The Effects of 'Hands Only(TM)' Cardiopulmonary Resuscitation (CPR) in CPR Education in Elementary School

PURPOSE: The success of cardiopulmonary resuscitation (CPR) depends on how soon after a heart attack the intervention is done and on how the quality of the CPR is. Although in Korea there are several CPR education courses, CPR done by bystanders to an attack remains very low. This might be related to different causes such as the complexity of the CPR sequence and the difficulty of learning CPR, specifically ventilation maneuvers. The American Heart Association (AHA) has recently recommended 'Hands Only(TM) CPR', without ventilation, for bystander rescuers. In the present study, we investigated the educational effects of 'Hands Only(TM) CPR' in elementary school students. We further analyzed the effects of this variable on CPR skill learning and retention for a 3 months period. METHODS: We selected two groups of 5th grade elementary school students to perform this study. One group received CPR education with ventilation (CPR with ventilation group); the other received 'Hands Only(TM) CPR' education ('Hands Only(TM) CPR' group). The Laerdal PC Skill Reporting system was used for both education sessions and for evaluation immediately after the sessions. Skill performance data, together with ventilation data and compression data were recorded for further comparisons. RESULTS: There were no differences between the two groups regarding chest compression (average rate, average duty cycle, registered with no error, average depth, etc.). The average chest compression count per minute was 118+/-12/min in the 'Hands Only(TM) CPR' group and 85+/-13/min in the CPR with ventilation group (p=0.001). Registered adequate compression depth was 23+/-29% in the 'Hands Only(TM) CPR' group and 23+/-31% in the CPR with ventilation group (p=0.962). The total hands off time was 18+/-7 seconds in the 'Hands Only(TM) CPR' group and 40+/-11 seconds in the CPR with ventilation group. After 3 months there were still no differences in chest compression between the two groups. The average count per minute at 3 months was 109+/-15/min in the 'Hands Only(TM) CPR' group and 83+/-17/min in the CPR with ventilation group (p=0.001). Registered adequate compression depth was 26+/-31% in the 'Hands Only(TM) CPR' group and 31+/-35% in the CPR with ventilation group (p=0.334). The total hands off time was 12+/-5 seconds in the 'Hands Only(TM) CPR' group and 31+/-12 seconds in the CPR with ventilation group (p=0.001). CONCLUSION: The 'Hands Only(TM) CPR' program in elementary school children increased the chest compression rate. However, there was no between groups difference in adequate compression depth. We were unable to demonstrate that the 'Hands Only(TM) CPR' education program in elementary school children led to a better effect.

The Effect of Decreases in Left Ventricle Volume and Area During Ventricular Fibrillation on Resuscitation Outcomes

PURPOSE: Dynamic changes in the dimensions of the left ventricle (LV) during cardiac arrest might influence the efficacy of CPR. However, the relationship between change in LV dimensions during cardiac arrest and CPR hemodynamics and outcomes have not yet been addressed. In the present study, we investigated changes in left ventricular volume and area during prolonged, untreated ventricular fibrillation (VF); we related those change to coronary perfusion pressure (CPP) during CPR and resuscitation outcomes. METHODS: In 12 domestic male pigs weighing 40+/-3 kg, VF was electrically induced and left untreated for 15 min. CPR was performed for 5 min prior to defibrillation. CPR was continued until the return of spontaneous circulation (ROSC) or for a maximum of 15 minutes. Mean aortic pressure and right atrial pressures were measured and CPP was calculated. LV dimensions were continuously assessed by echocardiographic measurement during the 15 minutes of interval VF. RESULTS: Six animals were successfully resuscitated. During the 15 minute interval of VF, LV area and volume were reduced in all animals. In animals that were not resuscitated, LV dimensions were significantly lower than those in resuscitated animals (p<0.01). These differences were observed after 10 minutes of VF. The animals with greater reduction in LV dimension during VF achieved significantly lower CPP during CPR in contrast to animals with larger LVs during VF. CONCLUSION: Greater decreases in LV volume and area during cardiac arrest are associated with low CPP during CPR and poor resuscitation outcomes. LV dimensions prior to starting CPR might therefore modulate the effectiveness of resuscitation interventions.