Three Different Cardiopulmonary Resuscitation (CPR) Training Methods

The survival rates for out-of-hospital cardiac arrest (OCA) remain low (approximately 5%), despite recent advances in advanced cardiac life support (ACLS) and expansion of emergency medical services (EMS) across Ontario and Canada. Although the survival rates for in-hospital cardiac arrest are higher, less than 20% ultimately survive to discharge. One of the most important determinants of survival from cardiac arrest appears to be initiation of early and effective chest compressions. Yet the quality of cardiopulmonary resuscitation (CPR) and basic life support (BLS) delivered by first responders is often poor. CPR appears to be delivered inconsistently, incompletely and with undue delays in both the in-hospital and out-of-hospital setting. In an effort to improve cardiac arrest outcomes, focus has recently shifted to methods for training in CPR. Optimal BLS (involving chest compressions, artificial ventilation, and the use of an automated external defibrillator where available) is difficult to perform well, to teach, and to retain at a high skill level. Most BLS training programs use hands-on instruction, printed materials, and global assessment for evaluation, which to date have not been shown to impact on the quality of the CPR/BLS provided. Guidelines for BLS have changed substantially since 2005, and the efficacy of the teaching programs aimed at laypersons or primary providers of emergency care is unknown. A potential result of these limitations in the teaching, training, evaluation, and retention of BLS skills is that CPR continues to be poorly performed both by trained lay rescuers and professional caregivers.

New technologies incorporated into commercially available defibrillators may help in the training and evaluation of BLS skills. These devices allow measurement of chest compression depth and rate and ventilation frequency with continuous real-time feedback provided to the caregiver by means of an on-screen icon, which is a simple visual measure of integrated CPR efficacy, as well as verbal prompts to encourage best performance. Electronic information is stored in the defibrillator for subsequent off-line analysis which can be used to provide additional visual feedback. Perhaps most importantly, these tools provide a quantitative measure of the quality of the resuscitation effort by integrating the various aspects of CPR performance.

To date no clinical study has assessed if such tools would facilitate both the training and testing of CPR skills using the new 2005 cardiac arrest guidelines. To answer this question, the investigators propose to conduct a clinical trial involving medical and nursing students (considered "lay rescuers"), randomized to three different teaching strategies. The advantage of this population is that they are relatively easy to access and in addition, provide a homogeneous population with similarities in background, education, motivation and personal expectations. They also represent a large proportion of individuals who, in time, will be exposed to and will respond to in-hospital cardiac arrests. By using medical and nursing students who are still in the formative stages of their concepts of allied health members, the investigators hope to provide an opportunity for them to work with, about and from each other.

The control group will receive standard teaching of BLS according to the ILCOR 2005 Guidelines, including appropriate chest compression rate, depth, and chest recoil with minimization of "hands-off" time, appropriate ventilation, and use of a standard defibrillator (Zoll M series). The first intervention group will receive training supplemented by the use of a novel defibrillator (Zoll R Series) which allows for real-time continuous feedback with both visual and audio prompts to optimize CPR performance, as well as additional off-line review of details of chest compressions (including rate and depth), "hands-off" time (time spent not doing chest compressions), and therapy sequencing. The second intervention group will receive training with the novel defibrillator (Zoll R Series) but will be tested with the standard defibrillator (Zoll M series).

Two hundred and forty consenting students will be randomly assigned to the standard training ("control") group, or to training and testing using the advanced feedback features ("intervention group 1"), or to training using the advanced feedback features but tested using the standard defibrillator ("intervention group 2"), in groups of 2. After a two hour training period all participants will be tested for approximately 5 minutes. Students in the control and intervention groups will be randomized to three groups: R-Series, R series and M series or M-Series defibrillators and tested using a scenario similar to the training session.

The primary outcome is total CPR fraction (percentage of time doing chest compressions during the scenario). Secondary outcomes are CPR fraction per minute, average rate of compressions per minute, total recorded hands-off time, average depth of compressions, and the average integrated "icon fullness" as an approximation of cardiac output. Overall performance in terms of integrated psychomotor skills, reasons for hands-off time, appropriate versus inappropriate use of the AED in terms of rhythm analysis, shock delivery and study participant self-assessment of performance will also be measured. After a 3 month period, students will be re-tested using the same testing scenario to assess for skill retention. No further BLS training will be given prior to retesting.

This will be the first study to evaluate objectively and in a controlled manner the usefulness of these new technologies in the teaching, learning and evaluation of CPR/BLS.