Open AccessED50 and ED95 of intrathecal hyperbaric ropivacaine for parturients undergoing cesarean section with prophylactic infusion of phenylephrine
Author(s) -
Wenping Xu,
Fei Xiao,
Yinfa Zhang,
Lin Li,
Xiangyang Chang
Publication year - 2018
Publication title -
medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.59
H-Index - 148
eISSN - 1536-5964
pISSN - 0025-7974
DOI - 10.1097/md.0000000000013727
Subject(s) - medicine , ropivacaine , anesthesia , phenylephrine , intrathecal , spinal anesthesia , sufentanil , surgery , blood pressure , radiology
Background: Studies have reported that the ED 50 of intrathecal ropivacaine was increased when using prophylactic infusion of phenylephrine to prevent spinal-induced hypotension. However, ED 95 is more meaningful to clinical practice than ED 50 . Therefore, we conducted this study to determine the 95% effective dose (ED 95 ) of intrathecal hyperbaric ropivacaine for cesarean section in parturients receiving prophylactic infusion of phenylephrine to prevent spinal-induced hypotension. Methods: A hundred of healthy parturients undergoing elective cesarean section under combined spinal-epidural anesthesia (CSEA) were enrolled in this randomized, double-blinded, dose-ranging study. Patients were randomly assigned to receive 7, 9, 11, 13 or 15 mg intrathecal hyperbaric ropivacaine respectively. The prophylactic phenylephrine infusion (50 μg/min) was initiated immediately at the same time of spinal injection. Successful spinal anesthesia was defined as a T5 sensory level achieved within 10 min after intrathecal drug administration and no epidural supplement was required during the surgery. The ED 95 was calculated with Probit analysis. Results: The ED 95 of intrathecal ropivacaine with 5 μg sufentanil for successful anesthesia was 15.2 mg (95%CI, 13.5–18.8 mg), when receiving prophylactic infusion of phenylephrine. Conclusion: Under the conditions of the present study, the ED 95 of intrathecal hyperbaric ropivacaine for successful spinal anesthesia for cesarean section in healthy parturient receiving prophylactic infusion of phenylephrine was 15.2 mg.