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Medical law relating to obstetric anaesthesia has unique issues. There are legal implications of caring for two patients simultaneously, mother and fetus, and issues may arise when the welfare of one is in conflict with that of the other. This chapter addresses the extent to which a woman can be forced to consider the needs of her fetus, case law relating to enforced caesarean sections, and the current legal position. Although the majority of expectant mothers have capacity, there are situations where this may not be the case. Law concerning the care of teenage obstetric patients, the difficult areas of capacity and consent in labour, and the role of birth plans are therefore explored. Fundamental topics in medical law such as battery, negligence, manslaughter, and confidentiality are addressed, in addition to law relating to the teaching and supervision of junior medical staff, and clinical research and its publication. The chapter also considers areas of developing importance such as the legal implication of clinical guidelines and the degree to which these may be viewed as a standard of care. Finally, the chapter offers, where possible, the obstetric anaesthetist some practical guidance on incorporating the current legal position in these key areas of medical law into everyday practice.

The risk to women’s health is increased during pregnancy, and maternal mortality is used as an indicator of general healthcare provision as well as a target for improving women’s health worldwide. Morbidity is more difficult to define than mortality but may also be used to monitor and improve women’s care during and after pregnancy. Despite international efforts to reduce maternal mortality, there remains a wide disparity between the rate of deaths in developed (maternal mortality ratio less than 10–20 per 100,000 live births) and developing (maternal mortality ratio as high as 1000 or more per 100,000 live births in some countries) areas of the world. Similarly, treatable conditions that cause considerable morbidity in developed countries but uncommonly result in maternal death (e.g. pre-eclampsia (pre-eclamptic toxaemia), haemorrhage, and sepsis) continue to be major causes of mortality in developing countries, where appropriate care is hampered by a lack of resources, skilled staff, education, and infrastructure. Surveillance systems that identify and analyse maternal deaths aim to monitor and improve maternal healthcare through education of staff and politicians; the longest-running and most comprehensive of these, the Confidential Enquiries into Maternal Deaths in the United Kingdom, was halted temporarily after the 2006–2008 report but is now active again. Surveillance of maternal morbidity is more difficult but systems also exist for this. The lessons learnt from such programmes are thought to be important drivers for improved maternal outcomes across the world.

There has been little published work defining 'normal' thromboelastography (TEG(®) ) values in healthy parturients, and few large studies defining reference ranges for traditional coagulation tests in this patient group. Our aim was to establish peri-operative reference ranges for TEG and for standard laboratory coagulation tests in our pregnant population. Fifty healthy term parturients presenting for elective caesarean section under spinal anaesthesia had blood samples taken pre-operatively, on arrival in the recovery room and, in a subset of 33 women, 4 h after routine thromboprophylaxis with enoxaparin 40 mg. All three samples had TEG analysis, the first and second having standard laboratory coagulation tests in addition. Reference ranges for our pregnant population were established, demonstrating a hypercoagulable state in term parturients and a significant effect of enoxaparin. The standard coagulation reference ranges were within 98% of the local non-pregnant ranges. These reference ranges provide a useful comparator for peri-operative TEG and routine coagulation analysis in term parturients.

Summary In a randomised controlled study, we compared the ease of railroading a GlideRite® nasal tracheal tube over a fibrescope with that of a pre-rotated RAE™ nasal tracheal tube. We studied 110 anaesthetised patients with no known airway difficulties undergoing elective dental or maxillofacial surgery. Impingement was more common with the GlideRite tubes (11/55 (20%)) compared with the pre-rotated RAE tubes (3/55 (5%); p = 0.02). The median (IQR [range]) time to intubation (GlideRite 7.6 (4.7–10.8 [3.0–46.2]) s; RAE 8.0 (6.2–10.7 [2.4–30.0]) s) and postoperative sore throat numerical ratings (GlideRite 2 (0–3 [0–10]); RAE 2 (0–5 [0–8])) were similar. A 90° anticlockwise pre-rotation of a standard nasal RAE tube has a higher initial rate of successful railroading at first attempt and is therefore superior to a GlideRite nasotracheal tube during nasal fibreoptic intubation.

