Association of low alanine aminotransferase values with extubation failure in adult critically ill patients: A retrospective cohort study

Abstract Background: Liberation from mechanical ventilation is a cardinal landmark during hospitalization of ventilated patients in intensive care units. Sufficient respiratory muscle strength and function are essential for successful extubation; therefore, decreased muscle mass and sarcopenia are associated with a high risk of failure. A low level of alanine aminotransferase (ALT) is a known biomarker of sarcopenia. This study was aimed to determine whether low levels of ALT are associated with increased risk of extubation failure among critically ill patients.Methods: This was a retrospective single-center cohort study of mechanically ventilated patients hospitalized in a medical intensive care unit and undergoing their first extubation. The primary outcome was extubation failure, which was defined as reintubation within seven days. Multivariable logistic regression was performed to determine whether ALT was an independent predictor of this outcome.Results: The study included 329 patients with a median age of 62.3 years (interquartile range [IQR] 48.13–71.16); 210 (63.83%) patients were at high risk for extubation failure and 83 (25.23%) failed the first extubation attempt. Low ALT values were more common among patients requiring reintubation (61.45% vs. 41.06%, P=0.002). Multivariable logistic regression analysis identified the age of 75 years or older and low ALT values as the only independent predictors of extubation failure, with adjusted odds ratio (OR) of 2.74 (95% confidence interval [CI] 1.23-6.11, p=0.01) and 2.14 (95% CI 1.16-3.96, p=0.02), respectively.Conclusions: Low ALT, an established biomarker of sarcopenia and frailty, is an independent risk factor for extubation failure among adult patients hospitalized in the medical intensive care unit. This simple laboratory parameter can be used as an effective adjunct predictor, along with other weaning parameters, and thereby facilitate the identification of high-risk patients.