Postoperative Hypoxemia

Postoperative hypoxemia is a common complication in the postanesthesia care unit (PACU). Patients who breathe through the mouth after tracheal extubation may receive limited benefit from standard nasal cannula oxygen therapy, because the nasal cavity functions as an ineffective dead space during mouth breathing. Clinical observations suggest that placing the prongs of a nasal cannula inside the mouth (transoral oxygen delivery) rapidly improves oxygenation in these patients. However, no randomized controlled trial has formally verified this effect. This single-center, randomized, controlled, crossover trial will enroll 64 adult patients identified as persistent mouth breathers after extubation in the PACU following elective thoracic or abdominal surgery under general anesthesia. Each participant will receive, in a randomized sequence, both standard nasal cannula oxygen delivery (4 L/min for 10 minutes) and transoral nasal cannula oxygen delivery (4 L/min for 10 minutes), separated by a 5-minute washout period, so that each participant serves as his or her own control. The primary outcome is the incidence of hypoxemia (peripheral oxygen saturation \[SpO2\] \<90% sustained for at least 10 seconds, or oxygenation index \[PaO2/FiO2 ratio\] \<300 mmHg) during each oxygen delivery period. Secondary outcomes include the incidence of SpO2 \<92%, time to achieve SpO2 \>=95%, oxygenation index measured by arterial blood gas analysis, need for escalation of oxygen therapy, vital signs, patient comfort and adverse effects, PACU length of stay, and respiratory complications within 24 hours after surgery. The results are expected to provide high-level evidence for optimizing oxygen therapy strategies for mouth-breathing patients in the PACU.

Using prospective real-world data, this study aims to determine whether the lateral decubitus position reduces the incidence of post-procedure hypoxemia in patients undergoing painless gastroscopy/colonoscopy, thereby providing a simple, non-invasive, and low-cost optimization strategy for clinical practice.

This prospective, randomized controlled study aims to investigate whether transnasal microstream end-tidal carbon dioxide (EtCO₂) monitoring in the post-anesthesia care unit (PACU) reduces the incidence of postoperative hypoxemia in elderly patients (65-80 years, ASA I-III, BMI 18-30 kg/m²) undergoing elective laparoscopic surgery under general anesthesia with endotracheal intubation. A total of 324 patients will be randomized 1:1 to either the control group (standard SpO₂ monitoring and clinical observation with oxygen delivery at 2 L/min via sampling line) or the experimental group (same oxygen delivery plus continuous real-time transnasal microstream EtCO₂ monitoring). The primary outcome is the incidence of hypoxemia (SpO₂ \< 90% for \>15 seconds) after extubation in the PACU. Secondary outcomes include severe hypoxemia (SpO₂ \< 85%), lowest SpO₂ during PACU stay, vital signs at specified time points, PACU length of stay, and other adverse events. Statistical analysis will use chi-square or Fisher's exact test for the primary outcome, with a sample size calculated to detect a reduction in hypoxemia from 33% (control) to 18% (experimental group) (α=0.05, power=80%, plus 20% dropout).

Through a multicenter, three-arm randomized controlled trial design, this study aimed to compare the effects of three positioning strategies-side-lying with elevated head position, supine with elevated head position, and standard side-lying position-on the incidence of hypoxemia during the recovery phase in patients undergoing painless gastroscopy and colonoscopy. The goal was to provide clinicians with a simple, non-invasive, and cost-effective optimization strategy.

This prospective observational study aims to evaluate the association between postoperative oxygenation, assessed by the SpO₂/FiO₂ ratio, and body mass index (BMI), STOP-BANG score, and postoperative analgesic methods in patients undergoing elective laparoscopic cholecystectomy in the reverse Trendelenburg position. Postoperative SpO₂ and FiO₂ values will be recorded within the first postoperative hour, and the SpO₂/FiO₂ ratio will be calculated. Analgesic techniques applied as part of routine clinical practice will be documented. The study does not involve any additional intervention beyond standard care. The findings are expected to contribute to a better understanding of factors associated with early postoperative oxygenation and hypoxemia risk.

Early postoperative hypoxemia is a frequent complication after elective ear, nose, and throat (ENT) surgery and may adversely affect recovery in the post-anesthesia care unit (PACU). Simple and non-invasive preoperative tools to identify patients at risk for early postoperative hypoxemia are limited. The ROX index, calculated using oxygen saturation, fraction of inspired oxygen, and respiratory rate, is an easily applicable bedside parameter that has been shown to predict respiratory deterioration in various clinical settings. However, its predictive value in the preoperative period for patients undergoing elective ENT surgery has not been well established. This prospective observational study aims to evaluate the association between the preoperative ROX index measured on room air and early postoperative hypoxemia in adult patients undergoing elective septorhinoplasty or endoscopic sinus surgery under general anesthesia. Early postoperative hypoxemia will be defined as oxygen saturation below 92% or the need for supplemental oxygen at a flow rate of 4 L/min or higher within the first 30 minutes after PACU admission. The predictive performance of the ROX index will be assessed using receiver operating characteristic (ROC) analysis.

The goal of this clinical trial is to learn which positioning strategy works better to prevent postoperative hypoxemia in surgical patients: semirecumbent positioning or lateral positioning. It will also learn about the safety and effectiveness of these two positioning approaches. The main questions it aims to answer are: Does semirecumbent positioning reduce the incidence of postoperative hypoxemia more effectively than lateral positioning? Does lateral positioning reduce the incidence of postoperative hypoxemia more effectively than semirecumbent positioning? What are the differences in patient comfort and recovery outcomes between these two positioning strategies? Researchers will compare semirecumbent positioning directly to lateral positioning to see which approach is more effective in preventing postoperative hypoxemia. Participants will: Be randomly assigned to either semirecumbent positioning or lateral positioning after surgery Have their oxygen levels and breathing monitored regularly during the postoperative period Receive standard post-surgical care with their assigned positioning strategy Be assessed for comfort levels and any positioning-related complications Have their recovery progress tracked throughout their hospital stay.