Obstetric anaesthesia: Journals & articles

Abstract
Pain management in pregnant and postpartum people with an opioid-use disorder (OUD) requires a balance between risks associated with opioid tolerance, including withdrawal or return to opioid use, considerations around social needs of the maternal-infant dyad, and the provision of adequate pain relief for the birth episode that is often characterized as the worst pain a person will experience in their lifetime. This multidisciplinary consensus statement between the Society for Obstetric Anesthesia and Perinatology (SOAP), Society for Maternal-Fetal Medicine (SMFM), and American Society of Regional Anesthesia and Pain Medicine (ASRA) provides a framework for pain management in obstetric patients with OUD. The purpose of this consensus statement is to provide practical and evidence-based recommendations and is targeted to health care providers in obstetrics and anesthesiology. The statement is focused on prenatal optimization of pain management, labor analgesia, and postvaginal delivery pain management, and postcesarean delivery pain management. Topics include a discussion of nonpharmacologic and pharmacologic options for pain management, medication management for OUD (eg, buprenorphine, methadone), considerations regarding urine drug testing, and other social aspects of care for maternal-infant dyads, as well as a review of current practices. The authors provide evidence-based recommendations to optimize pain management while reducing risks and complications associated with OUD in the peripartum period. Ultimately, this multidisciplinary consensus statement provides practical and concise clinical guidance to optimize pain management for people with OUD in the context of pregnancy to improve maternal and perinatal outcomes.

Abstract
Background: Hypertensive disorders of pregnancy (HDP) are a major contributor to maternal morbidity, mortality, and accelerated cardiovascular (CV) disease. Comorbid conditions are likely important predictors of CV risk in pregnant people. Currently, there is no way to predict which people with HDP are at risk of acute CV complications. We developed and validated a predictive model for all CV events and for heart failure, renal failure, and cerebrovascular events specifically after HDP.

Methods: Models were created using the Premier Healthcare Database. The inclusion criteria for the model dataset were delivery with an HDP with discharge from October 1, 2015 to December 31, 2020. Machine learning methods were used to derive predictive models of CV events occurring during delivery hospitalization (Index Model) or during readmission (Readmission Model) using a training set (60%) to estimate model parameters, a validation set (20%) to tune model hyperparameters and select a final model, and a test set (20%) to evaluate final model performance.

Results: The total model cohort consisted of 553,658 deliveries with an HDP. A CV event occurred in 6501 (1.2%) of the delivery hospitalizations. Multilabel neural networks were selected for the Index Model and Readmission Model due to favorable performance compared to alternatives. This approach is designed for prediction of multiple events that share risk factors and may cooccur. The Index Model predicted all CV events with area under the receiver operating curve (AUROC) 0.878 and average precision (AP) 0.239 (cerebrovascular events: AUROC 0.941, heart failure: AUROC 0.898, and renal failure: AUROC 0.885). With a positivity threshold set to achieve ≥90% sensitivity, model specificity was 65.0%, 83.5%, 68.6%, and 65.6% for predicting all CV events, cerebrovascular events, heart failure, and renal failure, respectively. CV events within 1 year of delivery occurred in 3018 (0.6%) individuals. The Readmission Model predicted all CV events with AUROC 0.717 and AP 0.022 (renal failure: AUROC 0.748, heart failure: AUROC 0.734, and cerebrovascular events AUROC 0.698). Feature importance analysis indicated that the presence of chronic renal disease, cardiac disease, pulmonary hypertension, and preeclampsia with severe features had the greatest effect on the prediction of CV events.

Conclusions: Among individuals with HDP, our multilabel neural network model predicted CV events at delivery admission with good classification and events within 1 year of delivery with fair classification.

Abstract in English, French
Purpose: To determine the optimal programmed intermittent epidural bolus (PIEB) volume for providing effective analgesia in 90% of patients (EV90) during the first stage of labour using the dural puncture epidural (DPE) technique to initiate labour analgesia.

Methods: We conducted a biased-coin up-and-down sequential allocation study. We included 40 nulliparous women requiring epidural labour analgesia. We used a 25G Whitacre spinal needle to puncture the dural mater and then administered a loading dose of 12 mL of ropivacaine 0.1% and sufentanil 0.3 μg·mL-1. Subsequently, the PIEB pump delivered boluses with an identical solution at a fixed 40-min interval, starting 1 hr after epidural initiation. The bolus volume for the first patient was 7 mL and was adjusted for subsequent patients according to the study protocol (bolus volume, 7-12 mL). The primary endpoint was effective analgesia, indicated by no need for patient-controlled or manual boluses within 6 hr after analgesia initiation or until complete cervical dilation, whichever came first. Outcome evaluators assessed the patients' pain ratings, Bromage scores, sensory blockade level, and maternal blood pressure hourly.

Results: Using the truncated Dixon and Mood method, the estimated EV90 was 9.2 mL (95% confidence interval [CI], 8.5 to 9.9) whereas the isotonic regression method yielded a value of 8.8 mL (95% CI, 8.6 to 9.8). None of the patients experienced a motor block. Two patients experienced hypotension without the need for vasopressors.

Conclusions: The estimated PIEB EV90 for ropivacaine 0.1% and sufentanil 0.3 μg·mL-1 approached 9 mL when DPE was combined with a fixed 40-min interval.

Study registration: ChiCTR.org.cn ( ChiCTR2300067281 ); first submitted 3 January 2023.

Keywords: dural puncture epidural; effective bolus volume; labour analgesia; programmed intermittent epidural bolus.

Abstract
Purpose: While regional anesthesia (RA) is considered preferable to general anesthesia (GA) for Cesarean delivery (CD), certain situations necessitate GA. This study reviewed the practice patterns around the use of GA for CD to identify modifiable predictors of GA with the goal of reducing GA rates.

Methods: This was a retrospective, case-control study. Patients undergoing urgent/emergent CD over a 3-year period were identified, from which 102 patients undergoing GA and 102 patients undergoing RA were randomly selected. The data included patient characteristics, obstetrical indications for CD, type/indication of anesthetic, characteristics of airway management (GA group)/neuraxial anesthesia (RA group), and neonatal outcomes.

Results: Abnormal fetal heart rate (aFHR) was the most common obstetrical indication for urgent/emergent CD amongst the cases (39%) and controls (39%). GA administration was most commonly due to "limited time due to maternal/fetal compromise" (56%), followed by "maternal contraindication to RA" (25%) and "inadequate RA" (17%). The most frequent modifiable anesthetic indication for GA was inadequate neuraxial anesthesia (17%). Anesthetic and obstetric predictors for GA included ASA classification [OR 0.11 (0.06-0.21)], emergency code activation [OR 13.55 (1.73-106.40)], failure to progress [OR 0.15 ((0.06-0.36)], labor in a patient scheduled for CD [OR 0.16 (0.05-0.57)], pregnancy-related illness [OR 8.63 (1.06-70.38)], cord/fetal prolapse [14.85(1.90-115.94)], and gestational age (OR 0.86 (0.81-0.92)).

Conclusion: Abnormal fetal heart rate, specifically bradycardia, was the most common obstetrical indication of GA for urgent/emergent CD, while inadequate neuraxial anesthesia was the most modifiable anesthetic indication. Our data suggest aFHR and cord/fetal prolapse as potentially modifiable risk factors for GA in certain situations.

Abstract
Purpose of review: Medication administration errors represent a significant yet preventable cause of patient harm in the peripartum period. Implementation of best practices contained in this manuscript can significantly reduce medication errors and associated patient harm.

Recent findings: Cases of medication errors involving unintended intrathecal administration of tranexamic acid highlight the need to improve medication safety in peripartum patients and obstetric anesthesia.

Summary: In obstetric anesthesia, medication errors can include wrong medication, dose, route, time, patient, or infusion setting. These errors are often underreported, have the potential to be catastrophic, and most can be prevented. Implementation of various types of best practice cost effective mitigation strategies include recommendations to improve drug labeling, optimize storage, determine correct medication prior to administration, use non-Luer epidural and intravenous connection ports, follow patient monitoring guidelines, use smart pumps and protocols for all infusions, disseminate medication safety educational material, and optimize staffing models. Vigilance in patient care and implementation of improved patient safety measures are urgently needed to decrease harm to mothers and newborns worldwide.

