Impact of Obesity on Neurologic Outcomes in Patients Undergoing Venoarterial Extracorporeal Membrane Oxygenation.

OBJECTIVE

To investigate the impact of body mass index (BMI) on neurologic outcomes in venoarterial extracorporeal membrane oxygenation (VA-ECMO)

DESIGN

Retrospective observational study

SETTING

Single center

PARTICIPANTS

Adults INTERVENTIONS: VA-ECMO MEASUREMENTS AND MAIN

RESULTS

Obese (BMI≥30 kg/m²) and nonobese (BMI<30 kg/m²) patient groups were compared. The primary outcome was neurologic outcomes at discharge, with "good" (modified Rankin Scale [mRS] score 0-3) and "poor" (mRS score 4-6). Secondary outcomes were acute brain injury (ABI) and mortality. Multivariable Cox regression was used to investigate risk factors for poor neurologic outcomes, adjusting for demographics, comorbidities, pre-ECMO PaO2, pericannulation PaCO2 change, lactate, central cannulation, and ABI. Spline regression was performed to assess the relationship between BMI and neurologic outcomes. The Kaplan-Meier estimator was used to evaluate 90-day survival. Among 214 patients (median age 58 years, 63% male), 104 were obese (median BMI, 35.4; interquartile range [IQR], 32.2-39.9), and 110 were nonobese (median BMI, 25; IQR, 23.2-27.5). Obese patients had higher rates of poor neurologic outcomes (91% vs 69%; p < 0.001) and ABI (50% vs 36%; p = 0.04). The Cox model identified associations of obesity (adjusted hazard ratio [aHR], 1.63, 95% confidence interval [CI], 1.15-2.31; p = 0.006) and ABI (aHR, 1.41; 95% CI, 1.01-1.96; p = 0.04) were associated with increased hazards of poor neurologic outcomes. Spline regression showed a fairly linear relationship between BMI and poor neurologic outcomes. Kaplan-Meier analysis suggested that the obese patients had a lower 90-day survival probability (p < 0.0001, log-rank test).

CONCLUSIONS

Obesity increased the hazard of poor neurologic outcomes, ABI, and mortality in this cohort of patients undergoing VA-ECMO, highlighting the importance of standardized neuromonitoring and early ABI detection, especially for obese patients. Further research is needed to explore the impact of obesity on neurologic outcomes independent of ABI.