[Anaesthesia for caesarean section. Comparison of two general anaesthetic regimens and spinal anaesthesia]

Esketamine versus Sufentanil Applied Prior to Placement of Suspension Laryngoscope

OBJECTIVE

In laryngeal microsurgery, the insertion of the suspension laryngoscope is a strong stimulus that may cause hemodynamic fluctuations and adverse cardiovascular events. The purpose of this study was to compare the effect of preemptive treatment with esketamine and sufentanil on maintaining hemodynamics and reducing the occurrence of adverse cardiovascular events during the insertion of suspension laryngoscope.

METHODS

In this double-blind randomized controlled trial, patients undergoing general anesthesia for laryngeal microsurgery were randomly assigned (1:1) to esketamine 0.5 mg kg-1 (esketamine group) and sufentanyl 0.125 μg kg-1 (sufentanil group) before inserting the laryngoscope, respectively.

RESULTS

During the insertion of suspension laryngoscope, the incidence of bradycardia (HR < 60 beats/min) was 39.3% (22/56) in esketamine group, lower than 60.0% (33/55) in sufentanil group (odds ratio [OR], 2.32 [95% CI, 1.11-5.08]; p = 0.029). The incidence of hypotension (MAP <65 mmHg) was 33.9% (19/56) in esketamine group, lower than 56.4% (31/55) in sufentanil group (odds ratio [OR], 2.52 [95% CI, 1.91-5.27]; p = 0.018). The frequency of hypotension in esketamine group was lower than that in sufentanil group (0.36 ± 0.52 vs. 0.56 ± 0.50, p = 0.035). The time-weighted average of HR dropping above 30% of baseline was smaller in esketamine group than in sufentanil group (0.52 ± 2.06 vs. 1.08 ± 2.77, p = 0.006).

CONCLUSIONS

These findings showed that compared with preemptive treatment of sufentanil (0.125 μg kg-1 ), esketamine (0.5 mg kg-1 ) was effective in reducing the incidence of cardiovascular adverse events, including bradycardia and hypotension induced by the insertion of suspension laryngoscope during the laryngeal microsurgery.

LEVEL OF EVIDENCE

2 Laryngoscope, 133:3021-3027, 2023.

Efficacy and Safety of Esketamine for Supplemental Analgesia During Elective Cesarean Delivery: A Randomized Clinical Trial

Importance

Epidural anesthesia is a primary choice for cesarean delivery, but supplemental analgesics are often required to relieve pain during uterine traction.

Objective

To investigate the sedative and analgesic effects of intravenous esketamine administered before childbirth via cesarean delivery with the patient under epidural anesthesia.

Design, Setting, and Participants

This multicenter, double-blind randomized clinical trial assessed 903 women 18 years or older who had full-term single pregnancy and were scheduled for elective cesarean delivery with epidural anesthesia in 5 medical centers in China from September 18, 2021, to September 20, 2022.

Intervention

Patients were randomized to receive intravenous injection of 0.25 mg/kg of esketamine or placebo before incision.

Main Outcomes and Measures

The coprimary outcomes included scores on the numeric rating scale of pain (an 11-point scale, with 0 indicating no pain and 10 indicating the worst pain; a difference of ≥1.65 points was clinically meaningful) and Ramsay Sedation Scale (a 6-point scale, with 1 indicating restlessness and 6 indicating deep sleep without response; a difference of ≥2 points was clinically meaningful) immediately after fetal delivery. Secondary outcomes included neonatal Apgar score assessed at 1 and 5 minutes after birth.

