Low-dose spinal anesthesia for cesarean section to prevent spinal-induced hypotension

The effect of adding dexmedetomidine or dexamethasone to bupivacaine-fentanyl mixture in spinal anesthesia for cesarean section

Background and Aims

Many strategies are available to prevent spinal-induced hypotension in cesarean section, especially the use of a low dose of spinal anesthesia combined with adjuvants. This study investigated the effect of adding either dexmedetomidine or dexamethasone to the intrathecal bupivacaine-fentanyl mixture on the postoperative analgesia duration, after elective cesarean section.

Material and Methods

This prospective, randomized, double-blind study was conducted on 90 full-term parturients undergoing elective cesarean section, who were randomly distributed into three groups. They all received spinal anesthesia with the bupivacaine-fentanyl mixture (2.5 ml), in addition to 0.5 ml normal saline (control group), 5 μg dexmedetomidine dissolved in 0.5 ml normal saline (dexmedetomidine group), or 2 mg dexamethasone (dexamethasone group). The time to the first request of morphine rescue analgesia was recorded, in addition to the total dose of morphine consumed in the first 24 h after surgery, the postoperative numerical rating score (NRS), and maternal and fetal outcomes.

Results

As compared to the control group and the dexamethasone group, the use of dexmedetomidine as an additive to the bupivacaine-fentanyl mixture significantly prolonged the time to the first request of rescue analgesia, decreased postoperative morphine consumption, and decreased the pain score 4 and 6 h after surgery. There was an insignificant difference between the control and dexamethasone groups.

Conclusion

The use of dexmedetomidine as an additive to bupivacaine-fentanyl mixture in spinal anesthesia for cesarean section prolonged the postoperative analgesia and decreased the postoperative opioid consumption in comparison to the addition of dexamethasone or normal saline.

Anesthetic management of fetal pulmonary valvuloplasty: A case report

Anesthesia management of fetal pulmonary valvuloplasty (FPV) is difficult, requiring careful consideration of both the mother and the fetus. Few reports have been published on specific anesthesia implementation and intraoperative management. We report the case of a pregnant woman who was treated with FPV under combined spinal epidural anesthesia (CSEA) with dexmedetomidine in the second trimester of pregnancy. Meanwhile, the application of fetal anesthesia through the umbilical vein was optimal. During the operation, the vital signs of the pregnant woman were stable with no complications and the fetal bradycardia was corrected by intracardiac injection of epinephrine. Four months postoperatively, a boy was born alive by full-term transvaginal delivery. CSEA may be a suitable anesthesia method for FPV surgery. Nevertheless, maternal hemodynamic stability maintenance, effective fetal anesthesia, and timely fetal resuscitation were necessary.

Intrathecal dexmedetomidine as an adjuvant to plain ropivacaine for spinal anesthesia during cesarean section: a prospective, double-blinded, randomized trial for ED50 determination using an up-down sequential allocation method

BACKGROUND

Intrathecal dexmedetomidine, as an adjuvant to local anesthetics, has been reported to improve the quality of spinal anesthesia and reduce the required local anesthetic dose. However, the optimal dosage regimen for intrathecal dexmedetomidine combined with plain ropivacaine for cesarean section (CS) remains undetermined. The present study aimed to determine the median effective dose (ED50) of intrathecal dexmedetomidine as an adjuvant to plain ropivacaine for spinal anesthesia during CS.

METHODS

Sixty parturients undergoing CS were randomly assigned to either group: plain ropivacaine 8 mg (Group Rop8) or plain ropivacaine 10 mg (Group Rop10). The initial dosage of intrathecal dexmedetomidine in each group was 5 µg. The effective dose was defined as a bilateral sensory block at the level of T6 or above to pinprick attained within 10 min after intrathecal injection, without the need for supplementary intraoperative epidural anesthesia. Effective or ineffective responses were determined, followed by a 1 µg increment or decrement in the dose of intrathecal dexmedetomidine for the next parturient using up-down sequential allocation. ED50 were calculated using probit regression.

