Dexmedetomidine as an Adjunct for Regional Anesthesia: A Cohort Study on Risk Factors and Outcomes of Intraoperative Neurological Deficits

Abstract

Background Carotid endarterectomy (CEA) is a common surgical procedure in patients with carotid artery stenosis, during which neurological deficits may occur, usually at the carotid cross-clamping period. Dexmedetomidine (Dexdor), a selective alpha-2 adrenergic agonist, has emerged as an adjuvant to regional anesthesia (RA) as it allows frequent and reliable neurological assessment while maintaining neuroprotective properties and hemodynamic stability. This study aims to evaluate the influence of dexmedetomidine as an adjunct to regional anesthesia on the risk factors and outcomes associated with intraoperative neurological deficits (IND).

Methods Patients undergoing CEA under RA at a tertiary referral center, who presented with IND during CEA were prospectively and consecutively recruited between January 2012 and January 2024. The control group comprised the immediately consecutive patient who underwent the same procedure without IND. From this sample, patients with the use of Dexmedetomidine as an adjunctive were selected and compared with those without it. Differences in demographics and comorbidities were assessed between the groups. A multivariable logistic regression was performed.

Results A total of 230 patients were included, with 45% presenting symptomatic stenosis at the time of surgery. Those submitted to CEA in the dexmedetomidine group were older on average, with a higher proportion of patients aged >75, higher prevalence of chronic obstructive pulmonary disease (COPD), lower degree of contralateral stenosis and less frequent coronary artery disease (CAD). A subset of patients with IND were analyzed and CAD remained significantly less frequent in the Dexdor group (19.1% vs. 47.8%, p=0.002), Factors that predict IND were identified with multivariable analysis. In both groups chronic kidney disease (CKD) emerged as a predictor (without Dexdor: aOR = 4.256, p=0.01, with Dexdor: aOR = 6.561, p=0.023). The group without Dexdor also includes contralateral stenosis (aOR = 1.301, p=0.007), while the group with Dexdor includes age-related white matter changes (ARWMC) in basal ganglia (aOR = 4.004, p=0.004) and distinguishes CAD with a protective effect (aOR = 0.224, p=0.016). Stroke rates were similar between groups (10.3% without Dexdor vs. 10.8% with Dexdor, p=0.911).

Conclusion Multivariable analysis showed CKD and contralateral stenosis as significant predictors of IND, with CKD being a stronger factor in the dexmedetomidine group, while ARWMC emerged as a risk factor and CAD identified a protective effect in patients receiving Dexdor. Dexmedetomidine neuroprotective and hemodynamic benefits did not affect overall stroke or IND rates significantly.