Results

A total of 600 women (mean [SD] age, 30.7 [4.3] years) were enrolled and randomized; all were included in the intention-to-treat analysis. Immediately after fetal delivery, the score on the numeric rating scale of pain was lower with esketamine (median [IQR], 0 [0-1]) than with placebo (median [IQR], 0 [0-2]; median difference, 0; 95% CI, 0-0; P = .001), but the difference was not clinically important. The Ramsay Sedation Scale scores were higher (sedation deeper) with esketamine (median [IQR], 4 [3-4]) than with placebo (median [IQR], 2 [2-2]; median difference, 2; 95% CI, 2-2; P < .001). The neonatal Apgar scores did not differ between the 2 groups at 1 minute (median difference, 0; 95% CI, 0-0; P = .98) and at 5 minutes (median difference, 0; 95% CI, 0-0; P = .27). Transient neurologic or mental symptoms were more common in patients given esketamine (97.7% [293 of 300]) than in those given placebo (4.7% [14 of 300]; P < .001).

Conclusions and Relevance

For women undergoing cesarean delivery under epidural anesthesia, a subanesthetic dose of esketamine administered before incision produced transient analgesia and sedation but did not induce significant neonatal depression. Mental symptoms and nystagmus were common but transient. Indications and the optimal dose of esketamine in this patient population need further clarification, but study should be limited to those who require supplemental analgesia.

Trial Registration

ClinicalTrials.gov Identifier: NCT04548973.

Effects of esketamine on analgesia and postpartum depression after cesarean section: A randomized, double-blinded controlled trial

BACKGROUND

The aim of this randomized double-blind placebo controlled clinical trial was to investigate the effects of different doses of esketamine combined with sufentanil for postoperative intravenous controlled analgesia after cesarean section and the incidence of postpartum depression.

METHODS

One hundred and sixty patients undergoing elective cesarean section, with a singleton term pregnancy and American Society of Anesthesiologists physical status II were selected. All patients were treated by a combined epidural with spinal anesthesia. They were randomly divided into 4 groups according to patient controlled intravenous analgesia formula. The consumption of sufentanil, times of effective press and remediate analgesia at 48 hours after cesarean section, incidence of postpartum depression (PPD) at 1 week and 6 weeks after the operation were recorded.

RESULTS

Comparison of cumulated dosage of sufentanil, times of effective press and rescue analgesia at 48 hours after operation: Group H was significantly lower than Group M, Group L, and Group C (P < .05), Group M significantly lower than group L and Group C (P < .05), and Group L significantly lower than Group C (P < .05). Comparison of the incidence of PPD at 1 week and 6 weeks later: Group H was significantly lower than Group M, Group L, and Group C (P < .01), Group M significantly lower than Group L and Group C (P < .01) and Group L significantly lower than Group C (P < .01). Compared with Group C, the incidence of nausea and vomiting was significantly reduced in Group H, Group M, and Group L (P < .05).

CONCLUSION

Esketamine combined with sufentanil used for patient controlled intravenous analgesia after elective cesarean section can reduce the consumption of sufentanil, improve postoperative analgesia, decrease the incidence of PPD at 1 week and 6 weeks and postoperative nausea and vomiting.

Perioperative intravenous ketamine for acute postoperative pain in adults

BACKGROUND

Inadequate pain management after surgery increases the risk of postoperative complications and may predispose for chronic postsurgical pain. Perioperative ketamine may enhance conventional analgesics in the acute postoperative setting.

OBJECTIVES

To evaluate the efficacy and safety of perioperative intravenous ketamine in adult patients when used for the treatment or prevention of acute pain following general anaesthesia.

SEARCH METHODS

We searched CENTRAL, MEDLINE and Embase to July 2018 and three trials registers (metaRegister of controlled trials, ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP)) together with reference checking, citation searching and contact with study authors to identify additional studies.

SELECTION CRITERIA

We sought randomised, double-blind, controlled trials of adults undergoing surgery under general anaesthesia and being treated with perioperative intravenous ketamine. Studies compared ketamine with placebo, or compared ketamine plus a basic analgesic, such as morphine or non-steroidal anti-inflammatory drug (NSAID), with a basic analgesic alone.

