Abstract
<jats:p>INTRODUCTION: Postoperative atelectasis is a frequent complication, yet predicting which patients will develop clinically significant hypoxemia remains challenging. Lung ultrasound (LUS) enables quantitative assessment of atelectasis severity, but its prognostic value for desaturation has not been fully established. OBJECTIVE: To determine whether quantitative assessment of postoperative atelectasis severity by lung ultrasound is an independent predictor of clinically significant desaturation, defined as a decrease in peripheral oxygen saturation (SpO2) to ≤ 90 %, in a heterogeneous cohort of surgical patients. MATERIALS AND METHODS: A retrospective observational study was conducted. A simplified 2‑zone LUS protocol was used preoperatively and postoperatively to assess atelectasis severity on a 0–3 scoring scale. The primary predictor was the total postoperative LUS score; the primary outcome was desaturation (SpO2 ≤ 90 %). Prognostic value was assessed using receiver operating characteristic (ROC) analysis and multivariable logistic regression. RESULTS: A total of 450 patients undergoing elective surgery under general anesthesia with mechanical ventilation were included (300 women [66.7 %], 150 men [33.3 %]; median age 51 years, range 18–84). The LUS score demonstrated high prognostic accuracy for desaturation (area under the ROC curve, AUC 0.85); the optimal cutoff was ≥ 3 points (sensitivity 73.8 %, specificity 82.8 %). In multivariable analysis, each 1-point increase in LUS score raised the odds of desaturation 2.95-fold (odds ratio, OR 2.95; p < 0.001), with higher body mass index (BMI) as additional independent predictor. CONCLUSIONS: Quantitative assessment of postoperative atelectasis by lung ultrasound is a strong independent predictor of clinically significant desaturation. LUS monitoring enables objective risk stratification for hypoxemia and helps identify patients who may benefit from targeted respiratory interventions and closer postoperative surveillance.</jats:p>