A comparison of intramuscular diamorphine and intramuscular pethidine for labour analgesia: a two-centre randomised blinded controlled trial.

OBJECTIVE: Intramuscular (i.m.) pethidine is used worldwide for labour analgesia and i.m. diamorphine usage has increased in the UK in the last 15 years. This trial aims to ascertain the relative efficacy and adverse effects of diamorphine and pethidine for labour pain. DESIGN: Prospective, parallel-arm randomised controlled trial with blinding of participants, care-givers and outcome assessors. SETTING: Maternity units in two District General Hospitals in the UK. POPULATION: After written informed consent, 484 women were randomised and recruited (244 diamorphine, 240 pethidine). Inclusion criteria included women 16 years or older, established labour, singleton pregnancy, 37-42 weeks of gestation and weight 60-120 kg. METHODS: On request of i.m. analgesia, participants received either 150 mg pethidine or 7.5 mg diamorphine based on computer-generated block randomisation. MAIN OUTCOME MEASURES: Maternal-reduction in pain intensity from baseline (10-cm visual analogue scale) at 60 minutes and over the 3-hour period after drug administration. Neonatal-requirement for resuscitation and Apgar score at 1 minute. RESULTS: Diamorphine provided modestly improved pain relief at 60 minutes, mean difference 1 cm (95% confidence interval [CI] 0.5-1.5), and over the 3 hours, mean difference 0.7 cm (95% CI 0.3-1.1). However, average length of labour in women receiving diamorphine was 82 minutes longer (95% CI 39-124) and therefore they experienced more pain overall. There were no statistically significant differences in primary neonatal outcomes. CONCLUSIONS: There is a modest difference between the analgesia provided by diamorphine or pethidine for labour analgesia but diamorphine is associated with significantly longer labours.

A national survey of obstetric early warning systems in the United Kingdom: five years on.

The Confidential Enquiries into Maternal Deaths in the UK have recommended obstetric early warning systems for early identification of clinical deterioration to reduce maternal morbidity and mortality. This survey explored early warning systems currently used by maternity units in the UK. An electronic questionnaire was sent to all 205 lead obstetric anaesthetists under the auspices of the Obstetric Anaesthetists' Association, generating 130 (63%) responses. All respondents reported use of an obstetric early warning system, compared with 19% in a similar survey in 2007. Respondents agreed that the six most important physiological parameters to record were respiratory rate, heart rate, temperature, systolic and diastolic blood pressure and oxygen saturation. One hundred and eighteen (91%) lead anaesthetists agreed that early warning systems helped to prevent obstetric morbidity. Staffing pressures were perceived as the greatest barrier to their use, and improved audit, education and training for healthcare professionals were identified as priority areas.

Informed consent for epidural analgesia in labour: a survey of UK practice.

Anaesthetists are legally obliged to obtain informed consent before performing regional analgesia in labour. A postal survey of consultant-led UK anaesthetic units was performed in September 2007 to assess practice regarding obtaining informed consent before inserting an epidural, and documentation of the risks discussed. The response rate was 72% (161/223). There was great variation between units regarding which risks women were informed about and the likely incidence of that risk. One hundred and twenty-three respondents out of 157 providing an epidural service (78%) supported a national standardised information card endorsed by the Obstetric Anaesthetists' Association, with all the benefits and risks stated, to be shown to all women before consenting to an epidural in labour.

Is preparation for emergency obstetric anaesthesia adequate? A maternal questionnaire survey.

BACKGROUND: Women are often unprepared for emergency obstetric procedures and need to receive information about anaesthesia quickly and succinctly. In the absence of previous studies, we sought feedback from women to find out how information was given, and particular areas of concern in order to define practice and improve women's experiences. METHODS: After Ethics Committee approval this prospective structured questionnaire study was conducted in a teaching and a district general hospital. Women were recruited up to 48 h after anaesthesia. RESULTS: Of 102 women studied, 55 had no prior knowledge of obstetric anaesthetic interventions and risks until told, usually by the obstetrician (n=47), just before the procedure. The most frightening aspect was anticipating the efficacy of regional anaesthesia (n=18), but 28 women were reassured by the explanation provided by the anaesthetist. All but two women expressed satisfaction with the content of information and the described attendant risks. Nevertheless, in contrast to our observed practice, 51 (50%) would have preferred having verbal information before labour preferably from an anaesthetist or midwife. CONCLUSIONS: Most women were unprepared for emergency obstetric anaesthesia. Many received information just before the event. After delivery they expressed a clear preference for earlier information.

Vital signs and other observations used to detect deterioration in pregnant women: an analysis of vital sign charts in consultant-led UK maternity units.

BACKGROUND: Obstetric early warning systems are recommended for monitoring hospitalised pregnant and postnatal women. We decided to compare: (i) vital sign values used to define physiological normality; (ii) symptoms and signs used to escalate care; (iii) type of chart used; and (iv) presence of explicit instructions for escalating care. METHODS: One-hundred-and-twenty obstetric early warning charts and escalation protocols were obtained from consultant-led maternity units in the UK and Channel Islands. These data were extracted: values used to determine normality for each maternal vital sign; chart colour-coding; instructions following early warning system triggering; other criteria used as triggers. RESULTS: There was considerable variation in the charts, warning systems and escalation protocols. Of 120 charts, 89.2% used colour; 69.2% used colour-coded escalation systems. Forty-one (34.2%) systems required the calculation of weighted scores. Seventy-five discrete combinations of 'normal' vital sign ranges were found, the most common being: heart rate=50-99beats/min; respiratory rate=11-20breaths/min; blood pressure, systolic=100-149mmHg, diastolic ≤89mmHg; SpO2=95-100%; temperature=36.0-37.9°C; and Alert-Voice-Pain-Unresponsive assessment=Alert. Most charts (90.8%) provided instructions about who to contact following triggering, but only 41.7% gave instructions about subsequent observation frequency. CONCLUSION: The wide range of 'normal' vital sign values in different systems suggests a lack of equity in the processes for detecting deterioration and escalating care in hospitalised pregnant and postnatal women. Agreement regarding 'normal' vital sign ranges is urgently required and would assist the development of a standardised obstetric early warning system and chart.

