Transesophageal lung ultrasound score is associated with arterial oxygenation and clinical outcomes in mechanically ventilated critically ill patients.

BACKGROUND: Transesophageal lung ultrasound (TELUS) has emerged as a novel modality that utilizes the esophageal acoustic window to obtain high-resolution images of posterior lung regions. However, its quantitative assessment and clinical relevance remain poorly explored. This study aimed to evaluate the feasibility and prognostic value of TELUS in critically ill patients, focusing on its association with arterial oxygenation and 28-day mortality. METHODS: In this prospective observational study, TELUS was performed in 69 mechanically ventilated ICU patients. TELUS imaging was acquired at three esophageal levels corresponding to posterior apical, mid, and basal lung regions. A semi-quantitative TELUS score was derived and its correlation with clinical variables was analyzed. Univariate and multivariate logistic regression analyses were employed to identify predictors of 28-day mortality. Receiver operating characteristic (ROC) analysis was used to assess the predictive performance of TELUS for mortality and severe hypoxemia (PaO₂/FiO₂ ≤ 100). RESULTS: Non-survivors had significantly higher TELUS scores compared to survivors (median 5 [IQR 4-6] vs. 4 [3-5], P = 0.001). Regional TELUS scores at the upper-aortic arch level and mid-esophageal level were elevated in non-survivors (P = 0.018 and P = 0.004, respectively). TELUS scores showed a significantly negative correlation with the PaO₂/FiO₂ ratio (r = -0.51, P < 0.0001), and positive correlations with PEEP (r = 0.32, P = 0.007) and SOFA scores (r = 0.26, P = 0.032). Multivariate analysis identified both SOFA (OR 1.31, 95% CI 1.08-1.63, P = 0.009) and TELUS scores (OR 1.72, 95% CI 1.08-2.96, P = 0.030) as independent predictors of 28-day mortality. ROC analysis showed that a TELUS score ≥ 4 predicted 28-day mortality and severe hypoxemia (PaO₂/FiO₂ ≤ 100), yielding areas under the ROC (AUCs) of 0.74 and 0.72, with high sensitivity (89% and 100%, respectively) and negative predictive values (92% and 100%, respectively.) CONCLUSION: TELUS is a feasible novel technique that provides a reliable assessment of posterior lung aeration in critically ill patients. TELUS scoring correlates with impaired oxygenation and is independently associated with 28-day mortality. These findings highlight the prognostic value of TELUS and support its potential integration into transesophageal cardiopulmonary ultrasound protocols.