DATA COLLECTION AND ANALYSIS

Two review authors searched for studies, extracted efficacy and adverse event data, examined issues of study quality and potential bias, and performed analyses. Primary outcomes were opioid consumption and pain intensity at rest and during movement at 24 and 48 hours postoperatively. Secondary outcomes were time to first analgesic request, assessment of postoperative hyperalgesia, central nervous system (CNS) adverse effects, and postoperative nausea and vomiting. We assessed the evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

We included 130 studies with 8341 participants. Ketamine was given to 4588 participants and 3753 participants served as controls. Types of surgery included ear, nose or throat surgery, wisdom tooth extraction, thoracotomy, lumbar fusion surgery, microdiscectomy, hip joint replacement surgery, knee joint replacement surgery, anterior cruciate ligament repair, knee arthroscopy, mastectomy, haemorrhoidectomy, abdominal surgery, radical prostatectomy, thyroid surgery, elective caesarean section, and laparoscopic surgery. Racemic ketamine bolus doses were predominantly 0.25 mg to 1 mg, and infusions 2 to 5 µg/kg/minute; 10 studies used only S-ketamine and one only R-ketamine. Risk of bias was generally low or uncertain, except for study size; most had fewer than 50 participants per treatment arm, resulting in high heterogeneity, as expected, for most analyses. We did not stratify the main analysis by type of surgery or any other factor, such as dose or timing of ketamine administration, and used a non-stratified analysis.Perioperative intravenous ketamine reduced postoperative opioid consumption over 24 hours by 8 mg morphine equivalents (95% CI 6 to 9; 19% from 42 mg consumed by participants given placebo, moderate-quality evidence; 65 studies, 4004 participants). Over 48 hours, opioid consumption was 13 mg lower (95% CI 10 to 15; 19% from 67 mg with placebo, moderate-quality evidence; 37 studies, 2449 participants).Perioperative intravenous ketamine reduced pain at rest at 24 hours by 5/100 mm on a visual analogue scale (95% CI 4 to 7; 19% lower from 26/100 mm with placebo, high-quality evidence; 82 studies, 5004 participants), and at 48 hours by 5/100 mm (95% CI 3 to 7; 22% lower from 23/100 mm, high-quality evidence; 49 studies, 2962 participants). Pain during movement was reduced at 24 hours (6/100 mm, 14% lower from 42/100 mm, moderate-quality evidence; 29 studies, 1806 participants), and 48 hours (6/100 mm, 16% lower from 37 mm, low-quality evidence; 23 studies, 1353 participants).Results for primary outcomes were consistent when analysed by pain at rest or on movement, operation type, and timing of administration, or sensitivity to study size and pain intensity. No analysis by dose was possible. There was no difference when nitrous oxide was used. We downgraded the quality of the evidence once if numbers of participants were large but small-study effects were present, or twice if numbers were small and small-study effects likely but testing not possible.Ketamine increased the time for the first postoperative analgesic request by 54 minutes (95% CI 37 to 71 minutes), from a mean of 39 minutes with placebo (moderate-quality evidence; 31 studies, 1678 participants). Ketamine reduced the area of postoperative hyperalgesia by 7 cm² (95% CI -11.9 to -2.2), compared with placebo (very low-quality evidence; 7 studies 333 participants). We downgraded the quality of evidence because of small-study effects or because the number of participants was below 400.CNS adverse events occurred in 52 studies, while 53 studies reported of absence of CNS adverse events. Overall, 187/3614 (5%) participants receiving ketamine and 122/2924 (4%) receiving control treatment experienced an adverse event (RR 1.2, 95% CI 0.95 to 1.4; high-quality evidence; 105 studies, 6538 participants). Ketamine reduced postoperative nausea and vomiting from 27% with placebo to 23% with ketamine (RR 0.88, 95% CI 0.81 to 0.96; the number needed to treat to prevent one episode of postoperative nausea and vomiting with perioperative intravenous ketamine administration was 24 (95% CI 16 to 54; high-quality evidence; 95 studies, 5965 participants).

AUTHORS' CONCLUSIONS

Perioperative intravenous ketamine probably reduces postoperative analgesic consumption and pain intensity. Results were consistent in different operation types or timing of ketamine administration, with larger and smaller studies, and by higher and lower pain intensity. CNS adverse events were little different with ketamine or control. Perioperative intravenous ketamine probably reduces postoperative nausea and vomiting by a small extent, of arguable clinical relevance.

