Increase in oxygen consumption after albuterol inhalation in ventilated infants and children

Objective: To determine if inhaled albuterol (salbutamol) increases oxygen consumption (V′o₂) in children and, if so, the duration of this effect.

Design: Oxygen consumption was measured by indirect calorimetry using the Argon dilution technique with a respiratory mass spectrometer. After measurement of baseline values, albuterol was administered and subsequent measurements were performed at 10 minutes, 1 hour, 2 hours, 3 hours, and 4 hours.

Setting: Multidisciplinary PICU in a university teaching hospital.

Patients: Eleven intubated infants and children (five girls, six boys) with a mean age of 20 months (range, 1 mo to 8 yr) and a mean weight of 10.7 kg (range, 3.1-23 kg) who required therapeutic albuterol inhalations.

Intervention: Nine hundred micrograms of albuterol (10 puffs) was administered by a metered-dose inhaler into a spacer through the inspiratory arm of the ventilator circuit near to the patient, during 10 mechanically assisted breaths.

Measurements and Main Results: All children showed an increase in V′o₂ within 10 minutes (mean increase 48.6%). The increased V′o₂ was still elevated (42.3% above baseline) at 1 hour, but 3 hours after albuterol inhalation, the V′o₂ was back to baseline in all patients. Heart rate increased significantly at 10 minutes, 1 hour, and 2 hours after inhalation.

Conclusion: There is a large increase in V′o₂ after albuterol inhalation. This effect lasts up to 3 hours.