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

Anaesthesia, Volume 77, No. 5, Year 2022

Interpretation

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. A working party was formed comprising anaesthetists with varying experience levels and frequency of obstetric anaesthesia practice (weekly vs. occasional) and a psychologist with expertise in psychological sequelae following medical intervention and patient representation. We performed a literature search in Medline, Embase, CINAHL and PubMed for material published between 1980 and December 2020. This period was chosen since before 1980, general anaesthesia was the dominant technique for caesarean section with neuraxial techniques gaining rapidly in popularity from this time. The search terms used were: ‘anesthesia’; ‘obstetrical’; ‘methods’; ‘spinal’; ‘epidural’; ‘cesarean section’; ‘pain measurement’; ‘drug effects’; ‘cold temperature’; ‘sensation’; ‘physical stimulation’; ‘Bromage’; and ‘air’. The resulting 44 publications were assessed for relevance by three authors (FP, DB and DL). Recommendations were developed on the basis of consensus opinion. The incidence of inadequate neuraxial anaesthesia for caesarean section varies according to definition, neuraxial technique and urgency of caesarean section. The word ‘failure’ may be used to describe blocks that have entirely failed (no evident sensorimotor block), partial blocks, for example a unilateral block or inadequate block height, or the use of adjuvants or requirement for conversion to general anaesthesia. Spinal anaesthesia has a faster onset, fewer complications and lower intra‐operative supplementation rates than epidural anaesthesia. In a prospective audit of 5080 caesarean sections from a single centre, Kinsella identified the rate of failure to achieve a pain‐free operation as 6% with spinal anaesthesia, 24% with epidural top‐up and 18% with combined spinal‐epidural [6]. The difficulties around the definition of ‘failure’ are illustrated by varying recommendations about acceptable conversion rates of neuraxial anaesthesia to general anaesthesia for emergency caesarean section, especially in time‐critical situations. The Royal College of Anaesthetists suggests that where general anaesthesia is given in the presence of a labour epidural which is not topped up, this is counted as a converted neuraxial technique, rather than primary general anaesthesia [7]. Using this definition, Kinsella found a general anaesthesia conversion rate of 4.9%, notably higher than the Royal College of Anaesthetists’ target of 3%. However, if cases where there was no attempt to ‘top‐up’ the epidural were excluded, the rate was 4.1% [6]. When no attempt was made to top‐up an indwelling epidural, the proportion of cases was higher for category‐1 caesarean section, which is unsurprising. Identifying risk factors for inadequate neuraxial block also depends on the definition of failure used. In his case series, Kinsella defined ‘failure’ as either pre‐operative failure to achieve a satisfactory block or intra‐operative failure leading to pain. Factors associated with pre‐operative failure included operative urgency, increased BMI, women having their first caesarean section and the indications for caesarean section of acute fetal distress or maternal medical condition. For intra‐operative failure, the inadequacy of pre‐operative anaesthetic block and duration of surgery were significant risk‐factors. When spinal anaesthesia was used, the use of a spinal opioid was associated with less pre‐operative failure [6]. When a labour epidural was extended for caesarean section, lower epidural top‐up volume was associated with less pre‐operative failure, and use of adrenaline was associated with both less pre‐operative and intra‐operative failure [6]. A systematic review and meta‐analysis of observational trials for failed conversion of labour epidural analgesia to caesarean section anaesthesia identified risk factors including an increased number of clinician‐administered boluses during labour, greater urgency of caesarean section and provision of anesthetic care by a non‐obstetric anaesthetist [8]. Regardless of how failure of neuraxial block is defined, the crucial element is that the anaesthetist recognises it is inadequate and can lead to pain and distress during surgery. Recognition and pro‐active management of failure are essential to mitigate this risk. The innervation of the uterus comes from sympathetic nerves from the inferior hypogastric plexus (T10–L1), and parasympathetic fibres of the uterus are derived from pelvic splanchnic nerves (S2–S4) [9]. Therefore, the level required for a lower transverse abdominal skin incision for caesarean section is the T10 dermatome. These innervations would suggest that a block height to low thoracic levels should be sufficient for caesarean section. However, several visceral organs send sympathetic afferent impulses to the thoracic spinal cord (T4–L2), and therefore a block height to higher thoracic dermatomes is required [10]. In a prospective study by Russell recording analgesic levels (loss of sharp pinprick sensation) and anaesthesia (loss of touch sensation) in 220 women during caesarean section, no woman with an anaesthetic level that remained above T5 experienced intra‐operative pain [11]. This suggests that loss of touch sensation up to and including T5 is required to minimise the risk of pain during caesarean section, a finding which has been widely endorsed. However, the study predates modern obstetric anaesthetic practice in that it included 70 women who received de‐novo epidural anaesthesia for caesarean section (now rarely used as a primary technique), and no patient received neuraxial opioids. Although the T5 dermatome is the putative target for acceptable block height for caesarean section, several other factors add complexity to this superficially straightforward standard. An important finding of Russell’s work, and confirmed by other studies, is that neuraxial anaesthesia is associated with a zone of differential sensory block at the cranial limits [12, 13]. Other studies have confirmed an inconsistent relationship between cold, sharp pinprick and touch used to assess neuraxial block and height of block; thus, one cannot be predicted by assessing the other [14, 15]. Loss of cold sensation may be observed several dermatomes higher than the loss of sharp pinprick sensation, and this, in turn, may be several dermatomes higher than the level at which touch is lost. Some authors have found that sharp pinprick and cold levels reversed, with loss of sharp pinprick sensation significantly higher than the loss of cold sensation, although the loss of touch sensation is still the lowest. For any modality, the effect does not change from total lack of sensation to completely normal sensation within a single dermatome, for example if using spraying ethyl chloride to assess block height to cold, a woman may feel ‘cold’ at one dermatome but ‘icy cold’ at another dermatome. There is no evidence to guide which point between no sensation and completely normal sensation represents the height of the block. These difficulties are compounded by the lack of consensus around the stimulus that should be used to test the sensory block. Kocarev et al. used various devices to assess block height after combined spinal–epidural anaesthesia in a group of women undergoing caesarean section [16]. Six tests were