Therapeutics
In out-of-hospital cardiac arrest, mechanical CPR did not improve survival compared with manual CPR
Rubertsson S, Lindgren E, Smekal D, et al. Mechanical chest compressions and simultaneous defibrillation vs conventional cardiopulmonary resuscitation in out-of-hospital cardiac arrest: the LINC randomized trial. JAMA. 2014;311:53-61.
Clinical impact ratings: E ★★★★★★✩ C ★★★★★✩✩ Question
Main results
In adults with out-of-hospital cardiac arrest, does mechanical cardiopulmonary resuscitation (CPR) improve 4-hour survival compared with guideline-directed manual CPR?
Mechanical and manual CPR did not differ for any outcome (Table). 10 serious adverse events occurred: 7 in the mechanical group and 3 in the manual group.
Methods
Conclusion
Design: Randomized controlled trial (LUCAS in Cardiac Arrest [LINC] study). ClinicalTrials.gov NCT00609778.
In adults with out-of-hospital cardiac arrest, mechanical cardiopulmonary resuscitation (CPR) with integrated defibrillation did not differ from manual CPR for survival at 4 hours or survival with good neurologic outcome at 6 months.
Allocation: Unclear allocation concealment.* Blinding: Unblinded.* Follow-up period: 6 months.
*See Glossary.
Setting: 4 advanced life support emergency medical systems in Sweden, 1 in the UK, and 1 in the Netherlands.
Sources of funding: Uppsala University and Physio-Control/Jolife AB. For correspondence: Dr. S. Rubertsson, Uppsala University, Uppsala, Sweden. E-mail [email protected]. ■
Patients: 2593 patients ≥ 18 years of age (mean age 69 y, 67% men) who had an unexpected, out-of-hospital cardiac arrest and were considered appropriate for resuscitation. Exclusion criteria were traumatic cardiac arrest, lack of fit of chest compression device because of body size, defibrillation before device arrival, return of spontaneous circulation (ROSC) after immediate defibrillation in crew-witnessed cardiac arrest, or pregnancy.
Commentary
Intervention: Mechanical CPR algorithm that included mechanical chest compressions using the LUCAS Chest Compression System (Physio-Control/Jolife AB) with defibrillation during compressions, and initial manual CPR until mechanical chest compressions were started (n = 1300); or guideline-directed manual CPR (n = 1293). Outcomes: 4-hour survival after successful ROSC. Other outcomes included ROSC, survival with good neurologic outcome (Cerebral Performance Category score 1 or 2 out of 5) at hospital discharge and 6 months, and serious adverse events. 2500 patients were needed to detect a 6% absolute increase in 4-hour survival from 25% with manual CPR to 31% with mechanical CPR (90% power). Patient follow-up: > 98% (intention-to-treat analysis). Mechanical CPR vs manual CPR in adults with out-of-hospital cardiac arrest† Outcomes Survival at 4 h
Mechanical CPR
Manual CPR
RBR (95% CI)
NNH
23.6%
23.7%
0.20% (−13 to 15)
NS
RBI (CI)
NNT
Return of spontaneous circulation
35.4%
34.6%
2.3% (−8 to 14)
NS
Survival with good neurologic outcome‡ at hospital discharge
8.3%
7.8%
7.1% (−17 to 39)
NS
Survival with good neurologic outcome‡ at 6 mo
8.5%
7.6%
11% (−14 to 44)
NS
†CPR = cardiopulmonary resuscitation; NS = not significant; RBR = relative benefit reduction; other abbreviations defined in Glossary. RBR, RBI, and CI calculated from event rates in article. ‡Cerebral Performance Category score 1 or 2 out of 5.
18 February 2014 | ACP Journal Club | Volume 160 • Number 4
Out-of-hospital cardiac arrest is the third highest killer of adults in developed countries, exacting a high toll on victims who may be struck down in the prime of their lives (1). Although survival with good neurologic function is rare, we know that early and effective CPR is key for improving outcomes. Mechanical devices are designed to improve delivery of CPR by increasing coronary perfusion pressure and make the recently dead heart more likely to respond to resuscitative maneuvers, such as defibrillation and vasopressors. There are 2 categories of such devices: 1 is band-like in nature, distributing compressive force across the chest; the other, evaluated in the LINC trial, is a piston and suction device intended to promote chest recoil and enhance cardiac output. Data supporting either intervention are limited in both quality and convincing evidence of efficacy (2, 3). The results of the LINC trial contribute to skepticism about the piston and suction-type devices. The selection of 4-hour survival as the primary outcome could be criticized as placing undue emphasis on a surrogate measure, and the lack of a convincing signal among secondary outcomes is telling. The use of automatic defibrillation, regardless of presenting rhythm, in the mechanical CPR group of the trial, along with the 1.5-minute delay to first shock, may have contributed to the lack of effect. Nevertheless, these devices should remain in the realm of research for the time being. Eddy Lang, MD University of Calgary Calgary, Alberta, Canada References 1. Taniguchi D, Baernstein A, Nichol G. Cardiac arrest: a public health perspective. Emerg Med Clin North Am. 2012;30:1-12. 2. Brooks SC, Bigham BL, Morrison LJ. Mechanical versus manual chest compressions for cardiac arrest. Cochrane Database Syst Rev. 2011;(1): CD007260. 3. Westfall M, Krantz S, Mullin C, Kaufman C. Mechanical versus manual chest compressions in out-of-hospital cardiac arrest: a meta-analysis. Crit Care Med. 2013;41:1782-9.
