Effects of hyperbaric spinal ropivacaine for caesarean section

Efficacy and safety of intrathecal adjuvants for perioperative management of cesarean delivery: a systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Cesarean section (CS) rates have increased globally, necessitating effective anesthesia management. Single-shot spinal anesthesia has limitations due to its duration and the dose-limiting adverse effects of local anesthetics.

OBJECTIVES

To evaluate the effectiveness and safety of intrathecal adjuvants combined with local anesthetics in the perioperative management of CS pain.

DESIGN

Systematic review with network meta-analysis.

DATA SOURCES

PubMed, Cochrane Library for Clinical Trials, and Embase.

ELIGIBILITY CRITERIA

We included women undergoing CS under single-shot spinal anesthesia with any intrathecal drug or placebo added to a long-acting local anesthetic. We selected single- or double-blind, parallel-group, randomized controlled trials (RCTs) reported in English. We excluded crossover, non-randomized, up-and-down dose-finding studies and clinical trials comparing the same drugs in all study arms.

RESULTS

We included 166 RCTs with 14 925 patients assigned to 32 interventions. Buprenorphine and diamorphine were the highest-ranked treatments for reducing pain intensity at 24 hours, though not statistically significant. Morphine alone or in combination with meperidine, neostigmine, epinephrine, or nalbuphine significantly increased the duration of effective analgesia and reduced opioid consumption. Dexmedetomidine and morphine significantly prolonged the motor block duration. The safety profile of intrathecal adjuvants was generally adequate.

CONCLUSIONS

While the strength of evidence, overall, was very low to low, our study suggests that while none of the interventions significantly reduced pain intensity at 24 hours, several significantly prolonged effective analgesia and reduced postoperative opioid consumption. Dexmedetomidine and morphine prolonged the duration of motor block. None of the intrathecal adjuvants evaluated significantly increased the occurrence of severe adverse events. Future large-scale RCTs are essential to provide more robust evidence.

PROSPERO REGISTRATION NUMBER

CRD42024479424.

Impact of Spinal Anesthesia Dosage in Elective Cesarean Section on the Duration of Stay in Post-Anesthesia Care Unit at the Women's Health Hospital, National Guard Health Affairs

In the field of obstetrics, cesarean sections have now become the most prominent procedure for the delivery of newborns. Cesarean sections may be handled with a variety of different anesthetic approaches, of which most focus seems to be on that of spinal forms, due to their rapid and effective action. Dosages of spinal anesthesia formulations differ depending on multiple variables, such as depth of anesthesia, level of analgesia, and desired duration of effects. Furthermore, length of stay in the hospital is also a crucial variable to take into account when using spinal anesthesia due to its implications for patient comfort, quality of care, and return to daily life. Hyperbaric bupivacaine is a mainstay agent in regard to cesarean section anesthesia, with the most commonly used dosages being 1.8 mL and 2.0 mL. This study aims to assess the difference in duration of stay in the post-anesthesia care unit between patients receiving 1.8 mL and 2.0 mL of 0.5% hyperbaric bupivacaine. Of the 306 patients who underwent elective cesarean sections, 63 patients received 2.0 mL of 0.5% hyperbaric bupivacaine and 243 patients received 1.8 mL of 0.5% hyperbaric bupivacaine.

No Difference between Spinal Anesthesia with Hyperbaric Ropivacaine and Intravenous Dexmedetomidine Sedation with and without Intrathecal Fentanyl: A Randomized Noninferiority Trial

