Background Morphine is widely used frequently in mechanically ventilated VLBW infants. The pharmacokinetics of morphine in VLBW infants is different than pediatrics and adult patients. There are still unanswered questions about the safety of morphine in such vulnerable group of infants.

Objective To determine if ventilated VLBW infants who are chronically exposed to higher doses of morphine during the first 2 weeks of life have a significant increase in the incidence of adverse outcome namely: BPD, IVH, ROP, NEC and sepsis.

Design/Methods A retrospective study of 60 VLBW infants (BW 937±227 g, GA 26.5±1.4 weeks) who required ventilation for more than 7 days and admitted to NICU from January 2000 through December 2005. Cumulative opiate exposure (mg/kg morphine) was recorded daily for the duration of hospitalization.

Results There were no significant differences between the 2 groups with regards to gestation, birth weight, incidence of RDS, need for surfactant, and incidence of PDA. SNAPPEII scores were higher in infants with higher opiate exposure. ROP, IVH, PVL, LOS, and bacteremia incidence was similar. Higher exposure was significantly associated with use of oxygen at 36 weeks corrected gestational age, time to achieve full feeding, NEC > stage II, hypotension, use of volume expansion for hypotension, inotrope use, steroids to treat hypotension, severe IVH, multiple bacteremias and sepsis related mortality.

Conclusion Higher opiate exposure during the first 2 weeks of life is associated with increased risk of NEC, hypotension and multiple bacteremias.