The analgesic efficacy of intravenous dexamethasone for post-caesarean pain: A systematic review with meta-analysis and trial sequential analysis

A narrative review of the literature relevant to obstetric anesthesiologists: the 2023 Gerard W. Ostheimer lecture

This narrative review of the 2023 Gerard W. Ostheimer lecture presented at the Society for Obstetric Anesthesia and Perinatology 2023 annual meeting summarizes 2022 literature relevant to obstetric anesthesiologists.

ANTENATAL STUDIES

Neonatal morbidity is reduced with antenatal maternal buprenorphine compared with methadone for treatment of opioid use disorder. Antenatal pregnancy allergy testing is safe and feasible.

ANALGESIA AND ANESTHESIA STUDIES

Intrathecal (IT) 3% chloroprocaine for cervical cerclage results in faster sensory block resolution and discharge readiness compared with bupivacaine. The ED90 of 3% chloroprocaine (with IT fentanyl 10 µg) is 49.5 mg. Dural puncture epidural technique does not improve the quality of labor analgesia in obese parturients compared with epidural analgesia. Low- (>0.08 to ≤0.1%) and ultra-low (<0.08%) concentrations of bupivacaine for epidural analgesia maintenance result in similar maternal and neonatal outcomes. Lower doses of first line uterotonic agents are non-inferior to higher doses (oxytocin 0.5 IU vs. 5 IU and carbetocin 20 vs. 100 µg) in patients at low risk for postpartum hemorrhage. Supplemental analgesia or conversion to general anesthesia is necessary in approximately 15% of elective cesarean deliveries. Intravenous dexamethasone improves analgesia outcomes, however optimal dosing and timing remain unclear; it may induce neonatal hypoglycemia in the setting of gestational diabetes.

POSTPARTUM STUDIES

A core outcome set may help evaluate enhanced recovery protocol implementation. History of migraine and accidental dural puncture (ADP) above the L3 level are associated with epidural blood patch (EBP) failure and ADP at or below L3 and >48 h interval between ADP and EBP are associated with success.

Sub-anesthetic dose of esketamine decreases postoperative opioid self-administration after spine surgery: a retrospective cohort analysis

The use of intraoperative sub-anesthetic esketamine for postoperative analgesia is controversial. In this study, the impact of sub-anesthetic esketamine on postoperative opioid self-administration was determined. Patients who underwent spinal surgery with patient-controlled analgesia (PCA) from January 2019 to December 2021 were respectively screened for analysis. Postoperative PCA was compared between patients who received a sub-anesthetic esketamine dose and patients who were not treated with esketamine (non-esketamine group) with or without propensity score matching. Negative binomial regression analysis was used to identify factors associated with postoperative PCA. Patients who received intraoperative sub-anesthetic esketamine self-administered less PCA (P = 0.001). Azasetron, esketamine, and dexamethasone lowered the self-administration of PCA (IRR with 95% confidential interval, 0.789 [0.624, 0.993]; 0.581 [0.458, 0.741]; and 0.777 [0.627, 0.959], respectively). Fixation surgery and drinking were risk factors for postoperative PCA (1.737 [1.373, 2.188] and 1.332 [1.032, 1.737] for fixation surgery and drinking, respectively). An intraoperative sub-anesthetic dose of esketamine decreases postoperative opioid self-administration. Azasetron and dexamethasone also decrease postoperative opioid consumption. The study is registered at www.chictr.org.cn (ChiCTR2300068733).

Outcomes and outcome measures utilised in randomised controlled trials of postoperative caesarean delivery pain: a scoping review

BACKGROUND

Inadequately treated postoperative pain following caesarean delivery can delay recovery and the ability to care for a newborn. Effectiveness studies of interventions to treat postoperative caesarean delivery pain measure different outcomes, limiting data pooling for meta-analysis. We performed a comprehensive review of existing outcomes with the aim of recommending core outcomes for future research.

METHODS

A scoping review to identify all outcomes reported in randomised controlled trials (RCTs) and clinical trial registries of interventions to treat or prevent postoperative caesarean delivery pain, with postoperative pain as a primary outcome measure. We searched PubMed, Web of Science, CINAHL, LILACS, Embase, CDSR and CRCT for studies from May 2016 to 2021. Outcomes were extracted and frequencies tabulated.

