Neonatal Intensive Care Pediatric Critical Care Medicine www.pccmjournal.org 443 Objective: We evaluated hemodynamic changes in preterm neo- nates with septic shock using functional echocardiography and studied the effects of vasoactive drugs on hemodynamic variables. Design: Prospective observational study. Setting: Level III neonatal ICU. Subjects and Patients: We enrolled 52 preterm neonates with septic shock (shock group) and an equal number of gestation and postnatal age-matched healthy neonates (control group). Interventions: We measured functional hemodynamic variables (left and right ventricular output, ejection fraction, isovolumetric relaxation time, and early passive to late active peak velocity ratio) by echocardiography in the shock group during initial fluid resus- citation, before initiation of vasoactive drugs, and again 30–40 minutes after initiation of vasoactive drug infusion. Control group underwent a single assessment after enrollment. We compared various hemodynamic variables between shock group and control group using paired t test or Wilcoxon signed-rank test. Measurements and Main Results: The baseline left ventricular output was significantly higher in neonates with septic shock as compared with controls (median [interquartile range], 305 mL/kg/ min [204, 393] vs 233 mL/kg/min [204, 302]; p < 0.001), but ejection fraction was similar between the two groups (55% ± 12% vs 55% ± 5%, p = 0.54). Other hemodynamic variables were comparable between the two groups. After vasoactive drug infusion, there was a significant increase in heart rate (152 ± 18 to 161 ± 18 beats/min, p ≤ 0.001) and right ventricular output (median [interquartile range], 376 [286, 468] to 407 [323, 538] mL/kg/min; p = 0.018) compared with the baseline, but left ven- tricular output and ejection fraction did not change significantly. Conclusions: We found an elevated left ventricular output but normal ejection fraction in preterm neonates with septic shock. This suggests that septic shock in preterm neonates is pre- dominantly due to vasoregulatory failure. Vasoactive drugs significantly increased right ventricular output, which was pre- dominantly due to increase in heart rate. (Pediatr Crit Care Med 2014; 15:443–450) Key Words: functional echocardiography; hemodynamic changes; myocardial dysfunction; neonate; septic shock; vasoregulatory failure I nternational pediatric sepsis consensus statement defines septic shock as cardiovascular organ dysfunction in pres- ence of sepsis (1). Shock is a state of cellular energy failure, which is an end result of various pathogenetic mechanisms like hypovolemia, vasoregulatory failure, and/or myocardial dysfunction. The hemodynamic changes in neonatal septic shock are not understood completely. As a result, the treat- ment of neonatal septic shock is empirical and is largely based on pediatric and adult data (2, 3). In adult septic shock, pre- dominant hemodynamic alteration is decreased systemic vas- cular resistance and elevated cardiac indices (4). In pediatric septic shock, nonhyperdynamic (2, 5–7) and hyperdynamic states with decreased systemic vascular resistance (8) have been described. The limited data about hemodynamic changes in neonatal septic shock mainly come from animal models (9–12). In these models, decreased peripheral vascular resis- tance (9, 12), as well as decreased myocardial performance, has been found (10, 11). Recently, hemodynamic changes have been described in neonates with late onset neonatal sepsis (13), Copyright © 2014 by the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies DOI: 10.1097/PCC.0000000000000115 *See also p. 494. 1 Neonatal Unit, Department of Pediatrics, Post Graduate Institute of Medi- cal Education and Research, Chandigarh, India. 2 Department of Cardiology, Post Graduate Institute of Medical Education and Research, Chandigarh, India. This work was performed at Post Graduate Institute of Medical Education and Research, Chandigarh, India. The study was registered with Clinical Trial Registry of India (CTRI/2011/091/000012). Dr. Saini conceptualized and designed the study, collected and analyzed the data, drafted the initial manuscript, and approved the final manuscript as submitted. Dr. Praveen Kumar helped in designing the study, supervised the data collection and data analysis, reviewed and revised the manuscript, critically evaluated the manuscript for scientific content, and approved the final manuscript as submitted. Dr. Manoj Kumar cross-checked the data collection, image quality, and interpretation; helped in preparation of the manuscript; and approved the final manuscript as submitted. Supplemental digital content is available for this article. Direct URL cita- tions appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (http://journals.lww.com/ pccmjournal). Dr Saini has received salary support from Council of Scientific and Indus- trial Research, New Delhi, India. The sponsor had no role in planning, con- duct, analysis, or publication of the study. Dr. Saini received salary support and Drs. P. Kumar and R. M. Kumar received partial salary support. For information regarding this article, E-mail: drpkumarpgi@gmail.com Hemodynamic Changes in Preterm Neonates With Septic Shock: A Prospective Observational Study* Shiv Sajan Saini, DM 1 ; Praveen Kumar, DM 1 ; Rohit Manoj Kumar, DM 2