Labor Epidural Analgesia to Cesarean Section Anesthetic Conversion Failure: A National Survey

Total spinal anaesthesia following obstetric neuraxial blockade: a narrative review

BACKGROUND

Total spinal anaesthesia (TSA) is an emergency caused by high neuraxial blockade. It is a recognised complication of all neuraxial techniques in obstetric anaesthesia. Its incidence and outcomes have not been evaluated. There is compelling evidence that TSA continues to be a problem in contemporary practice, having the capacity to cause significant morbidity and mortality if not recognised early and promptly treated. This review based on a literature search aims to clarify the epidemiology of TSA, summarise its pathophysiology, and identify risk factors and effective treatments.

METHODS

We performed a literature search using PubMed, Web of Science and Google Scholar databases using specified search terms for materials published using search terms. For each case, the type of block, the difficulty of the procedure, the dose of local anaesthetic, positivity of aspiration before and after the event, maternal outcome, Apgar score, onset of symptoms, cardiorespiratory and neurological manifestations, cardiorespiratory support employed, admission to an intensive care unit, cardiac arrest events and duration of mechanical ventilation were extracted.

RESULTS

A total of 605 cases were identified, of which 51 were sufficiently detailed for analysis. Although TSA is described after all neuraxial techniques, spinal after epidural was a particular concern in recent reports. Respiratory distress was universal but apnoea was not. The onset of apnoea was variable, ranging from 1 to 180 min. Hypotension was not invariable and occurred in approximately half of cases. Multiple fatalities and neurological injuries were reported, often in under-resourced areas when providers were not skilled in airway management or when recognition and intervention were delayed. In the most recent reports good outcomes were achieved when effective treatments were rapidly provided.

CONCLUSIONS

The available literature confirms that TSA remains an active clinical problem and that with prompt recognition and treatment good outcomes can be achieved. This requires anticipation and preparedness in all clinical areas where neuraxial techniques are performed.

Comparison of sequential and mixture injections of opioids and hyperbaric bupivacaine for subarachnoid block for lower segment caesarean section: a randomised controlled study

INTRODUCTION

Opioids are commonly added to local anaesthetic for subarachnoid block for caesarean section due to their synergistic effects. The physiochemical characteristics of opioids suggest premixing with hyperbaric bupivacaine may limit their distribution within the CSF. We studied the effect of a separate injection with a combination of bupivacaine, morphine and fentanyl on block characteristics, haemodynamic changes, postoperative pain and patient satisfaction.

METHOD

Following ethical approval and informed consent, a prospective double-blinded randomised controlled trial was performed in a university hospital. A total of 126 patients undergoing caesarean section were randomised to two groups. In group M, the premixed group, patients received 12 mg of hyperbaric bupivacaine, 20 mcg of fentanyl and 100 mcg of morphine injected as a single mixture. In group S, the separate injection group, patients received the same drugs in separate injections. Measurements included haemodynamics, block distribution, intra- and postoperative pain, as well as patient satisfaction.

RESULTS

Patients in both groups had similar block height, time to maximum sensory block, time to block regression and motor block. However, haemodynamics were different between the groups. The proportion of systolic hypotension episodes was greater in group S [159/1320 (12.05%)] than group M [113/1452 (7.78%)], with P = 0.0002. Moreover, a greater amount of ephedrine was administered in group S than group M, with values 12.09 (8.1) and 9.09 (8.5) mg respectively (P = 0.001). Additionally, postoperative pain, as measured by the Visual Analogue Scale (VAS), was greater in group M, with a VAS of 4.6 (1.7), vs. group S, which recorded a VAS of 3.8 (2.0) (P = 0.017).

CONCLUSION

Sequential injection of intrathecal opioids and hyperbaric bupivacaine resulted in greater early haemodynamic instability and slightly better postoperative analgesia without any difference in block height or patient satisfaction.

CLINICAL TRIAL REGISTRATION

NCT04403724.

Development and Validation of a Nomogram for the Failed Conversion of Labor Analgesia to Cesarean Section Anesthesia

Purpose

The conversion of epidural labor analgesia (ELA) to epidural surgical anesthesia (ESA) for intrapartum cesarean section (CS) often encounters failures. This study aimed to develop a nomogram for predicting the failure rate of this conversion.

