Predictive value of the modified ROX index for extubation failure in mechanically ventilated patients

Clinicians use several measures to determine whether patients will tolerate liberation from mechanical ventilation. This study aimed to evaluate the predictive value of the modified ROX index (mROX) for extubation failure. In addition, we sought to find its role in guiding personalized post-extubation non-invasive respiratory support.

Patients who received mechanical ventilation and underwent planned extubation between May 2015 and December 2021 in medical intensive care unit were included. The primary outcome was extubation failure, defined as reintubation or death within seven days of extubation. The mROX, calculated as the ratio of partial arterial oxygen pressure to fraction of inspired oxygen (PaO2/FiO2) divided by the respiratory rate, was used to predict extubation failure.

Of the 606 patients, 160 (26.4%) experienced extubation failure. An mROX value below 11.12 was identified as an independent predictor of extubation failure, with an area under the receiver operating characteristic curve of 0.743, demonstrating greater accuracy than traditional indices. The prophylactic application of non-invasive ventilation or high-flow nasal oxygen was associated with a lower risk of extubation failure in the moderate-risk group (11.12 ≤ mROX < 17.55), with an adjusted odds ratio of 0.43 (95% confidence interval, 0.20-0.91); however, this association was not significant in the high-risk (mROX < 11.12) or low-risk (mROX ≥ 17.55) groups.

The mROX is a reliable and clinically useful method for predicting extubation failure. It facilitates improved stratification of extubation risk, allows for more tailored post-extubation non-invasive respiratory support, and may enhance clinical outcomes during the critical processes of ventilator liberation and extubation.