The Total Inotrope Exposure Score: an extension of the Vasoactive Inotrope Score as a predictor of adverse outcomes after paediatric cardiac surgery

OBJECTIVE: The aim of the present study was to explore and compare the association between a new vasoactive score - the Total Inotrope Exposure Score - and outcome and the established Vasoactive Inotrope Score in children undergoing cardiac surgery with cardiopulmonary bypass DESIGN: The present study was a single-centre, retrospective study. SETTING: The study was carried out at a 21-bed cardiovascular ICU in a Tertiary Children's Hospital between September, 2010 and May, 2011 METHODS: The Total Inotrope Exposure Score is a new vasoactive score that brings together cumulative vasoactive drug exposure and incorporates dose adjustments over time. The performance of these scores - average, maximum Vasoactive Inotrope Score at 24 and 48 hours, and Total Inotrope Exposure Score - to predict primary clinical outcomes - either death, cardiopulmonary resuscitation, or extra-corporeal membrane oxygenation before hospital discharge - and secondary outcomes - length of invasive mechanical ventilation, length of ICU stay, and hospital stay - was calculated. Main results The study cohort included 167 children under 18 years of age, with 37 (22.2%) neonates and 65 (41.3%) infants aged between 1 month and 1 year. The Total Inotrope Exposure Score best predicted the primary outcome (six of 167 cases) with an unadjusted odds ratio for a poor outcome of 42 (4.8, 369.6). Although the area under curve was higher than other scores, this difference did not reach statistical significance. The Total Inotrope Exposure Score best predicted prolonged invasive mechanical ventilation, length of ICU stay, and hospital stay as compared with the other scores. CONCLUSION: The Total Inotrope Exposure Score appears to have a good association with poor postoperative outcomes and warrants prospective validation across larger numbers of patients across institutions.