RESUMO
OBJECTIVE: To explore the monitoring value of left ventricular functional parameters obtained by bedside ultrasound combined with clinically relevant indicators in patients with veno-arterial extracorporeal membrane oxygenation (VA-ECMO). METHODS: A retrospective study was conducted. A total of 24 patients receiving VA-ECMO adjuvant support in Renmin Hospital of Wuhan University from June 2018 to January 2020 were selected. The bedside ultrasound was performed on the first day of ECMO support, the day before weaning, the clinical indicators before weaning were obtained. The differences in clinical indicators and the left ventricular functional parameters between the two groups of whether weaning successfully were compared; univariate Logistic regression analysis was used to screen out the related factors affecting weaning. RESULTS: Sixteen patients were successful weaned and 8 patients failed. Compared with the weaning failure group, patients in the weaning success group required less continuous renal replacement therapy (CRRT, cases: 4 vs. 6, P < 0.05), mean arterial pressure (MAP) before weaning was higher [mmHg (1 mmHg = 0.133 kPa): 84.64±9.55 vs. 62.30±8.79, P < 0.05], and the pulse oxygen saturation (SpO2) was also higher (0.966±0.670 vs. 0.866±0.061, P < 0.05), while vasoactive-inotropic score (VIS), serum creatinine (SCr) and serum lactic acid (Lac) were lower [VIS score: 7.27±1.42 vs. 16.93±8.52, SCr (µmol/L): 123.60±83.64 vs. 213.10±117.39, Lac (mmol/L): 1.94±0.91 vs. 5.62±5.48, all P < 0.05]. Univariate Logistic regression analysis showed that the MAP, VIS, SCr, Lac, SpO2 before weaning were the related factors affecting weaning [odds ratio (OR) were 0.306, -0.740, -0.011, -0.632, -4.069; 95% confidence interval (95%CI) were 1.065-1.732, 0.235-0.899, 0.979-0.999, 0.285-0.992 and 0.001-0.208; P values were 0.014, 0.022, 0.038, 0.047, 0.002]. In the weaning success group, left ventricular ejection fraction (LVEF), velocity of mitralannulus in systolic (LatSa), maximum flow velocity of aortic valve (AV-Vmax), velocity-time integral (VTI), left ventricular global longitudinal strain (LVGLS), left ventricular global longitudinal strain rate (LVGLSr) were all increased on the day before ECMO weaning compared with the first day of ECMO support [LVEF: 0.40±0.05 vs. 0.28±0.07, LatSa (cm/s): 6.81±0.91 vs. 4.62±1.02, AV-Vmax (cm/s): 104.81±33.98 vs. 64.44±16.85, VTI (cm): 14.56±3.11 vs. 7.96±1.98, LVGLS: (-8.95±2.59)% vs. (-5.26±1.28)%, LVGLSr (1/s): -0.48±0.11 vs. -0.29±0.09], whereas the ECMO flow was significantly reduced (L/min: 1.46±0.47 vs. 2.64±0.31), the differences were statistically significant (all P < 0.05). There was no significant difference in left ventricular functional parameters between the first day of ECMO support and the day before ECMO weaning in the weaning failure group. Compared with the weaning failure group, the weaning success group had higher LVEF, LatSa, AV-Vmax, VTI, LVGLS, LVGLSr on the day before ECMO weaning [LVEF: 0.40±0.05 vs. 0.26±0.07, LatSa (cm/s): 6.81±0.91 vs. 4.31±1.03, AV-Vmax (cm/s): 104.81±33.98 vs. 67.67±18.46, VTI (cm): 14.56±3.11 vs. 7.75±2.77, LVGLS: (-8.95±2.59)% vs. (-4.81±1.81)%, LVGLSr (1/s): -0.48±0.11 vs. -0.30±0.10, all P < 0.05] and lower ECMO flow (L/min: 1.46±0.47 vs. 2.20±0.62, P < 0.05). CONCLUSIONS: Bedside echocardiographic left ventricular function parameters (LVEF, LatSa, AV-Vmax, VTI, LVGLS, LVGLSr) combined with clinical indicators (MAP, VIS, SCr, Lac, SpO2) were helpful to evaluate the therapeutic effect of patients receiving VA-ECMO support and can provide important guiding value in the selection of VA-ECMO weaning timing and the judgment of prognosis.