Continuous intravenous to oral morphine switch in very premature ventilated infants: A retrospective study on efficacy, efficiency, and tolerability

BACKGROUND: Continuous intravenous (IV) morphine is commonly used in ventilated neonates. Oral route is theoretically feasible but data on oral morphine in ventilated premature infants are lacking. OBJECTIVE: To assess the efficacy, efficiency, and tolerability of a continuous intravenous to oral morphine switch protocol. DESIGN: Retrospective study. SETTING: Single level III center's neonatal intensive care unit. PATIENTS: Ventilated premature infants hospitalized in the NICU in 2016 and 2017, receiving continuous IV morphine with an expected ventilation course of at least 72 more hours. We excluded patients treated for withdrawal syndrome or palliative care. INTERVENTIONS: Continuous IV to oral morphine switch with the same initial cumulated daily dose. MAIN OUTCOME MEASURES: Pain scores (ComfortNeo scale) and morphine doses were analyzed over time using Friedman's test in the 24 hours preceding and the 48 hours following the oral switch. Adverse effects attributable to opioids were collected. RESULTS: Seventeen infants were included with a median [IQR] gestational age at birth of 25.9 [24.6‐26.9] weeks and a median postnatal age at oral switch of 30 [22‐36] days. One patient's intravenous treatment had to be resumed because of a high ComfortNeo score. All others remained on oral morphine. No significant change over time was observed for ComfortNeo scores (P = .15). Median [IQR] doses were 13.5 [10‐20] µg/kg/h in the IV period and significantly increased to 15 [10‐25] µg/kg/h in the oral period (P = .009). No short‐term respiratory, digestive, or urinary adverse event was observed. After a median [IQR] duration of 13 [4‐20] days of oral morphine treatment, 11 (65%) patients showed signs of withdrawal. Upon hospital discharge, 16 infants (94%) had bronchopulmonary dysplasia and none had severe cerebral abnormality on brain imaging. CONCLUSION: Oral morphine might be useful in ventilated neonates in the NICU but deserves further studies and additional safety assessment.