used in random order to measure four sensory modalities: ethyl chloride (cold), calibrated Neuropen (sharp), standardised monofilament 10 g (pressure), Neurotip stroking (light touch), monofilament stroking (light touch) and cotton wool (light touch). The tests for light touch had the least dermatomal spread, and the more expensive tests did not confer any advantage over the least expensive test, cotton wool. Nor and Russell examined the effect of using different questions to assess the same stimulus in a group of women undergoing caesarean section under spinal anaesthesia [17]. The block height differed by a median value of two dermatomes depending on the question posed, suggesting that this is another variable to be defined. Finally, difficulties arise with the practical correlation of anatomical landmarks with specific dermatomes. Congreve et al. showed, in a study of 80 anaesthetists of all grades, that one in seven were at least two dermatomes outside the ‘correct’ demarcation of T5 [18]. Most textbooks state that a dense bilateral motor block in the lower limbs is essential. Inability to lift the legs against gravity demonstrates motor block of L1–4, but it does not provide information about the density of the block in the mid to upper thoracic segments. The Bromage scale and multiple modifications have been used to describe motor block [19, 20]. An increasing proportion of anaesthetists use the straight leg raise test to avoid confusion [21]. The assessment of sympathetic block as a component of overall block assessment during neuraxial anaesthesia has received little attention. Lumbar neuraxial anaesthesia results in temporary sympathectomy of the lumbar sympathetic chain and can be evidenced by the presence of warm, dry feet [22]. Autonomic fibres are the most vulnerable to local anaesthetic, and therefore the absence of sympathetic block suggests that the sensory nerve fibres are unlikely to be blocked [23]. A fall in blood pressure is not a reliable sign of sympathetic block as this can be caused by a multitude of factors and may be masked by the use of a vasopressor infusion. The dilemma over the most effective way to assess and ensure an acceptable neuraxial block for caesarean section has, as already mentioned, led to considerable variation in practice. There is inconsistency in the sensory block height considered adequate, how the sensory block is tested, the reference point used and even whether to test from blocked to unblocked areas or the other way round. A survey of obstetric anaesthetic practice published in 1997 found that 12% of anaesthetists did not routinely test the sensory block’s upper level and only 30% checked the lower level [24]. A comparison of practice between 2004 and 2010 showed that a block to T4 to cold remained the most commonly used standard for the sensory block, but an increasing number of anaesthetists were also evaluating block height to light touch [25]. In addition, there is a lack of consensus about which other modalities (motor block, sympathetic block), in addition to sensory block, to test. Hoyle and Yentis undertook a literature review of methods to assess sensory and motor block (but not sympathetic block) for caesarean section under neuraxial anaesthesia from randomised clinical trials and recommendations in 45 editions of seven anaesthetic textbooks [20]. They also found wide variation but did detect a trend over time towards the use of light touch to achieve a block height to T5. The majority of trial manuscripts did not report whether motor block was tested. When motor block was mentioned, fewer than half described the actual method to use. If the method was specified, the majority referred to the ‘Bromage scale’, although only 5% of these matched Bromage’s original description. The pre‐operative obstetric anaesthetic consultation differs from other medical consultations in that the woman will likely be undergoing a surgical procedure for reasons other than her own health. Furthermore, in an emergency setting, the time‐frame is constrained, making it challenging to share information or address a woman’s specific concerns [26, 27]. This is another reason to make every effort to anticipate emergencies to enable adequate discussion with a woman. This requires close co‐operation and communication between anaesthetists, obstetricians and midwives [28]. There is evidence that neuraxial anaesthesia is exclusively offered when discussing anaesthesia for caesarean section [29]. General anaesthesia should be discussed as a primary alternative to neuraxial anaesthesia and not just as a rescue technique. In the UK, ethical, professional and, more recently, legal standards mandate that the information a patient requires to give informed consent should be based on what a reasonable patient would expect to be told, rather than what a reasonable practitioner would expect to explain [30, 31]. In the words of the General Medical Council, doctors “must try to find out what matters to patients so they can share relevant information about the benefits and harms of proposed options and reasonable alternatives.” While formal signed consent for anaesthesia is not the norm in the UK, the anaesthetist should make a written record of the discussion, the information provided and the risks discussed. A developing emergency may necessitate a more truncated and mechanistic approach to seeking consent for the sake of safety. However, this approach should be maintained for as short a time as possible as it can exacerbate feelings of loss of control, increasing the risk of adverse psychological outcomes [32]. The professional and legal requirement to seek consent may result in the anaesthetist’s agenda taking precedence over that of the woman. In the context of neuraxial anaesthesia for caesarean section, this can be counterproductive as active exploration of a woman’s needs and concerns has been shown to reduce anxiety and increase overall satisfaction [33]. It should be kept in mind that administering a neuraxial block might be routine for the anaesthetist, but having a neuraxial block and caesarean section is part of a significant life event for the woman [34]. Her perception of events and how she responds will depend on previous experience, or lack thereof, (mis)information she may have learned from other sources and whether this is an emergency. Many women will be highly anxious regardless of urgency. From the outset, the anaesthetist needs to establish rapport with the woman to facilitate communication, vital to improving the assessment of the block. During the consultation, the anaesthetist needs to try to: Currently, there is no single, universally accepted method to test a neuraxial block before starting a caesarean section. The block required for caesarean section is no different if a spinal or epidural is used. However, the block from a spinal anaesthetic is more likely to be rapid, dense and easy to assess. The block from an epidural may be more challenging to assess, requiring careful and subtle evaluation. Multimodal testing should be used to assess the quality of a neuraxial block before commencing surgery, for example sensory block to light touch plus motor block. Light touch should be used as the primary testing modality, aiming for a block to sensation to T5 or higher. We consider that sensory testing, although essential, is more prone to error than testing of other modalities because it