Longitudinal Trends in the Incidence of Hyperactive Delirium and Its Causes of Change After Surgery for Degenerative Lumbar Disease: A Population-Based Study of 7250 Surgical Patients Over 11 Years.

Objectives: Delirium is one of the common complications in elderly patients after spinal surgery. Severe delirium can lead to a series of adverse consequences such as drainage tube removal, wound rupture, patient falls, and severe adverse effects. The current research on POD is mostly small sample studies. This study aimed to investigate longitudinal changes in the incidence of hyper-postoperative delirium in patients with lumbar degenerative disease at our institution over the past 11 years and to identify the potential causes of these changes.

Methods: This is a retrospective cohort study included 7250 patients who underwent surgical treatment for lumbar degenerative diseases at a single center from 2011 to 2021. These patients were diagnosed with delirium through the Confusion Assessment Method and then diagnosed with high activity delirium through the Richmond Agitation-Sedation Scale, totaling 130 cases. According to the incidence rate of hyper-postoperative delirium within 11 years, the trend test is divided into three groups: S1 upward trend (2011-2014), S2 downward trend (2015-2016) and S3 upward trend (2016-2021). The study collected variables from patients before, during, and after surgery, including gender, age, laboratory tests, anesthesia risk score, New York Heart Association cardiac function grading, number of surgical segments, surgical time, estimated intraoperative blood loss, anesthesia medication, and supplementary analgesic medication in the ward within 3 days after surgery. Kruskal Wallis one-way ANOVA test, Kruskal-Wallis H test, or chi-square test are used to evaluate inter group differences. p < 0.05 is considered statistically significant.

Results: The pooled incidence of hyper-postoperative delirium over the past 11 years was 1.79% (130/7250). The average age of 7250 patients was 54.5 ± 13 years, with a male/female ratio close to 1:1. We statistically analyzed the relevant influencing factors before, during, and after surgery of S1 and S3 in the incidence rate increase group and found no statistical difference between the two groups. Our research results show that the incidence of high activity delirium is correlated with age, number of surgical segments, surgical duration, use of dexmedetomidine, remifentanil, and benzodiazepines, with p < 0.05.

Conclusions: The reduced use of dexmedetomidine, increased use of benzodiazepines, and prolonged surgical time are the reasons for the increased incidence of hyper-postoperative delirium. The joint management of orthopedic surgeons and anesthesiologists during the perioperative period is of great significance in reducing the incidence of hyper-postoperative delirium in patients undergoing lumbar spine surgery.