Introduction: Therapeutic hypothermia (TH) is currently standard of care for neonatal encephalopathy (NE) secondary to hypoxic injury. There is variability among centers in morphine use during TH. We hypothesized that morphine administration during TH would not significantly impact the length of hospital stay (LOS), and need for and duration of ventilation or vasopressors.
Methods: Multi-centered study of retrospective and prospective chart review at Tufts Medical Center (TMC) and Norton Children's Hospital (NCH) in Louisville, KY. From January 2013 – December 2019, we identified all neonates undergoing TH from TMC for specifically moderate NE (to control for illness severity); moderately encephalopathic neonates from NCH were then matched by gestational age and birth weight. Group 1 received no or intermittent bolus of morphine (TMC)) versus Group 2 who received continuous infusion of morphine (NCH)). We collected antenatal and peripartum maternal and neonatal clinical and demographic data. Wilcoxon Rank Sum test was used for statistical analyses.
Results: 63 neonates were included - 34 in Group 1 and 29 in Group 2. Both groups had similar maternal and neonatal characteristics. Neonates in Group 2 had a statistically significant higher cumulative dose intake, longer median LOS, duration for ventilation and greater need and longer duration of vasopressor medications (Table 1). Group 2 also had a greater need for multiple vasopressors though this was not statistically significant (Table 1).
Discussion: Higher cumulative doses of morphine during TH for moderate NE was associated with a significant increase in the hospital LOS, and longer duration of ventilator and vasopressor support. Limitations of our study include a small sample size, clinical practice variations between the two institutions and potential confounding medical complications. In our final analysis, we aim to adjust for these confounding variables.
