Cardiac output during cardiopulmonary resuscitation at various compression rates and durations

Abstract

Davis, Robert W.; and Silver, Douglas I., "Cardiac output during cardiopulmonary resuscitation at various compression rates and durations" (1981) AbstractCardiac output during cardiopulmonary resuscitation (CPR) was measured by a modified indicator-dilution technique in 20 anesthetized dogs (6-12 kg) during repeated 1-to 2-min episodes of electrically induced ventricular fibrillation and CPR, produced by a mechanical chest compressor and ventilator. With compression rates from 20 to 140/min and compression durations (duty cycles) from 10 to 90% of cycle time, cardiac output (CO) was predicted by the equation:where CR is compression rate, DC is duty cycle, SVmax (19 ml) is the effective capacity of the pumping chamber, and kl (0.00207 min) and k2 (0.00707 min) are ejection and filling constants. This expression predicts maximal CO for DC = 0.40 and CR = 126/min as well as 90-100% of maximal CO for 0.3 < DC < 0.5 and 70 < CR < 150/min. Such mathematical analysis may prove useful in the optimization of CPR.

Cardiopulmonary Resuscitation with Interposed Abdominal Compression in Dogs

“…Improvements in blood pressures and blood flows during experimental CPR have, for example, been reported with increased duration of chest compression [2,3], with simultaneous chest compression and ventilation at high airway pressure [4,5,6], with negative diastolic airway pressure [7], and with abdominal binding [S]. These studies leave little doubt that improved blood flow is possible during CPR, and they provide valuable insights into mechanisms that generate blood flow during CPR [9].…”

Design of near-optimal waveforms for chest and abdominal compression and decompression in CPR using computer-simulated evolution

“…Since none of the 40 random seed values evolved into a radically different waveform, we can have some confidence that resuscitation research has not missed an important big idea. The three dimensional plots of Figure 8 strongly resemble those published in 1981 by Fitzgerald 47 to describe the influence of compression rate and duty cycle on chest compression only CPR in dogs using an analytical approach that focused on pump filling and emptying times. The concept of maximizing perfusion of the myocardium with 30 percent duty cycle and perfusion of the brain with about 60 percent duty cycle was advanced by Babbs and Thelander 48 in 1995 for interposed abdominal compression CPR (no decompression) using a digital computer model of the circulation implemented in SPICE.…”

Impedance Threshold Device Combined With High-Quality Cardiopulmonary Resuscitation Improves Survival With Favorable Neurological Function After Witnessed Out-of-Hospital Cardiac Arrest

“…Inadequate compression depth reduces the natural recoil. 37- 39 The ITD cannot function to enhance negative intrathoracic pressure during the decompression phase of CPR without adequate chest wall recoil. By contrast, when CPR is performed according to AHA and ILCOR recommendations, using either both hands or an ACD CPR device, the addition of the ITD provides important hemodynamic and survival benefits.…”