Safety guideline: neurological monitoring associated with obstetric neuraxial block 2020

Long-term effects of neuraxial analgesia

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.

Venous thromboembolism in pregnant obese Individuals

Venous thrombosis and thromboembolism (VTE) remain the leading cause of direct maternal deaths, occurring within 42 days of the end of pregnancy in the UK. Pregnancy is associated with an overall 10-fold higher incidence of VTE than in the non-pregnant state and has been reported to reach up to 30-fold higher in the puerperium. This increased risk is further exacerbated by maternal obesity in a relationship that appears to be proportional with increasing Body Mass Index (BMI). Maternal obesity is the most common health problem in women of reproductive age with clinically significant health risks to women during pregnancy and after delivery. It is associated with poor perinatal and maternal outcomes, The incidence of maternal obesity has increased significantly worldwide over the last few decades and increasingly, pregnancy is being complicated by extreme or morbid obesity. In this review we discuss the challenges associated with the diagnosis and management of VTE in obese pregnant women and provide a review of the available current evidence.

Appraisal of clinical practice guidelines and consensus statements on obstetric anaesthesia: a systematic review using the AGREE II instrument

OBJECTIVES

Despite the publication of hundreds of trials on obstetric anaesthesia, the management of these conditions remains suboptimal. We aimed to assess the quality and consistency of guidance documents for obstetric anaesthesia.

DESIGN

This is a systematic review and quality assessment using the Appraisal of Guidelines for Research and Evaluation (AGREE) II methodology.

DATA SOURCES

Data sources include PubMed and Embase (8 June 2023), three Chinese academic databases, six guideline databases (7 June 2023) and Google and Google scholar (1 August 2023).

ELIGIBILITY CRITERIA

We included the latest version of international and national/regional clinical practice guidelines and consensus statements for the anaesthetic management of pregnant patients during labour, non-operative delivery, operative delivery and selected aspects of perioperative monitoring, postpartum care and analgesia, published in English or Chinese.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently screened the searched items and extracted data. Four reviewers independently scored documents using AGREE II. Recommendations from all documents were tabulated and visualised in a coloured grid.

RESULTS

Twenty-two guidance documents (14 clinical practice guidelines and 8 consensus statements) were included. Included documents performed well in the domains of scope and purpose (median 76.4%, IQR 69.4%-79.2%) and clarity of presentation (median 72.2%, IQR 61.1%-80.6%), but were unsatisfactory in applicability (median 21.9%, IQR 13.5%-27.1%) and editorial independence (median 47.9%, IQR 6.3%-73.2%). The majority of obstetric anaesthesia guidelines or consensus centred on different topics. Less than 30% of them specifically addressed the management of obstetric anaesthesia perioperatively. Recommendations were concordant on the perioperative preparation, and on some indications for the choice of anaesthesia method. Substantially different recommendations were provided for some items, especially for preoperative blood type and screen, and for the types and doses of neuraxial administration.

CONCLUSIONS

The methodological quality in guidance documents for obstetric anaesthesia necessitates enhancement. Despite numerous trials in this area, evidence gaps persist for specific clinical queries in this field. One potential approach to mitigate these challenges involves the endorsement of standardised guidance development methods and the synthesis of robust clinical evidence, aimed at diminishing difference in recommendations.

High Neuraxial Block in Obstetrics: A 2.5-Year Nationwide Surveillance Approach in the Netherlands

BACKGROUND

High neuraxial block is a rare but serious adverse event in obstetric anesthesia that can ultimately lead to respiratory insufficiency and cardiac arrest. Previous reports on its incidence are limited to populations in the United Kingdom and the United States. Little is known about the incidence and clinical features of high neuraxial block in the Netherlands, where the presence of anesthesiologists in the labor and delivery unit is comparatively lower. We aimed to assess the incidence and clinical features of high neuraxial block in obstetrics and to formulate ways to improve obstetric anesthesia on a national level.