RESULTS

The ED50 of intrathecal dexmedetomidine with plain ropivacaine was 5.9 µg (95% confidence interval [CI], 4.9-7.4 µg) in Group Rop8 and 3.1 µg (95% CI, 0.1-4.8 µg) in Group Rop10 (P < 0.05). Hemodynamic stability, side effects, patient satisfaction and neonatal outcomes were comparable between the two groups.

CONCLUSIONS

The present data suggested that the ED50 of intrathecal dexmedetomidine as an adjuvant to 8 mg and 10 mg plain ropivacaine in spinal anesthesia during cesarean section was approximately 6 µg and 3 µg, respectively.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, identifier: ChiCTR2200055928.

Current status of the combined spinal-epidural technique in obstetrics and surgery

Epidural and spinal blocks are well-accepted neuraxial techniques but both have several disadvantages. Combined spinal-epidural (CSE) can combine the best features of both techniques and reduce or eliminate these disadvantages. It provides the rapidity, density, and reliability of subarachnoid block with the flexibility of catheter epidural technique to extend the duration of anesthesia/analgesia (and to improve spinal block). It is an excellent technique for determining minimum intrathecal drug doses. Although most commonly employed in obstetric practice, CSE is also used in a wide variety of non-obstetric surgical procedures including orthopedic, vascular, gynecological, urological, and general surgical procedures. The needle-through-needle technique remains the most commonly used method to perform CSE. Several technical variations including Sequential CSE and Epidural Volume Extention (EVE) are commonly used particularly in obstetric and high-risk patients such as those with cardiac disease where a slower onset of sympathetic block is desirable. The risks of complications such as epidural catheter migration through the dural hole, neurological complications, and subarachnoid spread of epidurally administered drugs are possible but have not been a clinically relevant problem in the 40+ years of their existence. In obstetrics, CSE is used for labor pain because it produces rapid-onset analgesia with reduced local anesthetic consumption and less motor block. The epidural catheter placed as part of a CSE is more reliable than a catheter placed as part of a conventional epidural. Less breakthrough pain throughout labor is noted and fewer catheters require replacing. Side effects of CSE include greater potential for hypotension and more fetal heart rate abnormalities. CSE is also used for cesarean delivery. The main purpose is to decrease the spinal dose so that spinal-induced hypotension can be reduced. However, reducing the spinal dose requires an epidural catheter to avoid intra-operative pain when surgery is prolonged.

Sufentanil vs. Dexmedetomidine as Neuraxial Adjuvants in Cesarean Section: A Mono-Centric Retrospective Comparative Study

Spinal anesthesia is the best choice for caesarean delivery. This technique is characterized by a complete and predictable nerve block with a fast onset and few complications. Several intrathecal adjuvants are used in order to improve the quality and duration of anesthesia and reduce its side effects. Sixty-two patients who underwent caesarean delivery under spinal anesthesia were included in this medical records review. In this retrospective study, after adopting exclusion criteria, we assessed 24 patients who received Hyperbaric Bupivacaine 0.5% 10 mg and dexmedetomidine 10 μg (G1), and 28 patients who received an institutional standard treatment with Hyperbaric Bupivacaine 0.5% 10 mg and sufentanil 5 μg (G2). We evaluated the difference in terms of motor and sensory block, postoperative pain, and adverse effects during the first 24 h following delivery and neonatal outcome. Our study found that the sufentanil group had a significantly lower requirement for analgesia than the dexmedetomidine group. Postoperative pain, assessed with the VAS scale, was stronger in G1 than in G2 (4 ± 2 vs. 2 ± 1, p-value < 0.01). Differences between the two groups regarding the intraoperative degree of motor and sensory block, motor recovery time, and neonatal Apgar scores were not noticed. Pruritus and shivering were observed only in G2. Itching and shivering did not occur in the dexmedetomidine group. Postoperative analgesia was superior in the sufentanil group, but the incidence of side effects was higher. Adjuvant dexmedetomidine prevented postoperative shivering.