RESULTS

Ninety RCTs and 11 trial registries were included. In total, 392 outcomes (375 inpatient and 17 outpatient) were identified and categorised. The most reported outcome domain was analgesia (n = 242/375, 64.5%), reported in 96% of inpatient studies, with analgesic consumption accounting for 108/375, 28.8% of analgesia outcomes. The second most common domain was pain intensity (n = 120/375, 32%), reported in 97% of inpatient studies, using the visual analogue scale (68/120, 59%) and the numerical reporting scale (37/120, 25%). Maternal and neonatal adverse effects accounted for 65/375 (17.3%) and 19/375 (5.1%) of inpatient outcomes, respectively.

CONCLUSIONS

Outcomes reported in RCTs for postoperative caesarean delivery pain vary widely. The results of this review suggest that standardisation is needed to promote research efficiency and aid future meta-analyses to identify optimal postoperative caesarean delivery pain management.

Analgesia after cesarean section - what is new?

PURPOSE OF REVIEW

Cesarean section is the most frequent surgical intervention, and pain following cesarean delivery unfortunately remains a common issue. The purpose of this article is to highlight the most effective and efficient options for postcesarean analgesia and to summarize current guidelines.

RECENT FINDINGS

The most effective form of postoperative analgesia is through neuraxial morphine. With adequate dosing, clinically relevant respiratory depression is extremely rare. It is important to identify women with increased risk of respiratory depression, as they might require more intensive postoperative monitoring. If neuraxial morphine cannot be used, abdominal wall block or surgical wound infiltration are very valuable alternatives. A multimodal regimen with intraoperative intravenous dexamethasone, fixed doses of paracetamol/acetaminophen, and nonsteroidal anti-inflammatory drugs reduce postcesarean opioid use. As the use of postoperative lumbar epidural analgesia impairs mobilization, double epidural catheters with lower thoracic epidural analgesia are a possible alternative.

SUMMARY

Adequate analgesia following cesarean delivery is still underused. Simple measures, such as multimodal analgesia regimens should be standardized according to institutional circumstances and defined as part of a treatment plan. Neuraxial morphine should be used whenever possible. If it cannot be used, abdominal wall blocks or surgical wound infiltration are good alternatives.

Efficacy of intravenous dexamethasone on postoperative pain after caesarean delivery under spinal anaesthesia with an intrathecal long-acting opioid: a systematic review and meta-analysis

PURPOSE

Intravenous dexamethasone is recommended in elective caesarean delivery to decrease postoperative pain. However, the efficacy of spinal anaesthesia with an intrathecal long-acting opioid such as morphine or diamorphine for caesarean delivery has not been systematically investigated.

METHODS

We searched all randomized controlled trials (RCTs) of pregnant women undergoing caesarean delivery under spinal anaesthesia with an intrathecal morphine or diamorphine via MEDLINE, CENTRAL, EMBASE, ICTRP, and ClinicalTrials.gov on May 18, 2022. Primary outcomes were time to first rescue analgesia, consumption of oral morphine equivalents, and incidence of drug-related adverse reactions. We evaluated the risk of bias for each outcome using the Risk of Bias 2. We conducted a meta-analysis using a random effects model. We evaluated the certainty of evidence with the GRADE approach.

RESULTS

Five RCTs (455 patients) were included. The results of intravenous dexamethasone were as follows: time to first rescue analgesia (mean difference [MD] 0.99 h, 95% confidence interval [CI] - 0.86 to 2.84; very low certainty) and consumption of oral morphine equivalents (MD - 6.55 mg, 95% CI - 17.13 to 4.02; moderate certainty). No incidence of drug-related adverse reactions was reported (very low certainty).

CONCLUSION

The evidence was very uncertain about the efficacy of intravenous dexamethasone on time to first rescue analgesia and the incidence of drug-related adverse reactions. Intravenous dexamethasone probably reduces the consumption of oral morphine equivalents. Anaesthesiologists might want to consider intravenous dexamethasone for postoperative pain after caesarean delivery under spinal anaesthesia with an intrathecal long-acting opioid.