relies on accurate interpretation by the woman of what the anaesthetist is asking. When sensory testing alone is used, especially when the language used by the anaesthetist is not the first language of the woman, the risk of intra‐operative pain may be increased. It is essential to allow sufficient time for the woman to respond when assessing a block, i.e. avoid is moving too rapidly along dermatomes. If ethyl chloride is used as an adjunct, the accuracy of determining a dermatomal level may be affected by the variation in the distribution of the spray of different commercial preparations, potentially covering more than one dermatome [35]. The dense sensory block required for caesarean section is associated with dense motor block of the lumbosacral plexus. If the mother can straight leg raise, no matter how high the loss of sensation, the block is unlikely to be suitable for anaesthesia for caesarean section [36]. Complete motor block of S1 (plantar‐flexion) is a characteristic of spinal anaesthesia but unusual with an epidural. Normal ankle motor function during epidural anaesthesia may indicate absent or inadequate sacral anaesthesia, which will likely result in pain during surgery. Although favoured as a strategy to determine block quality, there is no objective evidence suggesting that sympathetic block should be part of routine practice when assessing a block before caesarean section. However, it can be a helpful adjunct to sensory and motor testing to confirm bilateral spread. A sympathetic block of the feet does not develop until there is a well‐defined sensory block to T10. It can be assessed by feeling the temperature on the underside of the toes bilaterally. Differences in foot temperature or the dampness of the feet indicate an asymmetrical or unilateral block. Even if sensory testing does not demonstrate a difference, the quality of the block is unlikely to be as good on the cooler side. There is no evidence to guide when and how often a block should be assessed after neuraxial anaesthesia. The onset time will depend on the neuraxial technique and drugs used [37]. Early demonstration of some effect is likely to encourage patient confidence but testing too soon can have the opposite effect. Testing the block multiple times may increase patient anxiety. If testing is repeated multiple times, the woman may feel under increasing pressure to say that the block is working [34]. Before starting to test the block, it is essential to emphasise to the woman that she is the best judge of the block, and that everyone understands the importance of waiting until she is ready. While the practice of asking the surgeon to test the block with forceps before skin incision has been described, the responsibility for block assessment remains with the anaesthetist. Some useful tips to aid block assessment are shown in Box 1. It is essential that the assessment of the neuraxial block is comprehensively and accurately documented. This should include: Due to the variability in clinicians’ interpretation of dermatomes, it has been suggested that the most reproducible way of documenting the height of the sensory block is using a dermatome map on the anaesthetic chart or a similar figure [4]. In addition to the practical aspects of block assessment, it is essential to consider communication between the anaesthetist and woman. A good rapport between the woman and anaesthetist may improve the accuracy of sensory assessment. Testing the sensory block depends on the woman understanding what the anaesthetist wants to know and being able to communicate what she is experiencing. The reliability of the test will depend on the accuracy of a woman’s responses, which in turn can be affected by several factors, including: In the event of an inadequate neuraxial block for caesarean section, the response will be determined by the urgency of the caesarean section, the stage of caesarean section at which a woman experiences pain or discomfort and the primary neuraxial technique. The anaesthetist must maintain situational awareness and recognise that a ‘perfect’ block can fail, and there are no infallible tests [39]. Moreover, the effectiveness of a block may change over time and during a caesarean section. The woman is the principal source of information regarding the block’s efficacy and should be listened to carefully. It is not necessarily the neuraxial block’s failure but the inadequate or delayed management that causes the most distress to patients [34, 40]. If a clinician disregards the woman’s experience, it may compound her distress, which can contribute to psychological trauma; subjective birth experience is the strongest predictor of postnatal trauma [41, 42]. The anaesthetist should establish the nature of the woman’s pain, reassure her that she is being heard and that they will endeavour to make her more comfortable. Appropriate support can offer the best prospect of mitigating the long‐term adverse impacts of block failure. Management will depend on the urgency of surgery, stage of procedure and severity of the pain. The following steps should be taken: The anaesthetist should use their knowledge and expertise to decide when general anaesthesia should be offered and when it should be recommended. The woman should, if possible, be included in the discussion about how to proceed. Follow‐up is essential to minimise the development of long‐term psychological sequelae [41]. Ensure that everyone caring for the woman before and following discharge is aware of intra‐operative events. Follow‐up should be prompt and, if possible, undertaken by the anaesthetist who cared for her (in the case of a trainee anaesthetist, they should be supported by a senior colleague). Occasionally, the woman will feel unable to see the same anaesthetist, and a senior colleague should instead take over this role. A woman must be listened to and her accounts of events accepted as their genuine experience. An explanation as to the possible reasons for intra‐operative pain should be offered. Any questions or concerns the woman has should be addressed as fully as possible. Further follow‐up by senior staff may be appropriate if the woman remains distressed. Lack of, or insensitive postoperative management, can exacerbate longer term psychological consequences. A written record should be sent to the woman’s general practitioner and the community midwifery service. The woman should be advised to contact the anaesthetic department if she has ongoing concerns and should be assured that she has access to support should she need it. Women may delay reporting pain during surgery; the issue may only be raised if she becomes pregnant again. All women should be told they can ask for an appointment to see an anaesthetist to discuss events again and to plan anaesthetic management for their next delivery. The strategy for follow‐up and psychological support developed following the 5th National Audit into accidental awareness during general anaesthesia provides a framework that could be adapted for women who experience pain and distress during caesarean section under neuraxial anaesthesia [44]. The adverse impact on anaesthetists should not be overlooked. Irrespective of seniority, the clinician should have the opportunity to discuss events with another clinician. If the anaesthetist providing care was a trainee, a senior colleague should support them and accompany them when speaking to the woman.