Dural puncture epidural technique provides better anesthesia quality in repeat cesarean delivery than epidural technique: Randomized controlled study

BACKGROUND

Repeat cesarean deliverys involve a longer surgery and more severe visceral traction than primary cesarean deliverys. The dural puncture epidural (DPE) technique provides faster and more effective analgesia for labor, but there is no sufficient evidence to indicate whether it is suitable for parturients undergoing repeat cesarean delivery.

AIM

To determine the efficacy and safety of the DPE anesthesia technique in patients undergoing repeat cesarean delivery.

METHODS

Patients undergoing repeat cesarean delivery were randomly divided into the DPE and epidural anesthesia (EA) groups. A 25-G spinal needle was used for dural puncture via a 19-G epidural needle. The patients in the two groups were injected with 5 mL of 2% lidocaine followed by 15 mL of a mixture of 1% lidocaine + 0.5% ropivacaine as the epidural dosage. The primary outcome was the onset time of sensory block to the T6 dermatome level and the sensory and motor block degree.

RESULTS

A total of 115 women were included (EA: 57, DPE: 58). The mean time to sensory block to the T6 Level was significantly shorter in the DPE group than in the EA group (14.7 min vs 16.6 min; 95% confidence interval, 13.9 to 15.4 vs 15.8 to 17.4; P = 0.001). The cranial sensory block level was significantly higher at 5, 10, and 15 min after the initial dose in the DPE group than in the EA group (P < 0.05). The sacral sensory block level was significantly higher and the modified bromage score was significantly lower in the DPE group at each time point (P < 0.05). Adverse effects and neonatal outcomes were comparable between the two groups (P > 0.05).

CONCLUSION

The DPE technique provided higher-quality anesthesia than the EA technique, with a rapid onset of surgical anesthesia, better cranial and sacral sensory block spread and a higher motor block degree, without increasing the incidence of maternal or fetal side effects in patients undergoing repeat cesarean delivery.

Neuraxial and general anaesthesia for caesarean section

Caesarean section (CS) is one of the most performed operations worldwide. In many parts of the world, there has been a reduction in anaesthetic associated obstetric mortality, and this has been attributed to the increased use of neuraxial anaesthesia and improved safety of general anaesthesia, alongside improved training and organisational changes. In resource-limited countries, anaesthesia contributes disproportionately to maternal mortality, with one in seven deaths being due to anaesthesia. A major contributory factor to this is the severe shortage of trained anaesthetic providers. Goals for anaesthesia for CS include the woman's comfort and foetal well-being, focusing on strategies to minimise morbidity and mortality for both. Anaesthetic options for CS include neuraxial techniques (spinal or combined-spinal epidural or epidural extension of labour analgesia) and general anaesthesia. There is increasing evidence of the benefit of neuraxial techniques over general anaesthesia in terms of maternal and foetal outcomes. For elective CS, spinal and combined-spinal anaesthesia predominate. General anaesthesia is mainly reserved for Category 1 CS where there is an immediate threat to the life of the mother or the baby. This review discusses the practical aspects of neuraxial and general anaesthesia for CS.

Spinal hypotension in obstetrics: Context-sensitive prevention and management

Spinal hypotension during caesarean section remains a common complication, with important attendant maternal and fetal adverse outcomes. Research elucidating the mechanisms of spinal hypotension has led to the development and refinement of effective management strategies, with a particular emphasis on prophylactic vasopressor administration. This has proved effective in well-resourced settings, with maternal comfort and the elimination of nausea now considered the primary aim of treatment. In resource-limited settings, sophisticated strategies are not feasible due to insufficient equipment, staff, and expertise. Therefore, in these areas spinal hypotension remains an important cause of maternal and fetal morbidity and mortality. Translational, context-sensitive research in resource-limited settings has shown promise in implementing pragmatic strategies based on research from resource-rich environments. We review the current best practice for the prevention and treatment of spinal hypotension, with a special emphasis on effective strategies in resource-limited settings. We further suggest a research agenda to address the knowledge gap in specific contexts.