Abstract in English, French
Purpose: The purpose of our study was to determine the minimum effective dose of oxytocin maintenance infusion required to maintain adequate uterine tone in 90% of patients (ED90) after administration of the initial bolus at elective Cesarean delivery (CD) under spinal anesthesia.

Methods: We conducted a prospective, double-blind dose-finding study with biased coin up-down design. Immediately after delivery, a 1-IU oxytocin bolus was administered, followed by a maintenance infusion. The obstetrician assessed the uterine tone by palpation as satisfactory or unsatisfactory. In case of unsatisfactory response, the dose for the next patient was increased by 2 IU·hr-1. For satisfactory response, the dose for the next patient was either decreased by 2 IU·hr-1 with a probability of 1/9, or remained unchanged. The primary outcome was a satisfactory uterine tone from five minutes after delivery until discharge from postanesthesia care unit. The secondary outcomes were blood loss, need for additional uterotonics, and side effects.

Results: We analyzed data for 40 patients. The ED90 of oxytocin maintenance infusion was 4.5 IU·hr-1 (95% confidence interval, 3.3 to 5.5) based on the isotonic regression estimator. The median [interquartile range] blood loss was 861 [553-1,181] mL; 18% received additional uterotonics, and 38% developed hypotension post delivery.

Conclusion: Based on the results of this dose-finding study, we recommend a maintenance infusion rate of 4.5 IU·hr-1 following an oxytocin bolus of 1 IU for adequate uterine tone in pregnant patients undergoing elective CDs. This infusion rate is four-fold lower than that required without an initial bolus.

Study registration: ClinicalTrials.gov ( NCT04946006 ); first submitted 25 June 2021.

Abstract
Informatics describes the study and use of processes for obtaining and utilizing data. In the clinical context, these data are then used to inform and educate providers to improve patient care. In the current digital age, informatic solutions can help clinicians to understand past or current quality issues (afferent tools), to benchmark personal performance against national averages (feedback tools), and to disseminate information to encourage best practice and quality care (efferent tools). There are countless examples of how these tools can be adapted for use in obstetric anesthesia, with evidence to support their implementation. This article thus aimed to summarize the many ways in which informatics can help clinicians to harness the power of data to improve quality and safety in obstetric anesthesia.

Abstract
Childbirth-related posttraumatic stress disorder (CB-PTSD) is increasingly common and consequential for pregnant patients. Throughout the labor experience and beyond, anesthesiologists are central to creating a psychological safe space for patients and play an essential role in preventing, recognizing, and treating CB-PTSD. This narrative review summarizes the current literature surrounding risk factors for CB-PTSD that are relevant to anesthesiologists; patients' symptoms or signs anesthesiologists should look out for; and ways anesthesiologists may be involved in preventing and treating this condition.

Abstract
Background: Neuraxial opioids are commonly used after cesarean delivery (CD). However, they are not commonly used after vaginal delivery (VD) though some studies have suggested they may be beneficial from a pain perspective. However, they did not evaluate other potential benefits including patient satisfaction, impact on postpartum depression and breastfeeding (BF) success, or side effects such as pruritus.

Methods: Parturients who delivered vaginally with epidural analgesia were randomized to receive either 2 mg of preservative-free morphine (4 mL) or saline (4 mL) via the epidural catheter within 1 hour of VD. Routine analgesics were unchanged and included q 6-hour dosing of acetaminophen 975 mg orally and ketorolac 30 mg intravenous (IV). Hydromorphone 2 mg or oxycodone 10 mg were offered for breakthrough pain. Our primary outcome was opiate consumption in the first 24 hours after drug administration. Secondary outcomes included pain scores at 24 hours and 1 week postpartum as well as opiate consumption up to 1 week postpartum. Additional end points such as obstetric quality of recovery score (OBS-QOR10) breast feeding success, and an Edinburgh Postnatal Depression Score (EPDS) were also obtained.

Results: Data were analyzed for 157 parturients, 80 in the morphine group and 77 in the saline group. No difference was observed in the EDPS score predelivery or intention to BF. We found a statistically significant difference in the use of opioids in the first 24 hours, 3.8% (95% confidence interval [CI], 0.9%-11.3%) vs 14.3% (7.7%-24.5%) in the morphine and saline groups, respectively; and in total opioid dose, median (interquartile range, IQR [range]) of morphine milligram equivalent vs 0 (0-0 [0-47.5]) vs 0 (0-0 [0-72]), P = .023, in the morphine and saline groups, respectively. Verbal pain scores (0-10) at 24 hours were lower in the morphine group (median (IQR [range): 2.0 (1-4 [0-10]) vs 3.0 (1.5-5.0 [0-10]), P = .043. There was a greater incidence of pruritus in the morphine group versus saline group, 37.5% (95% CI, 27.1%-49.1%) vs 18.2% (95% CI, 10.6%-29.0%), P = .008. We did not find any differences in the OBS-QOR10, BF success, or EPDS at 6 weeks PP (P < .05).

Conclusions: A single epidural dose of 2 mg preservative-free morphine after VD was effective at decreasing pain and opioid use at 24 hours after VD but came at the cost of increased pruritus. We did not detect any differences in BF, recovery scores, or PPD. Future studies should focus on elucidating the role of neuraxial preservative-free morphine after VD.

Abstract
Background: Climate change has emerged as the single biggest global health threat of the twenty-first century. Nitrous oxide accounts for the largest carbon footprint amongst our use of anaesthetic gas. It is a potent greenhouse gas possessing a global warming potential of approximately 265 times that of carbon dioxide. Despite recent curtailment of its use, it remains extensively employed as an analgesic for women in labour.

Objectives: Assessment of the opinions of post-natal women and staff on nitrous oxide use and to investigate whether knowledge of its environmental harm would influence their choice of labour analgesia.

Design: Postnatal women and healthcare staff were invited to participate in a survey of nitrous oxide use as a labour analgesic and knowledge of its effect of the environment.

Setting: A single-centre study in a major obstetric tertiary referral centre in Ireland in 2021.

Main outcome measures: To evaluate the awareness and perceptions of postnatal women and staff regarding the environmental impact of nitrous oxide and if it would affect their decision to use it in the future.

Results: One hundred postnatal women and 50 healthcare staff completed the survey. One hundred and six post-natal women were invited to complete the survey, resulting in a response rate of 94%. Knowledge of nitrous oxide's environmental impact was low. After receiving information, 46% of patients were more inclined to seek epidural or request it earlier (54%) to limit their nitrous oxide use, while 51% would choose an alternative analgesia to avoid nitrous oxide altogether. Overwhelmingly, 99% believed they had the right to know about these harmful effects when choosing an analgesic option.

Conclusions: Patients should be informed of the environmental impact of nitrous oxide antenatally, empowering them to make informed decision on a climate friendly analgesic option if they wish.

Abstract
Purpose of review: This review article explores the potential longer-term implications of neuraxial analgesia in labour for both the mother and her child.

Recent findings: Neuraxial techniques for labour analgesia are well tolerated and effective, and long-term adverse sequelae are rare. Labour epidural analgesia is not independently associated with long-term headache, backache, postnatal depression or anal sphincter injury, and evidence supports that epidurals may offer protection against severe maternal morbidity, particularly in women at a higher risk of complications. However, there is an increasing awareness that postdural puncture headache may be associated with chronic headache, back pain and postnatal depression, emphasizing the need for adequate follow-up until symptoms resolve.For the neonate, a growing body of evidence refutes any association between epidural analgesia in labour and the later development of autism spectrum disorder. The clinical significance of epidural related maternal fever remains uncertain and is a research priority.

Summary: Women should continue to access the significant benefits of neuraxial analgesia in labour without undue concern about adverse sequelae for themselves or their offspring. Measures to prevent, appropriately manage and adequately follow-up women who have suffered complications of neuraxial analgesia, such as postdural puncture headache, are good practice and can mitigate the development of long-term sequelae.

