Comparison of low doses of intrathecal bupivacaine in combined spinal epidural anaesthesia with epidural volume extension for caesarean delivery

Abstract

Aims and Objectives:This study aims to compare relative efficacy of three different doses of intrathecal bupivacaine in combined spinal epidural anaesthesia (CSEA) for caesarean delivery.Materials and Methods:In a double blinded manner, 204 cases were randomized into three groups: I, II, and III to receive a dose of 4, 5.5, and 7 mg of hyperbaric bupivacaine with a fixed dose of 25 μg fentanyl intrathecally, and Dextran 40 w/v 10 mL given for epidural volume extension (EVE), in CSEA. Our primary outcome was the number of effective doses. The block characteristics and side effects were also monitored.Results:Out of 198 patients completing the study, 53, 63, and 65 in group I, II and III had effective doses. Mean Pi (probability of an effective dose) in group I, II, and III, was 0.81, 0.95, and 0.97, respectively. The Pb (superiority of one group over the other) of group II and III was higher than group I. The maximal sensory block height in group II and III (T2) was higher than group I (T3), with a shorter time required to achieve the same. Group I and II exhibited lesser motor blockade, lesser hypotension with early recovery as compared to group III. No significant adverse effects were observed between the groups.Conclusion:The intermediate dose of bupivacaine (5.5 mg) provided safe and effective anaesthesia for caesarean delivery with an additional advantage of lesser episodes of hypotension and partial motor blockade in CSEA.

Comparison of colloid preload versus coload under low dose spinal anesthesia for cesarean delivery

“…These findings are also supported by a similar study conducted with colloid preload demonstrating an 18% incidence of hypotension under low dose spinal anesthesia (9 mg). [ 2 ] However, our previous study showed a 17.4% incidence of hypotension under the similar spinal anesthetic doses (5.5 mg). [ 3 ] Higher incidence of hypotension in that the study could be accredited to use of crystalloid preload or due to higher sympathetic blockade (sensory block: T2-T3 level) as an effect of epidural volume extension.…”

“…[ 7 8 9 10 ] We chose a dose of 5.5 mg hyperbaric bupivacaine, considering its safety and efficacy in reduction of hypotension and low failure rates (5%) for cesarean delivery under spinal anesthesia. [ 2 ] With regard to colloid of choice, we opted for Hydroxyl ethyl starch (6%), considering its wider margin of safety against venous thrombosis and allergic reactions. [ 11 ] It is also considered to be safe for the neonate and placental transfer has been found to be negligible even at a 10% concentration in various experimental studies.…”

“…[ 1 ] Apart from this, low dose spinal anesthesia has also been shown to markedly reduce the incidence of hypotension by causing less intense sympathetic blockade and thus providing a stable SVR. [ 2 ]…”

Low dose hyperbaric bupivacaine 5 mg combined with 50 mcg fentanyl for cesarean section in maternal heart disease

“…The uterine blood flow is not autoregulated, so the uteroplacental perfusion is directly related to maternal blood pressure. 11 Hence, maternal blood pressure can be tolerated only by the mother but not by the fetus. One strategy to maintain both stable hemodynamics and adequate anesthesia block during spinal anesthesia in CS surgery is to use low-dose bupivacaine combined with opioid adjuvant.…”