ABSTRACT
Objective:To identify the feasibility of inferior vena cava variability (ΔDIVC) combined with rectus femoris atrophy fraction in predicting the outcome of weaning from invasive mechanical ventilation (IMV).Methods:From January to December 2021, the patients with the need for IMV admitted to the Affiliated Yixing Hospital of Jiangsu University were recruited into prospective case-control study. The patients who met the withdrawal criteria were treated with a 2-h spontaneous breathing trial (SBT) and then extubated immediately. Patients with stable spontaneous breathing after extubation for more than 48 h were classified as successful weaning group, and on the contrary, the other patients were classified as failed weaning group. The clinical data and withdrawal indexes of the two groups were evaluated. The correlation between ΔD IVC and rectus femoris atrophy fraction was assessed. The influencing factors of weaning outcome were observed. The diagnostic value of ΔD IVC, rectus femoris atrophy fraction and the combination of two indexes in predicting weaning success were calculated by a plotting receiver operating characteristic (ROC) curve. Results:Sixty IMV patients were included in this study, including 38 cases of successful weaning and 22 cases of failed weaning. The two groups were comparable with regard to clinical data (all P>0.05). The rectus femoris cross-sectional area in the two groups diminished gradually with the length of ICU stay ( F=3.266, 3.625, both P<0.05). The rectus femoris cross-sectional area at the first SBT was significantly lower than that on the first day of admission in both groups [the successful weaning group: (2.54±0.88) cm 2vs. (3.08±0.98) cm 2; the failed weaning group: (2.22±0.87) cm 2vs. (3.02±1.10) cm 2, both P<0.05], but there was no significant difference between the two groups (all P>0.05). Patients in the successful weaning group had higher ΔD IVC and higher rectus femoris atrophy fraction than those in the weaning failure group [ΔD IVC: (25.02±4.65)% vs. (20.30±3.16)%; rectus femoris atrophy fraction: (81.89±5.09)% vs. (72.68±8.98)%, both P<0.05]. There was a positive correlation between ΔD IVC and rectus femoris atrophy fraction ( r=0.346, P=0.007). Both ΔD IVC and rectus femoris atrophy fraction played an important role in affecting weaning success (all P<0.05). The area under the curve (AUC) of ΔD IVC combined with rectus femoris atrophy fraction for predicting the weaning success was 0.880, which was significantly higher than that of ΔD IVC (AUC=0.791) or rectus femoris atrophy fraction (AUC=0.826). Conclusions:The predictive value of ΔD IVC combined with rectus femoris atrophy fraction for successful weaning of patients undergoing IMV is relatively accurate, which can be used to guide weaning.
ABSTRACT
Objective To evaluate the diaphragm movement index of mechanical ventilation weaning patients by ultrosonography, and to explore its value for weaning. Methods Forty patients undergoing invasive mechanical ventilation for at least 48 hours admitted to emergency intensive care unit (EICU) of Hunan Provincial People's Hospital from September 2017 to February 2018 were enrolled. Low level pressure support ventilation (PSV) was used for spontaneous breathing test (SBT), and bedside M-mode ultrasonography was used to assess the diaphragm movement index of the patient within 1 hour of SBT, including the excursion of the diaphragm, diaphragmatic-rapid shallow breathing index (D-RSBI). The rapid shallow breathing index (RSBI) was measured by ventilator. The patients who met the clinical weaning criteria were weaned. According to the success or failure of the weaning, the patients were divided into the successful weaning group and the failure weaning group. The receiver operating characteristic (ROC) curve was used to evaluate the predictive value of each indicator to the failure of the weaning. Results A total of 40 patients were enrolled in the final analysis, including 28 patients in the successful weaning group and 12 patients in the failure weaning group. The excursion of the diaphragm in the failure weaning group was significantly less than that in the successful weaning group (mm: 9.56±2.13 vs. 13.66±4.10, P < 0.01), and the D-RSBI and RSBI were significantly higher than those in the successful weaning group [D-RSBI (times·min-1·mm-1): 2.06±0.68 vs. 1.44±0.66, RSBI (times·min-1·L-1): 61.70±25.00 vs. 44.91±14.51, both P < 0.05]. The area under the ROC curve (AUC) of diaphragm displacement, D-RSBI, and RSBI was 0.830, 0.851 and 0.711, respectively, and the predicted value of diaphragm excursion and D-RSBI was higher. When the optimal critical value of diaphragmatic excursion was 11.15 mm, the sensitivity of predicting weaning failure was 83.3%, the specificity was 71.4%; when the optimal critical value of D-RSBI was 1.42 times·min-1·mm-1, the sensitivity of predicting the failure of weaning was 91.7%, and the specificity was 82.1%. Conclusion Diaphragm excursion and D-RSBI of the diaphragmatic ultrosonography index could accurately predict the failure of the weaning, which was superior to the traditional RSBI in guiding weaning.