Anaesthetic interventions for prevention of awareness during surgery

BACKGROUND

General anaesthesia is usually associated with unconsciousness. 'Awareness' is when patients have postoperative recall of events or experiences during surgery. 'Wakefulness' is when patients become conscious during surgery, but have no postoperative recollection of the period of consciousness.

OBJECTIVES

To evaluate the efficacy of two types of anaesthetic interventions in reducing clinically significant awareness:- anaesthetic drug regimens; and- intraoperative anaesthetic depth monitors.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, ISSUE 4 2016); PubMed from 1950 to April 2016; MEDLINE from 1950 to April 2016; and Embase from 1980 to April 2016. We contacted experts to identify additional studies. We performed a handsearch of the citations in the review. We did not search trial registries.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) of either anaesthetic regimens or anaesthetic depth monitors. We excluded volunteer studies, studies of patients prior to skin incision, intensive care unit studies, and studies that only randomized different word presentations for memory tests (not anaesthetic interventions).Anaesthetic drug regimens included studies of induction or maintenance, or both. Anaesthetic depth monitors included the Bispectral Index monitor, M-Entropy, Narcotrend monitor, cerebral function monitor, cerebral state monitor, patient state index, and lower oesophageal contractility monitor. The use of anaesthetic depth monitors allows the titration of anaesthetic drugs to maintain unconsciousness.

DATA COLLECTION AND ANALYSIS

At least two authors independently scanned abstracts, extracted data from the studies, and evaluated studies for risk of bias. We made attempts to contact all authors for additional clarification. We performed meta-analysis statistics in packages of the R language.

MAIN RESULTS

We included 160 studies with 54,109 enrolled participants; 53,713 participants started the studies and 50,034 completed the studies or data analysis (or both). We could not use 115 RCTs in meta-analytic comparisons because they had zero awareness events. We did not merge 27 of the remaining 45 studies because they had excessive clinical and methodological heterogeneity. We pooled the remaining 18 eligible RCTs in meta-analysis. There are 10 studies awaiting classification which we will process when we update the review.The meta-analyses included 18 trials with 36,034 participants. In the analysis of anaesthetic depth monitoring (either Bispectral Index or M-entropy) versus standard clinical and electronic monitoring, there were nine trials with 34,744 participants. The overall event rate was 0.5%. The effect favoured neither anaesthetic depth monitoring nor standard clinical and electronic monitoring, with little precision in the odds ratio (OR) estimate (OR 0.98, 95% confidence interval (CI) 0.59 to 1.62).In a five-study subset of Bispectral Index monitoring versus standard clinical and electronic monitoring, with 34,181 participants, 503 participants gave awareness reports to a blinded, expert panel who adjudicated or judged the outcome for each patient after reviewing the questionnaires: no awareness, possible awareness, or definite awareness. Experts judged 351 patient awareness reports to have no awareness, 87 to have possible awareness, and 65 to have definite awareness. The effect size favoured neither Bispectral Index monitoring nor standard clinical and electronic monitoring, with little precision in the OR estimate for the combination of definite and possible awareness (OR 0.96, 95% CI 0.35 to 2.65). The effect size favoured Bispectral Index monitoring for definite awareness, but with little precision in the OR estimate (OR 0.60, 95% CI 0.13 to 2.75).We performed three smaller meta-analyses of anaesthetic drugs. There were nine studies with 1290 participants. Wakefulness was reduced by ketamine and etomidate compared to thiopental. Wakefulness was more frequent than awareness. Benzodiazepines reduces awareness compared to thiopental, ketamine, and placebo., Also, higher doses of inhaled anaesthetics versus lower doses reduced the risk of awareness.We graded the quality of the evidence as low or very low in the 'Summary of findings' tables for the five comparisons.Most of the secondary outcomes in this review were not reported in the included RCTs.

