CO(2) inhalation as a treatment for apnea of prematurity: a randomized double-blind controlled trial.

OBJECTIVE: To compare the effect of prolonged inhalation of a low concentration of CO(2) with theophylline for the treatment of apnea of prematurity.

STUDY DESIGN: Prospective, randomized, double-blind controlled trial of 87 preterm infants with apnea of prematurity (27-32 weeks' gestational age) assigned to either theophylline plus 0.5 L/min of room air via nasal prongs or placebo plus 0.5 L/min with CO(2) (about 1% inhaled) by nasal prongs for 3 days.

RESULTS: Apnea time significantly decreased in the theophylline group from 189±33 s/h (control) to 57±11, 50±9, and 61±13 (days 1-3) (P=.0001) and in the CO(2) group from 183±44 (control) to 101±26, 105±29, and 94±26 s/h (days 1-3) (P=.03). Seven infants in the CO(2) group but none in the theophylline group failed to complete the study due to severe apneas (P=.003).

CONCLUSIONS: Because theophylline was more effective in reducing the number and severity of apneas, inhalation of low concentration of CO(2), as used in the present study, cannot be considered as an alternative to theophylline in the treatment of apnea of prematurity. The less effectiveness of CO(2) treatment may have been related to the variability of the delivery of CO(2).