© 2014 American College of Physicians
Downloaded From: https://annals.org/pdfaccess.ashx?url=/data/journals/aim/929769/ by a Tufts University User on 08/02/2017
JC5
In out-of-hospital cardiac arrest, mechanical CPR did not improve survival compared with manual CPR
Rubertsson S, Lindgren E, Smekal D, et al. Mechanical chest compressions and simultaneous defibrillation vs conventional cardiopulmonary resuscitation in out-of-hospital cardiac arrest: the LINC randomized trial. JAMA. 2014;311:53-61.
Clinical impact ratings: E ★★★★★★✩ C ★★★★★✩✩ Question
Main results
In adults with out-of-hospital cardiac arrest, does mechanical cardiopulmonary resuscitation (CPR) improve 4-hour survival compared with guideline-directed manual CPR?
Mechanical and manual CPR did not differ for any outcome (Table). 10 serious adverse events occurred: 7 in the mechanical group and 3 in the manual group.
Methods
Conclusion
Design: Randomized controlled trial (LUCAS in Cardiac Arrest [LINC] study). ClinicalTrials.gov NCT00609778.
In adults with out-of-hospital cardiac arrest, mechanical cardiopulmonary resuscitation (CPR) with integrated defibrillation did not differ from manual CPR for survival at 4 hours or survival with good neurologic outcome at 6 months.
Allocation: Unclear allocation concealment.* Blinding: Unblinded.* Follow-up period: 6 months.
*See Glossary.
Setting: 4 advanced life support emergency medical systems in Sweden, 1 in the UK, and 1 in the Netherlands.
Sources of funding: Uppsala University and Physio-Control/Jolife AB. For correspondence: Dr. S. Rubertsson, Uppsala University, Uppsala, Sweden. E-mail [email protected]. ■
Patients: 2593 patients ≥ 18 years of age (mean age 69 y, 67% men) who had an unexpected, out-of-hospital cardiac arrest and were considered appropriate for resuscitation. Exclusion criteria were traumatic cardiac arrest, lack of fit of chest compression device because of body size, defibrillation before device arrival, return of spontaneous circulation (ROSC) after immediate defibrillation in crew-witnessed cardiac arrest, or pregnancy.
Commentary
Intervention: Mechanical CPR algorithm that included mechanical chest compressions using the LUCAS Chest Compression System (Physio-Control/Jolife AB) with defibrillation during compressions, and initial manual CPR until mechanical chest compressions were started (n = 1300); or guideline-directed manual CPR (n = 1293). Outcomes: 4-hour survival after successful ROSC. Other outcomes included ROSC, survival with good neurologic outcome (Cerebral Performance Category score 1 or 2 out of 5) at hospital discharge and 6 months, and serious adverse events. 2500 patients were needed to detect a 6% absolute increase in 4-hour survival from 25% with manual CPR to 31% with mechanical CPR (90% power). Patient follow-up: > 98% (intention-to-treat analysis). Mechanical CPR vs manual CPR in adults with out-of-hospital cardiac arrest† Outcomes Survival at 4 h
Mechanical CPR
Manual CPR
RBR (95% CI)
NNH
23.6%
23.7%
0.20% (−13 to 15)
NS
RBI (CI)
NNT
Return of spontaneous circulation
35.4%
34.6%
2.3% (−8 to 14)
NS
Survival with good neurologic outcome‡ at hospital discharge
8.3%
7.8%
7.1% (−17 to 39)
NS
Survival with good neurologic outcome‡ at 6 mo
8.5%
7.6%
11% (−14 to 44)
NS
†CPR = cardiopulmonary resuscitation; NS = not significant; RBR = relative benefit reduction; other abbreviations defined in Glossary. RBR, RBI, and CI calculated from event rates in article. ‡Cerebral Performance Category score 1 or 2 out of 5.
18 February 2014 | ACP Journal Club | Volume 160 • Number 4
Out-of-hospital cardiac arrest is the third highest killer of adults in developed countries, exacting a high toll on victims who may be struck down in the prime of their lives (1). Although survival with good neurologic function is rare, we know that early and effective CPR is key for improving outcomes. Mechanical devices are designed to improve delivery of CPR by increasing coronary perfusion pressure and make the recently dead heart more likely to respond to resuscitative maneuvers, such as defibrillation and vasopressors. There are 2 categories of such devices: 1 is band-like in nature, distributing compressive force across the chest; the other, evaluated in the LINC trial, is a piston and suction device intended to promote chest recoil and enhance cardiac output. Data supporting either intervention are limited in both quality and convincing evidence of efficacy (2, 3). The results of the LINC trial contribute to skepticism about the piston and suction-type devices. The selection of 4-hour survival as the primary outcome could be criticized as placing undue emphasis on a surrogate measure, and the lack of a convincing signal among secondary outcomes is telling. The use of automatic defibrillation, regardless of presenting rhythm, in the mechanical CPR group of the trial, along with the 1.5-minute delay to first shock, may have contributed to the lack of effect. Nevertheless, these devices should remain in the realm of research for the time being. Eddy Lang, MD University of Calgary Calgary, Alberta, Canada References 1. Taniguchi D, Baernstein A, Nichol G. Cardiac arrest: a public health perspective. Emerg Med Clin North Am. 2012;30:1-12. 2. Brooks SC, Bigham BL, Morrison LJ. Mechanical versus manual chest compressions for cardiac arrest. Cochrane Database Syst Rev. 2011;(1): CD007260. 3. Westfall M, Krantz S, Mullin C, Kaufman C. Mechanical versus manual chest compressions in out-of-hospital cardiac arrest: a meta-analysis. Crit Care Med. 2013;41:1782-9.
© 2014 American College of Physicians
Downloaded From: https://annals.org/pdfaccess.ashx?url=/data/journals/aim/929769/ by a Tufts University User on 08/02/2017
JC5
