Duration of Surgery and Intraoperative Blood Pressure Management Are Modifiable Risk Factors for Postoperative Neurocognitive Disorders After Spine Surgery

Abstract

Study Design. Prospective quasi-experimental observational study. Objective. The objective of this study was to evaluate whether duration of surgery is a modifiable risk factor for postoperative delirium (POD) after spine surgery and explore further modifiable risk factors. In addition, we sought to investigate the association between POD and postoperative cognitive dysfunction and persistent neurocognitive disorders. Summary of Background Data. Advances in spine surgery enable technically safe interventions in elderly patients with disabling spine disease. The occurrence of POD and delayed neurocognitive complications (e.g. postoperative cognitive dysfunction/persistent neurocognitive disorder) remain a concern since these contribute to inferior functional outcomes and long-term care dependency after spine surgery. Materials and Methods. This prospective single-center study recruited patients aged 60 years or above and scheduled for elective spine surgery between February 2018 and March 2020. Functional (Barthel Index, BI) and cognitive outcomes [Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) test battery; telephone Montréal Cognitive Assessment] were assessed at baseline, three (V3), and 12 months postoperatively. The primary hypothesis was that the duration of surgery predicts POD. Multivariable predictive models of POD included surgical and anesthesiological parameters. Results. Twenty-two percent of patients developed POD (n=22/99). In a multivariable model, duration of surgery [ORadj=1.61/h (95% CI, 1.20–2.30)], age [ORadj=1.22/yr (95% CI, 1.10–1.36)], and baseline deviations of intraoperative systolic blood pressure [25th percentile: ORadj=0.94/mm Hg (95% CI, 0.89–0.99); 90th percentile: ORadj=1.07/mm Hg (95% CI, 1.01–1.14)] were significantly associated with POD. Postoperative cognitive scores generally improved (V3, ΔCERAD total z-score: 0.22±0.63). However, this positive group effect was counteracted by POD [beta: −0.87 (95% CI, −1.31 to 0.42)], older age [beta: −0.03/yr (95% CI, −0.05 to 0.01)], and lack of functional improvement [ΔBI; beta: −0.04/point (95% CI, −0.06 to 0.02)]. Cognitive scores at twelve months remained inferior in the POD group, adjusted for baseline cognition/age. Conclusions. This study identified distinct neurocognitive effects after spine surgery, which are influenced by perioperative risk factors. Potential cognitive benefits are counteracted by POD, rendering its prevention critical in an aging population.

Serum Biomarkers of a Pro-Neuroinflammatory State May Define the Pre-Operative Risk for Postoperative Delirium in Spine Surgery

“…Due to the SARS-CoV-2 pandemic, we did not reach this planned sample size. Nonetheless, our primary hypothesis was confirmed given the larger than expected effect size [ 5 ]. Data collection was completed in March 2021.…”

“…If necessary, cerebral imaging should also be discussed with these patients to determine whether they have suffered structural brain damage perioperatively. Spinal surgery per se was not necessarily associated with POCD in the CONFESS study if these have a functional gain (i.e., postoperative Barthel index increases) and do not suffer POD [ 5 ]. Nonetheless, it is possible that the preclinical state of dementia/or neurodegenerative diseases, which induces a proinflammatory state of biomarkers, might be responsible for the higher risk of POD in the delirium cohort.…”

“…Postoperative delirium (POD) is a serious perioperative neurocognitive disorder (pNCD) that affects about 25% of patients undergoing non-cardiac surgery and has a detrimental impact on functional recovery, complication rates, and healthcare costs [ 3 ]. Delayed neurocognitive recovery (dNCR) can follow POD or develop independently and evolve into postoperative cognitive dysfunction (POCD) in about 30–50% of patients, who endure neurocognitive symptoms for ≥3 months following surgery [ 4 , 5 ]. POCD is associated with the risk of long-term care dependency and institutionalization [ 6 ].…”

“…Herein, we tested several sociodemographic, anesthesiological, and surgical characteristics. Although limiting the duration of surgery and meticulous management of intraoperative systolic blood pressure might decrease the risk of POD and POCD, we clearly found that spinal surgery per se performed with general anesthesia was not necessarily associated with POD [ 5 ]. Furthermore, the impact of medication on the incidence of POD was not significant.…”

“…Delayed neurocognitive recovery (dNCR) can follow POD or develop independently and evolve into postoperative cognitive dysfunction (POCD) in about 30-50% of patients, who endure neurocognitive symptoms for ≥3 months following surgery [4,5]. POCD is associated with the risk of long-term care dependency and institutionalization [6].…”