Abstract
Background: 3% chloroprocaine (CP) has been reported as the common local anesthetic used in pregnant women undergoing urgent cesarean delivery during labor analgesia period. However, 0.75% ropivacaine is considered a promising and effective alternative. Therefore, we conducted a randomized controlled trial to compare the effectiveness and safety of 0.75% ropivacaine with 3% chloroprocaine for extended epidural anesthesia in pregnant women.

Methods: We conducted a double-blind, randomized, controlled, single-center study from November 1, 2022, to April 30, 2023. We selected forty-five pregnant women undergoing urgent cesarean delivery during labor analgesia period and randomized them to receive either 0.75% ropivacaine or 3% chloroprocaine in a 1:1 ratio. The primary outcome was the time to loss of cold sensation at the T4 level.

Results: There was a significant difference between the two groups in the time to achieve loss of cold sensation (303, 95%CI 255 to 402 S vs. 372, 95%CI 297 to 630 S, p = 0.024). There was no significant difference the degree of motor block (p = 0.185) at the Th4 level. Fewer pregnant women required additional local anesthetics in the ropivacaine group compared to the chloroprocaine group (4.5% VS. 34.8%, p = 0.011). The ropivacaine group had lower intraoperative VAS scores (p = 0.023) and higher patient satisfaction scores (p = 0.040) than the chloroprocaine group. The incidence of intraoperative complications was similar between the two groups, and no serious complications were observed.

Conclusions: Our study found that 0.75% ropivacaine was associated with less intraoperative pain treatment, higher patient satisfaction and reduced the onset time compared to 3% chloroprocaine in pregnant women undergoing urgent cesarean delivery during labor analgesia period. Therefore, 0.75% ropivacaine may be a suitable drug in pregnant women undergoing urgent cesarean delivery during labor analgesia period.

Clinical trial number and registry url: The registration number: ChiCTR2200065201; http://www.chictr.org.cn , Principal investigator: MEN, Date of registration: 31/10/2022.

Abstract
Purpose of review: There is an increasing awareness of the significance of intraoperative pain during cesarean delivery. Failure of spinal anesthesia for cesarean delivery can occur preoperatively or intraoperatively. Testing of the neuraxial block can identify preoperative failure. Recognition of the risk of high neuraxial block in repeat spinal in case of preoperative failure is important.

Recent finding: Knowledge of risk factors for block failure facilitates prevention by selecting the most appropriate neuraxial procedure, adequate intrathecal doses and choice of technique. Intraoperative pain is not uncommon, and neither obstetricians nor anesthesiologists can adequately identify intraoperative pain. Early intraoperative pain should be treated differently from pain towards the end of surgery.

Summary: Block testing is crucial to identify preoperative failure of spinal anesthesia. Repeat neuraxial is possible but care must be taken with dosing. In this situation, switching to a combined spinal epidural or an epidural technique can be useful. Intraoperative pain must be acknowledged and adequately treated, including offering general anesthesia. Preoperative informed consent should include block failure and its management.

Abstract
Purpose: To explore the effect of dural puncture epidural (DPE) block technique on fetal heart rate variability (HRV) during labor analgesia.

Methods: Sixty full-term primiparas who were in our hospital from April 2021 to October 2021 were selected and randomized into epidural analgesia (CEA) and dural puncture epidural analgesia (DPEA) groups (n = 30). After a successful epidural puncture, routine epidural catheter (EC) was performed in CEA group, and spinal anesthesia needle (as an EC) was used to puncture the dura mater to subarachnoid space in DPE group. Anesthetics were injected through EC. The time when the temperature sensation plane reached T10 (W1) and visual analog pain score (VAS), baseline heart rate score, amplitude variation score, cycle variation score, acceleration score, deceleration score, and total score of the first contraction after W1 were recorded. Apgar scores at 1 min, 5 min, and 10 min of neonates after delivery were recorded.

Results: The onset time of anesthesia in CEA group was significantly longer than that in DPEA group (p < .05). However, there are no significant differences in W1, VAS, baseline heart rate score, amplitude variation score, cycle variation score, acceleration score, deceleration score, and total score of the first contraction after W1 between the two groups (p > .05). Moreover, the Apgar scores at 1 min, 5 min and 10 min of neonates after delivery were not notably different between the two groups (p > .05).

Conclusion: Compared with CEA, DPE block technique in labor analgesia relieves maternal pain without adverse effects on fetal HRV and newborns.

Abstract
The Gerard W. Ostheimer lecture is given annually to members of the Society for Obstetric Anesthesia and Perinatology. This lecture summarizes new and emerging literature that informs the clinical practice of obstetric anesthesiology. This is a narrative review of 2022 literature pertinent to maternal morbidity and mortality in all income settings globally. Themes associated with worse maternal mortality rate (MMR), challenges health care workers face, public health priority areas, and initiatives to help countries achieve the United Nations Sustainable Development Goal targets for MMR are discussed. MMRs are higher in low- and middle-income countries (LMICs) compared to high-income countries (HICs). Cesarean delivery rates are rising most rapidly in LMICs, warranting urgent maternal health care workforce planning efforts in these settings. Globally racial, ethnic, and geographical disparities in maternal mortality continue to be evident in global health care settings. In the United States, the MMR is rising. The evolving changes in abortion legislation in the United States may further negatively impact maternal morbidity and mortality. The need to implement American Society of Anesthesiologists-recommended obstetric anesthesia quality metrics to facilitate benchmarking and to improve patient experience and outcomes is discussed as well as the need for professional society guidance on minimum staffing levels in American labor and delivery units.

Abstract
Background: Three settings are required on a programmed intermittent epidural bolus (PIEB) pump for labor analgesia: the PIEB next bolus (PIEBnb), PIEB interval (PIEBi), and PIEB volume (PIEBv). The ideal settings for these parameters are still unknown. We hypothesized a mathematical modeling tool, response surface methodology (RSM), could estimate 3 PIEB pump parameters while balancing 3 clinically important patient outcomes simultaneously. The study objective was to use RSM to estimate PIEB settings (PIEBnb, PIEBi, and PIEBv) while maximizing maternal satisfaction, minimizing the need for clinician-administered boluses, and optimizing the ratio of delivered/requested patient-controlled epidural analgesia (PCEA) boluses simultaneously.

Methods: With institutional ethics approval, a double-blind randomized trial was completed in a tertiary care labor and delivery center. Nulliparous, English-speaking American Society of Anesthesiologists (ASA) physical status II patients aged 18 to 45 years at full term, single gestation in vertex presentation, in spontaneous labor and ≤7 cm cervical dilation were included. Patients with comorbidities, contraindications to neuraxial analgesia, using chronic analgesics, <152 cm, or body mass index (BMI) >45 kg/m2 were excluded. After informed consent, labor analgesia was initiated using 10 mL ropivacaine 0.2% with 10 µg/mL fentanyl solution and PCEA (volume 6 mL every 10 minutes). Patients were randomized to predetermined PIEB settings. RSM identified 3 pump settings that represented a stationary point that best maximized or minimized 3 outcomes simultaneously: PCEA ratio (a ratio closest to 1), clinician bolus (optimal is 0), and maternal satisfaction (visual analog scale, 0-100, ideal response is ≥90).

Results: Of 287 potential participants, 192 did not meet inclusion criteria or declined to participate, and 26 were withdrawn, leaving 69 patients for study inclusion. Using RSM, the suggested PIEB settings for all the primary study outcomes were as follows: PIEBnb = 29.4 minutes, PIEBi = 59.8 minutes, and PIEBv = 6.2 mL. These PIEB settings corresponded to the following clinical outcomes: maternal satisfaction at 93.9%, PCEA ratio at 0.77, and need for clinician bolus at 0.29. The dermatome sensory score was between T10 and T5 in 89% of the patients. The median lowest Bromage score was 4.

Conclusions: This novel study used a mathematical model to estimate PIEB pump settings while simultaneously maximizing 3 clinical outcomes. Equally weighted clinical outcomes prevent maximal outcome optimization and may not reflect patient priorities. Future studies or quality improvement endeavors could use RSM methodology to estimate PIEB pump settings targeting optimal values for a single clinical outcome of determined importance to parturients.

