Abstract 94: Lay Public Poorly Identifies Chest Compression Depth in Cardiopulmonary Resuscitation Recommendations
Introduction: Recent American Heart Association guidelines on the recommended depth of chest compressions have included both a relative and a fixed nominal depth goal. The recommendation for adults has been 2 inches or 5 centimeters. Debate exists as to whether this goal is achievable given the difficulty of determining a compression distance while performing CPR. We believed that beyond this impediment to the recommendation of a 2 inch or 5 cm compression depth, the lay public would be unable to accurately demonstrate this distance.
Methods: After determining self-reported previous CPR training, we asked 81 adults approached at random at a shopping mall to demonstrate what they believed to be 2 inches using the phrase “Can you show me between your thumb and index finger how long you think 2 inches is?” This distance was recorded on paper for later accurate measurement. A second group of 100 adults were asked the same question for a distance of 5 cm. Results were tabulated and are reported as median (+/− SD) and percent error with comparisons using the two-tailed t-test.
Results: Self-reported previous CPR training was present in 99/181 subjects (55%). Of 81 respondents to the question of 2 inches, the median distance demonstrated was 1.94in (SD=0.61in, range 0.81 to 3.81in). 40% of responses varied by >0.5 in from the goal of 2 inches. Of 100 respondents to the question of 5 cm the median distance was 4.27 cm (SD=2.76cm, range 0.58 to 12.55cm). 70% of responses varied by >1.25 cm from the goal of 5 cm. The average percent error between the 2 inch group and the 5 cm group was 25% vs. 46% (p<0.05). There was no statistically significant difference between trained and untrained respondents in either group.
Conclusions: Lay public adults in the United States only accurately identify 2 inches (+/− 0.5 in) 60% of the time. Even more significantly, they accurately identify 5 cm (+/− 1.25cm) only 30% of the time. This substantial error for both trained and untrained subjects in correctly displaying any distance, even in a non-stressful survey setting, calls into question the value of recommending a nominal compression depth for use in CPR. The striking lack of knowledge of centimeters versus inches by subjects in this study makes recommending a centimeter depth to an American audience unwise.
- © 2010 by American Heart Association, Inc.