Effects of methylergometrine and oxytocin on thoracic epidural pressure during cesarean section

• Published in: The journal of obstetrics and gynaecology research Vol. 29; no. 3; pp. 180 - 185
• Main Authors: Kikutani, Takehiko, Shimada, Yoichi
• Format: Journal Article
• Language: English
• Published: Melbourne, Australia Blackwell Publishing Ltd 01.06.2003
• Subjects: Blood Pressure; Cesarean Section; Epidural Space; Female; Humans; Methylergonovine - administration & dosage; oxytocics; Oxytocics - administration & dosage; Oxytocin - administration & dosage; Pregnancy; Pressure; spinal anesthesia; Thorax
• ISSN: 1341-8076; 1447-0756
• DOI: 10.1046/j.1341-8076.2003.00097.x

Aim:  The effects of oxytocics on thoracic epidural pressure during cesarean section were studied in 60 parturients, (American Society of Anesthesiologist physical status, class I or II) after obtaining informed consent. Methods:  The subjects were randomized to either a ergometrine (n = 30) or oxytocin treatment group (n = 30). The subjects were anesthetized with 11–12 mg of intrathecal isobaric bupivacaine (0.5%), and an epidural catheter was placed at Th 11/12, and was connected to a pressure transducer to continuously monitor thoracic epidural pressure. We analyzed epidural pressure, blood pressure, and heart rate 5 min after administering intrathecal bupivacaine (SAB5m), immediately before skin incision (pre‐incision), immediately after delivery of the placenta (placenta‐del), and 5 min after delivery of the fetus (CS5m). Results:  In both groups, epidural pressures were found to be elevated after delivery compared with their levels before the skin incisions were made, (P < 0.0001). Epidural pressures at placenta‐del (P = 0.0055) and CS5m (P < 0.0001) were higher than at SAB5m in the ergometrine group. Epidural pressures at placenta‐del were also higher than at SAB5m in the oxytocin group (P < 0.0001). Epidural pressures at placenta‐del were lower in the ergometrine group compared with the oxytocin group (P = 0.0122), but epidural pressures at CS5m were higher in the ergometrine group compared with the oxytocin group (P < 0.0001). Conclusions:  We conclude that there is an increase in thoracic epidural pressure after fetal delivery, which appears to be associated with uterine contraction.