Analgesic and Hemodynamic Effects of Epidural Clonidine, Clonidine/Morphine, and Morphine After Pancreatic Surgery--A Double-Blind Study

Abstract

This study characterizes analgesia an hemodynamics after epidural clonidine 8 micrograms/kg (Group C) or clonidine 4 micrograms/kg+morphine 2 mg (Group CM) in comparison to epidural morphine 50 micrograms/kg (Group M). Forty-five patients scheduled for pancreatectomy in combined general/epidural anesthesia were studied. The study drugs were administered 75 min postoperatively and for 10 h pain intensity (visual analog scale [VAS]), heart rate (HR), mean arterial pressure (MAP), and cardiac output (CO) were measured; filling pressures were kept > 5 mm Hg. Adequate analgesia could be achieved within 1 h in all patients of Groups C and CM, but only in six patients of Group M (P < 0.001). Quality of analgesia was comparable in all groups (VAS reduction 82% +/- 20%, mean +/- SD) but duration of analgesic action was longer in Groups CM (586 +/- 217 min) and M (775 +/- 378 min) compared to Group C (336 +/- 119 min) (P < 0.001). In Group M, no hemodynamic alterations occurred. In Groups C and CM, HR, CO, and MAP were reduced significantly compared to baseline within the first 15-90 min, while stroke volume and systemic vascular resistance remained stable. We conclude, that hemodynamic alteration after epidural clonidine under conditions of stable filling pressures is caused mainly by a decrease in HR. It is not an effect of analgesia but of the intrinsic antihypertensive action of clonidine.

Addition of epidural Clonidine enhances postoperative analgesia: A double-blind study in total knee- replacement surgeries

“…Ikeda Yoshikazu, Nishikawa Kiyonobu et al .,[18] in their study in 2003, concluded that epidural administration of Clonidine induces hypotension and bradycardia secondary to decreased sympathetic nerve activity. Michael G. Rock Mann, Wulf Seeling, et al .,[19] in their study in 1995 concluded, that homodynamic alteration after epidural clonidine under conditions of stable filling pressures is caused mainly by a decrease in HR. It is not an effect of analgesia but of the intrinsic antihypertensive action of clonidine.…”

Alpha‐2 and imidazoline receptor agonistsTheir pharmacology and therapeutic role

“…There was no change in the placebo group. Since then a number of studies have shown that epidural clonidine is effective and safe in the management of acute postoperative pain, improving analgesia and reducing opioid requirements [162,163]. Ciagarini and co-workers [164] reported that 75 mg of epidural clonidine increased the duration of epidural bupivacaine analgesia in labour with no adverse effects to mother or neonate.…”

Epidural ropivacaine combined with fentanyl or in combination with clonidine in infraumblical surgeries: a comparative study

“…8 The main site of action of fentanyl is the substantia gelatinosa in the dorsal horn of spinal cord, where it blocks the neural fibres carrying pain impulses both at pre-synaptic and post synaptic levels. 9 As fentanyl has no effect on sympathetic and motor neurons, it has advantages over local anaesthetics.…”