Background Pregnant women with heart disease (HD) are at an increased risk for maternal and neonatal adverse events. However, the effect of pregnancy on clinical status and ventricular function in women with HD has not been examined in a controlled study. Methods and results Ninety-three women with HD were studied longitudinally. Of these, fifty-three underwent clinical and echocardiographic evaluation before and 1.5±1.1 years after pregnancy (pregnancy group), whereas forty served as controls matched for age (28.6±4.6 versus 28.5±6.6, p =0.88), diagnosis, and length of follow-up (2.9±1.4 versus 2.6±1.1, p =0.23). NYHA functional class remained unchanged in both groups during follow-up. End diastolic and end systolic dimensions and shortening fraction of the morphologic left ventricle also remained unchanged. Furthermore, systemic and subpulmonary ventricular function remained unchanged in the pregnancy and control groups on semiquantitative analysis. Pregnancy, however, was associated with a persisting increase in subpulmonary ventricular size in patients with tetralogy of Fallot (ToF) which was not present in tetralogy controls. Furthermore, diagnosis of ToF was the only predictor of an increase in subpulmonary ventricular size after pregnancy on univariate logistic regression analysis (OR 8.8[95% CI 1.9–41.1], p =0.006). Conclusions In this longitudinal controlled study amongst women with HD no deleterious midterm effects of pregnancy on clinical status and right and left ventricular function were found. However, pregnancy was associated with a persisting increase in subpulmonary ventricular size, attributable to patients with repaired ToF. This may have prognostic implications and merits further investigation.

The aims of antenatal anaesthetic assessment are to: identify problems or potential problems; arrange investigations; refer to specialists for advice and/or treatment; institute treatment; discuss options for analgesia in labour and/or anaesthesia for operative delivery; formulate a management plan; and highlight special requirements (e.g. latex-free equipment, extra staff, intensive care bed). In the UK, few, if any, units have the manpower to assess every pregnant woman, therefore attention is targeted at high-risk patients. •The number of parturients with pre-existing disease is thought to be increasing owing to better management of their underlying condition and of their pregnancy and delivery. It is important to tailor a plan to their individual needs and this is best done antenatally. •Arrangements for antenatal anaesthetic assessment vary from ad hoc calls from the antenatal clinic to regular, formal, anaesthetic clinics. Some units have combined clinics with obstetricians and other specialists. Setting up and running an antenatal anaesthetic assessment service is discussed and a sample antenatal anaesthetic assessment record is provided. •A checklist is given of those who should be referred for antenatal anaesthetic assessment. Women may have musculoskeletal problems, ranging from back pain to scoliosis, and may be concerned about having an epidural. Other problems covered include cardiac disease, haematological problems, previous anaesthetic problems, neurological conditions, respiratory problems (e.g. asthma), allergic reactions, obesity and needle phobia.

We conducted a postal survey of lead obstetric anaesthetists in all consultant-led maternity units in the UK about drug errors and the measures taken to reduce or prevent them. Of the 179 out of 240 (75%) who responded, 70 (39%) knew of at least one drug error in their unit during the last year, with 28 of them (40%) experiencing more than one. Of the most recent errors, giving the wrong drug (most commonly thiopental instead of antibiotics or vice versa [14 cases], or suxamethonium instead of [Formula: see text] [8 cases] or other drugs [4 cases]) was the most common error, occurring in 27 units (15%). Errors involving epidural/spinal analgesia/anaesthesia (including drugs intended for these routes but given via other routes) occurred in 20 cases. Only 36 respondents (20%) described protocols for checking anaesthetic drugs. Methods described for reducing drug errors were use of coloured labels (20%) or pre-filled labelled syringes (6%), limiting the range of drugs available (6%) and keeping drugs in separate trays once drawn up (6%).

