Hyperbaric vs. isobaric bupivacaine for spinal anaesthesia for elective caesarean section: a Cochrane systematic review

Randomized Double-Blind Study of the Effect of Injectate Temperature on Intrathecal Bupivacaine Dose Requirement in Spinal Anesthesia for Cesarean Delivery

BACKGROUND

Increasing the temperature of intrathecal local anesthetics has been shown to increase the speed of onset and block height of spinal anesthesia. However, how this influences dose requirement has not been fully quantified. The aim of this study was to determine and compare the effective dose for anesthesia for cesarean delivery in 50% of patients (ED50) of intrathecal bupivacaine given at temperatures of 37 °C (body temperature) or 24 °C (room temperature).

METHODS

Eighty healthy parturients having elective cesarean delivery under combined spinal-epidural anesthesia were randomly assigned to receive intrathecal hyperbaric bupivacaine stored at 37 °C (body temperature group) or 24 °C (room temperature group). The first subject in each group received a bupivacaine dose of 10 mg. The dose for each subsequent subject in each group was varied with an increment or decrement of 1 mg based on the response (effective or noneffective) of the previous subject. Patients for whom the dose was noneffective received epidural supplementation after data collection with lidocaine 2% as required until anesthesia was sufficient for surgery. Values for ED50 were calculated using modified up-down sequential analysis with probit analysis applied as a backup sensitivity analysis. These values were compared and the relative mean potency was calculated.

RESULTS

The ED50 (mean [95% confidence interval, CI]) of intrathecal hyperbaric bupivacaine was lower in the body temperature group (6.7 [5.7-7.6] mg) compared with the room temperature group (8.1 [7.7-8.6] mg) (P < .05). The relative potency ratio for intrathecal bupivacaine for the room temperature group versus the body temperature group was 0.84 (95% CI, 0.77-0.93).

CONCLUSIONS

Warming hyperbaric bupivacaine to body temperature reduced the dose requirement for spinal anesthesia for cesarean delivery by approximately 16% (95% CI, 7%-23%).

Effects of Hyperbaric and Isobaric Bupivacaine on Hemodynamic Profiles and Block Characteristics Among Parturients Undergoing Elective Cesarean Section Under Spinal Anesthesia: A Randomized Controlled Trial

Background

Cesarean section (CS) is a surgical procedure where the baby is delivered through incisions made in the abdomen and uterus. Bupivacaine is a widely recognized local anesthetic available in different baricity and it is frequently used for spinal anesthesia. The baricity of bupivacaine impacts hemodynamic profiles and block characteristics.

Objective

To compare the effects of hyperbaric and isobaric bupivacaine on hemodynamic profiles and block characteristics among parturients undergoing elective cesarean section under spinal anesthesia at Dilla University Referral Hospital.

Methods

64 pregnant mothers scheduled for elective cesarean section under spinal anesthesia were randomly assigned to two groups: Group A received a dose of 12.5 mg of isobaric bupivacaine (n = 32), Group B received a dose of 12.5 mg of hyperbaric bupivacaine (n = 32). Prior to conducting the study, the necessary ethical approvals were obtained. For comparing numerical variables between the two groups, the independent Sample t-test or Mann-Whitney U-test was employed as needed. Repeated measurements were analyzed using mixed ANOVA. Categorical variables were assessed using either the chi-square test or Fisher's exact test. Statistical significance was set at P < 0.05, with a power of 90%.

Results

The mean Systolic Blood Pressure (SBP), Diastolic Blood pressure (DBP), and Mean Arterial Blood Pressure (MAP) showed significant decrement in the group receiving isobaric spinal anesthesia compared to those receiving hyperbaric bupivacaine. The decrement was observed from the 6th to 30th minute (p<0.05). Furthermore, the hyperbaric group had a faster onset time for achieving the maximum sensory block, with a median time of 3 (1) min compared to 4 (2) mins in the isobaric group (p<0.001).

Conclusion and Recommendation

We conclude that hyperbaric bupivacaine provides stable intraoperative hemodynamic parameters and an earlier onset of block than isobaric bupivacaine. Therefore, we recommend clinicians to use hyperbaric bupivacaine for cesarean delivery.