To enhance the duration of single-shot spinal anesthesia, intrathecal fentanyl and intravenous dexmedetomidine are widely used as adjuvants to local anesthetics. This noninferiority trial evaluated whether hyperbaric ropivacaine alone can produce a noninferior duration of sensory block in comparison to hyperbaric ropivacaine with intrathecal fentanyl in patients under dexmedetomidine sedation. Methods. Fifty patients scheduled for elective lower limb surgery under spinal anesthesia were randomly assigned in a double-blind fashion to receive either hyperbaric ropivacaine 15 mg (Group R) or hyperbaric ropivacaine 15 mg with intrathecal fentanyl 20 μg (Group RF). Intravenous dexmedetomidine (1 μg/kg for 10 min, followed by 0.5 μg/kg/h) was administered in both groups. The primary outcome of this study was the time to two-dermatomal regression of sensory block. The noninferiority margin for the mean difference was -10 min. Characteristics of the block, intraoperative and postoperative side effects, postoperative pain score, and analgesic consumption were assessed as secondary outcomes. Results. There was no difference in the two-dermatomal regressions of sensory block between the two groups (Group R 70.4 ± 10.2 min, Group RF 71.2 ± 12.4 min, p = 0.804) with a mean difference of 0.8 min (-7.2 to 5.6, 95% confidence interval). Thus, the noninferiority of hyperbaric ropivacaine alone was established. There were no significant differences in the secondary outcomes between the two groups. Conclusions. Under intravenous dexmedetomidine sedation, the duration of spinal anesthesia with hyperbaric ropivacaine alone was noninferior to that of hyperbaric ropivacaine with intrathecal fentanyl. This suggests that addition of intrathecal fentanyl to hyperbaric ropivacaine may not be necessary in patients receiving intravenous dexmedetomidine.

Spinal anesthesia for elective cesarean section. Bupivacaine associated with different doses of fentanyl: randomized clinical trial

OBJECTIVE

Assess patients submitted to elective cesarean section under spinal anesthesia, and the efficacy of different doses of fentanyl associated with bupivacaine.

METHODS

The study included 124 pregnant women randomly distributed into 4 groups (n = 31) according to different doses of fentanyl (15 μg, 10 μg, 7.5 μg), Groups I, II, and III, respectively, and control group IV, associated with 0.5% hyperbaric bupivacaine (10 mg). An epidural catheter was inserted in case epidural top-up was required. We assessed the anesthetic blockage characteristics, negative maternal and neonatal outcomes, and maternal side effects. Statistical analysis was performed using Kruskal-Wallis, Fisher's exact and chi-square tests. The level of significance was 5% (p < 0.05).

RESULTS

The quality of analgesia, time for the first complaint of pain and motor block recovery time were significantly better for groups that received fentanyl in comparison to controls (p < 0.001). None of the groups had negative maternal-fetal outcomes. Nausea was significantly more frequent in patients in Groups II (10 µg) and III (7.5 µg) when compared to Groups I (15 µg) and IV (no fentanyl). Vomiting was more frequent in Group III than in Group I (p = 0.006). The incidence of pruritus was significantly higher in the groups receiving fentanyl (p = 0.012).

CONCLUSIONS

Among the solutions studied, the spinal anesthesia technique using 15 µg of fentanyl associated with 10 mg of hyperbaric bupivacaine provided satisfactory analgesia and very low incidence of adverse effects for patients submitted to cesarean section.

TRIAL REGISTRATION NUMBER

UTN U1111-1199-0285.

REBEC

RBR-5XWT6T.

Effects of intrathecal opioids on cesarean section: a systematic review and Bayesian network meta-analysis of randomized controlled trials

PURPOSE

We aimed to compare the beneficial and harmful effects of opioids used as adjuncts to local anesthetics in patients undergoing cesarean section under spinal anesthesia.

METHODS

We searched electronic databases and ClinicalTrials.gov from their inception until March, 2021 without language restrictions. The primary outcome was the complete analgesia duration (Time to VAS > 0). Data were synthesized using the Bayesian random-effects model. Evidence confidence was evaluated using the Confidence In Network Meta-Analysis.

RESULTS

We identified 66 placebo-controlled randomized controlled trials (RCTs) comprising 4400 patients undergoing elective cesarean section. Compared with the placebo, intrathecal opioids (fentanyl, sufentanil, and morphine) significantly prolonged the analgesia duration by 96, 96, and 190 min, respectively (mean difference). Despite morphine ranking first, opioid efficacy was similar; the results were inconsistent with respect to other analgesic outcomes. Except for diamorphine, all opioids were associated with significant increases in the pruritus incidence. Sufentanil and morphine were associated with increases in the respiratory depression incidence.

CONCLUSIONS

We confirmed that intrathecal opioids benefit postoperative analgesia. Although morphine seems to be the most appropriate agent, some results were inconsistent, and the evidence confidence was often moderate or low, especially for adverse outcomes. Well-designed RCTs with an evidence-based approach are imperative for determining the most appropriate opioid for cesarean sections.

