title: Low dose clonidine premedication accentuates the hyperglycemic response to surgery.
abstract: OBJECTIVE
  To investigate the influence of low dose clonidine premedication on perioperative glucose homeostasis.
  
  
  METHODS
  Sixteen patients undergoing abdominal hysterectomy for benign uterine myoma were randomly assigned to receive either iv clonidine (1 microg x kg(-1)) 30 min before induction of general anesthesia (clonidine, n=8) or saline (control, n=8). Plasma concentrations of glucose, insulin, cortisol, epinephrine and norepinephrine were measured before, during and two hours after surgery. At the same time heart rate, mean arterial pressure and cardiac output were recorded.
  
  
  RESULTS
  In both groups, glucose concentrations significantly increased during and after surgery. Intraoperative glucose plasma concentration in the clonidine group was higher than in the control group (clonidine: 6.8 +/- 0.6 mmol x L(-1) vs control: 5.7 +/- 0.8 mmol x L(-1), P < 0.05). This was accompanied by a lower insulin plasma concentration (clonidine: 3.9 +/- 1.9 microU x mL(-1) vs control: 6.5 +/- 2.8 microU x mL(-1), P <0.05). Heart rate, mean arterial pressure and cardiac output remained unchanged throughout the study period without any differences between the groups. While norepinephrine plasma concentrations increased in the control group only (P <0.05), the plasma concentrations of epinephrine and cortisol increased in both groups (P <0.05). Clonidine significantly attenuated the cortisol response as reflected by lower intra- and postoperative cortisol plasma concentrations than in the control group (P <0.05).
  
  
  CONCLUSIONS
  Premedication with clonidine 1 microg x kg(-1) accentuates the hyperglycemic response to lower abdominal surgery caused by the decrease in insulin plasma concentrations.
authors.affiliation: Department of Anesthesia, McGill University, Montreal, Quebec, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Lattermann
authors.forename: T
authors.initials: T
authors.lastname: Schricker
authors.forename: M
authors.initials: M
authors.lastname: Georgieff
authors.forename: M
authors.initials: M
authors.lastname: Schreiber
mesh_terms: D000328:Adult; D000368:Aged; D003000:Clonidine / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D006943:Hyperglycemia / Q000517:prevention & control*; D007044:Hysterectomy; D008875:Middle Aged; D011183:Postoperative Complications / Q000517:prevention & control*; D011292:Premedication
chemical_list: D003000:Clonidine; D006854:Hydrocortisone