274 - The Role of Calcium Chloride During Resuscitation in Asphyxiated Neonates

Poster Number: 274
Publication Number: 274.3216

Background: Calcium chloride (CaCl2) is a frequently used medication in resuscitation of older children and adults, management of cardiac arrest and protection of the myocardium from hyperkalemia and hypermagnesemia. It enhances blood pressure and cardiac contractility and correction of hypocalcemia has shown to improve cardiac function in cardiac arrest. Perinatal asphyxia is known to cause lactic acidosis and electrolyte disturbances but administration of CaCl2 during neonatal CPR has not been studied.

Objective: To determine the impact of CaCl2 during neonatal resuscitation on (a) incidence and timing of return of spontaneous circulation (ROSC), (b) systemic and pulmonary hemodynamics and (c) serum electrolyte levels during and after resuscitation.

Design/Methods: In this blinded randomized controlled trial, near-term lambs are exteriorized, instrumented, and asphyxiated by umbilical cord occlusion. Resuscitation per NRP guidelines is initiated after 7 minutes of asystole. Lambs were randomized into a control group (3 mL Normal Saline flush after IV epinephrine) and study group (0.2 ml/kg of CaCl2 + NS=total of 3 mL flush after first dose of IV epinephrine at 5 min into resuscitation). Blood samples are collected to measure baseline blood gases and electrolytes before and during resuscitation. Systemic and pulmonary hemodynamics are constantly recorded during experiments. After 5 minutes of effective PPV and chest compressions, an IV dose of epinephrine is administered followed by one of the pre-prepared 3 mL flushes. IV epinephrine is repeated every 3 minutes followed by a 3 mL NS flush (no further CaCl2 doses in the study group). Lambs were resuscitated for 20 minutes or until ROSC and observed for 30 minutes post ROSC.

Results: Ten lambs were enrolled in this study. Three out of 5 lambs in the control group (60%) achieved ROSC, while 4 out of 5 lambs in the study group (80%) achieved ROSC (P=0.50). Mean time to ROSC in the control group was 6 minutes + 41 seconds (± 53 seconds). Mean time to ROSC in the study group was 6 minutes + 3 second (± 8 seconds) (P=0.29). Mean blood pressure, carotid and pulmonary artery flows were observed to be significantly higher in the study group after administration of CaCl2 compared to controls (P < 0.05) (Fig.1). Calcium levels were higher after ROSC (P < 0.05) (Fig.2).

Conclusion(s): CaCl2 resulted in higher blood pressures, carotid and pulmonary artery flows, and higher serum calcium levels. This is the first ever study to investigate the role of parenteral calcium in neonatal resuscitation in a transitional model of complete cardiac arrest secondary to severe perinatal asphyxia.