Norepinephrine intravenous prophylactic bolus versus rescue bolus to prevent and treat maternal hypotension after combined spinal and epidural anesthesia during cesarean delivery: a sequential dose-finding study

Abstract

Background: As a relatively new drug in obstetrical anesthesia, norepinephrine is less likely to induce bradycardia and decrease cardiac output, which makes it a potential alternative to phenylephrine. The purpose of this study was to determine the optimal norepinephrine bolus dose needed to either prevent or reverse hypotension after the use of combined spinal and epidural (CSE) anesthesia in 90% of women during elective cesarean delivery (CD).Methods: Eighty women undergoing elective CD were randomly allocated into either a prophylactic group or a rescue group in this dose finding study. If the women's systolic blood pressure (SBP) was maintained above 80% of their baseline, the next patient had an 8/9 th chance of receiving the same dose or a 1/9 th chance of receiving a lower dose. If the patient's SBP was not maintained, a higher dose was used for next patient.The primary outcome was the successful use of the norepinephrine bolus dose to maintain SBP above 80% of the baseline until after delivery. Secondary outcomes included nausea, vomiting, breathlessness, dizziness, hypertension, bradycardia due to hypotension and supplemental use of atropine and norepinephrine, upper sensory level of anesthesia, umbilical vein (UV) blood gases, and 1-and 5-minute Apgar scores. The 90% effective dose (ED 90 ) and 95% confidence interval (95% CI) were estimated using isotonic regression methods. Results:The estimated ED 90 of the norepinephrine prophylactic bolus was 10.85 µg (95% CI, 9.20-11.67 µg) and that of the norepinephrine rescue bolus was 12.3 µg (95% CI, 10.0-12.8 µg) using isotonic regression methods.Conclusions: For norepinephrine, either a prophylactic bolus dose of 11 µg or a rescue bolus dose of 12 µg was recommended for clinical practices.

Optimum Dose of Spinal Ropivacaine with or Without Single Intravenous Bolus of S-Ketamine During Elective Cesarean Delivery: A Randomized, Sequential Dose-Finding Study

“…Several methods have been proposed to reduce the incidence or severity of maternal hypotension after spinal anesthesia during cesarean delivery, including the use intrathecal adjuvant opioids to decrease the total dose of anaesthetics used, 8 prophylactic use of vasopressors, 4,9 and IV pre-load colloid liquid administration. 10 Zieleskiewicz et al 1 and Yao et al 3 used B ultrasound, Xu et al 20 and Toyama et al…”

“…[4][5][6][7] Thus, hypotension prevention is paramount to good outcomes. Methods such as intrathecal adjuvant opioid use to reduce the total dose of anaesthetics delivered, 8 prophylactic use of vasopressors, 4,9 and the use of intravenous (IV) pre-load colloid liquid 10 have been proposed to reduce the incidence or extent of maternal hypotension after spinal anesthesia during cesarean delivery. S-ketamine is an S + isomer of ketamine that is twice as potent as ketamine 11 ; it achieves sedation, analgesia, and sympathetic activation 12 with a relatively low risk of side effects to mothers or infants, 13 making it an optimum choice as an IV adjuvant for spinal anesthesia during cesarean delivery.…”

The transverse diameter of right common femoral vein by ultrasound in the supine position for predicting post-spinal hypotension during cesarean delivery

“…The incidence of post-spinal anesthesia hypotension during cesarean delivery is approximately 70% [1,2]. Post-spinal anesthesia hypotension can lead to adverse maternal and fetal outcomes, such as maternal nausea, vomiting, dyspnea, neonatal depressed Apgar scores, and fetal acidosis [3][4][5][6][7][8]. Therefore, effective prediction of maternal hypotension could have immense clinical importance.…”

The transverse diameter of right common femoral vein by ultrasound in the supine position for predicting post-spinal hypotension during cesarean delivery.

“…The incidence of post-spinal anesthesia hypotension during cesarean delivery was approximately 70% as reported [1,2]. Post-spinal anesthesia hypotension can also lead to adverse maternal and fetal outcomes, such as maternal nausea, vomiting and dyspnea or neonatal depressed Apgar scores and fetal acidosis [3][4][5][6][7][8]. Therefore, effective prediction of maternal hypotension could be of great clinical importance.…”