Abstract 158: Pediatric In-Hospital Cardiac Arrest Associated With Pulmonary Hypertension: A Common Pathophysiology

Abstract

Introduction: In laboratory studies, pulmonary hypertension (PH) during CPR worsens outcomes but can be ameliorated with inhaled nitric oxide (iNO). The prevalence of pre-arrest PH among children with IHCA and its impact on outcomes are not well described. Hypothesis: We hypothesized that among children with IHCA, pre-arrest PH would be common and associated with worse survival to discharge. Methods: Retrospective single-center cohort study of consecutive pediatric ICU patients (1/1/2006 - 12/31/2017) with an echocardiogram in the 48 hours preceding IHCA, excluding those with cyanotic congenital heart disease. Echocardiograms were analyzed by a cardiologist blinded to other patient data. PH was defined as abnormal septal position and/or peak tricuspid regurgitant velocity > 2.8 m/sec. Patient and arrest characteristics and treatments were compared between subjects with and without PH using non-parametric tests. Logistic regression evaluated the association between PH and outcome, adjusting a priori for age and initial arrest rhythm, as well as for candidate variables associated with survival (p<0.10). Results: Of 284 IHCA subjects, 57 (20%) had an evaluable echocardiogram. PH was present in 20/57 (35%); 9/20 (45%) had no prior clinical history of PH. Children with PH had worse RV systolic function as measured by median fractional area change (32% vs. 45%; p=0.005), RV global longitudinal strain (-15% vs. -21.1%; p=0.046), and tricuspid annular plane systolic excursion z-score (-4.50 vs. -3.53; p=0.17). Children with PH had more RV dilation (median RV:LV end-diastolic area ratio 0.90 vs. 0.52; p=0.005) and similar rates of qualitative LV dysfunction (45% vs. 59%, p=0.40). Children with PH were more likely to receive iNO [16/20 (80%) vs. 12/37 (32%); p<0.001] and isoproterenol [9/20 (45%) vs. 1/37 (3%); p<0.001] during CPR. There were no differences in other IHCA characteristics. On multivariable analysis, PH was not associated with ROSC [14/20 (70%) vs. 24/37 (65%); adjOR 1.30 (0.25 - 6.69); p=0.77] or survival to hospital discharge [8/20 (40%) vs. 10/37 (27%); adjOR 1.17 (0.22 - 6.44); p=0.85]. Conclusions: PH was present in 35% of children with IHCA. In a cohort with a high frequency of treatment with iNO during CPR, PH was not associated with survival.