METHODS

This nationwide, prospective, population-based cohort study was designed to identify cases of high neuraxial block requiring ventilatory support (with supraglottic airway device or tracheal intubation) or cardiopulmonary resuscitation between November 2019 and May 2022. Cases were prospectively collected using the Netherlands Obstetric Surveillance System (NethOSS) in all hospitals with a maternity unit. Complete case file copies were obtained to determine risk factors and clinical course.

RESULTS

During the study period, 5 cases of high neuraxial block requiring tracheal intubation were identified. The estimated incidence of high neuraxial block requiring tracheal intubation was 1 in 29,770 neuraxial procedures in labor (95% confidence interval, 1:12,758-1:91,659). Three of 5 identified cases occurred in the operating room after single-shot spinal anesthesia for Cesarean delivery after epidural analgesia in labor. One case developed in the labor ward due to an inadvertent intrathecal or subdural catheter placed for labor analgesia. The fifth case followed single-shot spinal anesthesia for elective Cesarean delivery. All 5 patients were successfully extubated in the operating room after Cesarean delivery, without the need for intensive care admission. There were no cardiac arrests and no neonatal deaths.

CONCLUSIONS

High neuraxial block requiring tracheal intubation is a rare but impactful complication in obstetric anesthesia, potentially affecting both mother and fetus. Spinal anesthesia after epidural analgesia in labor is a common cause of high neuraxial block. Meticulous follow-up of epidurals in labor facilitates conversion to surgical anesthesia and may therefore reduce the need for spinal anesthesia after epidural analgesia. Large-scale surveillance systems in obstetric anesthesia are needed to identify those at risk, as well as to formulate further strategies to mitigate this burden.

Emergencies in obstetric anaesthesia: a narrative review

We conducted a narrative review in six areas of obstetric emergencies: category-1 caesarean section; difficult and failed airway; massive obstetric haemorrhage; hypertensive crisis; emergencies related to neuraxial anaesthesia; and maternal cardiac arrest. These areas represent significant research published within the last five years, with emphasis on large multicentre randomised trials, national or international practice guidelines and recommendations from major professional societies. Key topics discussed: prevention and management of failed neuraxial technique; role of high-flow nasal oxygenation and choice of neuromuscular drug in obstetric patients; prevention of accidental awareness during general anaesthesia; management of the difficult and failed obstetric airway; current perspectives on the use of tranexamic acid, fibrinogen concentrate and cell salvage; guidance on neuraxial placement in a thrombocytopenic obstetric patient; management of neuraxial drug errors, local anaesthetic systemic toxicity and unusually prolonged neuraxial block regression; and extracorporeal membrane oxygenation use in maternal cardiac arrest.

The use of nitrous oxide 'cracking' technology in the labour ward: a case report and patient account

Nitrous oxide is a common choice of labour analgesia in many countries. However, its use is associated with significant cost to the environment as well as potential risks of long-term occupational exposure. Our hospital is one of a small number of healthcare providers in the United Kingdom trialling technology which catalytically destroys ('cracks') nitrous oxide to reduce greenhouse gas emissions and occupational exposure. When used in the setting of inhaled analgesia, cracking technology relies on capturing the patient's exhaled breath via a facemask or mouthpiece, a technique which requires some user skill and may be challenging for patients. In this report, we present the case of a primiparous 35-year-old consultant anaesthetist, who used nitrous oxide cracking technology with inhaled nitrous oxide analgesia (via a facemask) during labour. We present the patient's experiences and discuss the implications of using such technology on ambient nitrous oxide levels in the delivery room. Notably, despite this patient's professional expertise and familiarity with facemask use, nitrous oxide remained detectable throughout her labour, although generally at low levels. This illustrates that whilst this technology has the potential to reduce ambient nitrous oxide levels, its efficacy may vary depending on how it is used, with implications for patient education and support.