Spinal anesthesia in elective lumbar spinal surgery

Spinal anesthesia (SA) is gaining recognition as a safe and efficacious regional alternative to general anesthesia for elective lumbar surgery. However, unfamiliarity with management issues related to its use has limited the adoption of awake spine surgery, despite its benefits. Few centers in the United States routinely offer SA for elective lumbar surgery, and a comprehensive workflow to standardize SA for lumbar surgery is lacking. In this article, we examine recent literature on the use of SA in lumbar surgery, review the experience of our institution with SA in lumbar surgery, and provide a cohesive outline to streamline the implementation of SA from the perspective of the anesthesiologist. We review the critical features of SA in contemporary lumbar surgery, including selection of patients, methods of SA, intraoperative sedation, and management of several important technical considerations. We aimed to flatten the learning curve to improve the availability and accessibility of the technique for eligible patients.

Treatment of spinal anaesthesia-induced hypotension with cafedrine/theodrenaline versus ephedrine during caesarean section: Results from HYPOTENS, a national, multicentre, prospective, noninterventional study

BACKGROUND

In Germany, hypotension induced by spinal anaesthesia is commonly treated with a combination of cafedrine hydrochloride (C, 200 mg) and theodrenaline hydrochloride (T, 10 mg) in 2 ml. We compared the effectiveness of C/T with ephedrine.

OBJECTIVES

The primary objectives were to assess the speed of onset and the ability to restore blood pressure without an increase in heart rate. Secondary objectives were to evaluate maternal/foetal outcomes and the number of required additional boluses or other additional measures.

DESIGN

HYPOTENS was a national, multicentre, prospective, open-label, two-armed, noninterventional study comparing C/T with ephedrine in two prospectively defined cohorts. This study relates to the cohort of patients receiving spinal anaesthesia for caesarean section.

SETTING

German hospitals using either C/T or ephedrine in their routine clinical practice.

PATIENTS

Women aged at least 18 years receiving spinal anaesthesia for caesarean section.

INTERVENTIONS

Bolus administration of C/T or ephedrine at the discretion of the attending anaesthesiologist.

MAIN OUTCOME MEASURES

Endpoints within 15 min after initial administration of C/T or ephedrine were area under the curve between the observed SBP and the minimum target SBP; and incidence of newly occurring heart rate of at least 100 beats min-1.

RESULTS

Although effective blood pressure stabilisation was achieved with both treatments, this effect was faster and more pronounced with C/T (P < 0.0001). The incidence of tachycardia and changes in heart rate were higher with ephedrine (P < 0.01). Fewer additional boluses (P < 0.01) were required with C/T. Although favourable neonatal outcomes were reported in both groups, base deficit and lactate values were greater with ephedrine (P < 0.01). Physician satisfaction was higher with C/T.

CONCLUSIONS

After C/T, tachycardia was not a problem, providing an advantage over ephedrine. Fewer additional boluses were required with C/T, suggesting greater effectiveness. An increased base deficit with ephedrine suggests reduced oxygen supply or increased demands in foetal circulation.

TRIALS REGISTRATION

Clinicaltrials.gov: NCT02893241, German Clinical Trials Register: DRKS00010740.

Combined spinal epidural anesthesia in obese parturients undergoing cesarean surgery : A single-blinded randomized comparison of lateral decubitus and sitting positions

BACKGROUND

There is a significant increase in number of obese pregnant women worldwide. Obese parturients undergoing cesarean section have a higher risk for hypotension and require higher doses of vasopressors following spinal anesthesia compared to nonobese parturients.

OBJECTIVE

This study aimed to compare the maternal hemodynamic changes when combined spinal-epidural anesthesia (CSEA) is induced in the left lateral decubitus and sitting positions in obese pregnant women undergoing elective cesarean section.

MATERIAL AND METHODS

In this study, pregnant women with full-term gestation diagnosed as obese undergoing elective cesarean section were included. Two groups were formed: the CSEA was performed in left lateral position in group I (n = 50) and in sitting position in group II (n = 50). At the end of the CSEA procedure, patients were placed in the supine position. When the sensory block reached at the upper level of T6 dermatome, surgery was initiated. Hemodynamic, anesthetic and neonatal parameters were recorded.