Pregnant women were randomly assigned to receive, at booking, the usual written information pack either with or without the Obstetric Anaesthetists' Association's (OAA's) leaflet 'Pain Relief in Labour'. At 36 weeks' gestation, a structured interview was conducted at which we assessed the sources of information the women had used and their knowledge of specific aspects of obstetric analgesia and anaesthesia described in the OAA leaflet. The most useful sources of information overall were friends, family, midwives, books and information leaflets (no significant difference between the groups); 72% of all women felt they had received adequate information although 70% said they would have liked to have discussed methods of analgesia with an anaesthetist before delivery. Parturients allocated to receive the leaflet (n = 37) were more knowledgeable than those who received only standard booking information (n = 39) about all analgesic and anaesthetic techniques except for systemic pethidine, although this difference in knowledge only reached statistical significance for extending epidural analgesia for emergency Caesarean section. We conclude that the OAA leaflet improves women's knowledge of analgesic techniques and suggest that all information of this type be formally assessed in this manner; furthermore given the practical difficulties in conducting studies of this type, the latter should be adequately resourced, perhaps by the bodies that issue such leaflets.

The National Obstetric Anaesthetic Database was established in 1998 to support collection of national data on obstetric analgesia and anaesthesia. The first year's project aimed to determine the incidence, characteristics, contributing factors and management of postpartum headaches with anaesthetic interventions. A total of 65348 women were reported to have had anaesthetic interventions. There were individual records of 404 women in whom postdural puncture headache (PDPH) was diagnosed (47 mild, 134 moderate, 202 severe and 21 unspecified) and 571 in whom headache was not related to dural puncture (315 mild, 176 moderate, 44 severe and 36 unspecified). Recognised dural puncture occurred in 165 women (41%), 130 (79%) during labour. Placement of spinal catheters on dural puncture in 51 women did not influence headache severity. Abdominal compression used to test the diagnosis of PDPH was only positive in 56/186 parturients (30%). Epidural blood patch was performed in 240 women with PDPH, of whom 101 women (42%) received their first blood patch within two days of delivery. The incidence of headache ranged from 1.1% to 1.9% between all anaesthetic techniques but increased to 11% for women receiving multiple regional anaesthetics. The predominant characteristics of PDPH were limitation of daily activity ( n =305, 75%), severity (moderate/severe) and a postural element ( n =325, 80%), all significantly different from headache from other causes ( P =0.001). Shoulder/neck stiffness ( n =172, 43%) was the commonest symptom associated with PDPH.

The UK registry of high-risk obstetric anaesthesia was set up in late 1996 to collect reports of high-risk pregnancy, pool them into a central database and disseminate the results. At the time of analysis for this paper (December 31, 2001) 308 cardiorespiratory reports had been received. The five most common conditions, occurring in 125 cases (41% of the total), were arrhythmias (43 cases), cardiomyopathy (26 cases), aortic stenosis (24 cases), transposition of the great arteries (18 cases) and Marfan's syndrome (14 cases). We describe the features and management of these cases.

We conducted a two-part study to assess the practice of withholding neuromuscular blockade until the ability to ventilate the lungs using a bag and face mask (mask ventilation) has been established following induction of anaesthesia. The first part of the study consisted of a postal survey (71% response rate) of 188 anaesthetists in the Oxford region to assess their current practice. Thirty per cent of respondents always checked mask ventilation before administering a neuromuscular blocking drug, whereas 39% of respondents (all them consultants) never did this. A further 31% only did so in the case of known or anticipated difficulty with the airway. In the second part of the study, we measured inspired (V(TI)) and expired (V(TE)) tidal volumes before and after neuromuscular blockade in 30 patients undergoing general anaesthesia. The ratio V(TE)/V(TI) was used as a measure of the efficiency of ventilation. There was no difference in V(TE)/V(TI) before [mean (SD) 0.47 (0.13)] and after [0.45 (0.13)] neuromuscular blockade. We conclude that neuromuscular blockade does not affect the efficiency of mask ventilation in patients with normal airways.

Summary We investigated the attitudes of 96 patients and 163 anaesthetists to the need for obtaining informed consent before specialist airway techniques. Participants were asked to score six questions using a numerical scale, as to whether they thought consent was necessary before specific procedures, particularly in relation to fibreoptic intubtion used for teaching or maintaining skills. Significant differences in opinion were found between patients and anaesthetists despite a wide range of views. Overall, patients felt that specific consent was required for non-routine techniques, whilst anaesthetic respondents felt this was unnecessary, even if teaching. We conclude that guidance in obtaining consent is needed to support anaesthetists wishing to practice or teach fibreoptic intubation.

