU stay, without having any serious adverse effects. However, additional research is needed to clarify these findings.
IMPLICATIONS FOR PRACTICE
Bronchiolitis can cause children to become seriously ill, and no definite therapy is available. This review suggests that surfactant therapy might be an effective treatment for bronchiolitis in children who have needed to be mechanically ventilated. This could change the standard care for these sick children.
This review is based on 3 small studies, and although the results are promising, larger trials will need to be conducted to confirm this effect and answer questions about how the surfactant is best administered before guidelines will be changed. The 3 trials in the study adopted different approaches for administering the surfactant: one administered it after 12 hours of mechanical ventilation, another after 24 hours of mechanical ventilation, and another gave 2 doses of surfactant. It is not clear how these differences in doses and timings might modify the effect of the surfactant therapy, and these questions will need to be addressed before new guidelines are put into place.
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