Predictive value of diaphragmatic thickening fraction combined with MRC score for the outcome of weaning from mechanical ventilation in ICU-acquired weakness patients

Abstract

To explore the predictive value of diaphragmatic thickening fraction (DTF) combined with Medical Research Council-score (MRC score) on the outcome of weaning from mechanical ventilation in ICU-acquired weakness (ICU-AW) patients. A retrospective case-control study was conducted. The clinical data of mechanically ventilated patients with an MRC score of less than 48 admitted to the department of critical care medicine of the First Affiliated Hospital of Wannan Medical College from January 2022 to March 2023 were collected, including general information, ultrasound indicators, MRC scores, main clinical outcomes, and weaning outcomes. Patients were divided into successful weaning group and failed weaning group according to whether the patient could maintain effective autonomous breathing for at least 48 hours without using an invasive or non-invasive ventilator. The clinical data of the two groups were compared. Receiver operator characteristic curve (ROC curve) was plotted to analyze the predictive value of DTF and MRC score alone or in combination for successful weaning of patients. A total of 87 patients were enrolled, of which 58 were successful weaning and 29 were failed weaning. There were no statistically significant differences in general data such as gender, age, underlying disease, heart rate (HR), mean arterial pressure (MAP), pH value, blood lactic acid (Lac), oxygenation index (PaO2/FiO2), and severity scores between the two groups. Compared with the failed weaning group, the DTF and MRC scores of patients in the successful weaning group were significantly increased [DTF: (26.02±2.68)% vs. (22.79±5.40)%, MRC score: 38.90±2.78 vs. 33.24±3.78, both P < 0.05]. The duration of mechanical ventilation and the length of ICU stay of patients in the successful weaning group were significantly shorter than those in the failed weaning group [duration of mechanical ventilation (hours): 102.21±32.60 vs. 113.14±41.34, length of ICU stay (days): 6.48±2.18 vs. 10.11±4.01, both P < 0.05], and the re-intubation rate and ICU hospitalization cost were significantly lowered [re-intubation rate: 6.90% (4/58) vs. 27.59% (8/29), ICU hospitalization cost (10 000 RMB): 4.99±0.87 vs. 7.85±2.45, both P < 0.05]. ROC curve analysis showed that the area under the ROC curve (AUC) of DTF and MRC score for predicting successful weaning in ICU-AW mechanical ventilation patients was 0.839 [95% confidence interval (95%CI) was 0.746-0.931] and 0.799 (95%CI was 0.701-0.899), respectively. Using DTF ≥ 25.01% as the optimal cut-off value to predict successful weaning, the sensitivity was 82.76%, and the specificity was 72.41%. Predicting successful weaning based on an optimal cut-off value of MRC score of ≥ 35.50 had a sensitivity of 79.31% and a specificity of 70.69%. Based on the DTF ≥ 25.01% combined with MRC score ≥ 35.50, it was predicted that the weaning would be successful, with an AUC of 0.887 (95%CI was 0.812-0.962), sensitivity increased to 89.70%, and specificity increased to 79.30%. The DTF and MRC score have good guiding value for the selection of weaning timing and predicting the weaning outcomes in ICU-AW patients. Compared with independent DTF and MRC score, the combination of DTF and MRC score improves the predictive value of successful weaning in ICU-AW patients.