Postoperative Atelectasis

Pneumoperitoneum and Trendelenburg positioning during laparoscopic surgery promote atelectasis development, which has been reported in up to 90% of patients under general anesthesia and increases the risk of postoperative pulmonary complications. High-flow nasal cannula (HFNC) oxygen therapy may reduce post-extubation atelectasis through alveolar recruitment. This prospective observational cohort study aims to evaluate the role of HFNC in postoperative atelectasis monitored by lung ultrasonography (LUS) in patients undergoing elective laparoscopic surgery.

This single-center randomized controlled trial will evaluate whether real-time visual feedback from electrical impedance tomography (EIT) improves the immediate distribution of lung ventilation during incentive spirometry in adults with postoperative atelectasis. Approximately 60 participants will be randomized 1:1 to receive either EIT-guided visual feedback or standardized verbal guidance during one session of 30 incentive-spirometry breaths. The primary outcome is the change in dorsal ventilation fraction from before training to 5 minutes after training. Secondary outcomes include inspiratory capacity, ventilation homogeneity, dependent silent spaces, end-expiratory lung impedance, oxygenation, in-hospital intubation or reintubation, and intervention-related adverse events.

Atelectasis frequently develops during and after general anesthesia due to factors such as anesthesia-induced diaphragmatic dysfunction, reduced functional residual capacity, altered ventilation-perfusion matching, and surgical positioning. The development of atelectasis has been associated with postoperative hypoxemia and other pulmonary complications. Lung ultrasound (LUS) has emerged as a reliable, radiation-free bedside imaging modality for the detection and monitoring of atelectasis. LUS allows assessment of lung aeration through standardized ultrasound patterns and scoring systems, enabling dynamic evaluation in the perioperative period. This is a prospective, observational cohort study designed to compare the incidence and severity of atelectasis in patients undergoing surgery in the supine position versus the prone position under general anesthesia. Adult patients undergoing elective surgical procedures will be enrolled. No experimental intervention will be applied, and all anesthetic and surgical management will follow routine clinical practice. Lung ultrasound examinations will be performed at predefined time points after induction of anesthesia and before extubation. A standardized lung ultrasound protocol and scoring system will be used to assess lung aeration loss and detect the presence of atelectasis. The primary outcome of the study is the difference in atelectasis detected by lung ultrasound between supine and prone surgical positions. The secondary outcome is the change in lung ultrasound scores over time. This study aims to clarify the effects of supine and prone positions on perioperative atelectasis and to support the clinical use of lung ultrasound as a noninvasive monitoring tool in perioperative and anesthetic practice..

Patients with obstructive sleep apnea syndrome are at higher risk for respiratory complications after surgery. Oxygen depletion and respiratory distress are common in patients with obstructive sleep apnea syndrome. In this study, the effectiveness of the recruitment maneuver applied in the postoperative period will be investigated via lung ultrasound. Recruitment is a technique performed to improve the oxygen levels of patients. Patients diagnosed with obstructive sleep apnea syndrome between the ages of 18-65 will be included in the study and anesthesia and surgical procedures will be followed. The aim of the study is to compare the pulmonary complication rates between patients who underwent recruitment and those who did not, and to examine the effects of factors such as age and gender on these complications via lung ultrasound.