NEW YORK (Reuters Health) – In a prospective comparative study, infants with moderate-to-severe acute bronchiolitis caused by respiratory syncytial virus (RSV) saw significant improvement in their respiratory status within 60 minutes of breathing a mixture of 70% helium and 30% oxygen (heliox).
Dr. Federico Martinon-Torres and colleagues at Hospital Clinico Universitario de Santiago de Compostela in Spain report the findings in the January issue of Pediatrics.
They studied 38 infants between the ages of 1 month and 2 years who were consecutively admitted to a pediatric ICU for moderate-to-severe acute RSV bronchiolitis. The first 19 infants received usual supportive care and nebulized epinephrine, while the next 19 patients received usual care plus heliox delivered through a nonrebreather reservoir face mask.
Clinical score, heart rate, and respiratory rate improved in both study arms, but heliox-treated infants had significantly greater improvement in these measures as well as a reduction in the accompanying tachycardia and tachypnea.
Specifically, the total average decrease in clinical score was 4.2 points in heliox-treated infants versus 2.5 points in control infants. "Heart and respiratory rates were also significantly lower in the heliox group compared with the control group after 1 hour and stayed lower throughout the rest of the study period," the team reports.
Heliox administration lasted between 24 to 112 hours, averaging 53 hours. The fact that patients were "slowly weaned from heliox and continued to do well" suggests to the researchers that heliox may "maintain the patient in better respiratory condition while bronchiolitis follows its natural course."
There were no adverse effects associated with heliox inhalation and heliox-treated infants were discharged from the ICU an average of 45 hours sooner than conventionally treated infants.
Dr. Martinon-Torres and colleagues believe that heliox "might be considered a first step therapy" for moderate-to-severe bronchiolitis, but add that additional studies are needed to "establish the proper place of heliox in the therapeutic schedule of bronchiolitis."