Efficacy of low-dose bupivacaine in spinal anaesthesia for Caesarean delivery: systematic review and meta-analysis

Abstract

Spinal anaesthesia is the preferred anaesthetic technique for elective Caesarean deliveries. Hypotension is the most common side-effect and has both maternal and neonatal consequences. Different strategies have been attempted to prevent spinal-induced hypotension, including the use of low-dose bupivacaine. We conducted a systematic search for randomized controlled trials comparing the efficacy of spinal bupivacaine in low dose (LD ≤8 mg) with conventional dose (CD >8 mg) for elective Caesarean delivery. Thirty-five trials were identified for eligibility assessment, 15 were selected for data extraction, and 12 were finally included in the meta-analysis. We investigated sources of heterogeneity, subgroup analysis, and meta-regression for confounding variables (baricity, intrathecal opioids, lateral vs sitting position, uterine exteriorization, and study population). Sensitivity analysis was performed to test the robustness of the results. In the LD group, the need for analgesic supplementation during surgery was significantly higher [risk ratio (RR)=3.76, 95% confidence interval (95% CI)=2.38-5.92] and the number needed to treat for an additional harmful outcome (NNTH) was 4 (95% CI=2-7). Furthermore, the LD group exhibited a lower risk of hypotension (RR=0.78, 95% CI=0.65-0.93) and nausea/vomiting (RR=0.71, 95% CI=0.55-0.93). Conversion to general anaesthesia occurred only in the LD group (two events). Neonatal outcomes (Apgar score, acid-base status) and clinical quality variables (patient satisfaction, surgical conditions) showed non-significant differences between LD and CD. This meta-analysis demonstrates that low-dose bupivacaine in spinal anaesthesia compromises anaesthetic efficacy (risk of analgesic supplementation: high grade of evidence), despite the benefit of lower maternal side-effects (hypotension, nausea/vomiting: moderate grade of evidence).

Maternal Satisfaction of Spinal Anesthesia for Elective Cesarean Section in an Academic Hospital

“…Selection of the correct anesthetic method is multifactorial for mothers. Anesthesiologists usually prefer a method, which is safe and comfortable for the mother and is associated with the least fetal depression and the best surgical conditions for the gynecologist; spinal anesthesia has all these characteristics (3)(4)(5).…”

Association of lipophilic opioids and hyperbaric bupivacaine in spinal anesthesia for elective cesarean section. Randomized controlled study

“…However, the use of the local anesthetic alone is associated with a short duration of action and infrequent occurrence of nausea in the intraoperative period during uterine and peritoneal manipulation 1,2 . Hyperbaric bupivacaine is frequently employed in doses ranging from 4.0 to 15 mg. Doses below 10 mg used alone or 8.0 mg combined with an opioid are considered low doses of local anesthetics [2][3][4][5][6] .…”

“…Furthermore, there is a decrease in local anesthetic dose, minimizing the risk of maternal arterial hypotension and damage to the fetus [2][3][4][6][7][8][9] .…”

Low-Dose Bupivacaine Versus High-Dose Bupivacaine Along With Fentanyl for Spinal Anesthesia in Opioid-Dependent Mothers

“…The bupivacaine start time was faster, yet duration of anesthesia in levobupivacaine was longer (14). In a systematic research on 35 studies, bupivacaine with doses above and below 8 mg was evaluated.…”