Pralidoxime-Induced Potentiation of the Pressor Effect of Adrenaline and Hastened Successful Resuscitation by Pralidoxime in a Porcine Cardiac Arrest Model.

PURPOSE: Pralidoxime potentiated the pressor effect of adrenaline and facilitated restoration of spontaneous circulation (ROSC) after prolonged cardiac arrest. In this study, we hypothesised that pralidoxime would hasten ROSC in a model with a short duration of untreated ventricular fibrillation (VF). We also hypothesised that potentiation of the pressor effect of adrenaline by pralidoxime would not be accompanied by worsening of the adverse effects of adrenaline.

METHODS: After 5 min of VF, 20 pigs randomly received either pralidoxime (40 mg/kg) or saline, in combination with adrenaline, during cardiopulmonary resuscitation (CPR). Coronary perfusion pressure (CPP) during CPR, and ease of resuscitation were compared between the groups. Additionally, haemodynamic data, severity of ventricular arrhythmias, and cerebral microcirculation were measured during the 1-h post-resuscitation period. Cerebral microcirculatory blood flow and brain tissue oxygen tension (PbtO2 ) were measured on parietal cortices exposed through burr holes.

RESULTS: All animals achieved ROSC. The pralidoxime group had higher CPP during CPR (P = 0.014) and required a shorter duration of CPR (P = 0.024) and smaller number of adrenaline doses (P = 0.024). During the post-resuscitation period, heart rate increased over time in the control group, and decreased steadily in the pralidoxime group. No inter-group differences were observed in the incidences of ventricular arrhythmias, cerebral microcirculatory blood flow, and PbtO2 .

CONCLUSION: Pralidoxime improved CPP and hastened ROSC in a model with a short duration of untreated VF. The potentiation of the pressor effect of adrenaline was not accompanied by the worsening of the adverse effects of adrenaline.