Akademik Veri Yönetim Sistemi
Regional Anesthesia and Pain Medicine, cilt.25, sa.2 SUPPL., ss.1, 2000 (SCI-Expanded)
Introduction: Ropivacaine is a long-acting amide local anesthetic agent available for epidural analgesia during labor (1,2). It has lower toxicity and less intense motor block when compared with bupivacaine (2,3). Recent clinical studies comparing ropivacaine 0.25 or 0.20% with bupivacaine at equal concentrations reported comparable analgesia but also comparable motor blockade (3-5). An opioid can be combined with local anesthetic to reduce the dose of local anesthetic agent and to improve analgesia for the relief of labor pain. The purpose of the present study was to evaluate the effects of bupivacaine 0.25% compared with ropivacaine 0.25% combined with fentanyl for analgesia during labor Methods: After instutional (UAFM) review board approval and informed consent, 26 nulliparous women requiring epidural analgesia, ASA physical status I - II with an uncomplicated pregnancy and single fetus in vertex presentation were studied. All parturients were at term and none of them had any significant coexisting disease. After fluid loading with 500 ml lactated Ringer's solution, an epidural catheter was inserted at L2-3 or L3-4 lumbar level. Parturients were randomly allocated into two groups and the initial doses were given epidurally during active phase of labor when the cervical dilatations were between 3-7 cm. First group (n=14) received bupivacaine 0.25% 8 ml + 1 μgr/kg fentanil (B/F), second group (n=12) received ropivacaine 0.25% 8 ml + 1 μgr/kg fentanil (R/F). Top-up doses of bupivacaine 0.25% 3 ml and ropivacaine 0.25% 3 ml were given according to patients' pain (VAS >4). Efficacy of analgesia was evaluated using linear visual analog scale (VAS), sensory block was assessed using bilateral pinprick in the midclavicular line, motor block of the lower limbs was evaluated using a modified Bromage scale and the sedation scored on a five point scale. Maternal and fetal cardiovascular variables were measured every 5 min for 30 min after the initial dose and subsequently at 20 min intervals until the end of labor. Quality of analgesia was evaluated both by the investigator and the mother. Additionally, onset of pain relief, the duration of pain relief after the main dose, duration of labor and cumulative dosages were recorded. A neonatalogist evaluated the babies by the Apgar score at 1, 5 and 10 minutes after birth. p<0.05 was considered to be significant. Results: There were no significant demographic differences between groups in respect of age, weight, height, gestational age, effacement and cervical dilatation. The median onset time for pain relief after the loading dose was shorter in R/F group (10.2±3.13 min) than B/F group (13.5±4.43 min) (p<0.05) The duration of analgesia after the loading dose in B/F group lasted slightly longer than R/F group (98.6±21.2 vs 84.5±13.7 min) but there was no statistical significance. The total amount of local anesthetics and the duration of labor were similar in both groups. Adequate analgesia were obtained with both drugs as VAS scores remained stable and similar in both groups during the study period. Overall quality of analgesia as judged by parturients and investigator was satisfactory in both groups. Motor blockade was observed in two patients in B/F group whereas no patients had motor block in R/F group. Apgar scores were similar between groups. Discussion: The results suggest that epidural bupivacaine 0.25% and ropivacaine 0.25% combined with 1 μgr/kg fentanil are equipotent for epidural pain relief during labor. Ropivacaine 0.25% with 1 ugr/kg fentanil provides more reliable analgesia than bupivacaine-fentanyl combination as it has faster onset of analgesia and no motor block effect.