Comparison of equipotent doses of intrathecal hyperbaric prilocaine 2% and hyperbaric bupivacaine 0.5% for elective caesarean section: A prospective, randomised, controlled, two-centre clinical trial

BACKGROUND

Elective caesarean section is performed mainly under spinal anaesthesia using hyperbaric bupivacaine combined with opioids. Despite rapid onset, good quality anaesthesia, bupivacaine provides a long duration of motor block and is related to maternal hypotension. Current policies appeal for implementation of enhanced recovery procedures after caesarean section. Hyperbaric prilocaine is an intermediate-acting local anaesthetic known for its efficacy in ambulatory surgery. Evidence on the clinical relevance of intrathecal prilocaine use for caesarean section is currently lacking.

OBJECTIVES

We aimed to investigate whether hyperbaric prilocaine would offer a shorter motor block and recovery than bupivacaine, when comparing equipotent doses. We also assessed the characteristics of sensory block, maternal haemodynamics and side effects for both mother and newborn.

DESIGN

Prospective, randomised, double-blind, controlled, two-centre, clinical trial.

SETTING

One university teaching hospital and one general teaching hospital in Brussels, Belgium.

PATIENTS

American Society of Anesthesiologists' physical status 2 parturients (n = 40) undergoing caesarean section under spinal anaesthesia.

INTERVENTIONS

Patients were randomly assigned to receive spinal anaesthesia using hyperbaric prilocaine 50 mg or hyperbaric bupivacaine 10 mg, both given with sufentanil 2.5 μg and morphine 100 μg. An epidural catheter was introduced as a backup in case of failure.

MAIN OUTCOMES

The primary outcome was the motor block regression (modified Bromage scale 1 to 6). Secondary outcomes included sensory block characteristics, first unassisted ambulation, maternal side effects, newborns' parameters and overall satisfaction.

RESULTS

Median [IQR] motor block was significantly shorter in the hyperbaric prilocaine group (110 [104 to 150] min versus 175 [135 to 189] min, P = 0.001). First unassisted ambulation was achieved earlier after prilocaine (204.5 [177 to 246.5] min versus 314 [209.25 to 400] min, P = 0.007), and the incidence of maternal hypotension was significantly higher with bupivacaine (P = 0.033). No supplementary epidural analgesia was needed.

CONCLUSION

Prilocaine provides shorter motor block, faster recovery and better haemodynamic stability than bupivacaine while offering equivalent surgical anaesthesia.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT02973048, EudraCT: 2016-003010-26.

The impact of height on the spread of spinal anesthesia and stress response in parturients undergoing caesarean section: a prospective observational study

Background

The spread of spinal anesthesia was influenced by many factors, and the effect of body height on spinal anesthesia is still arguable. This study aimed to explore the impact of height on the spread of spinal anesthesia and the stress response in parturients.

Methods

A total of ninety-seven parturients were allocated into two groups according to their height: the shorter group (body height was shorter than 158 cm) and taller group (body height was taller than 165 cm). Spinal anesthesia was performed with the same amount of 12 mg plain ropivacaine in mothers of different heights. The primary outcome of the study was the success or failure of the spinal anesthesia. The secondary outcomes of the study were stress response, time to T6 sensory level, the incidence of hypotension, the satisfaction of abdominal muscle relaxation and patient VAS scores.

Results

The rate of successful spinal anesthesia in the shorter group was significantly higher than that in the taller group (p = 0.02). The increase of maternal cortisol level in the shorter group was lower than that in the taller group at skin closure (p = 0.001). The incidence of hypotension (p = 0.013), time to T6 sensory block (p = 0.005), the quality of abdominal muscle relaxation (p <  0.001), and VAS values in stretching abdominal muscles and uterine exteriorization (p <  0.001) in the shorter group were significantly different from those in the taller group. Multivariate analysis showed that vertebral column length (p <  0.001), abdominal girth (p = 0.022), amniotic fluid index (p = 0.022) were significantly associated with successful spinal anesthesia.

