Response to first dose of inhaled albuterol in mechanically ventilated preterm infants.

Background: Bronchodilator responses among preterm infants are heterogeneous. Bedside measurements may identify responders.

Study Design: Respiratory measurements (Resistance, Compliance, FiO) and pulse oximetry (SpO) patterns were downloaded from infants <30 weeks gestational age during the first 2 months of life. Mechanically ventilated infants who received albuterol were included (n = 33). Measurements were compared before and after first albuterol. Secondary analyses assessed subsequent doses.

Results: Median gestation and birthweight were 25 3/7 weeks and 730 g, respectively. Mean Resistance decreased post-albuterol (p = 0.007). Sixty-eight percent of infants were responders based on decreased Resistance. Compliance and FiO did not significantly differ. Percent time in hypoxemia (SpO< 85%) decreased post albuterol (p < 0.02). In responders, Resistance changes diminished with subsequent administration (all p = 0.01).

Conclusions: Ventilator resistance decreased in two-thirds of preterm infants, consistent with studies that utilized formal pulmonary function testing. Albuterol had a variable effect on delivered FiO; however, hypoxemia may be useful in evaluating albuterol response.