Systematic review and meta-analysis comparing low-flow duration of extracorporeal and conventional cardiopulmonary resuscitation

Abstract

Objectives: After cardiac arrest, a key factor determining survival outcomes is low-flow duration. Our aims were to determine the relation of survival and low-flow duration of extracorporeal cardiopulmonary resuscitation (ECPR) and conventional cardiopulmonary resuscitation (CCPR) and if these 2 therapies have different short-term survival curves in relation to low-flow duration.

Methods: We searched Embase, Medline, Web of Science and Google Scholar from inception up to April 2021. A linear mixed-effect model was used to describe the course of survival over time, based on study-specific and time-specific aggregated survival data.

Results: We included 42 observational studies reporting on 1689 ECPR and 375 751 CCPR procedures. Of the included studies, 25 included adults, 13 included children and 4 included both. In adults, survival curves decline rapidly over time (ECPR 37.2%, 29.8%, 23.8% and 19.1% versus CCPR-shockable 36.8%, 7.2%, 1.4% and 0.3% for 15, 30, 45 and 60 min low-flow, respectively). ECPR was associated with a statistically significant slower decline in survival than CCPR with initial shockable rhythms (CCPR-shockable). In children, survival curves decline rapidly over time (ECPR 43.6%, 41.7%, 39.8% and 38.0% versus CCPR-shockable 48.6%, 20.5%, 8.6% and 3.6% for 15, 30, 45 and 60 min low-flow, respectively). ECPR was associated with a statistically significant slower decline in survival than CCPR-shockable.

Conclusions: The short-term survival of ECPR and CCPR-shockable patients both decline rapidly over time, in adults as well as in children. This decline of short-term survival in relation to low-flow duration in ECPR was slower than in conventional cardiopulmonary resuscitation.

Trial registration: Prospero: CRD42020212480, 2 October 2020.

Keywords: Cardiac arrest; Cardiopulmonary resuscitation; Extracorporeal cardiopulmonary resuscitation; Heart arrest; Survival.

Figure 1:

Flowchart of study selection using the PRISMA guidelines.

Figure 2:

Relation between low-flow duration in minutes and hospital survival in percentage in adult patients treated with extracorporeal cardiopulmonary resuscitation (ECPR, red diagonal line: Hospital survival (%) = 2^{(5.5383–(0.02139*time (in min)))}), conventional cardiopulmonary resuscitation (CCPR) due to shockable initial cardiac rhythms (blue parabole: Hospital survival (%) = 2^{(7.5645–(0.1574*time (in min)))}), CCPR due to non-shockable initial cardiac rhythms (yellow dots no line). Calculated using LME models shown above. Due to one highly influencing study, no LME model could be created for CCPR patients with non-shockable cardia rhythm. LME: linear mixed effect (A color version of this figure appears in the online version of this article).

Figure 3:

Relation between low-flow duration in minutes and hospital term survival in percentage in children treated with extracorporeal cardiopulmonary resuscitation (ECPR, red upper diagonal line: Hospital survival (%) = 2^{(5.5139–(0.00442*time (min)))}), conventional cardiopulmonary resuscitation (CCPR) due to shockable initial cardiac rhythms (blue, parabole line: Hospital survival (%) = 2^{(6.8488–(0.08312*time (min)))}), CCPR due to non-shockable initial cardiac rhythms (yellow lower diagonal line: Hospital survival (%) = 2^{(4.4677–(0.0598*time (min)))}). Calculated using LME models shown above. LME: linear mixed effect (A color version of this figure appears in the online version of this article).