Effect of Ultrasound-assisted Lung Recruitment Maneuver on Preventing Perioperative Atelectasis

This study is based on the hypothesis that recruitment maneuver reduces perioperative atelectasis and associated complications, and lung ultrasonography can be used to detect this. Patients aged 1 to 14 years with an ASA physical status classification of 1 to 3 and undergoing surgical procedures with a minimum duration of 2 hours will be included in the study. Patients with an ASA physical status classification of 4, including those with defined pulmonary diseases (e.g., asthma requiring medication and having had two emergency visits in the past year), prematurity ( \<36 weeks gestation / bronchopulmonary dysplasia), cystic fibrosis, diagnosed syndromic conditions, congenital cardiac diseases, abnormal chest X-rays, chest wall deformities, or a history of previous thoracic surgery, as well as those undergoing laparoscopic surgery, will be excluded from the study. All patients will be premedicated with midazolam (0.05-1 mg/kg) if intravenous access is established, prior to transfer to the operating room. Upon arrival, standard monitoring will be initiated, including SpO2, ECG, and non-invasive blood pressure measurements. Following preoxygenation with 100% oxygen, induction will be performed using thiopental 5 mg/kg or propofol 2 mg/kg, fentanyl 2 mcg/kg, and rocuronium 0.6 mg/kg. After tracheal intubation, mechanical ventilation will be configured in pressure-controlled mode with a tidal volume of 8 ml/kg, PEEP of 5 cmH2O, FIO2 of 40%, and a respiratory rate adjusted to maintain ETCO2 within the range of 35-45 mmHg. Anesthesia maintenance will be achieved with sevoflurane and oxygen. During emergence, sugammadex 2 mg/kg will be administered as a neuromuscular reversal agent. The Aldrete scoring system will be employed for assessing patient readiness for transfer to the recovery unit. GROUP 1: PEEP will be set at 5 cmH2O, and no recruitment maneuver will be performed. GROUP 2: PEEP will be set at 5 cmH2O. Prior to extubation, a recruitment maneuver will be condu