RESULTS

In all patients, CSEA was successful and sufficient anesthesia was provided for surgery. Time to reach T6 dermatome sensory level in group II was found to be longer than group I (P = 0.011). At 20 min after spinal injection, the maximum sensory block level was similar in both groups. There were no significant differences between groups in terms of sensory block time and the time to requiring postoperative supplemental analgesics. There were no significant differences in terms of the volume of intravenous fluid administered, ephedrine and atropine requirements between groups. Both groups had similar systolic blood pressure, heart rate and oxygen saturation values during surgery and postoperatively. While both groups had similar diastolic blood pressure (DBP) values during surgery and at the 1st postoperative hour, group II had lower DBP values at the 2nd postoperative hour compared with group I (P = 0.04).

CONCLUSION

Left lateral decubitus and sitting positions during performance of CSEA lead to similar maternal hemodynamic changes in obese pregnant women undergoing cesarean section.

The effect of baricity of intrathecal bupivacaine for elective cesarean delivery on maternal cardiac output: a randomized study

BACKGROUND

Hemodynamic instability during spinal anesthesia for cesarean delivery is associated with adverse maternal and fetal outcomes. Plain and hyperbaric bupivacaine are commonly used for cesarean delivery, however, their distinctive pharmacologic properties may affect maternal hemodynamic profiles differently. The aim of this study was to compare hemodynamic profiles using a suprasternal Doppler cardiac output (CO) monitor in healthy term parturients randomized to receive plain or hyperbaric bupivacaine for cesarean delivery.

METHODS

One hundred-and-sixty-eight healthy parturients scheduled for elective cesarean delivery were randomly assigned to receive 10.9 mg of intrathecal 0.5% plain or hyperbaric bupivacaine, both with 0.2 mg morphine. The primary outcome was CO change after spinal anesthesia. Secondary outcomes were the incidence of hypotension, vasopressor use, and conversion to general anesthesia.

RESULTS

The mean (±SD) CO at baseline, 1 min and 5 min after spinal anesthesia, and after placental delivery was 4.6 ± 1.2, 5.4 ± 1.3, 5.1 ± 1.4, and 6.4 ± 1.7 L/min in the plain bupivacaine, and 4.5 ± 1.1, 5.2 ± 1.3, 4.9 ± 1.3, and 6.2 ± 1.9 L/min in the hyperbaric bupivacaine group. There were no significant differences in CO, mean arterial pressure, or systemic vascular resistance. Incidences of hypotension, vasopressor and supplemental analgesic use, and conversion to general anesthesia, were not different between groups.

CONCLUSIONS

Cardiac output changes after plain or hyperbaric bupivacaine were not different in term parturients undergoing spinal anesthesia for cesarean delivery. Further studies comparing block quality and the rate of conversion to general anesthesia are required.

What's new in obstetric anesthesia in 2018?

The Gerard W. Ostheimer Lecture presented at the annual meeting of the Society of Obstetric Anesthesia and Perinatology (SOAP) is a one-year summary of the literature published in domains of interest to anesthesiologists who manage and care for obstetric patients. One individual is asked to review the literature and present the lecture. This manuscript summarizes aspects of the Gerard W. Ostheimer Lecture presented at the 2019 SOAP meeting; the relevant literature from 2018 was summarized. The topics included in this review are maternal morbidity, antibiotic prophylaxis, anaphylaxis, the Lancet series on increasing cesarean delivery rates, the Robson Ten-Group Classification System, pelvic floor disorders, timing of delivery in nulliparous women, placenta accreta disorders, anesthesia for cesarean delivery, labor analgesia (including parturients with thrombocytopenia and tattoos, and epidural maintenance with the programmed intermittent epidural bolus technique), ultrasound use in obstetric anesthesia, and drugs in pregnancy.

