Antishivering effects of two different doses of intrathecal meperidine in caesarean section: a prospective randomised blinded study.

BACKGROUND AND OBJECTIVE: Shivering causes various adverse disturbances and interferes with monitoring. The optimal dose of intrathecal meperidine to prevent shivering without producing other side-effects remains unknown. This prospective randomised double-blinded study was conducted to compare the antishivering effects of two different doses of intrathecal meperidine.

METHODS: Seventy two parturients, scheduled for elective caesarean section under spinal anaesthesia, were enrolled in three different groups. Spinal anaesthesia consisted of bupivacaine 0.5% (10 mg) for the control group (M0), and the same dose of bupivacaine with meperidine 12.5 or 25 mg for the experimental groups (M1, M2). Blood pressure, heart rate, skin and core temperatures, sensory level, capnometry, pulse oximetry, Apgar scores, shivering intensity and intrathecal opioid-related side-effects were evaluated and recorded by a blinded observer. Data were analysed using analysis of variance, χ² test, Kruskal-Wallis H-test and Mann-Whitney U-test. A P value less than 0.05 was considered to be significant.

RESULTS: Shivering was more intense in group M0 than in groups M1 and M2 with P values of 0.003 and less than 0.001, respectively. The intensity of shivering was comparable in groups M1 and M2. As regards the incidence of significant shivering, it was found to be highest in M0 (4/24 ≈16.7%) in comparison with M1 (0/24) and M2 (0/24) (P = 0.03). Nausea and vomiting occurred more frequently with higher doses of meperidine (P < 0.001 and P = 0.003, respectively). Other complications were comparable.

CONCLUSION: The use of intrathecal meperidine for caesarean section during spinal anaesthesia for the prevention of shivering cannot be recommended as its use is associated with increased incidence of nausea and vomiting.