The Science Journal of the American Association for Respiratory Care

2008 OPEN FORUM Abstracts

A COMPARISON OF TWO COMPRESSION TO VENTILATION RATIOS ON RESCUER PERFORMANCE IN BLS

Phillip D. Hoberty1, Nicholas Mallas1, Rebecca Rosenstein1



Background: There is evidence that the 2005 American Heart Association (AHA) Guidelines, which call for the use of a 30:2 ratio of chest compressions to ventilations during adult one-rescuer Basic Life Support, result in improved perfusion pressures in the pulseless victim meaning a better coronary and cerebral blood flow. Older guidelines called for maintaining a 15:2 ratio and led to more frequent interruptions in compressions, a lower average perfusion pressure, and possibly over ventilation of the lungs. However, little is known about the effects of the change on performance of the rescuer.

Methods: We studied the two factors related to fatigue (exertion score (BorgS) and heart rate (HR)), two factors related to compression performance (compression depth (CD) and hand placement (HP)) and one factor related to maintaining the ratio (time of ventilations(VT)). Healthy volunteers from the membership of a major university's marching band were randomly divided into two groups. The age and gender mix of the groups were basically equal. Members of neither group had had previous BLS training or it had been several years ago. One group was taught adult one-rescuer BLS under the old ratio of 15:2, while the other group was taught adult one-rescuer BLS in a matching curriculum except for the ratio being 30:2. Both groups were asked to perform a 2-minute series of compressions and ventilations. All testing was done with stock Little Anne manikins from Leardal. We used a general linear model for repeated measures (SPSS v.15) to test for pre-post changes in HR, BORGS, and independent t-tests to test for HP, CD, and VT errors. We further tested for the effects or age and gender.

Results: None of these tests of fatigue or performance were significant -- showing the difference in ratio does not lead to rescuer fatigue or sloppiness, and the advantages in perfusion pressure make the longer time of chest compression and smaller numbers of breaths well worth the effort expended. We did find one difference, in that males in both groups were less likely to commit CD and HP errors during the 2-minute test.

Conclusion: We found that newer 30:2 does not lead to fatigue or inadequate performance. Men may be less prone to physical limitations of performance. Further research covering longer periods of time for one-rescuer resuscitation should be done to confirm these findings for arrest situations.