Relationship Between Body Mass Index and Spread of Spinal Anesthsia in Pregnant Women: A Randomized Controlled Trial

BACKGROUND The effect of body mass index (BMI) on the spread of spinal anesthesia is not completely clear. The aim of this study was to determine the dose requirements of ropivacaine and the incidence of hypotension in pregnant women with different BMIs during cesarean delivery. MATERIAL AND METHODS In this double-blind study, 405 women undergoing elective cesarean delivery were allocated to group S (BMI <25), group M (25 ≤BMI <30), or group L (BMI ≥30). Women in each group were further assigned to receive 7, 8, 9, 10, 11, 12, 13, 14, or 15 mg of spinal ropivacaine. RESULTS The ED50 and ED95 values of ropivacaine were 9.487 mg and 13.239 mg in Group S, 9.984 mg and 13.737 mg in Group M, and 9.067 mg and 12.819 mg in Group L. There were no significant differences among the 3 groups (p=0.915). Group L had a higher incidence of hypotension and a greater change in MAP after spinal anesthesia compared to the other 2 groups, and also required more doses of ephedrine than the other 2 groups when a dose of 15 mg ropivacaine was used. The incidence of hypotension had a positive correlation with the dose of ropivacaine (OR=1.453, p<0.001) and gestational age (OR=1.894, p<0.001). CONCLUSIONS Spinal ropivacaine dose requirements were similar in the normal BMI range. However, higher doses of spinal ropivacaine were associated with an increased incidence and severity of hypotension in obese patients compared with that in non-obese patients.

Effects of isobaric ropivacaine with or without fentanyl in subarachnoid blockade: A prospective double-blind, randomized study

Background:

The addition of fentanyl to ropivacaine has shown to improve the quality of analgesia without compromising its benefits such as early mobilization and early voiding.

Aim:

The aim of the study was to evaluate the effects of the isobaric ropivacaine in combination with fentanyl and compare it with the isobaric ropivacaine alone in spinal anesthesia for lower abdominal and lower limb surgeries.

Settings and Design:

Double-blinded randomized controlled trial.

Subjects and Methods:

Hundred patients belonging to American Society of Anesthesiologists physical status I and II scheduled for either lower abdominal or lower limb surgery under spinal anesthesia were included. The study was a prospective double-blinded randomized controlled trial where patients were randomly allocated into two groups to receive either 2.5 ml of 0.75% (18.75 mg) isobaric ropivacaine with 25 μg fentanyl (Group RF) or 2.5 ml of 0.75% (18.75 mg) isobaric ropivacaine with 0.5 ml of 0.9% saline (Group R) intrathecally.

Statistical Analysis:

Data analysis was done by Student's unpaired t-test. SPSS version 16 was used. P < 0.05 was considered as statistically significant.

Results:

We found no significant difference in hemodynamics, onset of sensory and motor block, peak level of block, recovery from motor block, return of micturition and incidence of side effects with the addition of fentanyl to ropivacaine. First request for analgesia was required earlier in the control group. There was also a significant prolongation of the duration of sensory block (mean - 341.6 min) and postoperative analgesia in Group RF (mean - 442.2 min) (P < 0.001).

Conclusion:

The addition of fentanyl to ropivacaine significantly prolongs the duration of postoperative analgesia with clinically insignificant influence on hemodynamics and motor blockade with minimal side effects.

Drug therapy for preventing post-dural puncture headache

BACKGROUND

Post-dural (post-lumbar or post-spinal) puncture headache (PDPH) is one of the most common complications of diagnostic, therapeutic or inadvertent lumbar punctures. Many drug options have been used to prevent headache in clinical practice and have also been tested in some clinical studies, but there are still some uncertainties about their clinical effectiveness.

OBJECTIVES

To assess the effectiveness and safety of drugs for preventing PDPH in adults and children.

SEARCH METHODS

The search strategy included the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library 2012, Issue 5), MEDLINE (from 1950 to May 2012), EMBASE (from 1980 to May 2012) and CINAHL (from 1982 to June 2012). There was no language restriction.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) that assessed the effectiveness of any drug used for preventing PDPH.

