Source
Institut für Anästhesie und Intensivmedizin, AUVA Unfallkrankenhaus Klagenfurt, Waidmannsdorferstr 35, 9021 Klagenfurt, Österreich. c.schlimp@gmx.at
Abstract
BACKGROUND:
In the postoperative period, α2-adrenergic agonists have an opioid sparing effect. In a previous, experimental study, it was also shown that clonidine attenuates remifentanil-induced hyperalgesia. In this study, we examined under clinical conditions whether early administration of a single dose of clonidine can inhibit remifentanil-induced hyperalgesia in patients undergoing elective surgery of the shoulder and with continuous intraoperative use of remifentanil.
PATIENTS AND METHODS:
In this study 40 patients received double-blind and randomized either 150 µg clonidine or placebo intravenously before skin incision. Anaesthesia was maintained with propofol and remifentanil (0.23 ± 0.09 µg/kg body weight/min) and morphine (0.1 mg/kg body weight) was administered 20 min before incision closure. Postoperatively, the patients were given a patient-controlled analgesia pump (PCA) with morphine.
RESULTS:
Overall morphine consumption as well as overall assessment of pain with the visual analogue scale in the first 24 h postoperatively did not differ significantly between the groups. Isolated pain scores at 12 h and 24 h were significantly enhanced in the clonidine group (p<0.05).
CONCLUSION:
An early single dose of 150 µg of clonidine did not reduce the postoperative morphine consumption and pain scores in patients undergoing elective surgery of the shoulder with remifentanil/propofol-based anaesthesia. After the effect of clonidine has presumably subsided the pain can even increase, therefore further studies with repetitive doses of clonidine should be carried out.