Summary The current recommendation of one consultant session per 500 deliveries with full sessional cover␣for units over 3000 deliveries is arbitrary and is not based on workload. The Audit Commission has questioned the wide variability of anaesthetic staffing on labour wards. The aim of this study was to investigate whether there is a relationship between current workload and obstetric anaesthetic staffing in five maternity units. In 1998, a 2-week diary of workload in the participating obstetric units was assessed in terms of staffing and clinical and nonclinical activities. The busiest time was 08:00 to 12:30. The working patterns between consultants and trainees varied considerably. Time spent on nonclinical activity by consultants averaged 51%. Any calculation of consultant sessions will need to take into account nonclinical activities. Other factors requiring consideration are the number of high-risk cases, as well as the number and experience of trainees.

The ability of glycopyrronium to reduce the severity of hypotension following subarachnoid block in parturients with a relative bradycardia was evaluated in a double-blind randomised controlled study. Women with a resting heart rate of < or = 80 beat x min(-1) presenting for elective Caesarean section were randomly allocated to receive either glycopyrronium 2 microg x kg(-1) or normal saline intravenously once positioned for combined spinal-epidural anaesthesia. Following spinal injection of 2.6 ml hyperbaric bupivacaine 0.5% and fentanyl 15 microg, women randomly allocated to the saline group were given 6 mg ephedrine so that all parturients received some prophylaxis against hypotension other than the fluid preload. Further ephedrine and fluid boluses were administered if mean arterial pressure fell 20% or more from resting values. Using a sequential analysis technique, analysis after the first 20 subjects indicated the study should be stopped, with no difference in ephedrine requirements or hypotension between the groups. We conclude that pretreatment with glycopyrronium 2 microg x kg(-1) is no more effective than 6 mg ephedrine in preventing hypotension following subarachnoid block in parturients with relatively low resting heart rates.

Forms were sent to members of the Obstetric Anaesthetists' Association requesting information on car-diorespiratory disease in pregnancy. Reports of 274 pregnancies in 259 women were received over four years (1997–2000). There were 83 valve lesions, 52 complex congenital heart disease, 112 miscellaneous heart disease and 27 respiratory disease. Half the mothers were classified as New York Heart Association grade I, 29% grade II, 14% grade III, 5% grade IV and six unknown. Thirty-nine mothers were seen by an anaesthetist only just before delivery. Regional analgesia for labour was more likely to be planned for severe (82%) than for mild symptoms (55%; P =0.039), but severity of symptoms did not affect choice of anaesthesia for caesarean section. Eighty-one women were delivered by elective caesarean section, 59 by emergency caesarean section, 82 had spontaneous and 49 assisted vaginal delivery. Three women suffered miscarriages. Regional analgesia was used in 73% of vaginal deliveries, Entonox® or pethidine in 15% and no analgesia in 12%. Spinal anaesthesia was used in 21% of caesarean sections, an incremental re-gional technique (incremental epidural or combined spinal-epidural) in 40% and general anaesthesia in 39%. Forty-three women were admitted to intensive care units electively and 10 unplanned. Ninety-five per cent survived pregnancy in the same state as antepartum, 2% deteriorated and seven died. Ninety-four per cent of babies (258 babies) were delivered in good condition, nine in poor condition and seven died. Despite lack of denominator data and potential biases among the reported cases, the Registry provides a valuable snapshot of current practice in the UK.