Abstract
Background: The hemodynamic effects of relatively low-dose epinephrine and phenylephrine infusions during cesarean delivery under spinal anesthesia were compared.

Methods: This randomized controlled trial included full-term pregnant women who underwent elective cesarean delivery. After spinal anesthesia, participants received either epinephrine (0.03 mcg/kg/min) or phenylephrine (0.4 mcg/kg/min) infusion that continued until 5 min after delivery. The primary outcome was a composite outcome of the occurrence of any of hypotension, hypertension, bradycardia, and/or tachycardia. Neonatal outcomes, including umbilical artery blood gas and Apgar scores, were assessed.

Results: In total, 98 patients in each group were analyzed, and the number of patients with the composite outcome was comparable between the epinephrine and phenylephrine groups (30/98 [31%] vs. 31/98 [32%], respectively; P = 0.877). However, the incidence of hypotension was likely lower in the epinephrine group than in the phenylephrine group (P = 0.066), and the number of hypotensive episodes per patient was lower in the epinephrine group than in the phenylephrine group. On the other hand, the incidence of tachycardia was higher in the epinephrine group than that in the phenylephrine group. The incidence of hypertension was comparable between the two groups and none of the participants developed bradycardia. Neonatal outcomes were comparable between the two groups.

Conclusions: Epinephrine and phenylephrine infusion produced comparable maternal hemodynamics and neonatal outcomes. Epinephrine was associated with a higher incidence of maternal tachycardia and likely lower incidence of maternal hypotension than phenylephrine. IRB number: MD-245-2022.

Abstract
Introduction: Maternal epilepsy is a critical condition that can significantly affect mothers and fetuses. Notably, the admission of a laboring mother with uncontrolled refractory status epilepticus (RSE) to the operating room presents a challenging scenario for anesthesiologists.

The main symptoms of the patient and the important clinical findings: A 30-year-old primigravida was transferred to the operating room for an emergency cesarean section. Cesarean section was performed after a provisional diagnosis of preeclampsia was made.

The main diagnoses, therapeutic interventions, and outcomes: Cesarean section was performed under general anesthesia. During the postoperative period, the patient exhibited no seizure activity in the brain; however, she experienced mild cognitive dysfunction for up to 6 months postdelivery. The neonate were discharged without any complications.

Conclusion: Inducing anesthesia in pregnant women with ongoing seizure activity are challenging; however, anesthesiologists provide judgment based on the balance between the safety of the mother and fetus and the balance between patient monitoring and the progression of anesthesia. This challenge can be addressed through multidisciplinary collaboration.

Abstract
Both endocannabinoid (EC) and endogenous opioid systems are involved in nociceptive processing and may work together synergistically based on preclinical models. This study evaluated the interactive effects of preoperative beta-endorphin concentrations (a key analgesic endogenous opioid) in cerebrospinal fluid (CSF) and ECs (CSF and plasma 2-arachidonoylglycerol [2-AG] and plasma anandamide [AEA]) on postoperative opioid use and pain intensity in a prospective cohort of n = 112 pregnant patients undergoing scheduled cesarean delivery. Maternal blood and CSF samples were collected preoperatively for beta-endorphin and EC assays. Patients completed measures of outpatient opioid use (number of tablets used and days of use) and average pain intensity at 2 weeks postoperatively. Results of general linear model analyses controlling for maternal age, BMI at time of delivery, and race revealed significant multiplicative interactions between EC and beta-endorphin concentrations on number of opioid tablets used (based on pill count), days of opioid use, and total milligram morphine equivalents used in the 2 week follow-up period. Elevated preoperative plasma and CSF 2-AG predicted reduced outpatient opioid analgesic use particularly for patients low in CSF beta-endorphin. Similar analyses for pain intensity at 2-week follow-up indicated a significant interaction (p<.02) characterized by higher preoperative beta-endorphin concentrations being associated with lower subsequent pain only for individuals with low preoperative plasma AEA concentrations. Further exploration of interactions between EC and endogenous opioid inhibitory systems as they influence responses to opioid analgesics in other clinical pain populations may help guide development of precision pain management approaches. PERSPECTIVE: In the postoperative setting of patients undergoing cesarean delivery, elevated endocannabinoids were linked to reduced outpatient opioid analgesic use in individuals who had low endogenous opioid concentrations in cerebrospinal fluid. Further exploration of interactions between these two inhibitory systems as they impact on responses to pain management interventions appears warranted.

Abstract
Background: Specific guidelines to manage caesarean delivery anaesthesia are lacking. A European multicentre study, ACCESS investigates caesarean delivery anaesthesia management in European centres. In order to identify ACCESS participating centres, a registration survey was created.

Objective: The aim of the current report is to describe the characteristics of ACCESS study participating centres, the rationale for the ACCESS study and the study methodology.

Design and setting: The ACCESS study is a European multicentre cross-sectional study to describe anaesthesia management for caesarean delivery (CD) using a snapshot (2-week) design. The ACCESS registration survey gathered: contact details for National Coordinators (NC); Lead Investigators (LI) per centre; centre annual CD volume; expected no. of CD during 2-week snapshot window; centre practice information; data collection language. The ACCESS registration survey was launched July 2022 (Google Forms, Google Inc., Mountain View, CA, USA) and distributed through personal connections, national and international societies, social media networks, during Euroanaesthesia 2023, through the European Society of Anaesthesiology and Intensive Care newsletter.

Results: The ACCESS registration survey identified Lead Investigators for 418 centres, in 32 countries, representing an anticipated number of 15,073 CD cases over the planned 12-month study period. A median (range) of 20 (2 to 400) CD cases are anticipated per centre during the 2-week snapshot window. Most 366/418 (87.6%) centres are small, ≤2000 annual CD cases, 42 are medium 2000-5000 cases and 10 are large, ≥5000 annual CD cases. Registered centres reported in 134 (32.0%) centres that anaesthesia for caesarean delivery is performed mostly by a specialist obstetric anaesthesiologist.

Conclusion: The ACCESS registration survey revealed variability in volume and CD practice as well as training-levels and staffing among European countries. The ACCESS study (https://www.access-study.org/) aims to generate practice data to guide CD anaesthetic management strategies.

Abstract
Purpose: To elucidate the clinical impact of the novel oxytocin protocol using a syringe pump with a stratified dose compared with the conventional practice of putting oxytocin into the bag.

Methods: This is a retrospective cohort study. We collected the data of the patients who underwent elective cesarean delivery under neuraxial anesthesia between June 2019 and May 2020. The patients were allocated to two groups according to oxytocin administration methods; the control group (the attending anesthesiologist put oxytocin 5-10 units in the infusion bag and adjusted manually after childbirth) and the protocol group (the oxytocin protocol gave oxytocin bolus 1 or 3 units depending on the PPH risk, followed by 5 or 10 unit h-1 via a syringe pump). We compared the total amount of oxytocin within 24 h postpartum, estimated blood loss, and adverse clinical events within 24 h postpartum between the two groups.

Results: During the study period, 262 parturients were included. Oxytocin doses of intraoperative and postoperative were significantly lower in the protocol group (9.7 vs. 11.7 units, intraoperative, 15.9 vs. 18 units, postoperative). The subgroup analyses showed that the impact was more remarkable in the low PPH risk than in the high PPH risk. The multivariate linear regression analyses also confirmed the difference. The groups had no significant difference in blood loss, requirement of additional uterotonics, and other adverse events.

Conclusions: Our oxytocin infusion protocol significantly reduced oxytocin requirements in elective cesarean delivery under neuraxial anesthesia without increasing blood loss. However, we could not find other clinical benefits of the novel protocol.

Abstract
Purpose: Adequate post-cesarean delivery analgesia can be difficult to achieve for women diagnosed with opioid use disorder receiving buprenorphine. We sought to determine if neuraxial clonidine administration is associated with decreased opioid consumption and pain scores following cesarean delivery in women receiving chronic buprenorphine therapy.

