ORIGINAL CONTRIBUTION Lidocaine Levels During CPR: Differences After Peripheral Venous, Central Venous, and Intracardiac Injections William G. Barsan, MD Richard C. Levy, MD Hannah Weir, BA Cincinnati, Ohio Drug administration via peripheral vein, central vein, and intracardiac routes is generally assumed to be equally effective during cardiopulmonary resus- citation (CPR). Experiments were performed in an animal model to evaluate this assumption. Twelve mongrel dogs weighing >20 kg were studied. Arterial blood pressure and electrocardiogram were monitored continuously. Cardiac outputs were evaluated before CPR to determine control. After thoracotomy and fibrillation of the heart, cardiac massage was started and the rate of com- pression adjusted to give 30% of control cardiac output. A lidocaine bolus of 1.5 mg/kg was given via peripheral vein in four dogs, central vein in four dogs, and intracardiac (left ventricle) in four dogs. Drug levels were sampled through an aortic catheter at the level of the coronary artery ostia every 20 sec for five min, every 30 sec for 10 rain, and every 60 sec for 15 min. There was no significant difference in the appearance of effective levels or time of peak levels in the three groups. The peak levels were highest in the central venous group, while peripheral venous and intracardiac peak levels were 63% and 31%, respectively, of the central venous peak. Duration of effective levels was 20 min in the intracardiac group, 14.5 min in the central venous group, and 9.6 min in the peripheral venous group. Further studies are needed to determine whether changes are needed in drug administration during CPR in man. Bar- san WG, Levy RC, Weir H: Lidocaine levels during CPR: differences after peripheral venous, central venous, and intracardiac injections• Ann Emerg Med 10:73-78, February 1981. cardiopulmonary resuscitation, drug administration routes; drugs, administration routes, during cardiopulmonary resuscitation INTRODUCTION Various routes of drug administration currently are recommended during cardiopulmonary resuscitation(CPR). 1-3 Although studies have been done com- paring the intrapulmonary route with other routes, 36 no research has compared the drug levels obtained from intracardiac, peripheral venous, and central 3 venous injections with or without CPR. Redding et al found intravenous, intra- cardiac, and intrapulmonary administration to be equally effective in resuscita- tion of dogs from cardiac arrest. They reported no significant time difference between the routes in achieving resuscitation, although the time intervals for resuscitation in the individual groups varied widely. From the Division of Emergency Medicine, University of Cincinnati Medical Center, Cincinnati, Ohio. Presented at the University Association for Emergency Medicine Annual Meeting in Tucson, Arizona, April 1980. Address for reprints: William G. Barsan, MD, University of Cincinnati Medical Center, Division of Emergency Medicine, 234 Goodman Street, Pavilion C, Room 409, Cincinnati, Ohio 45267 10:2 (February) 1981 Ann Emerg Med 73/9