[Pulse pressure loss after extracorporeal cardiopulmonary resuscitation is an independent predictor of ECMO weaning failure].

Objective: To analyze the predictors of successful weaning off extracorporeal membrane oxygenation (ECMO) after extracorporeal cardiopulmonary resuscitation (ECPR).

Methods: The clinical data of 56 patients with cardiac arrest who underwent ECPR in Hunan Provincial People's Hospital (the First Affiliated Hospital of Hunan Normal University) from July 2018 to September 2022 were retrospectively analyzed. According to whether ECMO was successfully weaning off, patients were divided into the successful weaning off group and the failed weaning off group. The basic data, duration of conventional cardiopulmonary resuscitation (CCPR, the time from cardiopulmonary resuscitation to ECMO), duration of ECMO, pulse pressure loss, complications, and the use of distal perfusion tube and intra-aortic balloon pump (IABP) were compared between the two groups. Univariate and multivariate Logistic regression analyses were performed to identify the risk factors for weaning failure of ECMO.

Results: Twenty-three patients (41.07%) were successfully weaned from ECMO. Compared with the successful weaning off group, patients in the failed weaning off group were older (years old: 46.7±15.6 vs. 37.8±16.8, P < 0.05), higher incidence of pulse pressure loss and ECMO complications [81.8% (27/33) vs. 21.7% (5/23), 84.8% (28/33) vs. 39.1% (9/23), both P < 0.01], and longer CCPR time (minutes: 72.3±19.5 vs. 54.4±24.6, P < 0.01), shorter duration of ECMO support (hours: 87.3±81.1 vs. 147.7±50.8, P < 0.01), and worse improvement in arterial blood pH and lactic acid (Lac) levels after ECPR support [pH: 7.1±0.1 vs. 7.3±0.1, Lac (mmol/L): 12.6±2.4 vs. 8.9±2.1, both P < 0.01]. There were no significant differences in the utilization rate of distal perfusion tube and IABP between the two groups. Univariate Logistic regression analysis showed that the factors affecting the weaning off ECMO of ECPR patients were pulse pressure loss, ECMO complications, arterial blood pH and Lac after installation [pulse pressure loss: odds ratio (OR) = 3.37, 95% confidence interval (95%CI) was 1.39-8.17, P = 0.007; ECMO complications: OR = 2.88, 95%CI was 1.11-7.45, P = 0.030; pH after installation: OR = 0.01, 95%CI was 0.00-0.16, P = 0.002; Lac after installation: OR = 1.21, 95%CI was 1.06-1.37, P = 0.003]. After adjusting for the effects of age, gender, ECMO complications, arterial blood pH and Lac after installation, and CCPR time, showed that pulse pressure loss was an independent predictor of weaning failure in ECPR patients (OR = 1.27, 95%CI was 1.01-1.61, P = 0.049).

Conclusions: Early loss of pulse pressure after ECPR is an independent predictor of failed weaning off ECMO in ECPR patients. Strengthening hemodynamic monitoring and management after ECPR is very important for the successful weaning off ECMO in ECPR.