Postoperative Delirium Following Posterior Lumbar Spinal Fusion: Epidemiology, Risk Factors, and Associated Complications.

BACKGROUND

Postoperative delirium (POD) is frequently reported in the elderly after major surgery. Several risk factors have been identified, including age, surgical complexity, and comorbidities.

METHODS

Posterior lumbar fusion patients were identified using PearlDiver and filtered into two cohorts based on the presence or absence of POD within 7 days of surgery. Epidemiological analyses were performed to examine trends in POD by age and year. Comparative analyses were performed on patient demographics and baseline cognitive status. After matching by age, sex, and comorbidities, electrolyte disturbances and 90-day postoperative complications were analyzed.

RESULTS

Among 476,482 no POD and 2591 POD patients, the mean age was 60.90 years, 57.6% were female, and the mean Charlson comorbidity index was 1.78. POD patients frequently had baseline cognitive impairment (P < 0.001). Incidence of POD decreased from 0.7% in 2010 to 0.4% in 2022 (P < 0.001) and increased with increasing patient age (P < 0.001). POD patients had higher length of stay (12 vs. 6 days, P < 0.001) and 90-day costs ($20,605 vs. $17,849, P < 0.001). After matching, POD patients had higher hypernatremia (5.8% vs. 3.5%, P = 0.001) and hypocalcemia (5.0% vs. 3.5%, P = 0.026). POD patients had higher 90-day postoperative complications (P < 0.05) than no POD patients.

CONCLUSIONS

Nearly 0.5% of patients who underwent posterior spinal fusion between 2010 and 2022 developed delirium, although incidence rates have decreased over time. POD was common in elderly patients with electrolyte disturbances who underwent multilevel fusions. Patients suffering from POD had higher rates of 90-day postoperative complications. Ongoing efforts to deliver interventions to mitigate the consequences of POD among spine surgery patients are warranted.