Abstract 52: An Evidence Based Animal Model Of Prolonged Ventricular Fibrillation Cardiac Arrest
Background: Promising basic science findings in cardiac resuscitation often do not translate into improved outcomes when studied in humans. One explanation is that the current animal models do not adequately reflect the out-of-hospital cardiac arrest (OHCA) clinical trial environment. The author sought to review the literature and devise a new model of prolonged VF with time intervals that more accurately simulate OHCA conditions.
Methods: A systematic review of the literature (01/90 –12/06) was conducted using PUBMED and a comprehensive list of appropriate MESH headings. All OHCA human clinical trials were included. The most relevant studies underwent explicit and detailed review. Mean values with 95%CI were calculated for each specified interval. Suitable conditions and establishment of appropriate times were then devised.
Results: Twenty-two papers with adequate detail for evaluation were examined, leading to the following recommendations: the duration of non-treatment (assuming no bystander CPR or first-responders) is 11” (3” for recognition and EMS activation, 7” response interval and 1” for paramedics to reach the patient); chest compressions are initiated immediately with passive oxygen insufflation; assuming they can be done simultaneously, IV access and intubation (ETI) are accomplished 4” after arrival; drugs are delivered by minute 16 - well into the metabolic phase; and 2” of CPR are needed to circulate the drugs for the first rescue shock (RS) at minute 18.
Conclusions: This proposed evidence based experimental model of prolonged untreated VF cardiac arrest has conditions and time intervals that simulate those of human OHCA clinical trials.