[Selection of the optimal anesthesia regimen for cesarean section]

Approximately one third of all children in Germany are delivered by cesarean section. Depending on the individual patient's condition and the situation, the anesthesiologist has to choose between a general or a regional anesthesia regimen. The decisive factor for the selection is the obstetric urgency (decision-delivery time) after ascertainment of the indications. Furthermore, the need for postoperative analgesia varies depending on the chosen anesthesia regimen.

Comparison of nalbuphine, ondansetron and placebo for the prevention of shivering after spinal anaesthesia for urgent caesarean delivery: a randomised double-blind controlled clinical trial

BACKGROUND

Shivering is a common complication of caesarean delivery with neuraxial anaesthesia. The effective prevention and treatment of shivering, especially before delivery, is important and difficult. We tested the hypothesis that prophylactic nalbuphine and ondansetron can prevent post-spinal anaesthesia shivering in parturients undergoing urgent caesarean delivery.

METHODS

Sixty parturients scheduled for urgent caesarean delivery before spinal anaesthesia were selected and divided randomly into three groups. After peripheral venous catheterisation, parturients were given intravenous nalbuphine 0.08 mg/kg (group N), ondansetron 8 mg (group O), or normal saline (group C).

RESULTS

The incidence of shivering and of severe (grade ≥3) shivering was significantly lower in group N (15% and 15%, respectively) than in group C (80% and 65%) before delivery (P <0.001 and P=0.003); and significantly less shivering was observed in group N than in group C in the first 30 min after anaesthesia (P=0.001). Up to 60 min after anaesthesia, the incidence of grade ≥3 shivering remained lowest in group N (P=0.003). According to the data during the period from anaesthesia until delivery, the number needed-to-treat for nalbuphine was 1.54 (95%CI 1.13 to 2.41). No significant differences were found between groups O and N or groups O and C at any time. The incidence of dizziness in group N was significantly higher than that of groups O or C (P=0.009).

CONCLUSION

Nalbuphine 0.08 mg/kg can prevent post-spinal anaesthesia shivering in parturients undergoing urgent caesarean delivery but causes transient dizziness, while ondansetron 8 mg had no significant effect.

The analgesic effects of intrathecal morphine in comparison with ultrasound-guided transversus abdominis plane block after caesarean section: a randomised controlled trial at a Ugandan regional referral hospital

Both transversus abdominis plane block and intrathecal morphine may produce prolonged postoperative analgesia, but the respective clinical outcomes of these anaesthetic techniques in resource-limited settings are not well described. We randomly assigned patients undergoing caesarean section to receive a hyperbaric bupivacaine (10 mg) spinal anaesthetic followed by an ultrasound-guided transversus abdominis plane block, or a hyperbaric bupivacaine (10 mg) spinal anaesthetic with 100 mcg intrathecal morphine, followed by a postoperative sham block. Supplemental postoperative analgesia included self-administered oral diclofenac 50 mg and paracetamol 1 g every 8 h. Numerical pain rating scores, the need for rescue medication, side-effects and patient satisfaction were recorded at 8, 16 and 24 h. We enrolled a total of 130 patients, with 65 women in each group. The mean numerical rating score for intrathecal morphine vs. transversus abdominis plane blocks at 8 h were: at rest, 2.5 vs. 3.1 (p = 0.04); with coughing, 4.3 vs. 4.8 (p = 0.07); and with movement, 3.6 vs. 4.2 (p = 0.06). At 16 h, respective scores were: 2.9 vs. 3.1 (p = 0.40) at rest; 4.0 vs. 4.3 (p = 0.19) with coughing; and 4.8 vs. 5.0 (p = 0.33) with movement. At 24 h, the respective scores were: 2.9 vs. 2.3 (p = 0.01); 4.6 vs. 4.2 (p = 0.04) with coughing; and 3.9 vs. 3.4 (p = 0.02) with movement. The need for rescue medication and the incidence of pruritis, sedation and nausea and vomiting were similar in both groups. Patient satisfaction with pain control was similar in both groups, with the majority of patients reporting satisfaction as good or excellent. Intrathecal morphine and transversus abdominis plane block provided clinically similar outcomes for pain relief after caesarean section.