Shock index and modified shock index among survivors and nonsurvivors of neonatal shock

Abstract

Background: Neonatal shock is associated with high mortality and morbidity. Shock index (SI), a ratio of heart rate (HR) to systolic blood pressure (BP), has been evaluated as a simple tool for early predictor of mortality in adult as well as pediatric patients. Objective: The objective of this study was to compare SI and modified SI (MSI) among survivors and nonsurvivors of neonatal shock and healthy controls. Materials and Methods: HR and BP were measured in neonates presenting with clinical shock at 0, 2, and 6 h after admission and in healthy controls. SI and MSI were calculated and compared between three groups. Results: The mean (standard deviation) SI was significantly higher at 2 and 6 h of admission (2.57 [0.54] vs. 2.93 [0.78], P = 0.029; 2.42 [0.41] vs. 3.04 [0.91], P = 0.0005) among nonsurvivors of neonatal shock as compared to survivors. MSI was also significantly raised at both 2 and 6 h of admission in nonsurvivors (3.32 [0.64] vs. 3.78 [1.05], P = 0.03; 3.16 [0.63] vs. 4.10 [1.85], P = 0.005). Conclusions: SI and MSI are significantly higher in nonsurvivors of neonatal shock than survivors and healthy controls. These metrics can be used as bedside tools for early identification of at-risk neonates with shock.