What is the role of chest compression depth during out-of-hospital cardiac arrest resuscitation?*

Abstract

Background The 2010 international guidelines for CPR recently recommended an increase in the minimum compression depth from 38 to 50 mm, although there are limited human data to support this. We sought to study patterns of CPR compression depth and their associations with patient outcomes in out-of-hospital cardiac arrest (OOHCA) cases treated by the 2005 guideline standards. Methods and Results We studied emergency medical services treated OOHCA patients from the Resuscitation Outcomes Consortium Epistry - Cardiac Arrest for whom electronic CPR compression depth data were available, from May 2006 to June 2009. We calculated anterior chest wall depression in millimeters and the period of active CPR (chest compression fraction) for each minute of CPR. We controlled for covariates including compression rate and calculated adjusted odds ratios for any return of spontaneous circulation (ROSC), 1-day survival, and hospital discharge. We included 1,029 adult patients from 7 U.S. and Canadian cities with these characteristics: mean age 68 years; male 62 %; bystander witnessed 40%; bystander CPR 37%; initial rhythms - VF/VT 24%, PEA 16%, asystole 48%, other non-shockable 12%; outcomes - ROSC 26%, 1-day survival 18%, discharge 5%. For all patients, median compression rate was 106 per minute, median compression fraction 0.65, and median compression depth 37.3 mm with 52.8% of cases having depth < 38 mm and 91.6% having depth < 50 mm. We found an inverse association between depth and compression rate (P<0.001). Adjusted odds ratios for all depth measures (mean values, categories, and in range) showed strong trends towards better outcomes with increased depth for all three survival measures. Conclusions We found suboptimal compression depth in half of patients by 2005 guideline standards and almost all by 2010 standards, as well as an inverse association between compression depth and rate. We found a strong association between survival outcomes and increased compression depth but no clear evidence to support or refute the 2010 recommendations of > 50 mm. While compression depth is an important component of CPR and should be measured routinely, the most effective depth is currently unknown.

Chest Diameter Measurement in Pediatric Patients for Chest Compression Feedback Calibration

“…The use of CPR feedback devices has increased chest compression quality, minimizing pauses and increasing compression depth in adults [4]. Current devices are designed for adult patients, for whom a fixed compression depth range is recommended.…”

“…Recent development of feedback devices, capable of real-time monitoring and guidance of chest compressions has contributed to improve CPR quality [4,5]. These devices are usually placed between the chest of the patient and the rescuer's hands, and guide rescuers towards the target compression depth and rate.…”

An evaluation of three methods of in-hospital cardiac arrest educational debriefing: The cardiopulmonary resuscitation debriefing study

“…[19][20][21][22] Initial audit data showed a chest compression depth standard deviation of 13.67, such that a sample size of 40 patient participants per hospital site in each study period was required to detect a clinically important 10mm improvement in chest compression depth at 90% power and significance level of 0.05. [23] Secondary outcomes included other CPR quality metrics and patient outcomes.…”

Use of computed tomography and mechanical CPR in cardiac arrest to confirm pulmonary embolism: a case study

“…3 Effective chest compressions with a depth of at least 38 mm and maintenance of a high rate are most relevant for the quality of CPR. 4 This may sometimes be difficult to implement in all environments with manual chest compressions. Using automated chest compression devices may help to ensure a continuous good performance of chest compressions and perfusion throughout the treatment, transport, and movement of patients.…”