Conclusions

It’s difficult to use a single factor to predict the spread of spinal anesthesia. Patient’s vertebral column length, amniotic fluid index and abdominal girth were the high determinant factors for predicting the spread of spinal anesthesia.

Trials registration

ChiCTR-ROC-17012030 (Chictr.org.cn), registered on 18/07/2017.

Usefulness of low-dose combined spinal epidural anesthesia for a woman with systemic lupus erythematosus, mechanical prosthesis in the mitral valve position, and worsening heart failure presenting for cesarean delivery

A 31-year-old woman, gravida one, para zero, at 32 weeks, 4 days gestation, with a history of antiphospholipid antibody syndrome, mitral valve replacement requiring anticoagulation, chronic diastolic heart failure, and systemic lupus erythematous was admitted to the hospital for worsening cardiac decompensation with superimposed pneumonia. She was on warfarin for anticoagulation at the time of hospital admission and eventually started on an intravenous heparin infusion. Cesarean delivery was planned due to comorbidities and anticoagulation status. After administration of betamethasone for fetal lung maturity, the patient's heparin infusion was discontinued approximately 16 hours prior to cesarean delivery. Upon obtaining laboratory testing that confirmed appropriate coagulation status, a low-dose combined spinal epidural anesthetic technique was used for cesarean delivery and the expected hemodynamic shifts due to spinal anesthesia were mitigated with a prophylactic norepinephrine infusion.

Comparison of General, Epidural, and Spinal Anesthesia in Laparoscopic TEP (Total Extraperitoneal Repair) for Inguinal Hernia

PURPOSE

Laparoscopic total extraperitoneal repair (TEP) is one of the most preferred minimally invasive methods for inguinal hernia repair. In our study, we aimed to compare the advantages and disadvantages of general anesthesia (GA), spinal anesthesia (SA), and epidural anesthesia (EA) for TEP operations.

MATERIALS AND METHODS

This is a retrospective study involving 221 patients who underwent TEP surgery for inguinal hernia between January 2018 and July 2020. Patients were divided into 3 groups as GA (n=77), SA (n=70), and EA (n=74). Demographic data of the patients, duration of anesthesia and surgery, perioperative and postoperative complications, postoperative pain, anatomical delineation, hospital stay and quality of life were evaluated.

RESULTS

Anesthesia time was the longest in the EA group (23.1±2.32 min) and significantly prolonged the operation time (P<0.001). When the visual analog scale scores were compared, it was observed that the patients in the GA group felt significantly more pain (P<0.001). While the rates of hypotension and headache were higher in regional anesthesia (P<0.001 and P<0.002), there was no significant difference in urinary retention, postoperative nausea/vomiting, and shoulder pain (P=0.274, 0.262, and 0.314, respectively). SA and EA groups were found to be superior compared with the GA group in terms of patient satisfaction (P<0.001).

CONCLUSION

Regional anesthesia (SA and EA) can be safely performed in TEP surgeries, gives results similar to the anatomical delineation satisfactory and complication rates of GA, and results in less postoperative pain.

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

Background

Post-spinal anesthesia hypotension during cesarean delivery is caused by decreased systemic vascular resistance due to the blockage of the autonomic nerves, which is further worsened by inferior vena cava (IVC) compression by the gravid uterus. This study aimed to assess whether peak velocity and diameter of the IVC below the xiphoid or right common femoral vein (RCFV) in the inguinal region, as measured on ultrasound, could reflect the degree of IVC compression and further identify parturients at risk of post-spinal hypotension.

Methods

Fifty-six parturients who underwent elective cesarean section with spinal anesthesia were included in this study; peak velocities and anteroposterior diameters of the IVC and peak velocities and transverse diameters of the RCFV were measured using ultrasound before anesthesia. The primary outcome was the ultrasound measurements of IVC and RCFV acquired before spinal anesthesia and their association with post-spinal hypotension. Hypotension was defined as a drop in systolic arterial pressure by > 20% from the baseline. Multinomial logistic regression analysis was used to identify the association between the measurements of IVC, RCFV, and post-spinal hypotension during cesarean delivery. Receiver operating characteristic curves were used to test the abilities of the identified parameters to predict post-spinal hypotension; the areas under the curve and optimum cut-off values for the predictive parameters were calculated.

