Addition of low dose meperidine [pethidine] to bupivacaine spinal anaesthesa: effects on shivesing and characteristics of block

The aim of this study was to investigate whether prophylactic intrathecal 20mg meperidine added to 0.5% hyperbaric bupivacaine would influence the incidence and severity of shivering in patients receiving spinal anaesthesia and whether it would affect the duration of sensory and motor blockade as well as postoperative analgesia Eighty patients of ASA physical status I or II presenting for surgery of inguinal hernia were divided into two equal groups according to the type of solution injected in the subarachnojd space. Patients of group I received 2Omg meperidine in addition to 0.5% bupivacaine while patients of group II received 0.5% bupivacajne alone. Shivering occurred in 5% of patients of group I and in 70% of patients in group II No single patient in group I experienced grade 2 or 3 shivering. The duration of sensory and motor blockade was significantly prolonged with addition of meperidire. Prolonged postoperative analgesia was obtained in meperidine - bupivacaine group which lasted for 19.4 +/- 4.5 hours compared to 9.6 +/- 2.8 in bupivacaine group. 70% of patients had no pain and required no analgesia up to 24 hours as regards complications pruritis occurred in the first group only [5 patients] which was experienced in the face and upper chest No early or late respiratory depression occurred in first group. it can be concluded that intrathecal 20mg meperidine added to bupivacaine reduced significantly the incidence and severity of shivering and significantly prolonged the duration of sensory and motor blockade as well as Postoperative analgesia with no deleterious effects on patients