LAUSR

OBJECTIVE To investigate the clinical predictive value of combined diaphragmatic and pulmonary ultrasound in acute respiratory failure patients with mechanical ventilation (MV). METHODS From January 2020 to August 2022, patients with acute respiratory failure admitted to People's Hospital Affiliated to Ningbo University who underwent invasive MV and weaning were enrolled. After meeting the weaning standards, spontaneous breathing test (SBT) was performed using T-tube. Right diaphragm excursion (DE), diaphragm thickness and lung ultrasound score (LUS) were collected by bedside ultrasound at 30 minutes of SBT, and rapid shallow respiratory index (RSBI), diaphragmatic-shallow respiratory index (D-RSBI) and diaphragmatic thickening rate (DTF) were calculated. According to the weaning outcome, the patients were divided into successful weaning group and failed weaning group. The clinical data of all patients were collected, and the ultrasound parameters and clinical indicators were compared between the two groups. Receiver operator characteristic curve (ROC curve) was used to evaluate the predictive value of D-RSBI, RSBI, DE combined with LUS score and DTF combined with LUS score for weaning failure patients. RESULTS A total of 77 patients were enrolled, including 54 cases in the successful weaning group and 23 cases in the failed weaning group. The right DE and DTF of patients in successful weaning group were significantly higher than those in failed weaning group [right DE (cm): 1.28±0.39 vs. 0.88±0.41, DTF: (32.64±18.27)% vs. (26.43±15.23)%, both P < 0.05], LUS score, RSBI and D-RSBI were significantly lower than those in failed weaning group [LUS score: 11.45±2.67 vs. 18.33±3.62, RSBI (times×min-1×L-1): 72.21±19.67 vs. 107.35±21.32, D-RSBI (times×min-1×mm-1): 0.97±0.19 vs. 1.78±0.59, all P < 0.05]. ROC curve analysis showed that when the cut-off value of D-RSBI and RSBI was 1.41 times×min-1×mm-1 and 56.46 times×min-1×L-1, the area under the ROC curve (AUC) for predicting weaning failure was 0.972 and 0.988; and the sensitivity was 95.7% and 87.0%, respectively; the specificity was 81.0% and 100.0%, respectively. The AUC of right DE combined with LUS score and DTF combined with LUS score in predicting weaning failure were 0.974 and 0.985, respectively, with a sensitivity of 91.3% and a specificity of 98.1%. CONCLUSIONS Combined assessment of diaphragmatic and pulmonary ultrasound is a good parameter to effectively predict weaning failure in MV patients, which has high application value in guiding weaning in MV patients, and is worthy of clinical application.