AI Digest

Study Justification:

– Pain during caesarean section under neuraxial anesthesia can lead to adverse psychological effects for women.
– Litigation related to pain during caesarean section is a common medicolegal claim against obstetric anaesthetists.
– Existing guidelines for caesarean section do not provide specific recommendations for anesthesia practice.
– This study aims to provide pragmatic advice and support for anaesthetists in caring for women during caesarean section.

Study Highlights:

– A working party of anaesthetists and a psychologist conducted a literature search and developed recommendations based on consensus opinion.
– The incidence of inadequate neuraxial anesthesia for caesarean section varies depending on factors such as technique and urgency.
– Spinal anesthesia has advantages over epidural anesthesia in terms of onset, complications, and supplementation rates.
– Risk factors for inadequate block include operative urgency, increased BMI, first caesarean section, and specific indications for the procedure.
– The level of block required for a caesarean section is debated, but a block height to low thoracic levels is generally recommended.
– Sensory testing, motor testing, and sympathetic block assessment are important for evaluating the quality of a neuraxial block.
– Communication and rapport between the anaesthetist and the woman are crucial for accurate block assessment.
– Inadequate block management should be prompt and tailored to the urgency and stage of the procedure.
– Follow-up and psychological support are essential to mitigate long-term psychological sequelae.

Recommendations for Lay Reader and Policy Maker:

– Ensure that women undergoing caesarean section receive appropriate pain management to prevent adverse psychological effects.
– Promote the use of standardized guidelines and best practices for neuraxial anesthesia during caesarean section.
– Emphasize the importance of non-technical skills and effective communication between anaesthetists and women.
– Encourage regular follow-up and psychological support for women who experience pain or distress during caesarean section.
– Support further research and collaboration between anaesthetists, psychologists, and patients to improve anesthesia practice in this area.

Key Role Players:

– Anaesthetists with expertise in obstetric anesthesia
– Obstetricians and midwives
– Psychologists specializing in psychological sequelae following medical intervention
– General practitioners and community midwifery services
– Senior colleagues to provide support and guidance for trainee anaesthetists

Cost Items for Planning Recommendations:

– Research and literature search costs
– Collaboration and coordination expenses for the working party
– Training and education programs for anaesthetists
– Follow-up and psychological support services for women
– Administrative costs for documentation and record-keeping
– Communication and dissemination of guidelines and recommendations

Strength of Evidence

The strength of evidence for this abstract is 7 out of 10.
The evidence in the abstract is based on a literature search and consensus opinion from a working party. However, there is no mention of specific studies or data presented. To improve the strength of the evidence, the abstract could include references to specific studies or provide more details about the methodology used in the literature search. Additionally, conducting a systematic review or meta-analysis on the topic would further enhance the evidence base.

