Trajectories of oral mucosal dryness and multidimensional influencing factors in patients undergoing spine surgery: a prospective longitudinal study

Oral mucosal dryness during the perioperative period is often underestimated in the postoperative rehabilitation of patients undergoing spine surgery. This study aimed to explore the oral mucosal dryness trajectories and their key influencing factors in these patients. This prospective cohort study included 303 patients undergoing spine surgery between February and July 2022. Data on oral mucosal dryness were collected at admission, 2 h, and 6 h post-surgery. Multidimensional factors, including physiological, psychological, and environmental variables, were recorded. Latent Growth Mixture Modeling was used to analyze different trajectories of oral mucosal dryness, and Lasso regression identified significant factors associated with dryness. Multivariate logistic regression was used to investigate the factors influencing each trajectory. We identified three distinct trajectories of oral mucosal dryness: moderate level increase (38.7%), persistently low level (46.3%), and high-level maintenance (15%). The moderate level increase trajectory was associated with factors including age, prolonged post-anesthesia care unit-to-ward transfer, obesity, antihypertensive use, higher preoperative pain scores, and elevated temperature, while increased environmental humidity and preoperative fluid infusion were associated with reduced risk. The high-level maintenance trajectory was associated with age, body temperature, pain score, plasma drainage, and higher ASA classification, whereas increased environmental humidity was associated with lower risk. Environmental humidity at 6 h postoperatively and preoperatively pain scores are common factors in oral mucosal dryness and warrant timely attention. Early interventions for high-risk groups at admission may help reduce postoperative oral mucosal dryness, but confirmatory interventional studies are needed. This trial was registered in the Chinese Clinical Trial Registry (ChiCTR2200064905) on October 21, 2022, retrospective registration.