Background and Aims We asked whether rates of apnea and bradycardia increase during phototherapy in preterm infants breathing spontaneously.
Methods Preterm infants (n=60, median gestational age 29 weeks (range 24–32), birth weight 1205 g (630–1750), age at study 3 d (1–10) receiving phototherapy for hyperbilirubinemia (total serum bilirubin 8.5 (4.2–16.1) mg/dl) underwent continuous registration of body temperature, heart rate, respiratory rate, arterial oxygen saturation, and transcutaneous (tc) pCO2 for 12 h (3 h before, 6 h during, 3 h after phototherapy). Rates of bradycardia (heart rate <80 bpm) and oxygen desaturation (< 80%) were determined for each of the 3 observation periods.
Results Body temperature (37.0/37.1/37.2°C; p<0.001) and heart rate (142/149/148 bpm; p<0.001) increased significantly, while tcpCO2 decreased (42.5/38.0/37.0 mmHg; p<0.001). Average oxygen saturation and respiratory rate remained unchanged. Rates of bradycardias and desaturations decreased after phototherapy, compared to rates before or during phototherapy (p<0.001 for both parameters), and numbers of infants with a least one bradycardia/3h declined (13/10/2).
Conclusions Phototherapy was not associated with increased cardiorespiratory instability. Unexpectedly, episodes of apnea and bradycardia decreased significantly during the first 3 hours after phototherapy.