Methods: This was a retrospective cohort study at a tertiary care teaching hospital of women undergoing cesarean delivery with or without neuraxial clonidine administration while receiving chronic buprenorphine. The primary outcome was opioid consumption (in morphine milligram equivalents) 0-6 h following cesarean delivery. Secondary outcomes included opioid consumption 0-24 h post-cesarean, median postoperative pain scores 0-24 h, and rates of intraoperative anesthetic supplementation. Multivariable analysis evaluating the adjusted effects of neuraxial clonidine on outcomes was conducted using linear regression, proportional odds model, and logistic regression separately.

Results: 196 women met inclusion criteria, of which 145 (74%) received neuraxial clonidine while 51 (26%) did not. In univariate analysis, there was no significant difference in opioid consumption 0-6 h post-cesarean delivery between the clonidine (8 [IQR 0, 15]) and control (1 [IQR 0, 8]) groups (P = 0.14). After adjusting for potential confounders, there remained no significant association with neuraxial clonidine administration 0-6 h (Difference in means 2.77, 95% CI [- 0.89 to 6.44], P = 0.14) or 0-24 h (Difference in means 8.56, 95% CI [- 16.99 to 34.11], P = 0.51).

Conclusion: In parturients receiving chronic buprenorphine therapy at the time of cesarean delivery, neuraxial clonidine administration was not associated with decreased postoperative opioid consumption, median pain scores, or the need for intraoperative supplementation.

Abstract
Purpose: More literature studies have reported that alfentanil is safe and effective for labor analgesia. However, there is no unified consensus on the optimal dosage of alfentanil used for epidural analgesia. This study explored the concentration at 90% of minimum effective concentration (EC90) of alfentanil combined with 0.075% ropivacaine in patients undergoing epidural labor analgesia to infer reasonable drug compatibility and provide guidance for clinical practice.

Methods: In this prospective, single-center, double-blind study, a total of 45 singleton term primiparas with vaginal delivery who volunteered for epidural labor analgesia were recruited. The first maternal was administered with 3 μg/mL alfentanil combined with 0.075% ropivacaine with the infusion of 10 mL of the mixture every 50 min at a background dose of 3 mL/h. In the absence of PCEA, a total of 15 mL of the mixture is injected per hour. The subsequent alfentanil concentration was determined on the block efficacy of the previous case, using an up-down sequential allocation with a bias-coin design. 30 min after epidural labor analgesia, the block of patient failed with visual analog score (VAS) > 3, the alfentanil concentration was increased in a 0.5 μg/mL gradient for the next patient, while the block was successful with VAS ≤ 3, the alfentanil concentration was remained or decreased in a gradient according to a randomized response list for the next patient. EC90 and 95% confidence interval were calculated by linear interpolation and prediction model with R statistical software.

Results: In this study, the estimated EC90 of alfentanil was 3.85 μg/mL (95% confidence interval, 3.64-4.28 μg/mL).

Conclusion: When combined with ropivacaine 0.075%, the EC90 of alfentanil for epidural labor analgesia is 3.85 μg/mL in patients undergoing labor analgesia.

Abstract
Purpose: A zone of differential block to cold has been recently documented during labour epidural analgesia, with an upper sensory block level (USBL) and a lower sensory block level (LSBL). We aimed to determine the correlation between USBL and LSBL to cold and pinprick and sensory block level to light touch during labour epidural analgesia.

Methods: We conducted a prospective observational study in patients requesting labour epidural analgesia. We placed an epidural catheter at L2/L3 or L3/L4, followed by a programmed intermittent epidural bolus plus patient-controlled epidural analgesia regimen. We assessed the sensory block levels 140 min after administering the loading dose. The primary outcomes were the USBL and LSBL to cold and pinprick and the sensory block level to light touch.

Results: We studied 30 patients. The median [interquartile range (IQR)] USBL and LSBL to ice were T7 [T7-T6] and T9 [T10-T8], respectively. The median [IQR] USBL and LSBL to pinprick were T8 [T10-T6] and T10 [T12-T10], respectively. There was a strong correlation between USBL to ice and pinprick (Spearman correlation coefficient, 0.57) and between LSBL to ice and pinprick (Spearman correlation coefficient, 0.52). There was no significant correlation between sensory block level to light touch and either USBL or LSBL to ice or pinprick.

Conclusion: We observed two sensory block levels to ice and pinprick. Further studies are required to understand if one modality-cold or pinprick-is superior to the other in assessing sensory block levels in this context. Light touch is unreliable as a modality of sensory block assessment during labour epidural analgesia.

Trial registration: ClinicalTrials.gov (NCT05187962); registered 12 January 2022.

Keywords: epidural; labour analgesia; sensory block.

Abstract
Objective: To clarify whether the duration from cervical ripening induction to labor onset is prolonged when epidural analgesia is administered following application of dinoprostone vaginal inserts vs. cervical ripening balloon.

Methods: This retrospective study included mothers with singleton deliveries at a single center between 2020-2021. Nulliparous women who underwent labor induction and requested epidural analgesia during labor after 37 weeks of gestation were included. The duration from cervical ripening induction to labor onset was compared between women using a dinoprostone vaginal insert and those using a cervical ripening balloon and between women who received epidural analgesia before and after labor onset.

Results: In the dinoprostone vaginal insert group, the duration was significantly shorter in the subgroup that received epidural analgesia after labor onset (estimated median, 545 [95% confidence interval: 229-861 min]) than the subgroup that received it before labor onset (estimated median, 1,570 [95% confidence interval: 1,226-1,914] min, p = 0.004). However, in the cervical ripening balloon group, the difference between subgroups was not significant. The length of labor among the groups was also not significantly different.

Conclusion: Epidural analgesia as labor relaxant adversely affected the progression of uterine cervical ripening when dinoprostone vaginal inserts were used, whereas it did not affect cervical ripening when a mechanical cervical dilatation balloon was used. The present results are significant for choosing the appropriate ripening method.

Abstract
Introduction: The Microsoft HoloLens is a head-mounted mixed reality device, which allows for overlaying hologram-like computer-generated elements onto the real world. This technology can be combined with preprocedural ultrasound during thoracic epidural placement to create a visual of the ideal needle angulation and trajectory in the users' field of view. This could result in a technically easier and potentially safer alternative to traditional blind landmark techniques.

Methods: Patients were randomly assigned to one of two groups: (1) HoloLens-assisted thoracic epidural technique (intervention-group H) or (2) traditional thoracic epidural technique (control-group C). The primary outcome was needling time (defined as skin puncture to insertion of epidural catheter) during the procedure. The secondary outcomes were number of needle punctures, number of needle movements, number of bone contacts, and epidural failure. Procedural pain and recovery room pain levels were also evaluated.

Results: Eighty-three patients were included in this study. The primary outcome of procedure time was reduced in the HoloLens group compared with control (4.5 min vs 7.3 min, p=0.02, 95% CI), as was the number of needle movements required (7.2 vs 14.4, p=0.01), respectively. There was no difference in intraprocedure or postprocedure pain, bone contacts, or total number of needle punctures. Three patients in the control group experienced epidural failure versus one patient in the HoloLens group.

Conclusions: This study shows that thoracic epidural placement may be facilitated by using a guidance hologram and may be more technically efficient.

Abstract
Purpose: Spinal anesthesia is a standard technique for cesarean delivery; however, it possesses a risk of hypotension. We hypothesised that the changes in the corrected flow time induced by the Trendelenburg position could predict the incidence of hypotension after spinal anesthesia for cesarean delivery.

Methods: Patients undergoing elective cesarean delivery under spinal anesthesia were enrolled. Before anesthesia induction, corrected flow time was measured in the supine and Trendelenburg positions (FTc-1 and FTc-2, respectively). Additionally, a percent change in corrected flow time induced by the Trendelenburg position was defined as ΔFTc. The primary endpoint was to investigate the ability of ΔFTc to predict the incidence of spinal anesthesia-induced hypotension until delivery. The receiver operating characteristics curves to assess the ability of FTc-1, FTc-2, and ΔFTc to predict the incidence of hypotension were generated.