Patients and Methods

A retrospective analysis was conducted on data from the Fujian Maternity and Child Health Hospital. Pregnant women (n=214) who underwent cesarean section after receiving labor analgesia. We performed correlation heat map and Lasso regression in terms of exclusion confounding factors and screening independent variables. A nomogram was developed to predict the occurrence.

Results

The developed nomogram incorporated variables such as pregnant history, weight, premature rupture of membranes (PROM), dural puncture epidural (DPE), anesthesiologist level of cesarean section (ALOCS), and Anesthesiologist level of labor analgesia (ALOLA). The model demonstrated good predictive performance, providing a practical tool for assessing the risk of failure in converting labor analgesia to cesarean section anesthesia.

Conclusion

The nomogram can aid anesthesiologists in making informed decisions and optimizing patient care. By utilizing the nomogram, clinicians can estimate the probability of conversion failure based on individual patient characteristics and clinical factors.

Risk factors for failure of conversion from epidural labor analgesia to cesarean section anesthesia and general anesthesia incidence: an updated meta-analysis

OBJECTIVES

Ongoing controversies persist regarding risk factors associated with the failure of transition from epidural labor analgesia to cesarean section anesthesia, including the duration of labor analgesia, gestational age, and body mass index (BMI). This study aims to provide an updated analysis of the incidence of conversion from epidural analgesia to general anesthesia, while evaluating and analyzing potential risk factors contributing to the failure of this transition to cesarean section anesthesia.

METHODS

We conducted an extensive literature search utilizing databases such as PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), WANGFANG, and the Chinese Biomedical Literature Database (CBM) up to September 30, 2022. The meta-analysis was performed using STATA 15.1 software. The quality of the included studies was assessed using the 11-item quality assessment scale recommended by the Agency for Healthcare Research and Quality (AHRQ).

RESULTS

A total of 9,926 studies were initially retrieved, and after rigorous selection, 19 studies were included in the meta-analysis. The overall incidence of conversion from epidural analgesia to general anesthesia was found to be 6% (95% confidence interval [CI]: 5-8%). Our findings indicate that, when compared to patients in the successful conversion group, those in the failure group tended to be younger (weighted mean difference [WMD] = -1.571, 95% CI: -1.116 to -0.975) and taller (WMD = 0.893, 95% CI: 0.018-1.767). Additionally, the failure group exhibited a higher incidence of incomplete block in epidural anesthesia, received a higher dosage of additional epidural administration, experienced a greater rate of emergency cesarean sections, and received anesthesia more frequently from non-obstetric anesthesiologists. However, no statistically significant differences were observed in gestational age, depth of the catheter insertion into the skin, epidural catheter specifics, duration of epidural analgesia, infusion rate of epidural analgesia, primiparity status, cervical dilatation during epidural placement, BMI, or weight.

CONCLUSION

Our study found that the incidence of conversion from epidural analgesia to cesarean section under general anesthesia was 6%. Notably, the failure group exhibited a higher rate of incomplete block in epidural anesthesia, a greater incidence of emergency cesarean sections, a more frequent provision of anesthesia by non-obstetric anesthesiologists, a higher dosage of epidural administration, and greater height when compared to the success group. Conversely, women in the failure group were younger in age compared to their counterparts in the success group.

Risk factors for epidural anesthesia blockade failure in cesarean section: a retrospective study

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.

CONVERSION RATE OF EPIDURAL ANALGESIA TO CAESAREAN SECTION REGIONAL OR GENERAL ANESTHESIA

Introduction

Epidural analgesia is acknowledged as the most common method of analgesia during labor. If emergent Caesarean section (CS) is indicated in parturient with existing labor epidural, the need for conversion from epidural analgesia to regional (RA) or general anesthesia (GA) increases accordingly. Recent guidelines suggest the rate of conversion to general anesthesia shows the quality of obstetric anesthesia care and should be under 5%.

The aim

The aim of this study is to determine the conversion rate from epidural analgesia to Caesarean section anesthesia in "Sveti Duh" University Hospital Zagreb in order to enhance the quality of anesthetic care for obstetric patients.