DATA COLLECTION AND ANALYSIS

Review authors independently selected studies, assessed risks of bias and extracted data. We estimated risk ratios (RR) for dichotomous data and mean differences (MD) for continuous outcomes. We calculated a 95% confidence interval (CI) for each RR and MD. We did not undertake meta-analysis because participants' characteristics or assessed doses of drugs were too different in the included studies. We performed an intention-to-treat (ITT) analysis.

MAIN RESULTS

We included 10 RCTs (1611 participants) in this review with a majority of women (72%), mostly parturients (women in labour) (913), after a lumbar puncture for regional anaesthesia. Drugs assessed were epidural and spinal morphine, spinal fentanyl, oral caffeine, rectal indomethacin, intravenous cosyntropin, intravenous aminophylline and intravenous dexamethasone.All the included RCTs reported data on the primary outcome, i.e. the number of participants affected by PDPH of any severity after a lumbar puncture. Epidural morphine and intravenous cosyntropin reduced the number of participants affected by PDPH of any severity after a lumbar puncture when compared to placebo. Also, intravenous aminophylline reduced the number of participants affected by PDPH of any severity after a lumbar puncture when compared to no intervention, while intravenous dexamethasone increased it. Spinal morphine increased the number of participants affected by pruritus when compared to placebo, and epidural morphine increased the number of participants affected by nausea and vomiting when compared to placebo. Oral caffeine increased the number of participants affected by insomnia when compared to placebo.The remainder of the interventions analysed did not show any relevant effect for any of the outcomes.None of the included RCTs reported the number of days that patients stayed in hospital.

AUTHORS' CONCLUSIONS

Morphine and cosyntropin have shown effectiveness for reducing the number of participants affected by PDPH of any severity after a lumbar puncture, when compared to placebo, especially in patients with high risk of PDPH, such as obstetric patients who have had an inadvertent dural puncture. Aminophylline also reduced the number of participants affected by PDPH of any severity after a lumbar puncture when compared to no intervention in patients undergoing elective caesarean section. Dexamethasone increased the risk of PDPH, after spinal anaesthesia for caesarean section, when compared to placebo. Morphine also increased the number of participants affected by adverse events (pruritus and nausea and vomiting)There is a lack of conclusive evidence for the other drugs assessed (fentanyl, caffeine, indomethacin and dexamethasone).These conclusions should be interpreted with caution, owing to the lack of information, to allow correct appraisal of risk of bias and the small sample sizes of studies.

Sugammadex: Another Milestone in Clinical Neuromuscular Pharmacology

Sugammadex is a revolutionary investigational reversal drug currently undergoing Phase III testing whose introduction into clinical practice may change the face of clinical neuromuscular pharmacology. A modified gamma-cyclodextrin, sugammadex exerts its effect by forming very tight water-soluble complexes at a 1:1 ratio with steroidal neuromuscular blocking drugs (rocuronium > vecuronium >> pancuronium). During rocuronium-induced neuromuscular blockade, the IV administration of sugammadex creates a concentration gradient favoring the movement of rocuronium molecules from the neuromuscular junction back into the plasma, which results in a fast recovery of neuromuscular function. Sugammadex is biologically inactive, does not bind to plasma proteins, and appears to be safe and well tolerated. Additionally, it has no effect on acetylcholinesterase or any receptor system in the body. The compound's efficacy as an antagonist does not appear to rely on renal excretion of the cyclodextrin-relaxant complex. Human and animal studies have demonstrated that sugammadex can reverse very deep neuromuscular blockade induced by rocuronium without muscle weakness. Its future clinical use should decrease the incidence of postoperative muscle weakness, and thus contribute to increased patient safety. Sugammadex will also facilitate the use of rocuronium for rapid sequence induction of anesthesia by providing a faster onset-offset profile than that seen with 1.0 mg/kg succinylcholine. Furthermore, no additional anticholinesterase or anticholinergic drugs would be needed for antagonism of residual neuromuscular blockade, which would mean the end of the cardiovascular and other side effects of these compounds. The clinical use of sugammadex promises to eliminate many of the shortcomings in our current practice with regard to the antagonism of rocuronium and possibly other steroidal neuromuscular blockers.