Effects of dexmedetomidine combined with etomidate on postoperative cognitive function in older patients undergoing total intravenous anaesthesia: a randomized, double-blind, controlled trial

Abstract

Background: Etomidate has been advocated for anesthesia in older and critically ill patients because of its hemodynamic stability. Clinical studies have shown that dexmedetomidine has neuroprotective and anti-inflammatory properties and improves postoperative cognitive dysfunction in older patients. The present study was to evaluate the effects of the combination of etomidate and dexmedetomidine with different anaesthesia time on postoperative cognitive function in older patients.

Methods: A total of 132 older patients undergoing ureteroscopic holmium laser lithotripsy were randomly divided into EN group and ED group equally. Patients whose surgery time was less than or equal to 1 h in each group were allocated to short-time surgery group (EN₁ group and ED₁ group), and whose surgery time was more than 1h were allocated to long-term surgery group (EN₂ group and ED₂ group). The primary outcome was the score of the Mini-Mental State Examination. The secondary outcomes were State-Trait Anxiety Inventory scores, Riker sedation agitation scores, Zung Self-Rating Depression Scale scores, the memory span for Arabic numerals, the plasma concentrations of S-100 calcium-binding protein B and neuron specific enolase, the time to spontaneous respiration, recovery, and extubation.

Results: The MMSE scores at t_2-3 were higher in ED₁ and ED₂ groups than in EN₁ and EN₂ groups (p<0.05). Compared with ED₁ and ED₂ groups, the ZSDS scores, the S-AI scores and the T-AI scores at t_1-2 were higher in EN₁ and EN₂ groups (p<0.05), respectively. The recalled Arabic numbers at t_1-3 were higher in ED₂ group than in EN₂ group (p<0.05). The plasma concentration of S-100β at t_1-2 in EN₁ group and t_1-3 in EN₂ group were higher than that in ED₁ and ED₂ groups (p<0.05), respectively. Compared with ED₁ and ED₂ groups, the plasma concentrations of NSE were higher at t_1-3 in EN₁ group and t_1-4 in EN₂ group (p<0.05), respectively.

Conclusion: The administration of dexmedetomidine could improve postoperative cognitive dysfunction, emergence agitation, depression and anxiety, attenuate the plasma concentrations of S-100β and NSE in older patients undergoing total intravenous anaesthesia with etomidate.

Trial registration: Registration number: ChiCTR1800015421, Date: 29/03/2018.

Keywords: Anxiety; Depression; Dexmedetomidine; Older patients; Postoperative cognitive dysfunction; etomidate.

Fig.1

Study flow diagram

Fig 2

The SBP at different time points in four groups. *p < 0.05 vs.T₀, ^# p < 0.05 vs.EN₁ and ^$ p < 0.05 vs.EN₂

Fig 3

The DBP a different time points in four groups. *p < 0.05 vs.T₀, ^# p < 0.05 vs.EN₁ and ^$ p < 0.05 vs.EN₂

Fig 4

The HR at different time points in four groups. * p < 0.05 vs.T₀, ^# p < 0.05 vs. EN₁ and ^$ p < 0.05 vs. EN₂