Abstract

A working party was formed comprising anaesthetists with varying experience levels and frequency of obstetric anaesthesia practice (weekly vs. occasional) and a psychologist with expertise in psychological sequelae following medical intervention and patient representation. We performed a literature search in Medline, Embase, CINAHL and PubMed for material published between 1980 and December 2020. This period was chosen since before 1980, general anaesthesia was the dominant technique for caesarean section with neuraxial techniques gaining rapidly in popularity from this time. The search terms used were: ‘anesthesia’; ‘obstetrical’; ‘methods’; ‘spinal’; ‘epidural’; ‘cesarean section’; ‘pain measurement’; ‘drug effects’; ‘cold temperature’; ‘sensation’; ‘physical stimulation’; ‘Bromage’; and ‘air’. The resulting 44 publications were assessed for relevance by three authors (FP, DB and DL). Recommendations were developed on the basis of consensus opinion. The incidence of inadequate neuraxial anaesthesia for caesarean section varies according to definition, neuraxial technique and urgency of caesarean section. The word ‘failure’ may be used to describe blocks that have entirely failed (no evident sensorimotor block), partial blocks, for example a unilateral block or inadequate block height, or the use of adjuvants or requirement for conversion to general anaesthesia. Spinal anaesthesia has a faster onset, fewer complications and lower intra‐operative supplementation rates than epidural anaesthesia. In a prospective audit of 5080 caesarean sections from a single centre, Kinsella identified the rate of failure to achieve a pain‐free operation as 6% with spinal anaesthesia, 24% with epidural top‐up and 18% with combined spinal‐epidural [6]. The difficulties around the definition of ‘failure’ are illustrated by varying recommendations about acceptable conversion rates of neuraxial anaesthesia to general anaesthesia for emergency caesarean section, especially in time‐critical situations. The Royal College of Anaesthetists suggests that where general anaesthesia is given in the presence of a labour epidural which is not topped up, this is counted as a converted neuraxial technique, rather than primary general anaesthesia [7]. Using this definition, Kinsella found a general anaesthesia conversion rate of 4.9%, notably higher than the Royal College of Anaesthetists’ target of 3%. However, if cases where there was no attempt to ‘top‐up’ the epidural were excluded, the rate was 4.1% [6]. When no attempt was made to top‐up an indwelling epidural, the proportion of cases was higher for category‐1 caesarean section, which is unsurprising. Identifying risk factors for inadequate neuraxial block also depends on the definition of failure used. In his case series, Kinsella defined ‘failure’ as either pre‐operative failure to achieve a satisfactory block or intra‐operative failure leading to pain. Factors associated with pre‐operative failure included operative urgency, increased BMI, women having their first caesarean section and the indications for caesarean section of acute fetal distress or maternal medical condition. For intra‐operative failure, the inadequacy of pre‐operative anaesthetic block and duration of surgery were significant risk‐factors. When spinal anaesthesia was used, the use of a spinal opioid was associated with less pre‐operative failure [6]. When a labour epidural was extended for caesarean section, lower epidural top‐up volume was associated with less pre‐operative failure, and use of adrenaline was associated with both less pre‐operative and intra‐operative failure [6]. A systematic review and meta‐analysis of observational trials for failed conversion of labour epidural analgesia to caesarean section anaesthesia identified risk factors including an increased number of clinician‐administered boluses during labour, greater urgency of caesarean section and provision of anesthetic care by a non‐obstetric anaesthetist [8]. Regardless of how failure of neuraxial block is defined, the crucial element is that the anaesthetist recognises it is inadequate and can lead to pain and distress during surgery. Recognition and pro‐active management of failure are essential to mitigate this risk. The innervation of the uterus comes from sympathetic nerves from the inferior hypogastric plexus (T10–L1), and parasympathetic fibres of the uterus are derived from pelvic splanchnic nerves (S2–S4) [9]. Therefore, the level required for a lower transverse abdominal skin incision for caesarean section is the T10 dermatome. These innervations would suggest that a block height to low thoracic levels should be sufficient for caesarean section. However, several visceral organs send sympathetic afferent impulses to the thoracic spinal cord (T4–L2), and therefore a block height to higher thoracic dermatomes is required [10]. In a prospective study by Russell recording analgesic levels (loss of sharp pinprick sensation) and anaesthesia (loss of touch sensation) in 220 women during caesarean section, no woman with an anaesthetic level that remained above T5 experienced intra‐operative pain [11]. This suggests that loss of touch sensation up to and including T5 is required to minimise the risk of pain during caesarean section, a finding which has been widely endorsed. However, the study predates modern obstetric anaesthetic practice in that it included 70 women who received de‐novo epidural anaesthesia for caesarean section (now rarely used as a primary technique), and no patient received neuraxial opioids. Although the T5 dermatome is the putative target for acceptable block height for caesarean section, several other factors add complexity to this superficially straightforward standard. An important finding of Russell’s work, and confirmed by other studies, is that neuraxial anaesthesia is associated with a zone of differential sensory block at the cranial limits [12, 13]. Other studies have confirmed an inconsistent relationship between cold, sharp pinprick and touch used to assess neuraxial block and height of block; thus, one cannot be predicted by assessing the other [14, 15]. Loss of cold sensation may be observed several dermatomes higher than the loss of sharp pinprick sensation, and this, in turn, may be several dermatomes higher than the level at which touch is lost. Some authors have found that sharp pinprick and cold levels reversed, with loss of sharp pinprick sensation significantly higher than the loss of cold sensation, although the loss of touch sensation is still the lowest. For any modality, the effect does not change from total lack of sensation to completely normal sensation within a single dermatome, for example if using spraying ethyl chloride to assess block height to cold, a woman may feel ‘cold’ at one dermatome but ‘icy cold’ at another dermatome. There is no evidence to guide which point between no sensation and completely normal sensation represents the height of the block. These difficulties are compounded by the lack of consensus around the stimulus that should be used to test the sensory block. Kocarev et al. used various devices to assess block height after combined spinal–epidural anaesthesia in a group of women undergoing caesarean section [16]. Six tests were used in random order to measure four sensory modalities: ethyl chloride (cold), calibrated Neuropen (sharp), standardised monofilament 10 g (pressure), Neurotip stroking (light touch), monofilament stroking (light touch) and cotton wool (light touch). The tests for light touch had the least dermatomal spread, and the more expensive tests did not confer any advantage over the least expensive test, cotton wool. Nor and Russell examined the effect of using different questions to assess the same stimulus in a group of women undergoing caesarean section under spinal anaesthesia [17]. The block height differed by a median value of two dermatomes depending on the question posed, suggesting that this is another variable to be defined. Finally, difficulties arise with the practical correlation of anatomical landmarks with specific dermatomes. Congreve et al. showed, in a study of 80 anaesthetists of all grades, that one in seven were at least two dermatomes outside the ‘correct’ demarcation of T5 [18]. Most textbooks state that a dense bilateral motor block in the lower limbs is essential. Inability to lift the legs against gravity demonstrates motor block of L1–4, but it does not provide information about the density of the block in the mid to upper thoracic segments. The Bromage scale and multiple modifications have been used to describe motor block [19, 20]. An increasing proportion of anaesthetists use the straight leg raise test to avoid confusion [21]. The assessment of sympathetic block as a component of overall block assessment during neuraxial anaesthesia has received little attention. Lumbar neuraxial anaesthesia results in temporary sympathectomy of the lumbar sympathetic chain and can be evidenced by the presence of warm, dry feet [22]. Autonomic fibres are the most vulnerable to local anaesthetic, and therefore the absence of sympathetic block suggests that the sensory nerve fibres are unlikely to be blocked [23]. A fall in blood pressure is not a reliable sign of sympathetic block as this can be caused by a multitude of factors and may be masked by the use of a vasopressor infusion. The dilemma over the most effective way to assess and ensure an acceptable neuraxial block for caesarean section has, as already mentioned, led to considerable variation in practice. There is inconsistency in the sensory block height considered adequate, how the sensory block is tested, the reference point used and even whether to test from blocked to unblocked areas or the other way round. A survey of obstetric anaesthetic practice published in 1997 found that 12% of anaesthetists did not routinely test the sensory block’s upper level and only 30% checked the lower level [24]. A comparison of practice between 2004 and 2010 showed that a block to T4 to cold remained the most commonly used standard for the sensory block, but an increasing number of anaesthetists were also evaluating block height to light touch [25]. In addition, there is a lack of consensus about which other modalities (motor block, sympathetic block), in addition to sensory block, to test. Hoyle and Yentis undertook a literature review of methods to assess sensory and motor block (but not sympathetic block) for caesarean section under neuraxial anaesthesia from randomised clinical trials and recommendations in 45 editions of seven anaesthetic textbooks [20]. They also found wide variation but did detect a trend over time towards the use of light touch to achieve a block height to T5. The majority of trial manuscripts did not report whether motor block was tested. When motor block was mentioned, fewer than half described the actual method to use. If the method was specified, the majority referred to the ‘Bromage scale’, although only 5% of these matched Bromage’s original description. The pre‐operative obstetric anaesthetic consultation differs from other medical consultations in that the woman will likely be undergoing a surgical procedure for reasons other than her own health. Furthermore, in an emergency setting, the time‐frame is constrained, making it challenging to share information or address a woman’s specific concerns [26, 27]. This is another reason to make every effort to anticipate emergencies to enable adequate discussion with a woman. This requires close co‐operation and communication between anaesthetists, obstetricians and midwives [28]. There is evidence that neuraxial anaesthesia is exclusively offered when discussing anaesthesia for caesarean section [29]. General anaesthesia should be discussed as a primary alternative to neuraxial anaesthesia and not just as a rescue technique. In the UK, ethical, professional and, more recently, legal standards mandate that the information a patient requires to give informed consent should be based on what a reasonable patient would expect to be told, rather than what a reasonable practitioner would expect to explain [30, 31]. In the words of the General Medical Council, doctors “must try to find out what matters to patients so they can share relevant information about the benefits and harms of proposed options and reasonable alternatives.” While formal signed consent for anaesthesia is not the norm in the UK, the anaesthetist should make a written record of the discussion, the information provided and the risks discussed. A developing emergency may necessitate a more truncated and mechanistic approach to seeking consent for the sake of safety. However, this approach should be maintained for as short a time as possible as it can exacerbate feelings of loss of control, increasing the risk of adverse psychological outcomes [32]. The professional and legal requirement to seek consent may result in the anaesthetist’s agenda taking precedence over that of the woman. In the context of neuraxial anaesthesia for caesarean section, this can be counterproductive as active exploration of a woman’s needs and concerns has been shown to reduce anxiety and increase overall satisfaction [33]. It should be kept in mind that administering a neuraxial block might be routine for the anaesthetist, but having a neuraxial block and caesarean section is part of a significant life event for the woman [34]. Her perception of events and how she responds will depend on previous experience, or lack thereof, (mis)information she may have learned from other sources and whether this is an emergency. Many women will be highly anxious regardless of urgency. From the outset, the anaesthetist needs to establish rapport with the woman to facilitate communication, vital to improving the assessment of the block. During the consultation, the anaesthetist needs to try to: Currently, there is no single, universally accepted method to test a neuraxial block before starting a caesarean section. The block required for caesarean section is no different if a spinal or epidural is used. However, the block from a spinal anaesthetic is more likely to be rapid, dense and easy to assess. The block from an epidural may be more challenging to assess, requiring careful and subtle evaluation. Multimodal testing should be used to assess the quality of a neuraxial block before commencing surgery, for example sensory block to light touch plus motor block. Light touch should be used as the primary testing modality, aiming for a block to sensation to T5 or higher. We consider that sensory testing, although essential, is more prone to error than testing of other modalities because it relies on accurate interpretation by the woman of what