Combining intrathecal bupivacaine and meperidine during caesarean section to prevent spinal anaesthesia-induced hypotension and other side-effects. 
This study compared intrathecal hyperbaric bupivacaine with low-dose intrathecal plain bupivacaine plus different doses of meperidine (pethidine), administered sequentially, with regard to blood pressure stability, post-operative analgesia and incidence of side-effects in 80 parturients undergoing caesarean section.  Patients were randomly assigned to one of four groups (n=20 each group): the HB group received 10 mg hyperbaric bupivacaine intrathecally; the BM35, BM30 and BM25 groups received 5 mg plain bupivacaine plus 35, 30 or 25 mg of meperidine intrathecally, respectively.  The incidence of hypotension in the BM25 group was significantly lower than in the HB group.  Nausea and vomiting were less prevalent in the BM25 group than in the HB and BM35 groups.  In conclusion, sequential administration of 5 mg plain bupivacaine and 25 mg meperidine intrathecally provided better blood pressure stability and a lower incidence of side-effects than bupivacaine alone, without affecting quality of anaesthesia or surgical and patient satisfaction.