Results

A longer transverse diameter of the RCFV was associated with the occurrence of post-spinal hypotension (odds ratio = 2.022, 95% confidence interval [CI] 1.261–3.243). The area under the receiver operating characteristics curve for the prediction of post-spinal hypotension was 0.759 (95% CI 0.628–0.890, P = 0.001). A transverse diameter of > 12.2 mm of the RCFV could predict post-spinal hypotension during cesarean delivery.

Conclusions

A longer transverse diameter of RCFV was associated with hypotension and could predict parturients at a major risk of hypotension before anesthesia.

Trial registration

This study was registered at http://www.chictr.org.cn on 16, May, 2018. No. ChiCTR1800016163.

Determination of the ED95 of intrathecal hyperbaric prilocaine with sufentanil for scheduled cesarean delivery: a dose-finding study based on the continual reassessment method

BACKGROUND

Scheduled cesarean section is routinely performed under spinal anesthesia using hyperbaric bupivacaine. The current study was undertaken to determine the clinically relevant 95% effective dose of intrathecal 2% hyperbaric prilocaine co-administered with sufentanil for scheduled cesarean section, using continual reassessment method.

METHODS

We conducted a dose-response, prospective, double-blinded study to determine the ED95 values of intrathecal hyperbaric prilocaine used with 2,5 mcg of sufentanil and 100 mcg of morphine for cesarean delivery. Each parturient enrolled in the study received an intrathecal dose of hyperbaric prilocaine determined by the CRM and the success or failure of the block was assessed as being the primary endpoint.

RESULTS

The doses given for each cohort varied from 35 to 50 mg of HP, according to the CRM, with a final ED95 lying between 45 and 50 mg of Prilocaine after completion of the 10 cohorts. Few side effects were reported and patients were globally satisfied.

CONCLUSIONS

The ED95 of intrathecal hyperbaric prilocaine with sufentanil 2.5 μg and morphine 100 μg for elective cesarean delivery was found to be between 45 and 50 mg. It may be an interesting alternative to other long-lasting local anesthetics in this context.

TRIAL REGISTRATION

The study was registered on January 30, 2017 - retrospectively registered - and results posted at the public database clinicaltrials.gov ( NCT03036384 ).

Fixed Dose versus Height-Adjusted Conventional Dose of Intrathecal Hyperbaric Bupivacaine for Caesarean Delivery: A Prospective, Double-Blinded Randomised Trial

The optimal intrathecal dose of local anaesthetic for caesarean section (CS) anaesthesia is still being debated. We performed a study to compare the effectiveness and safety of spinal anaesthesia with 12.5 mg of hyperbaric bupivacaine and a dosing regimen of conventional doses adjusted to parturient height. One hundred and forty parturients scheduled for elective CS were enrolled. The fixed-dose group (FD) received a spinal block with 12.5 mg of hyperbaric bupivacaine with fentanyl, whereas the adjusted-dose group (AD) received a height-adjusted dose of bupivacaine (9-13 mg) with fentanyl. Sensory block ≥ T5 dermatome within 10 min and no need for supplementary analgesia were set as the composite primary outcome (success). Rates of successful blocks and complications were compared. Complete data were available for 134 cases. Spinal anaesthesia was successful in 58 out of 67 patients in the FD group and 57 out of 67 in the AD group (p > 0.05). Eight spinals in each group failed to produce a block ≥ T5 in 10 min, and one patient in the FD group and two in the AD group required i.v. analgesics despite sensory block ≥ T5. No differences were noted in terms of hypotension, bradycardia and nausea between the FD and AD groups. Compared to the height-adjusted dose regimen based on conventional doses of hyperbaric bupivacaine, the fixed dose regimen of 12.5 mg was equally effective and did not increase the risk of spinal block-related complications.