Neuraxial and general anaesthesia for caesarean section

Caesarean section (CS) is one of the most performed operations worldwide. In many parts of the world, there has been a reduction in anaesthetic associated obstetric mortality, and this has been attributed to the increased use of neuraxial anaesthesia and improved safety of general anaesthesia, alongside improved training and organisational changes. In resource-limited countries, anaesthesia contributes disproportionately to maternal mortality, with one in seven deaths being due to anaesthesia. A major contributory factor to this is the severe shortage of trained anaesthetic providers. Goals for anaesthesia for CS include the woman's comfort and foetal well-being, focusing on strategies to minimise morbidity and mortality for both. Anaesthetic options for CS include neuraxial techniques (spinal or combined-spinal epidural or epidural extension of labour analgesia) and general anaesthesia. There is increasing evidence of the benefit of neuraxial techniques over general anaesthesia in terms of maternal and foetal outcomes. For elective CS, spinal and combined-spinal anaesthesia predominate. General anaesthesia is mainly reserved for Category 1 CS where there is an immediate threat to the life of the mother or the baby. This review discusses the practical aspects of neuraxial and general anaesthesia for CS.

Prevention and management of intra-operative pain during caesarean section under neuraxial anaesthesia: a technical and interpersonal approach

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.

Obesity decreases the EC50 of epidural ropivacaine when combined with dexmedetomidine for labor analgesia

OBJECTIVES

This study aims to estimate the EC50 of ropivacaine when co-administered with dexmedetomidine for epidural labor analgesia in antepartum obese and non-obese parturients.

METHODS

Sixty parturients scheduled for epidural labor analgesia were enrolled and divided into antepartum obesity (AO) and control (CON) groups, according to their body mass index at labor. Both groups received 0.5 µg/mL dexmedetomidine with ropivacaine as anesthetics. The concentration of ropivacaine was initially set at 0.125% and varied by 0.01% according to the up-and-down rule for sequential allocation. Hemodynamic parameters were monitored and pain intensity was assessed using a visual analog scale.

RESULTS

When co-administered with dexmedetomidine, the EC50 of ropivacaine was 0.095% (95% confidence interval [CI]: 0.090-0.100%) and 0.070% (95% CI: 0.062-0.076%) in CON and AO groups, respectively. There was a significant difference between the two groups (P < 0.001). EC95 values of ropivacaine were 0.084% (95% CI: 0.077-0.122%) and 0.106% (95% CI: 0.101-0.128%) in AO and CON groups, respectively.

CONCLUSION

Patients with antepartum obese may require decreased ropivacaine concentration for epidural labor analgesia when co-administered with 0.5 µg/mL dexmedetomidine.

Adjuvant Sufentanil Decreased the EC50 of Epidural Ropivacaine for Labor Analgesia in Healthy Term Pregnancy

Objective

The optimal concentration of ropivacaine as epidural labor analgesia combined with sufentanil has not been established. This study aimed to determine the median effective concentration (EC50) of epidural ropivacaine for labor analgesia in healthy term pregnancy when co-administered with sufentanil as an adjuvant or alone.

Patients and Methods

Sixty healthy parturients scheduled for epidural labor analgesia were enrolled in the study. They were divided into a saline group (Group C) and an epidural sufentanil (0.5 µg/mL) group (Group S). The initial concentration of ropivacaine was set at 0.125%, which was then varied by 0.01% using the up-and-down sequential allocation method. The hemodynamics were continuously monitored during delivery. A visual analog scale was used to evaluate the degree of pain. The Ramsay sedation score, duration of the labor stages, the onset of epidural analgesia, and adverse effects were recorded. Neonatal outcomes were evaluated using the Apgar scores and umbilical artery blood gas analysis.

Results

The EC50 of ropivacaine was 0.085% (95% CI, 0.079–0.090%) in Group S and 0.109% (95% CI, 0.105–0.112%) in Group C. The EC95 of ropivacaine was 0.096% (95% CI, 0.090–0.118%) in Group S, and 0.116% (95% CI, 0.113–0.127%) in Group C. The difference between the groups was statistically significant (p < 0.001). The stable hemodynamics, satisfactory analgesia, and good neonatal outcomes were comparable in both groups (P > 0.05).

Conclusion

The EC50 of ropivacaine was reduced by 22% when co-administered with sufentanil for epidural labor analgesia in primipara. (www.chictr.org.cn; registration number: ChiCTR2000039547).