ABSTRACT

Introduction:

Clonidine, α2 agonist, is known to prolong the action of local anaesthetics, and provide a satisfactory analgesia; haemodynamic changes observed after its intrathecal (IT) administration. The aim of the study was to determine whether IT clonidine administration can reduce local anaesthetic and the effect on the cardiovascular system and postoperative analgesia.

Material and Methods:

After the approval from the Ethics committee and informed consent, 60 patients, between 18-70., ASA I or more, and who were scheduled for elective lower extremity procedures under unilateral spinal anaesthesia, participated in the study. After crystalloid preloading spinal puncture was performed at L4-5 intervertebral space with 25 gauge Quincke needle. Patients were randomized into three groups. Group I 10mg 0.5% hyperbaric bupivacaine, Group II 10mg 0.5% hyperbaric bupivacaine+ 50μg clonidine and Group III 10mg 0.5% hyperbaric bupivacaine+75μg clonidine received IT over 40 seconds while the patients were lying lateral position and the side to be operated dependent. Patients remained in the lateral position for 15 minutes. Noninvasive mean arterial blood pressure and heart rate were measured before spinal blockade and then 5th, 15th, 30th and 45th minutes. We also recorded motor block regression time and first analgesic need. The data were evaluated by using Mann- Withney U and Wilcoxon tests considering p<0.05 significant.

Results:

No significant differences were observed regarding height, age, weight,gender and ASA statue. In all groups heart rate and mean arterial blood pressure showed decrease after spinal blockade. In clonidine treated groups although they had haemodynamic changes we observed significantly prolonged motor block and postoperative analgesia.

Conclusion:

The addition of clonidine to hyperbaric bupivacaine, exerting minimal haemodynamic influence and guaranting a satisfactory postoperative analgesia, seems to be particularly useful in unilateral spinal anaesthesia.