Abstract
Following the return of spontaneous circulation after cardiac arrest, neurological dysfunction, airway or ventilatory compromise can impede transport to early percutaneous coronary intervention, necessitating pre-hospital or emergency department anaesthesia to facilitate this procedure. There are no published reports of the ideal induction agents in these patients. We sought to describe haemodynamic changes associated with a midazolam (0.1mg/kg) fentanyl (2mcg/kg) rocuronium (1mg/kg) regimen developed from expert opinion, and adherence to the protocol by our pre-hospital teams. We performed a retrospective review of electronic vital-signs recorded during induction of return of spontaneous circulation patients over a 30-month period. We analysed the changes in systolic blood pressure and heart rate using a repeated-measures design, and the rate of new hypotension or hypertension. Sixty four patients had four consecutive measurements for analysis (one pre-induction and three post-induction). Systolic blood pressure was significantly lower than the pre-induction value at all three post-induction measurements. Heart rate did not differ between any time-point. New episodes of hypotension (systolic pressure <90mmHg) occurred in 6% at the first measurement post-induction (95%CI 2% to 15%) and 16% at the third measurement (95%CI 8% to 27%). Three patients (5%; 95%CI 1% to 13%) had a hypertensive response. Median midazolam dose given at induction was 0.04mg/kg, only 14% of patients received 0.1mg/kg midazolam. Adherence to recommended fentanyl and rocuronium doses was high. Overall, systolic blood pressure reduced post-induction and systolic pressures <90mmHg may occur more often at later measurements (up to 9 minutes). Changes in heart rate and new hypertension were uncommon.