Effects of dexmedetomidine and clonidine as propofol adjuvants on intra-operative hemodynamics and recovery profiles in patients undergoing laparoscopic cholecystectomy: A prospective randomized comparative study

Abstract

Context: Alpha-2 (α2) adrenergic receptor agonists, clonidine and dexmedetomidine, are widely used as adjuvants during anesthesia for analgesic, sedative, sympatholytic, and cardiovascular stabilizing effects.

Aims: We compared effects of clonidine and dexmedetomidine (as propofol adjuvants) on intra-operative hemodynamics, recovery time, and postoperative cognitive function impairment.

Subjects and methods: Forty-five American Society of Anesthesiologists I and II patients, scheduled for laparoscopic cholecystectomy were divided into three groups (n = 15). Group C patients received bolus of clonidine 3 μg/kg followed by a continuous infusion; Group D patients received dexemedetomidine 1 μg/kg and a continuous infusion; and Group P patients received a bolus of normal saline followed by an infusion. Intra-operative mean arterial pressure (MAP) and pulse rate (PR) were measured throughout the surgery. Bispectral index was maintained at 55 ± 5 by titrating propofol infusion rate. The time between the interruption of anesthesia and eye opening (recovery time) was measured. Cognitive function was assessed using short mental status questionnaire at 15, 30, 45, and 60 min postoperatively.

Results: The sympathetic response to laryngoscopy and extubation on MAP and PR were significantly reduced with the use of clonidine and dexmedetomidine (P < 0.05). The recovery was delayed (P < 0.05) with both the drug combinations and it was more pronounced with dexmedetomidine (P < 0.05). Dexmedetomidine group showed cognitive impairment in a postoperative period lasting up to an hour.

Conclusions: When co-administered with propofol, both clonidine, and dexmedetomidine attenuate sympathetic response to laryngoscopy and extubation but cause delay in the recovery from anesthesia. Dexmedetomidine causes impairment of postoperative cognitive functions.

Keywords: Clonidine; cognitive dysfunction; dexmedetomidine; hemodynamics; recovery time.

Figure 1

Variation of mean arterial pressure (MAP) and pulse rate (PR) during surgery. (a) Variation of MAP during surgery, hypertensive response during laryngoscopy, and extubation in Group P was significantly higher when compared to preoperative values (b) variation of PR during surgery, PR during laryngoscopy, and extubation was significantly higher in Group P; and significantly lower in Group C and D when compared to preoperative values

Figure 2

Comparison of anesthetic infusion rate and recovery time between Group P, C, and D. (a) Propofol infusion rate was highest in Group P and it significantly lower in Group C and D compared to Group P (b) patients in group D took the longest time to regain normal cognition, which was significantly higher than Group P and C. Recovery time in Group C was also significantly higher when compared to Group P

Figure 3

Number of patients with normal cognitive functions in Group P, C, and D at different time points. At 30 min, all the patients in Group P and C had regained normal cognition, and none in Group D were showing normal cognitive functions. Till 60 min, only 10 patients were showing normal cognitive function in Group D, and 5 were still displaying improper cognition