Analgosedation with low-dose morphine for preterm infants with CPAP:: risks and benefits

Background: CPAP is widely used in preterm infants on NICUs but it poses a stressful stimulus to the patient, sometimes requiring the use of analgosedative drugs. Aim: The aim of this study is to evaluate the risks and benefits associated with the use of low-dose morphine in preterm infants with CPAP, especially apnea. Methods: Sixty-four CPAP-treated preterm infants, who received a low single dose of morphine (recommended 0.01 mg/kg), were included in this prospective study. Observation-time was 4 h prior to injection, directly before injecting, until 15 min and 15-30 min, 30 min-1 h, 1-2 h, 2-3 h, 3-4 h, 4-5 h and 5-6 h after injection. For all observation periods incidence of apnea, heart rate, respiratory rate and a score for analgesia and for sedation were recorded. Results: Sixty-four preterm infants (29.6 +/- 3.3 weeks gestational age (GA), birth weight 1401 +/- 735 g) received 0.025 +/- 0.012 mg/kg morphine i.v. on the day 10-13 of life. The decrease in heart and respiratory rate, scores for analgesia and sedation were significant. The overall incidence of apnea did not increase compared to the 4 h pre-morphine period. Six patients (9.3%) experienced considerable delayed apnea. This group was significantly younger in GA (p < 0.001) and lighter in birth weight (p = 0.002). Conclusion: Morphine in dosage less than half of recommended dosage has a high analgetic and sedative potential. The danger of delayed severe apnea has to be taken into consideration in the clinical situation, especially in patients < 28 weeks.