Written by Nick Zelt
Registry study data finds the criteria to start extracorporeal cardiopulmonary resuscitation (ECPR) of age <75, time from emergency call to hospital arrival within 45 minutes and initial shockable rhythm to be predictive of good neurological outcomes and survival at one month.
Why does this matter?
ECPR presents itself as a possibility for significantly bettering outcomes after OHCA. Studies have shown significant benefits in cases where conventional advanced life support protocols fail. With this established possibility of benefit, patient selection is important, and widely accepted criteria for initiating ECPR do not exist. Japan bases much of their patient selection on the results of the SAVE-J study, but these criteria have not been scrutinized since original study.
Not to be CRITICAL of this acronym but…
This study was an analysis of data from the Comprehensive Registry of Intensive Care for OHCA Survival (CRITICAL) which prospectively collects data on OHCA patients from multiple centers in Japan. All adult patients with OHCA due to a medical cause (i.e. trauma excluded) who underwent ECPR over a 7-year period were included. The primary outcome was survival with good neurological outcome, defined as Cerebral Performance Category 1 or 2 at one month. The secondary outcome was one-month survival.
They include 517 patients with a median age of 60 years, and males accounted for a majority (84.7%). One-month survival with a favourable neurological outcome and one-month survival were seen in 64 (12.4%) and 115 (22.2%) patients, respectively. The authors sought to analyze the relationship between outcomes and the potential ECPR inclusion criteria of age <75, time duration from emergency call to hospital arrival within 45 minutes and initial rhythm of ventricular fibrillation or pulseless ventricular tachycardia. 60% of included patients met all three criteria.
Rates of good neurological survival were higher if all three criteria were met (16.1%) vs. if none of the criteria were satisfied (2.3%, p-value 0.004). When only two out of three criteria were met, the most important factor was age <75, though the difference was non-significant (p-value 0.088). Results were similar for the secondary outcome of one-month survival.
The major limitation of this study is selection bias since these criteria were likely to have informed patient selection for ECPR. These three criteria are unlikely to be enough to capture all good candidates for ECPR, and generalizability of these data isn’t known. Additionally, though popular for decision tools to do, dichotomizing for age is inelegant and does not take into account the variability of how healthy one can be at a certain age.
Clinical outcomes among out-of-hospital cardiac arrest patients treated by extracorporeal cardiopulmonary resuscitation: The CRITICAL study in Osaka. Resuscitation. 2022 Jun 14:S0300-9572(22)00568-8. doi: 10.1016/j.resuscitation.2022.06.007. Epub ahead of print.