Effectiveness of ultrasound parasternal intercostal muscle thickness fraction and diaphragmatic thickness fraction on successful weaning from mechanical ventilation

Background Weaning from mechanical ventilation (MV) may constitute up to 50% of the whole time of MV for a patient in intensive care. Aim To study the effectiveness of ultrasound measurements of diaphragmatic and parasternal intercostal muscle fraction thickness in predicting successful weaning from MV. Patients and methods This prospective controlled randomized study was carried out on 150 cases who had been admitted to the intensive care unit and placed on MV for more than 48 h. They were randomly divided into three groups: control groups, where patients were extubated according to conventional criteria, diaphragmatic group, where patients were extubated according to conventional and diaphragmatic thickness fraction (DTF) greater than 28% and parasternal group, where parasternal intercostal thickness fraction (PTF) was added as an additional extubation parameter. Criteria of successful spontaneous breathing trial, DTF, PTF, and incidence of reintubation were recorded. Results The hypoxic index showed no group differences initially (P = 0.560) or after 30 min (P = 0.717) but decreased in all groups (P < 0.001) and it did not differ according to the age and sex. The rate of respiration and rapid shallow breathing index increased significantly in all groups (P < 0.001). Diaphragmatic thickness varied significantly (P ≤ 0.030), and parasternal thickness changed within groups (P < 0.001). Reintubation rates were higher in the Control group (40%) compared with the Diaphragmatic (20%) and Parasternal groups (12%) (P = 0.003). Conclusion Ultrasound assessment of diaphragmatic (DTF) and PTF aids in predicting weaning success. DTF (cutoff 40%) showed high specificity (95.6%) and positive predictive value (80%), while PTF (cutoff >8.5%) effectively predicted reintubation (area under the curve = 0.967). Combining DTF and PTF reduced reintubation rates and improved weaning outcomes. These tools enhance decision-making in diaphragmatic dysfunction or high respiratory workload, benefiting mechanically ventilated patients.