Pulmonary Atelectasis

This prospective randomized clinical trial aims to evaluate the effects of different fresh gas flow rates on postoperative pulmonary aeration using lung ultrasonography in patients undergoing elective laparoscopic cholecystectomy. Patients will be randomly assigned to receive either low-flow anesthesia (0.5 L/min) or high-flow anesthesia (4 L/min) during maintenance of general anesthesia. The primary objective is to compare postoperative lung ultrasound scores and the incidence of atelectasis between the two groups.

Robotic prostate surgery is commonly performed under general anesthesia with carbon dioxide pneumoperitoneum and steep Trendelenburg positioning. These conditions may reduce lung volumes, impair respiratory mechanics, and increase the risk of atelectasis and postoperative pulmonary complications. Recruitment maneuvers combined with individualized positive end-expiratory pressure may improve intraoperative oxygenation and lung compliance; however, the optimal timing of recruitment maneuver application in robotic prostate surgery remains unclear. This prospective randomized study aims to compare the effects of recruitment maneuver timing on postoperative pulmonary complications in adult patients undergoing elective robotic prostate surgery. Participants will be randomized into two groups. In the Supine Recruitment Group, the recruitment maneuver will be performed before carbon dioxide insufflation while the patient is in the supine position, followed by individualized PEEP determination. In the Trendelenburg Recruitment Group, the recruitment maneuver will be performed after pneumoperitoneum and Trendelenburg positioning, followed by individualized PEEP determination. Patients will be evaluated for postoperative pulmonary complications up to postoperative 72 hours or until discharge, whichever occurs first.

Detecting possible atelectasis and other respiratory problems that may develop immediately after extubation via lung ultrasonography can reduce pulmonary complications by performing necessary interventions such as oxygen support, respiratory exercises, mobilization, and non-invasive mechanical ventilation applications at an early stage. In addition, although low-flow anesthesia is frequently used in daily anesthesia practice, publications showing the effects of its use in laparoscopic cholecystectomy operations on pulmonary complications are limited. On this occasion, this study can be presented as a contribution to the literature.

The purpose of this multicenter, randomized controlled trial (ULTRASVENT-2) is to evaluate the effect of different positive end-expiratory pressure (PEEP) levels on postoperative oxygenation and lung aeration in adult patients undergoing elective non-cardiac and non-thoracic surgery under general anesthesia. Moving away from traditional binary outcomes, this study utilizes a continuous functional metric, the non-invasive oxygenation index SpO2/FiO2 (S/F ratio), as the primary endpoint to precisely capture the degree of respiratory function preservation. Patients will be stratified into four distinct surgical cohorts based on the type and aggressiveness of the procedure: non-abdominal surgery, major open abdominal surgery, major laparoscopic abdominal surgery, and low-trauma laparoscopic surgery. This adaptive design aims to investigate how protective PEEP strategies interact with varying degrees of surgical trauma and intraoperative pneumoperitoneum, allowing the optimization of mechanical ventilation parameters for routine clinical practice.

The most common cardiac surgeries are myocardial revascularization and valve replacement or plastic surgery. In the postoperative period of cardiac surgeries, the incidence of pulmonary complications ranges from 30% to 50% and is associated with increased length of hospital stay and morbidity and mortality. To reduce or minimize the occurrence of these complications, respiratory physiotherapy employs positive pressure reexpansion therapies, such as continuous positive airway pressure (CPAP) and positive pressure support with positive end-expiratory pressure (PS+PEEP). The goal of this clinical trial is to compare the effects of two positive pressure therapies, CPAP versus PS+PEEP, on the incidence of pulmonary complications in patients in the postoperative period of myocardial revascularization and valve replacement or plastic surgery, with mild to moderate pulmonary dysfunction. The main question it aims to answer is: Do patients in the immediate postoperative period of myocardial revascularization or valve replacement/plastic surgery, exhibiting mild to moderate pulmonary dysfunction, experience a comparable reversal of pulmonary conditions when treated with PS+PEEP versus CPAP? Participants will undergo the following assessments: spirometry, respiratory muscle strength testing, handgrip strength testing, and electrical impedance tomography. In the immediate postoperative period, participants will be randomized into two treatment groups: • Control Group PS+PEEP - application of 4 sets of 20 repetitions with PS to provide a tidal volume equal to 10ml/kg of predicted body weight, PEEP equal to 10 cmH2O, and inspired oxygen fraction (FiO2) to achieve peripheral oxygen saturation (SpO2) between 92-94%; • Experimental Group CPAP - application of CPAP at 10 cmH2O with FiO2 to achieve SpO2 between 92-94% for 30 minutes.

Atelectasis is a common complication in patients undergoing surgery under general anesthesia, particularly in obese patients. Postoperative atelectasis could last for more than 24h and contribute to a variety of other complications, including hypoxemia and pneumonia. We plan to conduct a single-center, randomized controlled trial in patients undergoing bariatric surgery to test the hypothesis that driving pressure guided PEEP could reduce the postoperative atelectasis.