Methods

We retrospectively included in the study all parturients who received epidural labor analgesia but needed subsequent regional or general anesthesia for Caesarean section in our institution for the period of 1st January 2021 to 31st December 2021. After the data analysis on the conversion rate from epidural analgesia to Caesarean section anesthesia had been performed, we compared our data to current standards and relevant literature findings.

Results

Altogether 1202 epidural catheters were placed for labor analgesia in the study period, and in 199 of these cases, the emergent Caesarean section was indicated. Epidural analgesia was converted to epidural anesthesia (EA) in 153 (76,9%) parturients, to general anesthesia in 40 (20,1%), and to spinal anesthesia (SA) in six (3%) parturients. After comparison with recommended quality standards and with the results of similar studies by other authors, our findings show a significantly higher rate of conversion from epidural analgesia to general anesthesia than has been desirable since then.

Conclusion

In order to reach the required quality standards regarding the conversion rate from epidural analgesia to Caesarean section anesthesia, it is necessary to improve the organization of the work of the obstetric anesthesiology team according to the principle of subspecialization. It is imperative to implement the best clinical practice protocols for obstetric anesthesiologists, but also to enhance the communication and coordination with the obstetric team.

Anesthetic Conversion of Preexisting Labor Epidural Analgesia for Emergency Cesarean Section and Efficacy of Levobupivacaine with or Without Magnesium Sulphate: A Prospective Randomized Study

Background: For pregnant women who require an emergency cesarean section (CS), extending labor epidural analgesia as quickly as feasible to good quality anesthesia is a critical issue. This indicates the presence of functional labor epidural analgesia and reduces the need for general anesthesia. Addition of magnesium increases anesthetic and analgesic qualities of epidural anesthesia. Objectives: The purpose of this trial was to assess the role of adding magnesium sulfate (MgSO4) with levobupivacaine to speed up the conversion of labor epidural analgesia into enough anesthesia for emergency CS. Methods: Fifty parturients were randomly assigned to receive 19.5 mL of levobupivacaine 0.5% with either 0.5 mL of normal saline 0.9% (Group I) or 0.5 mL of MgSO4 10% (Group II) after receiving labor epidural analgesia. We documented the onset of block (loss of pinprick to T6), number of patients needing additional analgesia, the time needed for sensory and motor blockade to recover, and the adverse effects. Results: The frequency of patients receiving intraoperative supplements was comparable in the study groups (P = 0.491), although the onset of the block was faster in Group II than in Group I (P = 0.000*). Group II took substantially longer to recover from sensory and motor blockade than Group I (P = 0.001* and P = 0.001*, respectively). In both groups, the occurrence of adverse events was similar. Conclusions: Adding 50 mg of MgSO4 to levobupivacaine 0.5% accelerated the epidural top, and both sensory onset and motor blocks period were prolonged as compared to levobupivacaine alone when extending epidural analgesia for emergency CS.

The Current Role of General Anesthesia for Cesarean Delivery

Purpose of the Review

The use of general anesthesia for cesarean delivery has declined in the last decades due to the widespread utilization of neuraxial techniques and the understanding that neuraxial anesthesia can be provided even in urgent circumstances. In fact, the role of general anesthesia for cesarean delivery has been revisited, because despite recent devices facilitating endotracheal intubation and clinical algorithms, guiding anesthesiologists facing challenging scenarios, risks, and complications of general anesthesia at the time of delivery for both mother and neonate(s) remain significant. In this review, we will discuss clinical scenarios and risk factors associated with general anesthesia for cesarean delivery and address reasons why anesthesiologists should apply strategies to minimize its use.

Recent Findings

Unnecessary general anesthesia for cesarean delivery is associated with maternal complications, including serious anesthesia-related complications, surgical site infection, and venous thromboembolic events. Racial and socioeconomic disparities and low-resource settings are major contributing factors in the use of general anesthesia for cesarean delivery, with both maternal and perinatal mortality increasing when general anesthesia is provided. In addition, more significant maternal pain and higher rates of postpartum depression requiring hospitalization are associated with general anesthesia for cesarean delivery.

Summary

Rates of general anesthesia for cesarean delivery have overall decreased, and while general anesthesia no longer is a contributing factor to anesthesia-related maternal deaths, further opportunities to reduce its use should be emphasized. Raising awareness in identifying situations and patients at risk to help avoid unnecessary general anesthesia remains crucial.