Clinical Research Directory

Effect of taVNS on Perioperative Anxiety in Major Abdominal Surgery

It is reported that over 50% of patients undergoing major abdominal surgery experience perioperative anxiety, which often triggers a vicious cycle of "anxiety-pain-gastrointestinal dysfunction" and significantly hinders postoperative recovery. Existing pharmacological and psychological interventions are limited by adverse effects such as respiratory depression, paralytic ileus, and poor patient compliance. While transcutaneous auricular vagus nerve stimulation (taVNS) has shown promise as a non-invasive neuromodulation technique for chronic neuropsychiatric disorders, high-quality evidence regarding its application in anxiety-susceptible perioperative populations is still lacking. This multicenter, randomized, parallel-group, double-blind, sham-controlled trial aims to recruit 282 patients undergoing elective major abdominal surgery across four centers in Mainland China. Eligible participants will be randomized (1:1) to receive either taVNS or sham stimulation for 60 minutes daily from two days prior to surgery through the day of the operation. The primary outcome is the incidence of perioperative anxiety from the day of surgery to 72 hours postoperatively, while secondary outcomes include depression, sleep quality, pain intensity, postoperative delirium, frailty scores, quality of recovery, time to first flatus and defecation, and length of hospital stay.

Optimal Interval for Periodic Alveolar Recruitment Maneuvers Achieving 90% Lung Re-expansion During Intraoperative Ventilation

This study aims to determine the optimal interval for periodic alveolar recruitment maneuvers (PARM) that can achieve effective lung re-expansion in 90% of patients undergoing intraoperative mechanical ventilation during abdominal laparoscopic surgery in the low Trendelenburg position. Identifying the most effective frequency of PARM is crucial for establishing lung-protective ventilation strategies, with the ultimate goal of reducing intraoperative atelectasis, decreasing postoperative pulmonary complications, and accelerating recovery. Patients are randomized using a biased-coin sequential design. PARM is initially applied every 0.5 hours, and the effectiveness of lung re-expansion is evaluated before the end of surgery. The primary outcome is the effectiveness of recruitment, assessed by a combination of lung ultrasound scores and shunt fraction. Secondary outcomes include mechanical power at the end of surgery, time-weighted average mechanical power during ventilation, postoperative P/F ratio, dead space fraction, air test results, intraoperative adverse events, incidence of respiratory failure in the PACU and postoperative period, and postoperative length of stay. This trial is expected to provide robust evidence for defining the optimal RM interval in protective ventilation protocols for patients undergoing laparoscopic abdominal surgery, thereby contributing to improved perioperative respiratory outcomes.