Results: Finally, 40 patients were included, and of those, 26 (65%) developed spinal anesthesia-induced hypotension. The areas under the curve for FTc-1, FTc-2, and ΔFTc were 0.591 (95% CI: 0.424 to 0.743) (P = 0.380), 0.742 (95% CI: 0.579 to 0.867) (P = 0.004), and 0.882 (95% CI: 0.740 to 0.962) (P < 0.001) respectively, indicating ΔFTc as the best predictor among these three parameters. The best threshold for ΔFTc was 6.4% (sensitivity: 80.8% (95% CI: 53.8 to 96.2), specificity: 85.7% (95% CI: 42.9 to 100.0)).

Conclusions: This study demonstrated that changes in the corrected carotid flow time induced by the Trendelenburg position could serve as a good predictor of spinal anesthesia-induced hypotension for cesarean delivery.

Abstract
Airway management is required during general anaesthesia and is essential for life-threatening conditions such as cardiopulmonary resuscitation. Evidence from recent trials indicates a high incidence of critical events during airway management, especially in neonates or infants. It is important to define the optimal techniques and strategies for airway management in these groups. In this joint European Society of Anaesthesiology and Intensive Care (ESAIC) and British Journal of Anaesthesia (BJA) guideline on airway management in neonates and infants, we present aggregated and evidence-based recommendations to assist clinicians in providing safe and effective medical care. We identified seven main areas of interest for airway management: i) preoperative assessment and preparation; ii) medications; iii) techniques and algorithms; iv) identification and treatment of difficult airways; v) confirmation of tracheal intubation; vi) tracheal extubation, and vii) human factors. Based on these areas, Population, Intervention, Comparison, Outcomes (PICO) questions were derived that guided a structured literature search. GRADE (Grading of Recommendations, Assessment, Development and Evaluation) methodology was used to formulate the recommendations based on those studies included with consideration of their methodological quality (strong '1' or weak '2' recommendation with high 'A', medium 'B' or low 'C' quality of evidence). In summary, we recommend: 1. Use medical history and physical examination to predict difficult airway management (1С). 2. Ensure adequate level of sedation or general anaesthesia during airway management (1B). 3. Administer neuromuscular blocker before tracheal intubation when spontaneous breathing is not necessary (1С). 4. Use a videolaryngoscope with an age-adapted standard blade as first choice for tracheal intubation (1B). 5. Apply apnoeic oxygenation during tracheal intubation in neonates (1B). 6. Consider a supraglottic airway for rescue oxygenation and ventilation when tracheal intubation fails (1B). 7. Limit the number of tracheal intubation attempts (1C). 8. Use a stylet to reinforce and preshape tracheal tubes when hyperangulated videolaryngoscope blades are used and when the larynx is anatomically anterior (1C). 9. Verify intubation is successful with clinical assessment and end-tidal CO 2 waveform (1C). 10. Apply high-flow nasal oxygenation, continuous positive airway pressure or nasal intermittent positive pressure ventilation for postextubation respiratory support, when appropriate (1B).

Abstract
Background: Ondansetron has been reported to attenuate the incidence of spinal anesthesia-induced hypotension (SAIH) and norepinephrine requirement during cesarean section. However, no quantitative study has evaluated the extent of this effect. This study aimed to determine the dose-response of prophylactic infusion of norepinephrine to prevent SAIH in parturients who received intravenous ondansetron or placebo before spinal anesthesia for cesarean section. The median effective dose (ED50) and 90% effective dose (ED90) were compared to evaluate the effect of ondansetron versus placebo on the norepinephrine requirement.

Materials and methods: 150 parturients undergoing cesarean section were randomized to receive either 0.1 mg/kg ondansetron or saline control 10 min before spinal anesthesia. The parturients were randomly assigned to one of five different norepinephrine infusion groups: 0.02, 0.04, 0.06, 0.08 or 0.10 µg/kg/min. An effective infusion dose of norepinephrine was defined as non-occurrence of hypotension during the study period. The values for ED50 and ED90 of norepinephrine infusion were determined using probit regression. Differences between the two groups were evaluated by comparing the relative median potency with 95% confidence intervals (CIs).

Results: The ED50 values were 0.033 (95% CIs, 0.024-0.043) µg/kg/min in group C and 0.021 (95% CIs, 0.013-0.029) µg/kg/min in group O. The ED90 values were 0.091 (95% CIs 0.068-0.147) µg/kg/min in group C and 0.059 (95% CIs 0.044-0.089) µg/kg/min in group O, respectively. The estimate of the relative median potency for norepinephrine in group C versus group O was 0.643 (95% CIs, 0.363-0.956). The incidence of side effects was comparable between groups. No significant difference in neonatal outcomes.

Conclusion: Intravenous ondansetron 0.1 mg/kg before spinal anesthesia significantly reduced the dose requirement of prophylactic norepinephrine infusion in parturients undergoing elective cesarean section. This finding is potentially useful for clinical practice and further research.

Abstract
Background: Among assisted reproductive technologies, frozen thawed embryo transfer (FET) is associated with increased blood loss at delivery. Anesthesiologists need to be aware of new factors that affect postpartum blood loss. This study investigated whether FET cycles with or without hormonal support affect the amount of postpartum bleeding.

Methods: We conducted a retrospective cohort study of patients admitted for delivery at a single university hospital between January 2015 and December 2018. Patients were divided into no-assisted reproductive technology (No-ART), hormonal cycle FET (HC-FET) and natural cycle FET (NC-FET) group. The primary outcome was the amount of blood loss after delivery (median [interquartile range]), which was compared among the three groups. Multiple regression analysis was performed to investigate the factors affecting blood loss.

Results: Between 2015 and 2018, 3187 women delivered neonates. In vaginal delivery, postpartum blood loss in the HC-FET group (1060 [830] g) was significantly greater than in the NC-FET group (650 [485] g, P = 0.001) and in the No-ART group (590 [420] g P < 0.001). Multiple linear regression analysis showed that HC-FET (P < 0.001) was one of the independent factors for the amount of bleeding. In cesarean delivery, the HC-FET group had more blood loss than the No-ART group (910 [676] g vs. 784 [524] g, P = 0.039). However, HC-FET was not an independent factor for postpartum blood loss.

Conclusions: The HC-FET group had more blood loss than the No-ART group for both vaginal and cesarean deliveries. Furthermore, HC-FET was an independent factor that increased postpartum blood loss in vaginal deliveries.

Abstract
Background: Epidural anesthesia (EA) is the regional anesthesia technique preferred over spinal anesthesia for pregnant women requiring cesarean section and post-operative pain control. EA failure requires additional sedation or conversion to general anesthesia (GA). This may be hazardous during sedation or GA conversion because of potentially difficult airways. Therefore, this retrospective study aimed to determine the risk factors for epidural failure during cesarean section anesthesia.

Methods: We retrospectively analyzed parturients who underwent cesarean section under EA and catheterization at the Chang Gung Memorial Hospital in Taiwan between January 1 and December 31, 2018. Patient data were collected from the medical records. EA failure was defined as the administration of any intravenous anesthetic at any time during a cesarean section, converting it into GA.

Results: A total of 534 parturients who underwent cesarean section were recruited for this study. Of them, 94 (17.6%) experienced EA failure during cesarean section. Compared to the patients with successful EA, those with EA failure were younger (33.0 years vs. 34.7 years), had received EA previously (60.6% vs. 37%), were parous (72.3% vs. 55%), and had a shorter waiting time (14.9 min vs. 16.5 min) (p < 0.05). Younger age (OR 0.91, 95% CI 0.86-0.95), history of epidural analgesia (OR 2.61, 95% CI 1.38-4.94), and shorter waiting time (OR 0.91, 95% CI 0.87-0.97) were estimated to be significantly associated with a higher risk of epidural anesthesia failure.

Conclusion: The retrospective study found that parturients of younger age, previous epidural catheterization history, and inadequate waiting time may have a higher risk of EA failure. Previous epidural catheterization increased the risk of EA failure by 2.6-fold compared to patient with no history of catheterization.