Unfractionated heparin is widely used for prophylaxis against venous thromboembolism after Caesarean section. We performed a survey of thromboprophylactic methods after elective Caesarean section in 50 maternity units in the United Kingdom. We found that a variety of regimens were used. Thirteen (26%) used subcutaneous unfractionated heparin at standard (non-pregnant) doses. We then studied anti-Xa activity in women following elective Caesarean section under regional anaesthesia. Initially, eight women were given 5000 U unfractionated heparin subcutaneously after surgery and anti-Xa activity was measured 1, 2, 3, 4, 5, 6, 8 and 10 h after administration. There was no detectable anti-Xa activity in any of the samples so the dose was increased to 7500 U in a further five women and a single anti-Xa assay performed at 3 h when peak activity should occur. Again, no activity was detected so the dose was increased to 10 000 U heparin in a final group of 10 women and anti-Xa activity measured at 0.5, 1, 1.5, 2, 3, 4, 5 and 6 h. Although there was some activity after 10 000 U heparin, the level was below that accepted for prophylaxis. If anti-Xa activity is an appropriate monitor of prophylactic unfractionated heparin, doses up to 10 000 U are inadequate. Since there is evidence that enoxaparin is effective at producing adequate prophylactic anti-Xa activity following Caesarean section, we suggest abandoning the use of unfractionated heparin in favour of enoxaparin for this purpose.

Nitrous oxide (N 2 O) has been used for obstetric analgesia for over a century, although there is wide regional variation. In the UK, it remains one of the most commonly used forms of analgesia in labour despite little objective evidence of its efficacy. Most of its side effects are theoretical and transient and this has contributed to its popularity. N 2 O forms part of the routine general anaesthetic technique for Caesarean section and gynaecological surgery although there are theoretical risks in its usage for the latter. Despite the decline in use of N 2 O for anaesthesia generally, there appears to be no obvious replacement for N 2 O analgesia for labour.

Five patients with valvular or fixed subvalvular aortic stenosis presented to a high-risk obstetric anaesthetic clinic over a 3-year period. All five were assessed during pregnancy and admitted at full term. A low-dose lumbar epidural analgesia regimen was used during labour and delivery. The use of pre-assessment and planned admission, invasive monitoring, epidural analgesia and interventional assisted delivery is discussed with reference to this patient group, and other aspects of peripartum management of concern to the anaesthetist.

We conducted a prospective randomised study to compare the intubating laryngeal mask tracheal tube with a standard tube, for ease of tracheal intubation over a fibrescope. Thirty-six patients were investigated, using a sequential analysis technique. Ease of intubation was improved when the intubating laryngeal mask tracheal tube was used compared with the standard tube (p = 0.0009). Median (interquartile range [range]) intubation times (time from the tube's tip being level with the patient's teeth to successful placement) were 1.5 (1–2.3 [1–3]) s when the intubating laryngeal mask tracheal tube was used and 5 (3–7.3 [3–13]) s when the standard tube was used (p

We conducted a prospective double-blind randomised trial to compare bupivacaine 0.5%; a 50 : 50 mixture of bupivacaine 0.5%/lignocaine 2% with 1 : 200 000 adrenaline (final concentration); and lignocaine 2% with 1 : 200 000 adrenaline for converting a low-dose labour epidural into a block adequate for emergency Caesarean section. Ninety patients were studied, 30 in each group. There was no difference between the groups in the time taken for bilateral loss of cold sensation to reach T4. Onset time was unaffected by the existing sensory level pre-Caesarean section top-up; the number of low-dose top-ups in labour; the total dose of bupivacaine in labour; or maternal weight or height. Three patients in the lignocaine with adrenaline group had blocks that reached the cervical dermatomes and three in the same group required general anaesthesia for inadequate anaesthesia, compared with none in the other groups (both p = 0.04).

Analgesia, Anaesthesia and Pregnancy focuses on pre-empting problems and maximising quality of care. Every chapter of this well-established practical guide has been completely updated and revised. All aspects of obstetric medicine relevant to the anaesthetist are covered, from pre-pregnancy management to conception, throughout pregnancy, to postnatal care. The authors have identified over 150 potential complications, each covered in two parts: 'problems/special considerations' and 'management options', with key points prominently displayed for quick reference. A section on organisational aspects such as record keeping, training protocols and guidelines makes this an important resource for any labour ward or hospital dealing with pregnant women. Presented in a clear, structured format, this practical summary will be invaluable to any anaesthetist encountering obstetric patients, whether they are a practiced consultant or still in training. It will also be useful for obstetricians, neonatologists, midwives, nurses and operating department practitioners wishing to extend or update their knowledge.