the anaesthetist is asking. When sensory testing alone is used, especially when the language used by the anaesthetist is not the first language of the woman, the risk of intra‐operative pain may be increased. It is essential to allow sufficient time for the woman to respond when assessing a block, i.e. avoid is moving too rapidly along dermatomes. If ethyl chloride is used as an adjunct, the accuracy of determining a dermatomal level may be affected by the variation in the distribution of the spray of different commercial preparations, potentially covering more than one dermatome [35]. The dense sensory block required for caesarean section is associated with dense motor block of the lumbosacral plexus. If the mother can straight leg raise, no matter how high the loss of sensation, the block is unlikely to be suitable for anaesthesia for caesarean section [36]. Complete motor block of S1 (plantar‐flexion) is a characteristic of spinal anaesthesia but unusual with an epidural. Normal ankle motor function during epidural anaesthesia may indicate absent or inadequate sacral anaesthesia, which will likely result in pain during surgery. Although favoured as a strategy to determine block quality, there is no objective evidence suggesting that sympathetic block should be part of routine practice when assessing a block before caesarean section. However, it can be a helpful adjunct to sensory and motor testing to confirm bilateral spread. A sympathetic block of the feet does not develop until there is a well‐defined sensory block to T10. It can be assessed by feeling the temperature on the underside of the toes bilaterally. Differences in foot temperature or the dampness of the feet indicate an asymmetrical or unilateral block. Even if sensory testing does not demonstrate a difference, the quality of the block is unlikely to be as good on the cooler side. There is no evidence to guide when and how often a block should be assessed after neuraxial anaesthesia. The onset time will depend on the neuraxial technique and drugs used [37]. Early demonstration of some effect is likely to encourage patient confidence but testing too soon can have the opposite effect. Testing the block multiple times may increase patient anxiety. If testing is repeated multiple times, the woman may feel under increasing pressure to say that the block is working [34]. Before starting to test the block, it is essential to emphasise to the woman that she is the best judge of the block, and that everyone understands the importance of waiting until she is ready. While the practice of asking the surgeon to test the block with forceps before skin incision has been described, the responsibility for block assessment remains with the anaesthetist. Some useful tips to aid block assessment are shown in Box 1. It is essential that the assessment of the neuraxial block is comprehensively and accurately documented. This should include: Due to the variability in clinicians’ interpretation of dermatomes, it has been suggested that the most reproducible way of documenting the height of the sensory block is using a dermatome map on the anaesthetic chart or a similar figure [4]. In addition to the practical aspects of block assessment, it is essential to consider communication between the anaesthetist and woman. A good rapport between the woman and anaesthetist may improve the accuracy of sensory assessment. Testing the sensory block depends on the woman understanding what the anaesthetist wants to know and being able to communicate what she is experiencing. The reliability of the test will depend on the accuracy of a woman’s responses, which in turn can be affected by several factors, including: In the event of an inadequate neuraxial block for caesarean section, the response will be determined by the urgency of the caesarean section, the stage of caesarean section at which a woman experiences pain or discomfort and the primary neuraxial technique. The anaesthetist must maintain situational awareness and recognise that a ‘perfect’ block can fail, and there are no infallible tests [39]. Moreover, the effectiveness of a block may change over time and during a caesarean section. The woman is the principal source of information regarding the block’s efficacy and should be listened to carefully. It is not necessarily the neuraxial block’s failure but the inadequate or delayed management that causes the most distress to patients [34, 40]. If a clinician disregards the woman’s experience, it may compound her distress, which can contribute to psychological trauma; subjective birth experience is the strongest predictor of postnatal trauma [41, 42]. The anaesthetist should establish the nature of the woman’s pain, reassure her that she is being heard and that they will endeavour to make her more comfortable. Appropriate support can offer the best prospect of mitigating the long‐term adverse impacts of block failure. Management will depend on the urgency of surgery, stage of procedure and severity of the pain. The following steps should be taken: The anaesthetist should use their knowledge and expertise to decide when general anaesthesia should be offered and when it should be recommended. The woman should, if possible, be included in the discussion about how to proceed. Follow‐up is essential to minimise the development of long‐term psychological sequelae [41]. Ensure that everyone caring for the woman before and following discharge is aware of intra‐operative events. Follow‐up should be prompt and, if possible, undertaken by the anaesthetist who cared for her (in the case of a trainee anaesthetist, they should be supported by a senior colleague). Occasionally, the woman will feel unable to see the same anaesthetist, and a senior colleague should instead take over this role. A woman must be listened to and her accounts of events accepted as their genuine experience. An explanation as to the possible reasons for intra‐operative pain should be offered. Any questions or concerns the woman has should be addressed as fully as possible. Further follow‐up by senior staff may be appropriate if the woman remains distressed. Lack of, or insensitive postoperative management, can exacerbate longer term psychological consequences. A written record should be sent to the woman’s general practitioner and the community midwifery service. The woman should be advised to contact the anaesthetic department if she has ongoing concerns and should be assured that she has access to support should she need it. Women may delay reporting pain during surgery; the issue may only be raised if she becomes pregnant again. All women should be told they can ask for an appointment to see an anaesthetist to discuss events again and to plan anaesthetic management for their next delivery. The strategy for follow‐up and psychological support developed following the 5th National Audit into accidental awareness during general anaesthesia provides a framework that could be adapted for women who experience pain and distress during caesarean section under neuraxial anaesthesia [44]. The adverse impact on anaesthetists should not be overlooked. Irrespective of seniority, the clinician should have the opportunity to discuss events with another clinician. If the anaesthetist providing care was a trainee, a senior colleague should support them and accompany them when speaking to the woman.

