Influence of a rapid volume infusion during advanced cardiopulmonary resuscitation of severely asphyxic near-term lambs

Objectives We assessed whether an infusion of normal saline volume during chest compression resuscitation, compared with standard intravenous epinephrine, would increase diastolic blood pressure, achieve return of spontaneous circulation (ROSC) and maintain physiological stability after ROSC. Methods Near-term fetal lambs were asphyxiated until mean blood pressure reached 10–12mm Hg and heart rate was <60beats per minute. Resuscitation was commenced with ventilation and chest compressions. Lambs were randomly allocated to: standard care (20 µg/kg intravenous epinephrine; n=8) or volume infusion (20mL/kg over 2min; n=10). After two allocated treatment doses, rescue intravenous epinephrine was administered if ROSC was not achieved by 8min. Lambs achieving ROSC were monitored for 60min. Cerebral histology was assessed for micro-haemorrhages. Results Blood pressure and cerebral blood flow during chest compressions was higher in volume infusion lambs. ROSC occurred in 8/8 standard care lambs. Of the volume infusion lambs, 5/10 achieved ROSC in response to allocated treatment, and despite increased diastolic pressure, 3/10 required rescue epinephrine and 2/10 did not achieve ROSC. For 2min after ROSC, blood pressure, heart rate and arterial partial pressure of arterial oxygen (PaO₂) was higher in standard care lambs compared with volume infusion lambs. The number of periventricular white matter micro-haemorrhages was higher in volume infusion lambs. Conclusions Volume infusion with saline improved blood pressure stability during and after cardiopulmonary resuscitation but was inferior to intravenous epinephrine in achieving ROSC and reducing cerebral micro-haemorrhages. The use of volume infusion during resuscitation in moderately asphyxiated euvolaemic newborns is unlikely to have clinical benefit.