The influence of epidural pethidine on shivering during lower segment caesarean section under epidural anaesthesia

A prospective study of 94 patients undergoing elective lower segment caesarean section under epidural anaesthesia was performed in order to determine the incidence of shivering and the influence of epidural pethidine. Epidural anaesthesia was established with bupivacaine 0.5% with adrenaline, with or without additional lignocaine 2% with adrenaline, to total 20-25 ml. With the injection of epidural local anaesthesia an extra 5 ml of solution was administered into the epidural space--pethidine 25 mg preservative-free, in normal saline, or normal saline alone. Patient, administering anaesthetist and observer were blinded to the nature of the test substance. Shivering was assessed by an independent observer and subsequently rated by the patient. Other side-effects also recorded were nausea, vomiting, pruritus and drowsiness. The incidence of shivering was 36% in the control (saline) group and 11% in the pethidine group. The difference was highly significant (P less than 0.01). There was no significant difference in the incidence of maternal nausea, vomiting, drowsiness or pruritus, or neonatal Apgar scores. Cord blood samples were assayed for pethidine, revealing low or absent pethidine concentrations.