Can ultrasound of the diaphragm predict if a neurocritical patient on mechanical ventilation will breathe on their own?

For neurocritical patients on mechanical ventilation, doctors need reliable ways to predict whether they can breathe on their own before removing the breathing tube. Diaphragm ultrasound is a non-invasive tool that measures diaphragm movement and thickness. Research suggests that combining diaphragm ultrasound with a breathing index called the Diaphragmatic Rapid Shallow Breathing Index (D-RSBI) can help predict weaning success in these patients.

What the research says

A 2026 study of 128 neurocritical patients found that those who successfully weaned off mechanical ventilation had higher diaphragm excursion (DE) and diaphragm thickening fraction (DTF) on ultrasound, and lower D-RSBI scores, compared to those who failed weaning ⁶¹⁰. The differences were statistically significant, meaning the measurements were clearly different between the two groups ⁶¹⁰. Another 2023 study in a neurointensive care unit found that ultrasound-based diaphragm function, including excursion and thickness fraction, helped predict extubation failure, though it was not the only factor ¹¹. While these results are promising, the 2026 study notes that the combined approach needs external validation in larger studies before it can be widely used in clinical practice ⁶¹⁰.

What to ask your doctor

• Could diaphragm ultrasound be used to assess my family member's readiness to breathe on their own?
• What is the Diaphragmatic Rapid Shallow Breathing Index (D-RSBI) and how is it measured?
• How do diaphragm ultrasound results compare to other weaning predictors like the traditional rapid shallow breathing index?
• Are there any risks or limitations to using diaphragm ultrasound for this purpose?
• Is this technique routinely used in this hospital's neurointensive care unit?