Coronary perfusion pressure response to high-dose intraosseous versus standard-dose intravenous epinephrine administration after prolonged cardiac arrest

Background: This study was done to compare coronary perfusion pressure (CPP) prior to the first rescue shock (RS) among a group of animals that received intraosseous (IO) epinephrine 0.1 mg/ kg (high-dose epinephrine [HDE]) with a group that received intravenous (IV) epinephrine 0.01 mg/kg (standard-dose epinephrine [SDE]) during cardiac arrest resuscitation using a swine model of prolonged out-of-hospital ventricular fibrillation (VF) cardiac arrest. Methods: This was a sec-ondary analysis of prospectively collected data from two IACUC approved protocols. Seventy-nine Yorkshire swine (25 -35 kg) were surgically instrumented under anesthesia and VF was electri-cally induced. After 10 minutes of untreated VF in the IO study (n = 26) and 12 minutes of un-treated VF in the IV study (n = 53), resuscitation commenced with closed chest compressions (CCC). A single dose of epinephrine (HDE IO or SDE IV, respectively) was given and flushed with saline. The CCC and RS attempts were standardized for all animals. The CPP was defined as aortic diastol-ic pressure minus right atrial diastolic pressure measured 2.5 minutes after medication delivery. Descriptive statistics were used to analyze the data. Results: Baseline group characteristics were mathematically the same. Just prior to the first RS, HDE IO resulted in a mean CPP of 33.2 mmHg (95%CI: 26.6, 39.9), while SDE IV resulted in a mean CPP of 25.0 mmHg (95%CI: 20.5, 29.4). Con-clusion: This observation study reaffirms the assertion that HDE IO may be required to generate CPP values similar to SDE IV during resuscitation of prolonged VF