Inadequate neuraxial anaesthesia during caesarean delivery: a survey of practitioners

BACKGROUND

We aimed to determine the knowledge, training, practices and attitudes of obstetric anaesthetic practitioners with regard to failed neuraxial anaesthesia for caesarean delivery.

METHOD

We performed a contemporaneous and representative survey in an innovative fashion. We conducted an international cross-sectional study of obstetric anaesthetic practitioners at the Annual Scientific Meeting of the Obstetric Anaesthetists' Association (OAA 2021). Validated survey questions were collected in real time using an audience response system.

RESULTS

Of the 426 participants who logged into the survey system, 356 provided responses (4173 responses to 13 questions, across all grades/seniority of practitioner). The number of responses to questions ranged from 81% to 61%. Survey responses suggest that it is routine for respondents to inform patients about the difference between pain and expected intra-operative sensations, (320/327, 97.9%) but less routine to inform patients of the risk of intra-operative pain (204/260, 78.5%), or the possibility of conversion to general anaesthesia. (290/309 93.8%). Only 30% of respondents reported the use of written guidelines for follow-up of patients who experience intra-operative pain under neuraxial anaesthesia, and only 23% reported formal training in management of intra-operative pain under neuraxial anaesthesia. Respondents felt that inadequate block duration, prolonged surgery, and patient anxiety were contributory factors to failed anaesthesia, and the contributory factors differed between grade/seniority of practitioner. Modalities used to test a block were cold, motor block and light touch, with approximately 65% of respondents routinely using three modalities.

CONCLUSIONS

Our study survey found that the consent process may not always be adequately comprehensive, and that standardised documentation and testing of the block and focused training may be beneficial to prevent patient dissatisfaction and the chance of litigation.

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.

Regional anaesthesia: risk, consent and complications

The risks of regional anaesthesia relate primarily to the technical nature of the procedure, chief among them being neurological. While rare, the direct relationship between nerve damage and the procedure itself means that patients need to be aware of this complication when consent is sought. In order to give valid consent, a patient must be informed. The extent of the information required has been defined by a 2015 legal ruling which established that the standard is the expectation of a reasonable patient, rather than the information deemed consequential by a reasonable doctor. The implications of this for clinicians are profound, and mean that the process of consent must, for example, include alternatives to the proposed treatment. Additionally, patients must have capacity and give their consent without coercion. Effective communication of risk can be challenging. As well as the barriers to comprehension that can result from language, literacy and numeracy, clinicians need to be aware of their own biases, often in favour of a regional anaesthetic approach. Patients also have biases, and doctors must be aware of these in order to best target their provision of information. Careful use of language and employing adjuncts such as information leaflets and visual aids can help to maximise the individual's autonomy. Particular care must be taken in special situations such as where patients have capacity issues or time is limited by the emergency nature of the intervention.

Audio/visual recording of doctors in hospitals: Guideline from the Association of Anaesthetists

Guidelines are presented that summarise the legal position regarding the audio/visual recording of doctors and others in hospitals. In general, there are few, if any, legal grounds for refusing a request by patients to record procedures and/or discussions with clinicians, although some staff may feel uncomfortable being recorded. Trusts and others are advised to draw up local policies and ensure staff and patients are adequately informed.

Strength of commonly used spinal needles: the ability to deform and resist deformation

We investigated the strength of commonly used spinal needles in relation to the amount of deformation, and registered forces during standardised testing. We investigated differences between manufacturers for the same length and gauge of Luer and non-Luer needles, and examined the effect of the internal stylet in terms of needle strength. A specialised rig was designed to perform the testing in both the horizontal and axial plane, reflecting common industrial tests and clinical use. Needles from four commonly used manufacturers were used (Vygon, Becton Dickinson, B Braun, and Pajunk). Needles of 25 G and 27 G were tested in 90-mm and 120-mm lengths. We found significant differences in terms of the size of final deformation and 'toughness'/resistance to deformation between needles of different brands. There were also significant differences between horizontal tests conducted as an industry standard and our own axial test. This may have bearing on clinical use in terms of the incidence of bending and breakage. The presence of the internal stylet resulted in significantly greater toughness in many needles, but had little effect on the degree of deformation. Comparison of Luer and non-Luer needles of the same brand and size showed few significant differences in strength. This result is reassuring, given the imminent change from Luer to non-Luer needles that is to occur in the UK.

