Abstract 30: Incomplete Chest Recoil During Piglet CPR Worsens Hemodynamics

Abstract

Background : Incomplete chest recoil during cardiopulmonary resuscitation (CPR) (ie, leaning on the chest during the decompression phase) is purported to decrease venous return, and thereby decrease forward blood flow. Aim To determine the effect of 10% and 20% lean on hemodynamics during piglet CPR. Methods : 10 piglets (10.7±1.2 kg) were anesthetized with isoflurane and instrumented with micromanometer-tipped catheters in the right atrium (RA) and aorta (Ao). After induction of ventricular fibrillation, CPR was provided in three-minute epochs with no lean, 10% lean, or 20% lean while aortic systolic pressure (AoS) was targeted at 80–90 mmHg. Because the mean force to attain 80 –90 mm Hg AoS was 18 kg in preliminary studies, 10% and 20% lean were provided as 1.8 and 3.6 kg weights on the chest, respectively. Left ventricular myocardial blood flow (MBF) and cardiac index (CI) were determined by fluorescent, color-microsphere technique. Statistics: paired t -test and repeated measurement ANOVA for parametric, Wilcoxon Rank Sum Test and Friedman’s ANOVA for non-parametric data. Results : 10% and 20% lean resulted in higher right atrial diastolic pressure (RAD) and lower coronary perfusion pressure (CPP) than no lean. Hemodynamics were not different with 10% lean vs. 20% lean. Mean 10%–20% lean resulted in substantially lower MBF and CI than no lean (Table ). Conclusions : 10–20% leaning during CPR increases RAD, decreases CPP, and substantially decreases MBF and CI. Table