The absolute lactate levels versus clearance for prognostication of post-cardiotomy patients on veno-arterial ECMO.

AIMS: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is a life-saving procedure for supporting patients with cardiogenic shock after cardiac surgery. This work aimed to analyse the impact of changes in blood lactate levels on the survival of patients on post-cardiotomy ECMO (PC-ECMO) and whether lactate clearance (LC) performs better than absolute lactate levels. METHODS AND RESULTS: We retrospectively analysed the data of adult patients who received PC-ECMO at our centre between 2016 and 2022. The primary outcome was the in-hospital mortality rate. Arterial lactate levels were measured at ECMO initiation, peak and 12 and 24 h after VA-ECMO support. LC was calculated at 12 and 24 h. Out of 2368 patients who received cardiac surgeries, 152 (median age, 48 years; 57.9% of them were men) received PC-ECMO. Of them, 48 (31.6%) survived and were discharged, while 104 (68.4%) died during the index hospitalization. Non-survivors had higher frequencies of atrial fibrillation (41.35% vs. 12.5%, P < 0.001), chronic kidney disease (26.9% vs. 6.3%, P = 0.004), prolonged cardiopulmonary bypass (237 vs. 192 min, P = 0.016) and aortic cross-clamping times (160 vs. 124 min, P = 0.04) than survivors. Non-survivors had a significantly higher median Sequential Organ Failure Assessment (SOFA) score at ECMO initiation (13.5 vs. 9, P < 0.001) and a lower median Survival After Veno-arterial ECMO (SAVE) score (-3 vs. 3, P < 0.001) with higher SAVE classes (P < 0.001) than survivors. After 12 h of VA-ECMO support, the blood lactate level was negatively correlated with LC in survivors (r = -0.755, P < 0.001) and non-survivors (r = -0.601, P < 0.001). After 24 h, the same negative correlation was identified between survivors (r = -0.764, P < 0.001) and non-survivors (r = -0.847, P < 0.001). Blood lactate levels measured at 12 h to determine hospital mortality [>8.2 mmol/L, area under the receiver operating characteristic curve (AUROC): 0.868] and 24 h (>2.6 mmol/L, AUROC: 0.896) had the best performance, followed by LC-T12 (<21.94%, AUROC: 0.807), LC-T24 (<40.3%, AUROC: 0.839) and peak blood lactate (>14.35 mmol/L, AUROC: 0.828). The initial pre-ECMO blood lactate (>6.25 mmol/L, AUROC: 0.731) had an acceptable ability to discriminate mortality but was less than the following measurements and clearance. Kaplan-Meier curves demonstrated that LC of <21.94% at T12 h and <40.3% at T24 h was associated with decreased survival (log-rank P < 0.001). Cox proportional hazards regression analysis for mortality revealed that LC of <21.94% at T12 h had an adjusted hazard ratio (HR) of 2.73 [95% confidence interval (CI): 1.64-5.762, P < 0.001] and LC of <40.3% at T24 h had an adjusted HR of 1.98 (95% CI: 1.46-4.173, P < 0.001). The predictors of hospital mortality after PC-ECMO were the lactate level at 12 h [odds ratio (OR): 1.67, 95% CI: 1.121-2.181, P = 0.001], initial SOFA score (OR: 1.593, 95% CI: 1.15-2.73, P < 0.001), initial blood lactate (OR: 1.21, 95% CI: 1.016-1.721, P = 0.032) and atrial fibrillation (OR: 6.17, 95% CI: 2.37-57.214, P = 0.003). Bivariate models using lactate levels and clearance at the same points revealed that blood lactate levels performed better than the clearance percentage. CONCLUSIONS: Serial measurements of arterial blood lactate and LC help in obtaining early prognostic guidance in adult patients supported by VA-ECMO after cardiac surgery. Absolute lactate levels, compared with LC at the same time points, demonstrated better performance in differentiating mortality.

Validation of Prognostic Scores in Extracorporeal Life Support: A Multi-Centric Retrospective Study.