Abstract
Objectives: To summarize and appraise the use of dexmedetomidine in epidural labor analgesia, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs).

Methods: We conducted the literature search about the RCTs of epidural labor analgesia with or without dexmedetomidine from inception until Nov 1,2022 in the following databases: PubMed, the Cochrane Library and Embase. The primary outcome was visual analogue scale(VAS) within 2h after epidural intubation. The secondary outcomes included the duration of the first and second labor stage, Apgar score, umbilical blood pH, dosage of analgesics, and side effects.

Results: 8 RCTs including 846 parturients were included. The VAS score of dexmedetomidine group was significantly lower than that of the control group at the time of 15min(MD -1.41,95%CI -2.23,-0.59)、30min(MD -1.02,95%CI -1.70,-0.33)、60min(MD -0.90,95%CI -1.36,-0.44)、90min(MD -0.70,95%CI -1.16,-0.23). The incidence of pruritus in dexmedetomidine group was lower than that of control group（MD 0.28,95%CI 0.11,0.74）but the incidence of maternal bradycardia was higher (MD 6.41,95%CI 1.64,25.04). There were no significant difference in other outcomes.

Discussion: Dexmedetomidine combined with local anesthetic for epidural labor analgesia can improve the VAS score of parturients. Except for the increased incidence of maternal bradycardia, it seems to be safe for the parturients and fetuses.

Abstract
Anaesthesia for caesarean section occurs commonly and places specific demands on anaesthetists. We analysed 469 narratives concerning anaesthesia for caesarean section, entered by Australian and New Zealand anaesthetists into the webAIRS incident reporting system between 2009 and 2022. As expected, compared with the remaining 8978 database entries, the 469 incidents were more likely to be emergency cases (relative risk (RR) 1.95), more likely to occur between 18:00 and 22:00 hours (RR 1.81) and between 22:00 and 07:59 hours (RR 4.40) and more likely to be undertaken using neuraxial anaesthesia (RR 9.18). Most incidents involved more than one event. The most commonly reported incidents included intraoperative neuraxial anaesthesia complications (180, 38%), medication errors or issues (136, 29%), equipment issues (49, 10%), obstetric haemorrhage (38, 8%), maternal cardiac arrests (28, 6%), endotracheal tube issues (28, 6%) and neonatal resuscitation (24, 5%). Inadequate neuraxial block, reported in 95 incidents, was the most common intraoperative neuraxial complication. Allergic reactions, reported in 30 incidents, were the most common medication issue, followed by 17 associated with oxytocin and 16 syringe swaps. Thirty-eight reports included significant maternal haemorrhage, with eight of those incidents including maternal cardiac arrest. There was one maternal death and eight incidents with neonatal deaths reported, affecting nine neonates. Problems with intraoperative neuraxial anaesthesia were the most commonly reported events. Implementation of specific strategies are encouraged to enhance preparation for conversion to general anaesthesia and to mitigate medication errors, particularly those relating to oxytocic use and neuraxial anaesthesia medications.

Abstract
Purpose: Peripartum pain has been associated with postpartum depression (PPD), and labour epidural analgesia (LEA) may be able to modify this risk. The objective of this historical cohort study was to examine the association between LEA and PPD among primiparous patients.

Methods: With institutional research ethics board approval, a provincial perinatal database was searched for primiparous patients who delivered a liveborn singleton infant between 2004 and 2018. Those patients who experienced PPD following their first delivery were identified by a history of PPD in the perinatal records of their second pregnancy. We used logistic regression to compute odds ratios (ORs) for the association between LEA and PPD and performed an adjusted analysis to control for confounding variables.

Results: A total of 35,437 primiparous patients were identified, 67% (n = 23,599) of whom received LEA. In the cohort, 3.7% (n = 1,296) of patients developed PPD. Patients who received LEA had increased odds of developing PPD compared with patients who did not receive LEA (adjusted OR, 1.29; 95% confidence interval [CI], 1.12 to 1.48). In a multivariable regression model, LEA remained a significant predictor for PPD, as did body mass index, pre-existing anxiety, and maternal antidepressant use.

Conclusion: This historical cohort study found an association between LEA and PPD among primiparous patients who subsequently had a second pregnancy in the same province. The findings call into question the hypothesis that LEA decreases the risk for PPD and further illustrates the complexities of PPD.

Abstract
Purpose: Doses of spinal bupivacaine adjusted to patient height or height/weight have been shown to provide hemodynamic stability during cesarean section. However, their effects in short stature parturients are unknown.

Methods: In this double-blind, randomized clinical trial, we randomly assigned short parturients (height < 150 cm) undergoing elective cesarean section, to receive doses of intrathecal hyperbaric bupivacaine either height or height/weight-adjusted, in a 1:1 ratio. The primary outcome was post-spinal hypotension (defined as systolic blood pressure [SBP] < 90% of baseline between spinal administration and delivery of the baby). Secondary outcomes included severe post-spinal hypotension (SBP < 80% of baseline), post-delivery hypotension (SBP < 90% and < 80% of baseline), intraoperative bradycardia, nausea and vomiting, shivering, rescue analgesic needed, and spinal block characteristics.

Results: A total of 112 patients underwent randomization. Post-spinal hypotension (SBP < 90% of baseline) occurred in 52% of the patients in the height/weight group and in 55% in the height group (difference - 3.5%: 95% confidence interval [CI] - 22 to 14.8, P = 0.705). There was no significant difference between the two groups in the occurrences of post-spinal severe hypotension (SBP < 80% of baseline), post-delivery hypotension, and spinal block characteristics. Six patients (11%) in the height/weight group needed intraoperative rescue analgesic compared to none in the height group (P = 0.027).

Conclusion: We found that height-based dosing in short parturients provides the optimal trade-off between intraoperative hemodynamic instability and provision of pain-free anesthesia.

Keywords: Cesarean section; Hypotension; Short stature; Spinal anesthesia.

Abstract
Background: Guidelines from the Obstetric Anaesthetists' Association and Difficult Airway Society state that 'a videolaryngoscope should be immediately available for all obstetric general anaesthetics'.

Objective: To report the incidence of videolaryngoscopy use, and other airway management safety interventions, in an obstetric population before and after various quality improvement interventions.

Design: Prospective data collection was undertaken over 18 months, divided into three separate 6-month periods: June to November 2019; March to August 2021; January to June 2022. These periods relate to evaluation of specific quality improvement interventions.

Setting: The project was carried out in a large tertiary referral obstetric unit.

Patients: We identified 401 pregnant women (> 20 weeks' gestation) and postnatal women (up to 48 h post delivery) undergoing an obstetric surgical procedure under general anaesthesia.

Interventions: To standardise practice, an intubation checklist was introduced in December 2020 and multidisciplinary staff training in August 2021.

Main outcome measures: Primary outcome measures were use of a Macintosh-style videolaryngoscope and tracheal intubation success. Secondary outcome measures were use of an intubation checklist; low flow nasal oxygen; and ramped patient positioning.

Results: Data from 334 tracheal intubations (83.3% of cases) were recorded. Videolaryngoscope use increased from 60% in 2019, to 88% in 2021, to 94% in 2022. Tracheal intubation was successful in all patients, with 94% first pass success overall and only 0.9% requiring three attempts. Use of secondary outcome measures also increased: low flow nasal oxygen from 48% in 2019 to 90% in 2022; ramped positioning from 95% in 2021 to 97% in 2022; and checklist use from 63% in 2021 to 92% in 2022.

Conclusions: We describe the successful adoption of simple safety measures introduced into routine practice. These comprised videolaryngoscopy, ramped positioning and low flow nasal oxygen. Their introduction was supported by the implementation of an intubation checklist and multidisciplinary team training.

