Andres Neset

Video analysis of dispatcher–rescuer teamwork–Effects on CPR technique and performance

OBJECTIVE We wanted to study the effect of continuous dispatcher communication on CPR technique and performance during 10min of simulated cardiac arrest. METHOD We reviewed video recordings and manikin data from 30 CPR trained lay people who where left alone in a simulated cardiac arrest situation with a manikin in a home-like environment (in a small, confined kitchen with the disturbing noise of a radio). CPR was performed for 10min with continuous telephone instructions via speaker function from a dispatcher. The dispatcher was blinded for CPR performance and video. Dispatcher communication, compression technique and ventilation technique was scored as accomplished or failed in the 1st and 10th minute. RESULTS 29/30 rescuers were able to hear instructions, answer questions from the dispatcher and perform CPR in parallel. Rescuer position beside manikin was initially correct for 13/30, improving to 21/30 (p=0.008). Compression technique was adequate for the whole episode, with an insignificant trend for improvement; 29 to 30/30 using straight arms, 28 to 30/30 in a vertical position over chest and 24 to 27/30 counting loudly. 17/29 placed their hands between the nipples initially, improving to 24/29 (p=0.065). Mean compression rate improved from 84 to 101min(-1) (p<0.001), and compression depth maintained adequate (43 to 42mm). Initially, 17/29 used chin-lift manoeuvre, 14/30 used head-tilt and 19/29 used nose pinch to manage open airways, compared to 18, 20 and 22/29 (ns) in the 10th minute, respectively. Successful delivery of ventilation improved from 13/30 to 23/30 (p=0.006). CONCLUSION Bystander and dispatcher can communicate successfully during ongoing CPR using a telephone with speaker function. CPR technique and quality improved or did not change over 10min with continuous dispatcher assistance. These results suggest a potential for improved bystander CPR using rescuer-dispatcher teamwork.

A randomized trial of the capability of elderly lay persons to perform chest compression only CPR versus standard 30:2 CPR

AIM OF THE STUDY Early cardiopulmonary resuscitation (CPR) improves survival after cardiac arrest, but there is a discrepancy between the age group normally attending CPR-classes and the age group most likely to witness a cardiac arrest. We wanted to study if elderly lay persons could perform 10min of CPR on a realistic manikin with continuous chest compressions (CCC) and conventional CPR (30:2). METHODS Volunteers were tested 5-7 months after CPR-classes. They were randomized to CCC or 30:2, and to receive feedback (FB) or not. Quality of CPR, age adjusted maximum heart rate (HRmax), and subjective exhaustion ratings were measured and evaluated in a blinded fashion. Temporal development and group differences were evaluated with ANOVA procedures. RESULTS All 64 volunteers were able to perform CPR for 10min and rated their efforts as mild to moderate in concordance with a mean HRmax of 78%. Quality of CPR was similar in all groups, except for chest compression rate that was slightly higher and had less variability in the FB group. Overall chest compression depth was 41+/-4.5mm. Analysis of temporal development of chest compression depth revealed a small initial decline before leveling off. As expected, CCC group had less pauses and higher total number of chests compressions. CONCLUSION Lay people in the age group 50-76 were able to perform CPR with acceptable quality for 10min and we found only very slight temporal quality deterioration. This makes training programs for the elderly meaningful to improve survival after cardiac arrest.

Quality of CPR performed by trained bystanders with optimized pre-arrival instructions

OBJECTIVE Telephone-CPR (T-CPR) can increase initiation of bystander CPR. We wanted to study if quality oriented continuous T-CPR would improve CPR performance vs. standard T-CPR. METHOD Ninety-five trained rescuers aged 22-69 were randomized to standard T-CPR or experimental continuous T-CPR (comprises continuous instructions, questions and encouragement). They were instructed to perform 10 min of chest compressions-only on a manikin, which recorded CPR performance in a small, confined kitchen. Three video-cameras captured algorithm time data, CPR technique and communication. Demography and training experience were captured during debriefing. RESULTS Participants receiving continuous T-CPR delivered significantly more chest compressions (median 1000 vs. 870 compressions, p=0.014) and compressed more frequently to a compression rate between 90 and 120 min(-1) (median 87% vs. 60% of compressions, p<0.001), compared to those receiving standard T-CPR. This also resulted in less time without compressions after CPR had started (median 12s vs. 64 s, p<0.001), but longer time interval from initiating contact with dispatcher to first chest compression (median 144 s vs. 84 s, p<0.001). There was no difference in chest compression depth (mean 47 mm vs. 48 mm, p = 0.90) or in demography, education and previous CPR training between the groups. CONCLUSION In our simulated scenario with CPR trained lay rescuers, experimental continuous T-CPR gave better chest compression rate and less hands-off time during CPR, but resulted in delayed time to first chest compression compared to standard T-CPR instructions.

A randomized trial on elderly laypersons' CPR performance in a realistic cardiac arrest simulation

Bystander cardiopulmonary resuscitation (CPR) is important for survival after cardiac arrest. We hypothesized that elderly laypersons would perform CPR poorer in a realistic cardiac arrest simulation, compared to a traditional test.

Effects of adrenaline on rhythm transitions in out-of-hospital cardiac arrest

We wanted to study the effects of intravenous (i.v.) adrenaline (epinephrine) on rhythm transitions during cardiac arrest with initial or secondary ventricular fibrillation/tachycardia (VF/VT).