Multiple prognostic scores have been developed for both veno-arterial (VA) and veno-venous (VV) extracorporeal membrane oxygenation (ECMO), mostly in single-center cohorts. The aim of this study was to compare and validate different prediction scores in a large multicenter ECMO-population. METHODS: Data from five ECMO centers included 300 patients on VA and 329 on VV ECMO support (March 2008 to November 2016). Different prognostic scores were compared between survivors and non-survivors: APACHE II, SOFA, SAPS II in all patients; SAVE, modified SAVE and MELD-XI in VA ECMO; RESP, PRESET, ROCH and PRESERVE in VV ECMO. Model performance was compared using receiver-operating-curve analysis and assessment of model calibration. Survival was assessed at intensive care unit discharge. RESULTS: The main indication for VA ECMO was cardiogenic shock; overall survival was 51%. ICU survivors had higher Glasgow Coma Scale scores and pH, required cardiopulmonary resuscitation (CPR) less frequently, had lower lactate levels and shorter ventilation time pre-ECMO at baseline. The best discrimination between survivors and non-survivors was observed with the SAPS II score (area under the curve [AUC] of 0.73 (95% CI 0.67-0.78)). The main indication for VV ECMO was pneumonia; overall survival was 60%. Lower PaCO2, higher pH, lower lactate and lesser need for CPR were observed among survivors. The best discrimination between survivors and non-survivors was observed with the PRESET score (AUC 0.66 (95% CI 0.60-0.72)). CONCLUSION: The prognostic performance of most scores was moderate in ECMO patients. The use of such scores to decide about ECMO implementation in potential candidates should be discouraged.

Early lactate changes improve the outcome prediction for extracorporeal membrane oxygenation.

OBJECTIVES: Serial lactate (clearance) data are commonly used for risk stratification in patients receiving veno-arterial extracorporeal life support (ECLS). METHODS: We retrospectively analysed 855 patients who had undergone ECLS due to cardiac (n = 578) and non-cardiac (n = 277) aetiologies between 2002 and 2013 at National Taiwan University Hospital. Serial lactate (clearance) data were collected before ECLS and at 8, 16, 24, 48 and 72 h after ECLS. To investigate the impact of lactate (clearance) levels on 180-day survival, we performed linear mixed model and joint model analyses using the Bayesian approach. RESULTS: Among the 855 patients, 564 (65.9%) patients died within 180 days after ECLS cannulation. The joint model showed that the effect of lactate on survival was null in both the reduced model and the fully adjusted model. However, an effect of lactate clearance on survival was observed in the reduced model [estimate 0.004; 95% confidence interval (CI) 0.002-0.006] and the fully adjusted model (estimate 0.003; 95% CI 0.001-0.005). In a further secondary analysis, lactate clearance (hazard ratio 0.861; 95% CI 0.813-0.931) at 16 h after ECLS cannulation was determined to be a risk factor for mortality. According to a receiver operating characteristic curve analysis, the SAVE score combined with lactate clearance (area under curve = 0.881) showed good outcome discrimination. CONCLUSIONS: Incorporating lactate clearance at 16 h after ECLS cannulation into the SAVE system improved the predictive value for mortality in patients receiving ECLS.

ECMO Cardio-Pulmonary Resuscitation (ECPR), trends in survival from an international multicentre cohort study over 12-years.

BACKGROUND: Use of Extracorporeal Membrane Oxygenation during cardiopulmonary resuscitation (ECPR) is increasingly being deployed as an adjunct to conventional CPR. It is unknown if this has been associated with improved outcomes. AIMS: To describe trends in survival and patient demographics for ECPR patients in the international Extracorporeal Life Support Organisation (ELSO) database over the past 12 years and identify factors associated with changes in survival. METHODS: Patients greater than 16 years of age who received ECPR between January 2003 and December 2014 were extracted from the ELSO registry and were divided into three 4-year cohorts (Cohort 1: 2003-2006, Cohort 2: 2007-2010, Cohort 3: 2011-2014). Univariable analysis was performed to compare demographics and outcomes of patients across the three cohorts. Univariable and multivariable analyses were then performed to identify factors independently associated with survival. RESULTS: 1796 patients treated with ECPR were extracted from the registry, aged 50 (±18.5) years. Annual ECPR episodes increased over 10-fold, from 35 to over 400 per year. Survival to hospital discharge was 29% overall (27% cohort 1, 28% cohort 2, 30% cohort 3 (p=0.71)). Age, body weight and documented comorbidities increased over time. There was a reduction in complications associated with ECMO usage. After adjusting for confounders there was no change in the odds of survival over the time period examined. INTERPRETATION: Over the period 2003-2014, survival to hospital discharge was 29% for patients who require ECPR. Despite advances in provision of ECMO care and increasing co-morbidities of patients, there has been no change in risk-adjusted survival over time.