Trajectory of severity of postoperative delirium symptoms and its prospective association with cognitive function in patients with gastric cancer: results from a prospective observational study

Purpose: Delirium is a common neurocognitive complication in cancer. Despite this, the studies examining the trajectory of the severity of delirium symptoms and its impact on health outcome in gastric cancer is rather limited. This study examined the trajectory of delirium symptom severity (DSS) following resection surgery for gastric cancer and its prospective association with cognitive function. Methods: A three-wave prospective observational study was conducted with 242 gastric cancer patients admitted for resection surgery at a teaching hospital in South Korea from May 2016 to November 2017. DSS was assessed by the clinical staff before and 1, 2, 3, and 7 days after surgery using the Delirium Rating Scale-Revised-98. A survey including the Functional Assessment of Cancer Therapy-Cognitive Scale (FACT-Cog) and Mini-Mental State Examination (MMSE) was administered before surgery (T0), 7 days after (T1), and 3 to 6 months after surgery (T2). Results: Out of 242 participants, 48.8% (118) completed the survey at all three time points, 43.4% (105) did so for two time points, and 7.9% (19) for one time point. No cases of full delirium were observed over four postoperative time points. Latent growth curve modeling analyses indicated that DSS declined over 3 days after surgery. Age and anesthesia time were positively associated with the initial level of DSS. A medication history for memory complaints was related to a slower recovery from delirium symptoms. While the use of propofol as an anesthetic agent was associated with lower initial DSS, it predicted a slower recovery from DSS. A higher initial DSS predicted a lower T1 MMSE score. Conclusions: Severity of postoperative delirium symptoms predicts a short-term and objective cognitive function post-surgery. Monitoring and timely treatment of postoperative delirium symptoms is needed to diminish cognitive consequences in gastric cancer patients.