Low-dose dexmedetomidine provides hemodynamics stabilization during emergence and recovery from general anesthesia in patients undergoing carotid endarterectomy: a randomized double-blind, placebo-controlled trial

Co-administration of dexmedetomidine with total intravenous anaesthesia in carotid endarterectomy reduces requirements for propofol and improves haemodynamic stability: A single-centre, prospective, randomised controlled trial

BACKGROUND

Total intravenous anaesthesia guided by electroencephalography and neurophysiological monitoring may be used for carotid endarterectomy. Reduction of brain metabolic demand during cross-clamping of the internal carotid artery with propofol titrated to burst suppression requires effect-site concentrations that may delay emergence and interfere with intraoperative neurophysiological monitoring.

OBJECTIVE

To test the hypothesis that dexmedetomidine decreases the effect-site concentration of propofol required for burst-suppression in patients undergoing carotid endarterectomy.

DESIGN

Randomised controlled trial.

PARTICIPANTS

Patients undergoing carotid endarterectomy.

SETTING

University Hospital of Berne, Switzerland, from October 2018 to September 2024.

INTERVENTIONS

Patients were randomised into a control (n = 23) and a dexmedetomidine groups (n = 22). Total intravenous anaesthesia was administered to both groups. Patients in the dexmedetomidine group received an intravenous bolus of dexmedetomidine (0.4 μg kg-1 over 10 min) before induction, followed by a continuous intravenous infusion (0.4 μg kg-1 h-1). The effect-site concentrations of propofol were titrated against frontal electroencephalography parameters. Burst suppression was induced with propofol during cross-clamping of the internal carotid artery.

OUTCOME MEASURES

The primary outcome was the effect-site concentration of propofol required for burst-suppression. The secondary outcomes were the requirement for vasoactive substances, neurophysiological monitoring parameters, and postoperative delirium.

RESULTS

The effect-site concentration of propofol required for burst suppression was 4.0 μg ml-1 [3.50 to 4.90] (median [interquartile range]) in the dexmedetomidine group compared with 6.0 μg ml-1 [5.5 to 7.3] in the control group (P < 0.001). Less norepinephrine was required in the dexmedetomidine group (total 454 μg [246 to 818] compared with 1000 μg [444 to 1326] (P = 0.015) in the control group). Dexmedetomidine did not affect intraoperative neurophysiological monitoring.

CONCLUSION

Co-administration of dexmedetomidine to total intravenous anaesthesia for carotid endarterectomy decreased the effect-site concentrations of propofol required for burst suppression by 33%. The propofol-sparing effect and peripheral alpha-agonism of dexmedetomidine may explain the reduced requirement for vasopressors.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT04662177.

Progress on the Mechanisms and Neuroprotective Benefits of Dexmedetomidine in Brain Diseases

INTRODUCTION

Dexmedetomidine, a highly specific α2 agonist, has been extensively utilized in clinical sedation and surgical anesthesia since its introduction in 2000 due to its excellent sympatholytic, sedative, and analgesic effects. This review aimed to identify new approaches for the treatment of patients with brain disorders by thoroughly describing the mechanism of action of dexmedetomidine and examining its neuroprotective effects from the standpoints of basic and clinical research.

METHODS

The PubMed and Web of Science databases were searched using the keywords dexmedetomidine and related brain diseases, although relevant articles from the last decade were included for detailed summarization and analysis.

RESULTS

Dexmedetomidine has shown strong neuroprotective effects, such as protection of the blood-brain barrier, decreased neuronal death, maintained hemodynamic stability, and reduced postoperative agitation and cognitive dysfunction. Furthermore, dexmedetomidine has been shown to exert various neuroprotective effects, including anti-inflammatory and antioxidative stress effects, modulation of autophagy, and reduction of apoptosis in cerebral diseases.

CONCLUSIONS

Dexmedetomidine acts as a neuroprotective agent against brain diseases during all phases of treatment. However, clinical trials with larger sample sizes are required to optimize dosage and dosing strategies.

Outcomes of Dexmedetomidine with Local Regional Anesthesia in Carotid Endarterectomy

BACKGROUND

Adequate sedation to complement regional techniques in carotid endarterectomy (CEA) can be challenging. Dexmedetomidine has both analgesic and amnesic properties and is reported to be a safe and acceptable alternative to conventional general endotracheal anesthesia (GETA). Outcomes observing dexmedetomidine in conjunction with regional anesthesia in CEA are not well described or known.

OBJECTIVE

Compare the immediate (during hospitalization) and short-term (within 30 days of hospitalization) postoperative outcomes in patients who underwent CEA using GETA versus local regional anesthesia (LRA) alone versus dexmedetomidine with LRA at a single institution to determine whether dexmedetomidine is a safe adjunct and if there are anesthesia advantages over LRA alone.

METHODS

A retrospective cohort study from January 2015 to December 2019 at Saint Joseph Mercy Ann Arbor. Patients were stratified into three groups based on anesthesia type: GETA, LRA, and dexmedetomidine (D) + LRA. Primary outcomes included stroke, myocardial infarction (MI), and death. Patient demographics were characterized and adjusted using propensity score weighting.