AUTHORS' CONCLUSIONS

Anaesthetic depth monitors may have similar effects to standard clinical and electrical monitoring on the risk of awareness during surgery. In older studies comparing anaesthetics in a smaller portion of the patient sample, wakefulness occurred more frequently than awareness. Use of etomidate and ketamine lowered the risk of wakefulness compared to thiopental. Benzodiazepines compared to thiopental and ketamine, or higher doses of inhaled anaesthetics versus lower doses, reduced the risk of awareness.

Intravenous ketamine during spinal and general anaesthesia for caesarean section: systematic review and meta-analysis

BACKGROUND

Intravenous ketamine has been used during general and regional anaesthesia for caesarean section. No systematic review and meta-analysis on the desired effects and adverse effects of ketamine administration during caesarean section have yet been performed.

METHODS

After a systematic literature search a meta-analysis was conducted with the random effects model. Weighted mean difference (WMD) or risk ratio and 95% confidence intervals (CIs) were computed.

RESULTS

Twelve randomised controlled double-blind trials comprising 953 patients were included: seven studies reported on spinal anaesthesia and five on general anaesthesia. Significant differences in the aforementioned outcome variables were found only in the spinal anaesthesia studies. In the spinal anaesthesia studies the time to the first analgesic request was significantly longer in ketamine-treated women, the WMD was 49.36 min (95% CI 43.31-55.41); visual analogue scale pain scores at rest 2 h after surgery were significantly lower. No differences were observed for maternal nausea, vomiting, pruritus, and psychomimetic effects. Only few data were found for neonatal outcomes.

CONCLUSIONS

We conclude that ketamine enhances post-operative analgesia after caesarean section under spinal anaesthesia. There is a paucity of data for several maternal adverse effects as well as for neonatal well-being. Further studies are needed for general anaesthesia.

Anaesthesia for Caesarean section and neonatal acid-base status: a meta-analysis

Spinal anaesthesia is generally preferred for Caesarean section. Its superiority for the baby is often assumed. Umbilical artery acid-base status provides a valid index of fetal welfare. Twenty-seven studies reporting neonatal acid-base data with different types of anaesthesia were used to compare umbilical artery or vein pH and base deficit, using random-effect meta-analysis. Cord pH was significantly lower with spinal than with both general (difference: -0.015; 95% CI -0.029 to -0.001; 13 studies, 1272 subjects) and epidural anaesthesia (difference -0.013; 95% CI -0.024 to -0.002; 11 studies, 828 subjects). Larger doses of ephedrine contributed to the latter effect (p = 0.023). Sixteen studies reported a base deficit, which was significantly higher for spinal than for general (difference 1.109; 95% CI 0.434-1.784 mEq.l(-1); seven studies, 695 subject) and epidural anaesthesia (difference 0.910; 95% CI 0.222-1.598 mEq.l(-1); seven studies, 497 subjects). Spinal anaesthesia cannot be considered safer than epidural or general anaesthesia for the fetus.

What’s new and novel in obstetric anesthesia? Contributions from the 2003 scientific literature

THE PREGNANT PATIENT: Age; maternal disease; prophylactic antibiotics; gastroesophageal reflux; obesity; starvation; genotyping; coagulopathy; infection; substance abuse; altered drug responses in pregnancy; physiological changes of pregnancy. THE FETUS: Fetal monitoring; intrauterine surgery. THE NEWBORN: Breastfeeding; maternal infection, fever, and neonatal sepsis evaluation. OBSTETRIC COMPLICATIONS: Embolic phenomena; hemorrhage; preeclampsia; preterm delivery. OBSTETRIC MANAGEMENT: External cephalic version and cervical cerclage; elective cesarean delivery; fetal malpresentation; vaginal birth after cesarean delivery; termination of pregnancy. OBSTETRIC ANESTHESIA: Analgesia for labor and delivery; anesthesia for cesarean delivery; anesthesia for short obstetric operations; complications of anesthesia. MISCELLANEOUS: Consent; ethics; history; labor support; websites/books/leaflets/journal announcements.