Abstract
BACKGROUND: Vasopressin (VA) and norepinephrine (NE) are pressors that are increasingly being used in neonates. More recently, there has been wider application of NE in the management of neonatal warm septic shock. While biological rationale is sound given the speculation of low VA levels in septic sate, use of VA in septic shock remains underexplored in neonates. OBJECTIVES: To describes the utilization of VA and NE in neonates with warm septic shock, focusing on their effects on physiological indices of cardiorespiratory stability and overall outcomes across three tertiary Neonatal Intensive Care Unit (NICU) in Canada. DESIGN/METHODS: This was a retrospective study that involved neonates with warm septic shock who received VA or NE between Jan 2015-Dec 2020 at 3 Canadian level-III NICU. Receipt of both VA and NE were excluded. Data was collected from medical records on demographic information, dosing details, cardiorespiratory parameters and clinical outcomes. Independent t-tests (or Mann-Whitney U tests) and chi-square tests (or Fisher’s exact tests) were used to compare groups for continuous and categorical variables, respectively; repeated measures analysis of variance were used to examine trends in physiological parameters over time between groups. RESULTS: 58 neonates (VA: 21, NE: 37) were included in this analysis. Mean gestational age (GA) and birth weight were significantly higher in VA group compared to NE group- mean GA (SD) in weeks was 27.1 (4.1) in VA group and 24.9 (2.8) in NE group, p= 0.015 (Table 1). VA was used more frequently as a second line agent in 57.1%, while NE as first line agent in 62.2%, p=0.016. Notably, VA neonates had significantly higher mean FiO2 (SD) at initiation compared to NE group (71.1[34.1] Vs 47.5[24.5], p 0.026) with earlier postnatal age for its use (8.4[7.2] Vs 13.7[9.1] days, p=0.025). Enhancement in physiological parameters were observed over the course of treatment with both agents as shown in Figure 1, with similar treatment response to each agent. Mortality within the first 7 days of use was 38.1% (n=8) and 27% (n=10), p=0.381 in the VA and NE group, respectively. Median length of hospital stay (IQR) was significantly shorter in VA group at 21 (11-38) days compared to NE group at 56 (24-126) days. Other outcomes were comparable between groups (Table 1). CONCLUSION: This study describes the use of VA and NE- two uniquely distinct pressors- in neonatal septic shock, providing pragmatic insights into its use. While use of VA in septic shock looks promising, further prospective studies exploring its use as first line agent in septic shock and further detailing its cardiopulmonary effects and safety profiles are warranted. [Figure: see text] [Figure: see text]