Materials

N/A

Innovations

Based on the provided information, here are some potential innovations that can be used to improve access to maternal health:

1. Development of standardized guidelines: Creating specific guidelines for the prevention and management of intra-operative pain during caesarean sections under neuraxial anesthesia can help improve the quality of care and reduce the risk of adverse psychological sequelae.

2. Collaborative approach: Involving a multidisciplinary team of anaesthetists, psychologists, and patients in the development of guidelines and recommendations can ensure that all perspectives are considered and that the recommendations are practical and effective.

3. Improved training and education: Providing comprehensive training and education for anaesthetists on best practices for caesarean sections under neuraxial anesthesia can help improve their skills and knowledge in preventing and managing intra-operative pain.

4. Standardized assessment methods: Developing standardized methods for assessing the quality of a neuraxial block before starting a caesarean section can help ensure consistency and accuracy in block assessment.

5. Enhanced communication and patient-centered care: Emphasizing the importance of effective communication between anaesthetists and patients can help build rapport, improve patient satisfaction, and ensure that the patient’s needs and concerns are addressed.

6. Follow-up and support: Implementing a system for postoperative follow-up and support can help identify and address any ongoing concerns or psychological sequelae experienced by the patients.

7. Continuous quality improvement: Establishing mechanisms for continuous quality improvement, such as regular audits and feedback loops, can help identify areas for improvement and ensure that best practices are consistently implemented.

It is important to note that these recommendations are based on the specific context provided in the description and may need to be tailored to the local healthcare system and resources available.

AI Innovations Description

The recommendation described in the provided text is focused on improving the prevention and management of intra-operative pain during caesarean section under neuraxial anesthesia. The goal is to reduce the risk of adverse psychological sequelae and medicolegal claims against obstetric anaesthetists.

The recommendation emphasizes the importance of non-technical skills and offers advice on best practices to support anaesthetists in caring for women during caesarean section. It also aims to encourage standardization of practice in this area.

To develop this recommendation into an innovation to improve access to maternal health, the following steps can be taken:

1. Collaborative Effort: Form a working party comprising anaesthetists, psychologists, and patients to develop and refine the recommendation. This collaborative approach ensures that the innovation takes into account the perspectives and needs of all stakeholders.

2. Literature Review: Conduct a comprehensive literature search to gather evidence and identify best practices related to preventing and managing intra-operative pain during caesarean section under neuraxial anesthesia. This will provide a solid foundation for the innovation.

3. Consensus Building: Use the gathered evidence to develop specific recommendations based on consensus opinion. Engage the working party members in discussions and decision-making processes to ensure that the recommendations are well-informed and supported by the group.

4. Standardization of Practice: Develop guidelines and protocols based on the recommendations to promote standardization of practice among anaesthetists. These guidelines should provide clear instructions on assessing block quality, testing sensory and motor function, and managing inadequate blocks.

5. Training and Education: Implement training programs to educate anaesthetists on the new guidelines and protocols. This will ensure that they have the necessary knowledge and skills to effectively prevent and manage intra-operative pain during caesarean section.

6. Documentation and Communication: Emphasize the importance of comprehensive and accurate documentation of block assessment, management decisions, and patient communication. Develop standardized forms or templates to facilitate consistent documentation across different healthcare settings.

7. Follow-up and Support: Establish a system for postoperative follow-up and support for women who experience pain during caesarean section. This can include providing information, addressing concerns, and offering psychological support to mitigate the potential long-term adverse effects.

By implementing these recommendations and innovations, access to maternal health can be improved by ensuring that women receive appropriate pain management during caesarean section, reducing the risk of adverse psychological outcomes, and promoting standardized and high-quality care.

AI Innovations Methodology

Based on the provided description, here are some potential recommendations for improving access to maternal health:

1. Develop specific guidelines: Create guidelines that provide specific recommendations for the prevention and management of intra-operative pain during caesarean section under neuraxial anesthesia. These guidelines should address the technical and interpersonal aspects of care, emphasizing the importance of non-technical skills and best practices.

2. Collaborative effort: Encourage collaboration between anaesthetists, psychologists, and patients to develop these guidelines. This multidisciplinary approach ensures that the recommendations are comprehensive and take into account the perspectives of all stakeholders involved in maternal health.

3. Literature review: Conduct a thorough literature search to gather evidence and information on the topic. This review should include relevant publications from reputable sources, such as Medline, Embase, CINAHL, and PubMed. The search should cover a specific time period, such as from 1980 to December 2020, to focus on recent developments in anesthesia techniques for caesarean sections.

4. Consensus-based recommendations: Develop recommendations based on consensus opinion. After assessing the relevance of the identified publications, a working party comprising anaesthetists with varying experience levels and a psychologist should come to a consensus on the recommendations. This ensures that the recommendations are practical and applicable in real-world scenarios.

To simulate the impact of these recommendations on improving access to maternal health, a methodology could be developed as follows:

1. Define key indicators: Identify key indicators that reflect access to maternal health, such as the rate of successful pain-free caesarean sections under neuraxial anesthesia, the incidence of inadequate anesthesia, and the rate of conversion to general anesthesia.

2. Collect baseline data: Gather baseline data on these indicators before implementing the recommendations. This data will serve as a reference point for comparison and evaluation.

3. Implement recommendations: Put the recommendations into practice by disseminating the guidelines to anaesthetists and healthcare facilities involved in maternal health. Ensure that healthcare providers are trained and educated on the new guidelines.

4. Monitor and evaluate: Continuously monitor and evaluate the impact of the recommendations on the identified indicators. This can be done through data collection, such as tracking the rate of successful pain-free caesarean sections and the incidence of inadequate anesthesia. Compare the post-implementation data with the baseline data to assess the effectiveness of the recommendations.

5. Adjust and refine: Based on the evaluation results, make adjustments and refinements to the recommendations as necessary. This iterative process allows for continuous improvement and optimization of access to maternal health.

By following this methodology, the impact of the recommendations on improving access to maternal health can be simulated and assessed. It provides a systematic approach to measure the effectiveness of the recommendations and make evidence-based decisions for further improvement.

Author

Dima Health

Statistics:

Citations: 12

Identifiers:

DOI: 10.1111/anae.15717

ISSN: 00032409

Research Areas:

Community Interventions, Environmental, Health System and Policy, Maternal Access, Maternal and Child Health, Mental Health, Noncommunicable Diseases, Quality of Care, Social Determinants, Violence and Injury, Workforce

Study Design:

Cohort Study, Cross Sectional Study, randomised-control-trial

Study Approach:

Mixed-methods, Quantitative, Systematic Review

Participants Gender:

Female