Initial pH and shockable rhythm are associated with favorable neurological outcome in cardiac arrest patients resuscitated with extracorporeal cardiopulmonary resuscitation

Abstract

Background: There is uncertainty about best selection criteria for extracorporeal cardiopulmonary resuscitation (eCPR) in the setting of refractory cardiac arrest. We aimed to identify factors associated with a favorable neurological outcome, and to build a score calculable at the time of ECMO insertion predicting the prognosis. Methods: Retrospective analysis of all patients who underwent eCPR between 2010 and 2017 in a single university hospital. Primary end point was survival with favorable neurological outcome at intensive care unit (ICU) discharge defined as a Cerebral Performance Category of 1 or 2.Results: Overall low-flow time of the 113 included patients was 84 minutes. Eighteen patients (16%) survived with a favorable neurological outcome. By multivariate logistic regression analysis, initial shockable rhythm, and arterial blood pH at the time of eCPR implantation ≥7.0, were independent predictors of survival with favorable neurological outcome. All of the patients presenting with both nonshockable rhythm and pH <7.0 at the time of eCPR implantation died in the ICU. Conclusions: At the time of eCPR start, only initial shockable rhythm and arterial pH ≥7.0 predicted neurological outcome. A selection of the patients who might benefit from eCPR, based upon initial rhythm and arterial pH rather than on low flow time, should be further evaluated.

Arterial Oxygen and Carbon Dioxide Tension and Acute Brain Injury in Extracorporeal Cardiopulmonary Resuscitation Patients: Analysis of the Extracorporeal Life Support Organization Registry

“…In addition to pre-ECMO hypoxia and on-ECMO hyperoxia discussed above, lower pre-ECMO pH and requiring renal replacement therapy (RRT) on-ECMO were strongly associated with composite ABI. Pre-ECMO pH has been reported as an independent predictor of survival (27), with pH ≥ 7.0 being associated with better neurological outcome in ECPR patients (28). Especially in ECPR patients with severe metabolic acidosis post-cardiac arrest, pre-ECMO pH is likely a function of the duration of cerebral anoxia/hypoxia prior to the arrest (28).…”

“…Pre-ECMO pH has been reported as an independent predictor of survival (27), with pH ≥ 7.0 being associated with better neurological outcome in ECPR patients (28). Especially in ECPR patients with severe metabolic acidosis post-cardiac arrest, pre-ECMO pH is likely a function of the duration of cerebral anoxia/hypoxia prior to the arrest (28). RRT reflects acute renal failure from hemodynamic instability and lack of adequate perfusion, which are also risk factors for ABI (29).…”

Prediction of Neurological Outcomes in Out-of-hospital Cardiac Arrest Survivors Immediately after Return of Spontaneous Circulation: Ensemble Technique with Four Machine Learning Models

“…Initial laboratory data immediately after ROSC have a significant association with neurological outcomes in cardiac arrest survivors. 11 12 13 14 15 16 Establishing prediction models by adding widely available laboratory data might have contributed to the improvement of model performance, despite a smaller sample size than those of previous studies.…”

“…In recent studies, initial laboratory results at hospital arrival after OHCA, such as arterial pH, 11 12 serum potassium level, 13 14 and serum creatinine level, 15 16 have been reported to be associated with neurological outcomes after cardiac arrest. Machine learning is a crucial component in the establishment of prediction models that include laboratory test results as features since a variety of laboratory tests are performed and conventional statistical techniques have difficulty handling them.…”

Extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest - who, when, and where?

“…Although not always available prior to ECPR implementation, blood-based biomarkers including pH and lactate provide prognostic information for potential candidates of ECPR. A pH > 7 at the initiation of ECPR was associated with favorable neurologic outcomes in retrospective analysis, whereas lactic acidosis ≥13mmol/L predicted poor neurologic outcomes [33 ▪ ,34 ▪ ]. Biomarkers can be combined with other clinical variables to develop predictive models such as the Survival After venoarterial ECMO score to provide guidance for ECPR candidacy [35].…”