Return of spontaneous circulation and long‐term survival according to feedback provided by automated external defibrillators

Abstract

BackgroundWe aimed to investigate the effect of automated external defibrillator (AED) feedback mechanisms on survival in out‐of‐hospital cardiac arrest (OHCA) victims. In addition, we investigated converting rates in patients with shockable rhythms according to AED shock waveforms and energy levels.MethodsWe collected data on OHCA occurring between 2011 and 2014 in the Capital Region of Denmark where an AED was applied prior to ambulance arrival. Patient data were obtained from the Danish Cardiac Arrest Registry and medical records. AED data were retrieved from the Emergency Medical Dispatch Centre (EMDC) and information on feedback mechanisms, energy waveform and energy level was downloaded from the applied AEDs.ResultsA total of 196 OHCAs had an AED applied prior to ambulance arrival; 62 of these (32%) provided audio visual (AV) feedback while no feedback was provided in 134 (68%). We found no difference in return of spontaneous circulation (ROSC) at hospital arrival according to AV‐feedback; 34 (55%, 95% confidence interval (CI) [13–67]) vs. 72 (54%, 95% CI [45–62]), P = 1 (odds ratio (OR) 1.1, 95% CI [0.6–1.9]) or 30‐day survival; 24 (39%, 95% CI [28–51]) vs. 53 (40%, 95% CI [32–49]), P = 0.88 (OR 1.1 (95% CI [0.6–2.0])). Moreover, we found no difference in converting rates among patients with initial shockable rhythm receiving one or more shocks according to AED energy waveform and energy level.ConclusionsNo difference in survival after OHCA according to AED feedback mechanisms, nor any difference in converting rates according to AED waveform or energy levels was detected.

Adult Advanced Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations

“…The evidence updates restricted the search to January 2008 to January 2020 and identified one large RCT conducted in 2013 45 and 20 observational studies. 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 In addition, there is an ongoing multicentre RCT of real-time amplitude spectrum area to guide defibrillation (NCT03237910). Although the VF waveform analyses and outcomes studied were highly heterogeneous, given the amount of data available, an updated SysRev was suggested.…”

Basic life support

“…Eine Cluster-RCT [ 106 ] und sechs Beobachtungsstudien [ 51 , 55 , 107 , 109 , 110 ] bewerteten die Einflüsse dieser Geräte auf das Überleben bis zur Entlassung aus dem Krankenhaus sowie auf das Überleben 30 Tage nach dem Ereignis. Weder die Cluster-RCT mit niedriger Sicherheit (relatives Risiko 0,91; 95 %-CI 0,69–1,19; p = 0,5) [ 106 ] noch die Beobachtungsstudien ergaben einen mit diesen Geräten verbundenen Nutzen [ 51 , 55 , 107 , 109 – 111 ].…”

“…Es wurde kein Nutzen für das „30-Tage-Überleben“ festgestellt (relatives Risiko 1,66; 95 %-CI −17,7–14,9, p = 0,8) – eine weitere Beobachtungsstudie mit geringer Zuverlässigkeit bewertete die Wirkung eines Metronoms auf das 7‑Tage-Überleben und fand ebenfalls keinen Unterschied (3/17 vs. 2/13; p = 0,9) [ 114 ]. Zwei Beobachtungsstudien bewerteten die Wirkung eines Metronoms auf einen ROSC und fanden keinen Unterschied im Ergebnis (angepasstes relatives Risiko 4,97; 95 %-CI −21,11–11,76, p = 0,6 und 7/13 vs. 8/17, P = 0,7) [ 111 , 114 ].…”

Adult Basic Life Support

“… Outcome Studies No. of Patients Results Survival with favorable neurological outcome 1 cluster RCT, 150 low-certainty evidence (downgraded for very serious risk of bias) 4 observational, 151 , 152 , 153 , 154 very-low-certainty evidence (downgraded for very serious risk of bias) 1586 No difference: Relative risk 1.02; 95% CI, 0.76–1.36; P = 0.9 Absolute risk 0.19% (95% CI, −3.18% to 2.82%), or 2 more patients/1000 survived with the intervention (95% CI, 24 fewer patients/1000 to 36 more patients/1000 survived with the intervention) Better outcome with feedback: Adjusted odds ratio 2.69 (95% CI, 1.04–6.94) 153 1100 No difference:Adjusted relative risk 5.75%; 95% CI, -18.51% to 3.85%152Adjusted odds ratio 0.92; 95% CI, 0.37–2.301512/16 versus 0/16; P=0.14154 Survival to hospital discharge 1 cluster RCT,150low-certainty evidence (downgraded for very serious risk of bias) 6 observational: 5 in adults 127 , 131 , 151 , 153 , 155 and 1 in children, 156 very-low-certainty evidence (downgraded for very serious risk of bias) 1586 No difference: Relative risk: 0.91 (95% CI, 0.69–1.19); P?=?0.5Absolute risk: -1.16% (95% CI, -4.37% to 2.02%), or 9 fewer patients/1000 survived with the intervention (95% CI, 31 fewer patients/1000 to 19 more patients/1000 survived with the intervention) 1592 No difference: Adjusted odds ratio 0.90; 95% CI, 0.39–2.06; P?=?0.80),151Adjusted relative risk -0.91; 95% CI, -11.18 to 12.33),152Adjusted relative risk 5.23; 95% CI, -0.49 to 10.89),153Adjusted relative risk -0.18; 95% CI, -11.46 to 8.64),155Adjusted relative risk 1.37; 95% CI, -2.47 to 6.91),1318 children (ages 1–7 yr) with IHCA (1/4 versus 1/4)156 Survival to 30 days 1 observational, 157 very-low-certainty evidence (downgraded for seriou...…”

“… Outcome Studies No. of Patients Results Survival to 30 days 1 observational, 157 very-low-certainty evidence (downgraded for serious risk of bias) 196 No difference: Relative risk 1.66; 95% CI, −17.71 to 14.86; P =0.8 157 Survival to 7 days 1 observational, 161 very-low-certainty evidence (downgraded for serious risk of bias) 30 No difference: 3/17 versus 2/13; P = 0.9 161 ROSC 2 observational, 157 , 161 very-low-certainty evidence (downgraded for serious risk of bias) 236 No difference: Adjusted relative risk 4.97; 95% CI, −21.11 to 11.76; P = 0.6 157 7/13 versus 8/17; P =0.7 161 CI indicates confidence interval; and ROSC, return of spontaneous circulation. …”