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

Background: Liberation from mechanical ventilation is a cardinal landmark during hospi-talization of ventilated patients. Decreased muscle mass and sarcopenia are associated with a high risk of extubation failure. A low level of alanine aminotransferase (ALT) is a known biomarker of sarcopenia. This study 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 undergoing their first extubation. The study’s outcome was extubation failure within 48 h and 7 days. Multivariable logistic and Cox regression were performed to determine whether ALT was an independent predictor of these out-comes. Results: The study included 329 patients with a median age of 62.4 years (IQR 48.1–71.2); 210 (63.8%) patients were at high risk for extubation failure. 66 (20.1%) and 83 (25.2%) failed the extubation attempt after 48 h and 7 days, respectively. Low ALT values were more common among patients requiring reintubation (80.3–61.5% vs. 58.6–58.9%, p < 0.002). Multivariable logistic regression analysis identified ALT as an independent predictor of extubation failure at 48 h and 7 days. ALT ≤ 21 IU/L had an adjusted hazard ratio (HR) of 2.41 (95% CI 1.31–4.42, p < 0.001) for extubation failure at 48 h and ALT ≤ 16 IU/L had adjusted HR of 1.94 (95% CI 1.25–3.02, p < 0.001) for failure after 7 days. Conclusions: Low ALT, an established biomarker of sarcopenia and frailty, is an independent risk factor for extubation failure among hospitalized patients. This simple laboratory pa-rameter can be used as an effective adjunct predictor, along with other weaning parameters, and thereby facilitate the identification of high-risk patients.