Optimum dose of spinal ropivacaine with or without single intravenous bolus of S-ketamine during elective cesarean delivery: a randomized, double-blind, sequential dose-finding study

Abstract

Background Maternal hypotension after spinal anaesthesia occurs at a high rate during caesarean delivery and can lead to adverse maternal or foetal outcomes. The aim of this study was to determine the optimal dose of spinal ropivacaine for caesarean section with or without intravenous single bolus of S-ketamine and to observe the rates of hypotension associated with both methods. Methods Eighty women undergoing elective caesarean delivery were randomly allocated into either a ropivacaine only or ropivacaine with intravenous S-ketamine group. If the upper sensory level of the patient reached T6 and the visual analogue scale (VAS) scores remained below 3 points before delivery, the next patient had a 1/9th chance of receiving a lower dose or an 8/9th chance of receiving the same dose as the previous patient. If the patient had VAS scores of more than 2 points or needed an extra epidural rescue bolus before delivery, a higher dose was used for the next patient. The primary outcome was the successful use of spinal ropivacaine to maintain patient VAS score of < 3 points before delivery and the incidence of post-spinal hypotension in both groups. Secondary outcomes included the rates of hypotension-related symptoms and interventions, upper sensory level of anaesthesia, level of sedation, neonatal outcomes, Edinburgh Postnatal Depression Scale scores at admission and discharge, and post-operative analgesic effect. The 90% effective dose (ED90) and 95% confidence interval (95% CI) were estimated by isotonic regression. Results The estimated ED90 of ropivacaine was 11.8 mg (95% CI: 11.7–12.7) with and 14.7 mg (95% CI: 14.6–16.0) without intravenous S-ketamine, using biased coin up-down sequential dose-finding method. The rates of hypotension and associated symptoms were significantly lower in S-ketamine group than in the ropivacaine only group. Conclusions A spinal dose of ropivacaine 12 mg with a single intravenous 0.15 mg/kg bolus dose of S-ketamine may significantly reduce the risk of hypotension and induce sedation before delivery. This method may be used with appropriate caution for women undergoing elective caesarean delivery and at a high risk of hypotension or experiencing extreme nervousness. Trial registration http://www.chictr.org.cn (ChiCTR2000040375; 28/11/2020).

Efficacy and Safety of Esketamine for Supplemental Analgesia During Elective Cesarean Delivery

“…In the study by Zhang et al, use of low-dose esketamine (0.15 mg/kg) was associated with a decreased incidence of hypotension during spinal anesthesia for cesarean delivery. It is therefore recommended that ketamine and esketamine should be considered for women undergoing elective cesarean delivery and at a high risk of hypotension . In accordance with these results, we also found that patients given esketamine had higher mean arterial blood pressure and heart rate, but again, the effects were transient and only significant at 5 minutes after study drug administration and immediately after fetal delivery.…”

“…In fact, low-dose ketamine and esketamine have been used prophylactically in women undergoing cesarean delivery and are reported to be effective in improving analgesia and relieving depression . In a sequential dose-finding study, an intravenous dose of 0.15 mg/kg of esketamine injected before surgery significantly reduced the 95% effective dose of spinal ropivacaine for cesarean delivery . We therefore adopted a prophylactic regimen.…”

“…Esketamine can stimulate the sympathetic nervous system and increase blood pressure and heart rate, especially when given in high doses . In the study by Zhang et al, use of low-dose esketamine (0.15 mg/kg) was associated with a decreased incidence of hypotension during spinal anesthesia for cesarean delivery. It is therefore recommended that ketamine and esketamine should be considered for women undergoing elective cesarean delivery and at a high risk of hypotension .…”

Does adding ketamine to morphine in a patient-controlled intravenous analgesia pump after orthopedic surgeries help better management of postoperative pain in obese patients? A double-blinded clinical trial

“…In another research, the mean consumption of ketamine during the first 24 hours after major abdominal surgery in obese patients amounted to 3.2 mg/h (15,16). However, no measurable impact was found.…”

Routine Prophylactic Esketamine for the Prevention of Maternal Pain During Cesarean Delivery

“…The authors report no clinically significant difference in numeric rating scale (NRS) pain scores at any of the 8 prespecified time points, which ranged from immediately through 12 hours (median difference in NRS scores, 0; 95% CI, 0-0). In contrast, median (IQR) sedation scores were significantly increased during the operative period (2 in the placebo group vs vs 4 [3][4] in the esketamine group), suggesting that mothers were "light asleep but responding to touch or pain." Placental transfer of esketamine was evident in the small subsample (n = 13) of neonatal blood samples, yet neonatal outcomes (Apgar scores and acid-base status) were similar between the groups.…”