Postoperative Thirst After Laparoscopic Sleeve Gastrectomy: An Observational Study Protocol Investigating Incidence and Associated Factors

Jing Sang,1, Guanyu Yang,1, Liumei Li,1 Jiayao Tian,2 Zhentao Sun,3 Qinjun Chu1 1Department of Anesthesiology and Perioperative Medicine, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan, People’s Republic of China; 2The First Clinical Medical College, Lanzhou University, Lanzhou, Gansu, People’s Republic of China; 3Department of Anesthesiology, Pain and Perioperative Medicine, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, People’s Republic of ChinaThese authors contributed equally to this workCorrespondence: Zhentao Sun, Department of Anesthesiology, Pain and Perioperative Medicine, the First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou, Henan, 450052, People’s Republic of China, Tel +8613603455483, Email fccsunzt@zzu.edu.cn Qinjun Chu, Department of Anesthesiology and Perioperative Medicine, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Tongbai North Road 16, Zhengzhou, Henan, 450007, People’s Republic of China, Tel +8613643711142, Email jimmynetchu@163.comIntroduction: Postoperative thirst is a common yet under-investigated issue following metabolic and bariatric surgery (MBS), such as sleeve gastrectomy (SG), despite its significant impact on patient comfort and recovery. While studies in other surgical fields report a high prevalence of this distressing symptom, its incidence and predictors remain unquantified in the MBS population. This study aims to prospectively determine the incidence of postoperative thirst (primary outcome), the incidence of moderate-to-severe thirst, and the factors associated with postoperative thirst (secondary outcomes) in adults undergoing SG.Methods: This prospective, single-center, observational cohort study will enroll adults (age ≥ 18, ASA class 2‒3) undergoing elective SG. Based on a preliminary incidence of 90% from a 10-patient pilot study, we plan to enroll 180 patients. The primary outcome—incidence of postoperative thirst—will be assessed immediately upon arrival in the post-anesthesia care unit using the Numeric Rating Scale (NRS), with thirst defined as an NRS score ≥ 1. Moderate-to-severe thirst will be defined as an NRS score ≥ 4. We will collect demographic, perioperative, and intraoperative data to investigate factors potentially associated with postoperative thirst. A two-stage analytical approach will be employed: variable selection using Least Absolute Shrinkage and Selection Operator (LASSO) regression, followed by multivariable binary logistic regression to identify factors associated with postoperative thirst.Discussion: The findings from this protocol will clarify the epidemiology of postoperative thirst in MBS and help identify modifiable perioperative risk factors. This evidence will inform nursing practices and the optimization of postoperative care pathways, supporting better recovery and comfort for individuals undergoing MBS. Results are intended to provide a basis for further interventional studies and contribute to improved perioperative management in MBS.Trial Registration: Registered at the Chinese Clinical Trial Registry on May 9, 2025. Trial Registration Number: ChiCTR2500102147.Keywords: metabolic and bariatric surgery, sleeve gastrectomy, postoperative thirst, incidence, factors