Safety guideline: skin antisepsis for central neuraxial blockade

Concise guidelines are presented that recommend the method of choice for skin antisepsis before central neuraxial blockade. The Working Party specifically considered the concentration of antiseptic agent to use and its method of application. The advice presented is based on previously published guidelines, laboratory and clinical studies, case reports, and on the known properties of antiseptic agents.

Detection of inner tube defects in co-axial circle and Bain breathing systems: a comparison of occlusion and Pethick tests

The performance of the occlusion and Pethick tests in detecting faulty inner tubes in co-axial circle and Bain systems was compared. Twelve co-axial circle and 12 Bain anaesthetic breathing systems were tested using the occlusion and the Pethick tests. For each system, three tubes were intact, and the remaining nine had a defect deliberately created in the inner tube (three proximal, three middle and three distal). The investigators were blinded to which of the tubes were defective, and to each other's results. The results showed 100% specificity for both tests. The sensitivity of the occlusion test for detecting faulty breathing systems was found to be good (98%). Our results suggest that the occlusion test should be performed in preference to the Pethick test when testing co-axial circle and Bain systems.

Cerebral haemodynamics in pregnancy and pre-eclampsia as assessed by transcranial Doppler ultrasonography

BACKGROUND

Altered cerebral circulation, as reported during normal pregnancy, and in patients with pre-eclampsia, can be associated with changes in cerebral vascular reactivity and/or cerebral autoregulation. The aim of our study was to perform a comparative assessment of cerebral haemodynamics, including vascular reactivity and autoregulation, in pre-eclamptic patients, healthy pregnant women, and healthy non-pregnant women.

METHODS

Thirty patients with pre-eclampsia were recruited. Age- and height-matched healthy pregnant (n=30) and non-pregnant control (n=30) groups were also recruited. Monitoring included transcranial Doppler ultrasonography, end-tidal carbon dioxide and non-invasive arterial pressure measurement. Cerebral autoregulation was assessed by performing the transient hyperaemic response (THR) test. The cerebrovascular reactivity to carbon dioxide (CRCO(2)) was assessed by measuring middle cerebral artery blood flow velocity (MCAFV) after induced changes in end-tidal carbon dioxide. Estimated cerebral perfusion pressure (eCPP) and critical closing pressure (CrCP) were calculated using established formulae. Statistical analysis included ANOVA with Tukey's pairwise comparisons.

RESULTS

Mean arterial pressure (MAP) was increased in pre-eclampsia (P<0.05). Mean MCAFV was lower in healthy pregnancy (P<0.05), but in pre-eclampsia it was similar to the non- pregnant group. When compared with the non-pregnant group, mean eCPP was higher in the healthy pregnant and pre-eclamptic groups (P<0.05). There were no meaningful differences in cerebral autoregulation or CRCO(2).

CONCLUSIONS

Healthy pregnancy increases eCPP, presumably by decreasing CrCP. In pre-eclampsia, eCPP is maintained at the same level as in healthy pregnancy despite an increased MAP. Pre-eclampsia has no significant effect on cerebral autoregulation or CRCO(2).

The occupational exposure of midwives to nitrous oxide — a comparison between two labour suites

The study of midwives' occupational exposure to nitrous oxide in a poorly ventilated maternity unit in 1992 was instrumental in ensuring that the replacement building had Department of Health approved ventilation. We have repeated the study in the new unit. There was a trend for 8-hour time weighted average exposure to nitrous oxide to be lower in the new building. This difference was significant amongst those midwives who spent a greater time looking after women using Entonox and thus were more at risk from its detrimental effects. We discuss these findings and the ramifications for other maternity units under the new COSHH regulations.

Latex anaphylaxis during late pregnancy

A case of anaphylaxis to a latex urethral catheter in a 33-year-old at full term pregnancy is presented. The diagnosis is based on clinical findings and supported by subsequent immunological tests. She was managed with cardiopulmonary resuscitation, concomitant caesarean section and intravenous adrenaline. Despite the good maternal outcome the child showed early signs of severe perinatal asphyxia, the long-term sequelae of which remain to be seen. This report discusses this unusual cause of anaphylaxis and highlights the problems of resuscitation in the pregnant patient.