Serum Total Bilirubin With Hospital Survival in Adults During Extracorporeal Membrane Oxygenation

Abstract

Background: Extracorporeal membrane oxygenation (ECMO) is widely used for refractory cardiopulmonary failure treatment. The disadvantage of ECMO is its higher risk profile and clinical resource consumption. This observation examines the role of serum total bilirubin (TBIL) as a predictor of adult patient outcomes on ECMO support.

Methods: This retrospective observation reports a single-center experience with adults on ECMO support between 2018 and 2021. Data were collected regarding demographics, ECMO details, laboratory parameters, and outcomes. We examined the elevation of TBIL to predict survival and variables associated with hyperbilirubinemia.

Results: The patients who died within 28 days had a twofold higher peak level of TBIL than those who survived [73.10 (38.60, 98.64) vs. 34.50 (24.03, 54.85); P = 0.003]. Univariate logistic regression analyses demonstrated that high TBIL was remarkably associated with an elevated risk of 28-day mortality (OR: 7.25; 95% CI: 2.31-25.49; P = 0.001) and total mortality (OR: 5.71; 95% CI: 1.82-20.66; P = 0.001). The TBIL value was 65 μmol/L as the best cut-off value, and the observation group was divided into a high TBIL subgroup (n = 21) or a low TBIL subgroup (n = 39). The demographic and clinical features did not show a difference, whereas Sequential Organ Failure Assessment (SOFA) and APACHE II scores and ALT, AST, and LAC before ECMO initiation correlated with high or low TBIL (P < 0.05). For coagulation function at the time of TBIL peak, the levels of prothrombin time (PT), activated partial thromboplastin time (APTT), prothrombin time activity (PTA), and fibrinogen (FIB) were different between the two subgroups (P < 0.05). The SOFA score was potentially associated with hyperbilirubinemia after ECMO initiation, and the prediction accuracy was 0.800.

Conclusion: Serum total bilirubin elevation appears after ECMO initiation and correlates with survival, while other markers of liver injury do not. Serum total bilirubin is an easy-to-measure biomarker to be a predictor of survival after ECMO initiation.

Keywords: extracorporeal membrane oxygenation; hyperbilirubinemia; prognosis; survival; total bilirubin.

FIGURE 1

Flow diagram of patient enrolment. ECPR, extracorporeal cardiopulmonary resuscitation.

FIGURE 2

Identification of optimal cut-off value for peak TBIL based on (A) the receiver operating curve method; (B) Chi-square test with maximum statistics; (C) logistic regression with minimum AIC; or (D) logistic regression with maximum C-index. TBIL, total bilirubin; AIC, Akaike information criterion; C-index, concordance index.

FIGURE 3

High TBIL during ECMO indicated poor primary outcome (A,B), poor secondary outcome (C–G) and abnormal coagulation function (H–K). TBIL, total bilirubin; ECMO, extracorporeal membrane oxygenation; ICU, intensive care unit; PT, prothrombin time, APTT, activated partial thromboplastin time; PTA, prothrombin time activity; FIB, fibrinogen.

FIGURE 4

Spearman correlation analysis of peak TBIL and other simultaneous clinical parameters. TBIL, total bilirubin; PT, prothrombin time, APTT, activated partial thromboplastin time; PTA, prothrombin time activity; FIB, fibrinogen; SOFA, Sequential Organ Failure Assessment.

FIGURE 5

Ranking of the potential indictors for the occurrence of high TBIL during ECMO based on the random forest algorithm. All variables were demographic features or parameters obtained before ECMO. A greater importance value suggested a closer relationship between the variable and the occurrence of high TBIL during ECMO.