Diaphragmatic ultrasound for extubation readiness: The role of thickening fraction

Timely extubation is essential in ICU patients, yet traditional predictors such as the rapid shallow breathing index (RSBI) have limited accuracy. Diaphragm and lung ultrasound offer promising, non-invasive alternatives for assessing extubation readiness.

We conducted a prospective observational study nested within a randomized trial in a university ICU. Adult patients undergoing a spontaneous breathing trial with planned extubation were evaluated. Diaphragmatic excursion (DE), diaphragmatic thickening fraction (DTF), and the modified lung ultrasound score (mLUS) were assessed by ultrasound at the 30th minute of the trial. The primary outcome was extubation success within 48 h.

A total of 128 patients were included; 92.2 % succeeded in extubation and 7.8 % failed. DTF was significantly higher in the success group (42.1 % ± 31.7 %) compared to the failure group (20.9 % ± 24.2 %, p = 0.042). DE and mLUS showed no significant differences between groups.

Diaphragmatic thickening fraction was significantly associated with extubation success, whereas diaphragmatic excursion and lung ultrasound scores were not. Ultrasound assessment of DTF may enhance clinical decision-making for weaning from mechanical ventilation.