Abstract
Oxytocin is widely used to prevent atonic postpartum haemorrhage after caesarean delivery. Initial treatment failure rates are high and inadequate dosing may contribute. Excessive doses, however, are associated with serious adverse effects. The pharmacokinetic data from this context are sparse and there is a lack of data in the immediate postpartum minutes after an initiating bolus. The pharmacodynamic data from this context are exclusively from dose-effect studies, with some suggesting that higher doses of oxytocin are required to provide adequate uterine tone in obese compared with non-obese women. We aimed to perform a pharmacokinetic and pharmacodynamic study that would facilitate more precise weight-based oxytocin dosing. We measured arterial oxytocin concentration, uterine tone and haemodynamic parameters in 25 women in the first 40 min after exogenous oxytocin administration at elective caesarean delivery. Serum oxytocin concentrations varied considerably between individuals. We constructed a one-compartment pharmacokinetic model of exogenous oxytocin deposition, after its administration with an initiating bolus and a maintenance infusion, at elective caesarean delivery. Body weight was evaluated as a potential covariate but was not included in the model due to lack of statistically significant reduction in the objective function. We calculated the volume of distribution and clearance (mean [coefficient of variation]) as 156.1 l [18%] and 83 ml.s-1 [32%] but found no within-individual correlation between serum oxytocin concentration and uterine tone or haemodynamic parameters. In conclusion, we observed a large variation in serum oxytocin concentrations between individuals receiving similar doses of oxytocin and were unable to establish weight-based dosing of exogenous oxytocin at caesarean delivery. Our findings suggest that future studies on oxytocin pharmacokinetics would need large sample sizes. In the absence of such data, oxytocin dosing should continue to be guided by uterine tone assessments and adjusted according to a strategy based on the best evidence from dose-effect studies.

Abstract
Objective: We aimed to compare the labor analgesia effects of nonpharmaceutical analgesia and pharmaceutical analgesia on parturient women.

Methods: One hundred and four parturient women with spontaneous births were selected and randomly divided into pharmaceutical and nonpharmaceutical analgesia groups. Before and after analgesia, the Visual Analogue Scale (VAS), parturient satisfaction with analgesia, serum pain stress factors (substance P [SP], neuropeptide Y [NPY], nerve growth factor [NGF], and prostaglandin E2 [PGE2]), duration of labor, vaginal bleeding at 2 h postpartum, postpartum urinary retention and dysuria incidence, Apgar score of 1 min and 5 min after birth, and neonatal cord blood gas analysis (pH, partial pressure of oxygen [PO2 ], partial pressure of carbon dioxide [PCO2 ], and lactate [Lac]) were compared in the two groups.

Results: VAS scores were lower and the analgesia satisfaction was higher in the pharmaceutical analgesia group than in the nonpharmaceutical analgesia group (all p < .05). Serum levels of SP, NPY, NGF, and PGE2 in the pharmaceutical analgesia group were lower than those in the nonpharmaceutical analgesia group (all p < .05). The first and second stages of labor were longer and the bleeding volume at 2 h postpartum was greater in the pharmaceutical analgesia group than those in the nonpharmaceutical analgesia group (all p < .05). Reduced Lac and PCO2 levels and increased PO2 level were found in the pharmaceutical analgesia group in comparison to the nonpharmaceutical analgesia group (all p < .05).

Conclusion: This study demonstrates that the analgesic effect and neonatal condition of the pharmaceutical analgesia are better than the nonpharmaceutical analgesia, but the labor duration and postpartum bleeding volume of the pharmaceutical analgesia are greater than those of the nonpharmaceutical analgesia.

Abstract
From the 1950s to the end of the 1980s the implementation of the so-called paracervical block (PCB) belonged to the therapeutic measures for pain relief. Due to its apparent simplicity and lack of potential risks the method was performed by the obstetricians themselves. The method is especially suitable for the painful opening period during the birth process. The procedure attained worldwide popularity up to the date when potential associated risks, namely for the fetus, became evident and is nowadays regarded as obsolete. The origins of the regional anesthesia procedure can be traced to Philipp Gellert, a Jewish physician from Dresden, Germany, who in 1926 first reported on his experiences with the method. Comparable to the anesthetic procedure performed decades later, he combined the nerve block with pudendal anesthesia and the administration of a uterine tonic. As further biographical information about Gellert, who was murdered in 1942 due to his Jewish roots, has not yet become widely known, the eventful history of the anesthetic procedure he once described are sketched and his biography is outlined.

Abstract
Objective: The co-existence of chronic pain conditions with anxiety and/or depression is common in the general population but poorly described during pregnancy. In this study, we sought to describe trends in chronic pain among a sample of delivering people and describe the co-existence of chronic pain with anxiety and/or depression among delivering people.

Methods: This cross-sectional study used data from Optum's de-identified Clinformatics® Data Mart Database between 2008 and 2021, for delivering persons with coverage by single employer-based health plan. We computed predicted margins from generalized estimating equations to determine the marginal predicted probability of chronic pain among all delivering and non-delivering persons who identify as women with and without diagnosed anxiety and/or depression.

Keywords: affective and sensory-dimensions of pain; ascending signaling pathways; cerebrospinal fluid and solute movement; dorsal root ganglion and blood brain barrier; dorsal root ganglion and macrophage; intrathecal and drug distribution; intrathecal and neuropathology; intrathecal and neurotoxins; intrathecal and transfection; pain and nociception.

abstract
Trauma is the leading nonobstetric cause of maternal death and affects 1 in 12 pregnancies in the United States. Adhering to the fundamentals of the advanced trauma life support (ATLS) framework is the most important component of care in this patient population. Understanding the significant physiologic changes of pregnancy, especially with regard to the respiratory, cardiovascular, and hematologic systems, will aid in airway, breathing, and circulation components of resuscitation.

Keywords: Obstetric anesthesia; Spina bifida; Ultrasound.

The International Journal of Obstetric Anesthesia is the only journal publishing original articles devoted exclusively to obstetric anesthesia and bringing together all three of its principal components; anesthesia care for operative delivery and the perioperative period, pain relief in labour and care of the critically ill obstetric patient.

​Obstetric Anesthesia Digest provides timely summaries of the world literature in obstetric anesthesia. Each quarterly issue features dozens of clear, concise summaries of the most significant recent articles, frequently accompanied by insightful commentary by one of the Digest's renowned editorial consultants. The comprehensive coverage includes editorials and reviews, special articles, case reports, and "Short Takes"- abbreviated abstracts of secondary papers

The articles surveyed cover all aspects of anesthesia and analgesia as they relate to the mother, fetus, and neonate, providing a fast and easy means to stay current in this fast-changing field.

Regional Anesthesia & Pain Medicine, the official publication of the American Society of Regional Anesthesia and Pain Medicine (ASRA Pain Medicine), is a monthly journal that publishes peer-reviewed scientific and clinical studies to advance the understanding and clinical application of regional techniques for surgical anesthesia and postoperative analgesia. Coverage includes intraoperative regional techniques, perioperative pain, chronic pain, obstetric anesthesia, paediatric anesthesia, outcome studies, and complications.

Abstract
Obstetric general anaesthesia technique usually involves intravenous induction and maintenance with volatile agents. Total intravenous anaesthesia has gained in popularity in non-obstetric practice because of environmental concerns associated with volatile inhalational anaesthetics and evidence of a superior recovery profile. Publications on the use of total intravenous anaesthesia for caesarean delivery are sparse. The limited evidence suggests that total intravenous anaesthesia may confer benefits for caesarean delivery, including reducing the risk of haemorrhage. However, there are practical barriers to utilising total intravenous anaesthesia in obstetric anaesthesia. We discuss the evidence and potential role of total intravenous anaesthesia for caesarean delivery.

Abstract
A woman who experiences pain during caesarean section under neuraxial anaesthesia is at risk of adverse psychological sequelae. Litigation arising from pain during caesarean section under neuraxial anaesthesia has replaced accidental awareness under general anaesthesia as the most common successful medicolegal claim against obstetric anaesthetists. Generic guidelines on caesarean section exist, but they do not provide specific recommendations for this area of anaesthetic practice. This guidance aims to offer pragmatic advice to support anaesthetists in caring for women during caesarean section. It emphasises the importance of non-technical skills, offers advice on best practice and aims to encourage standardisation. The guidance results from a collaborative effort by anaesthetists, psychologists and patients and has been developed to support clinicians and promote standardisation of practice in this area.