Prevention of apnea and bradycardia in low-birthweight infants.

The efficacy of theophylline in preventing severe apnea was evaluated in 17 low-birthweight infants (mean weight, 1,400 gm). Apnea was detected and accurately quantified by 13-hour pneumogram recordings and correlated with serum theophylline levels. Nursing observations coupled with on-line alarm systems detected only 39% of severe apneic episodes as compared to the pneumogram recording technique. Theophylline in six hourly oral doses(1.5 to 4.0 mg/kg) yielded two-hour serum concentrations of 6.6 to 11.0 mug/ml which completely controlled apneic spells exceeding 20 seconds in duration and markedly reduced 10- 19-second apneic episodes and any resultant bradycardia. At these serum levels, toxicity was not observed. Therapy with theophylline should be instituted at a dose of 2 to 3 mg/kg every six hours and the optimum therapeutic dose should be individualized as determined by objective quantitation of apnea and serum theophylline concentration.