RESULTS

Three hundred seventy nine patients met inclusion criteria; 182 patients in the GETA group, 66 in the D + LRA, and 131 in LRA. There were no significant differences across anesthesia groups in primary outcomes of stroke, MI, and death during the admission. The GETA group had significantly longer length of stay (LOS) compared to the D + LRA group (LOS = 1.51 days versus 0.85 days; P = 0.011) and the LRA group (LOS = 1.08 days; P = 0.003). However, there was no significant difference in hospital LOS between the D + LRA group and LRA only groups (P = 0.952). There was no significant difference between stroke (LRA 0.87%, GETA 0.85%, and LRA + Dex 3.52%), MI (LRA 0%, GETA 0.49%, LRA + Dex 0%), or death (LRA 5.24%, GETA 1.16%, LRA + Dex 0%), within 30 days between all three of the anesthesia groups. There was no significant difference in postoperative pain scores when comparing the GETA group (mean 1.3, standard deviation [SD] 2.5) to LRA (mean 1.2, SD 2.1) and between LRA and D + LRA (mean 0.9, SD 2.1). Procedure time (time of skin incision to closure) and total room time were comparable among all three anesthesia groups (LRA 2.2 hr, SD 2.2; GETA 2.1 hr, SD 0.5; LRA + Dex 2.1 hr, SD 0.5).

CONCLUSIONS

The use of dexmedetomidine in addition to LRA is a safe and acceptable alternative to conventional GETA or LRA alone in CEA with shorter length of hospital stay when compared with GETA, improved patient tolerance based on physician observation, and similar rates of immediate and short-term complications and postoperative pain scores.

Protective effects of dexmedetomidine on the survival of random flaps

BACKGROUND

Random flaps can be used to repair wounds and improve shape and functional reconstruction, but inflammation and necrosis limit their application. Modified McFarlane flap models were constructed on the backs of rats. We hypothesized that dexmedetomidine (DEX) could improve the survival rate of ischemic random flaps.

METHODS

Sixty rats were randomly divided into three groups: a low-dose DEX group (DEX-L group, 10 μg/kg/D), a high-dose DEX group (DEX-H group, 20 μg/kg/D) and a control group (0.9 % saline equivalent). On day 7 after flap construction, the survival percentage of the flap model was calculated. Hematoxylin and eosin staining (H&E) was used to evaluate the histopathological status of the flaps and microvessel density (MVD). Lead oxide/gelatin angiography was used to detect angiogenesis, and laser Doppler flow imaging (LDF) was used to detect blood perfusion. The levels of superoxide dismutase (SOD) and malondialdehyde (MDA) in the middle areas of the flaps were measured to show the level of oxidative stress. The expressions of Toll-like receptor (TLR4), nuclear factor-kappa B (NF-κB), interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α) and vascular endothelial growth factor (VEGF) were detected by immunohistochemistry.

RESULTS

DEX significantly increased the average survival percentage of the flaps and reduced ischemia and necrosis of the distal end of the flaps. SOD activity significantly increased, while MDA significantly decreased, indicating that DEX reduces oxidative damage. The expression of inflammatory immunoregulatory proteins (TLR4, NF-κB) was downregulated, and the levels of inflammatory factors (IL-1β, IL-6 and TNF-α) were lower. In addition, DEX upregulated VEGF expression, promoted angiogenesis, and increased blood perfusion.

CONCLUSION

In random flap transplantation, a high dose of DEX is beneficial to flap survival.

The Effects of Intraoperative Dexmedetomidine Use and Its Different Dose on Postoperative Sleep Disturbance in Patients Who Have Undergone Non-Cardiac Major Surgery: A Real-World Cohort Study

OBJECTIVE

The study aimed to investigate the effects of intraoperative dexmedetomidine on postoperative sleep disturbance for different surgical patients and compare such effects between different dose of dexmedetomidine.

METHODS

A total of 7418 patients undergoing nine types of non-cardiac major surgeries were retrospectively studied. Patients were separated into DEX (dexmedetomidine) or Non-DEX (Non-dexmedetomidine) groups based on the use of dexmedetomidine during surgery. The patients who reported they could not fall asleep during the night or woke up repeatedly during the most of the night at the day of the surgery and whose NRS were >6 were defined as cases with severe sleep disturbance. Propensity score matched analysis based on all preoperative baseline data was performed along with logistic regression analysis including different surgery types and dosage of dexmedetomidine use.

RESULTS

In both of the unmatched cohort (OR, 0.49 [95% CI: 0.43-0.56]) and matched cohort (0.49 [95% CI: 0.42-0.58]), the DEX group had a significantly lower incidence of severe sleep disturbance than the Non-DEX group. In the subgroup analysis, for gynecological and urological surgery population, the ORs for DEX-group reached 0.21 (95% CI, 0.13-0.33; P<0.0001) and 0.30 (95% CI,0.19-0.47; P<0.0001), respectively. In addition, low-dose dexmedetomidine (0.2-0.4 μg·kg^-1·h^-1) showed the greatest effect with an odds ratio of 0.38 (95% CI: 0.31-0.44; P<0.0001), and the incidence of severe sleep disturbance in the low-dose group was significantly lower (11.5% vs. 17.7% vs. 16.5%, P<0.0001) than that in the medium- (0.4-0.6 μg·kg^-1·h^-1) and high-dose (0.6-0.8 μg·kg^-1·h^-1) groups.

CONCLUSION

Intraoperative dexmedetomidine use can significantly decrease the incidence of severe sleep disturbance on the day of surgery for patients undergoing non-cardiac major surgery, and the effects were most significant in patients receiving gynecological and urological surgery. Furthermore, low-dose dexmedetomidine (0.2-0.4 μg·kg^-1·h^-1) is most effective for prevention of postoperative sleep disturbance.