215 Cardiac Output Monitoring: Experimental Study in An Infant Shock Animal Model Comparing Pulmonary Arterial Thermodilution, Femoral Arterial Thermodilution and Bioreactance

Abstract

Introduction: Bioreactance, is a new non-invasive for cardiac output measurement (NICOM). We compared NICOM bioreactance to pulmonary and femoral thermodilution (PATD and FATD) in an infant shock animal model. Methods: A prospective study was made in 9 Maryland pigs weighing 9 to 12 kg. Swan-Ganz and arterial PiCCO were introduced for PATD and FATD measurements respectively. 4 dual surface electrodes were placed at the thoracic body surface for NICOM measurement. In each animal, 7 cardiac index (CI) measurements were made simultaneously by PATD, FATD and NICOM before, during, and after hypovolemia and during and after volume infusion. Results: The mean CI was 4.32 ± 1.52 L/min/1.77 m2 with PATD, 3.49 ± 0.79 L/min/1.77 m2 with FATD and 2.61 ± 1.18 L/min/1.77 m2 with NICOM (p < 0.001). Mean differences between PATD and FATD were 0.84 (1.87 to 3.51) L/min/1.77 m2, between PATD and NICON 1.95 (-1.79 to 5.69) L/min/1.77 m2, and between FATD and NICOM 1.06 (-1.40 to 3.52) L/min/1.77 m2. Moderate correlation was found between PATD and FATD r = 0.43 (p= 0.01) and no correlations between bioreactance and PATD and FATD. CI measured by three methods decreased with hypovolemia and increased during volume infusion but only CI values measured with PATD and FATD were significant (p= 0.001). Changes recorded with bioreactance were small without significant differences between hypovolemia and infusion (p = 0.181). Conclusion: PATD and FATD have a similar answer during hypovolemic shock and volume infusion. Bioreactance underestimates CI values during hypovolemia and volume expansion.