Written information about epidural analgesia for women in labour: did it improve knowledge?

There is evidence that despite a distressed appearance, women in labour should be informed about the side effects and risks associated with epidural analgesia. An audit of 100 women who had used epidural analgesia for labour in our hospital and who had received a verbal explanation of the benefits, risks and side effects of epidural analgesia showed that the level of knowledge was low. An A5 laminated epidural information card was prepared summarising this information. The midwife and the anaesthetist used the card during labour as a focus for verbal discussion and as written reinforcement for the woman and her partner. A repeat audit of a further 100 women showed a statistically significant improvement in the level of knowledge about epidural analgesia. This audit suggests that the use of a written information card is beneficial. It improves and reinforces the process of giving information thus assisting the consent process.

Obstetric anaesthesia training in the Wessex region before and after introduction of Calman training.

We canvassed the opinions of anaesthetic trainees by questionnaire in 1995 and 1998, before and after the introduction of Calman training in which the registrar and senior registrar grades were replaced by the specialist registrar grade. We received replies from 106 trainees in 1995 (90%) and 115 (92%) in 1998. The survey results demonstrate that the total experience in obstetric anaesthesia gained by trainees has not decreased. Experience of regional techniques (epidural, spinal and combined spinal-epidural) increased, but the proportion of senior trainees who had performed fewer than 20 general anaesthetics for caesarean section rose from 0/23 in 1995 to 4/33 (12%). In 1998, the majority of senior trainees had experience of general anaesthesia for fetal distress, severe preeclampsia, eclampsia and massive obstetric haemorrhage. Only a minority had experienced failed intubation or a total spinal. In 1995, 5/21 (24%) of senior house officers agreed or strongly agreed that they were on call before they felt confident about dealing with common problems. The proportion was still 4/23 (17%) in 1998.

A national survey of obstetric early warning systems in the United Kingdom.

BACKGROUND: Despite recommendations in the two most recent Confidential Enquiries into Maternal and Child Health (CEMACH) reports, and improvements in patient care using early warning scoring systems (EWS) in the general adult population, no validated system currently exists for the obstetric population. METHODS: We performed an Obstetric Anaesthetists' Association (OAA) approved postal survey of all UK consultant-led obstetric anaesthetic units in November 2007 to assess opinions on the value and of such a system and how it could be implemented, and invited comments and samples of systems already in use. RESULTS: The response rate was 71%. Of those who replied a median usefulness score of 80% for a standardised national obstetric EWS was demonstrated. Eighty-nine percent of units thought it would be possible to implement a system, and although 96% of UK hospitals already use a non-obstetric EWS, only 23% of respondents thought this to be relevant to obstetric physiology and disease. Nine units returned copies of their obstetric EWS. Using extracts from some of the submitted versions we have designed and implemented a system locally and submitted it to the OAA for consideration. CONCLUSIONS: The survey results support CEMACH recommendations for a nationally agreed obstetric EWS.

Prescribing intramuscular opioids for labour analgesia in consultant-led maternity units: a survey of UK practice.

BACKGROUND: Intramuscular opioids are widely used for analgesia in labour. We conducted a postal survey to establish current prescribing and monitoring guidelines for intramuscular opioids in consultant-led obstetric units in the UK. METHODS: A postal questionnaire was sent between December 2005 and January 2006 to the lead obstetric anaesthetist of all 234 consultant-led obstetric units in the UK. We enquired about dose regimens of intramuscular opioids in labour and monitoring of mother, fetus and neonate. RESULTS: The response rate was 71%; 84.4% of responding units used pethidine and 34.1% diamorphine. Meptazinol and morphine were available in 13.8% and 13.2% of units respectively. Some units used more than one opioid. The choice of opioid was dictated mainly by tradition (65.3%) and familiarity (40.7%). Prophylactic antiemetics were co-administered in 73.7% of units, the most commonly used being prochlorperazine (30.5%). Vital signs were monitored in 91.6% of units: in total 10.2% measured haemoglobin oxygen saturations and 4.8% respiratory rate. Pain scores were recorded in 13.7% of units. CONCLUSIONS: When compared with previous studies the use of intramuscular diamorphine is increasing in UK consultant-led obstetric units, although pethidine remains the widely used opioid. At present this change cannot be justified by a suitably powered, randomised study comparing intramuscular pethidine with diamorphine.

Caesarean section in a patient with torsion dystonia.

We present a case of torsion dystonia in a 35-yr-old primigravida who presented for a Caesarean section under general anaesthesia. She had limb contractures and severe kyphoscoliosis associated with limited respiratory reserve and function. General anaesthesia was induced using thiopental and divided doses of mivacurium for rapid sequence induction. After the delivery of a healthy male baby, she received i.v. morphine and bilateral iliohypogastric, ilioinguinal blocks and had an uneventful recovery. Technical issues of supine positioning, intubation and respiratory support need to be considered during anaesthesia planning. Although regional anaesthesia is commonly offered for caesarean section, maternal compromise and technical factors may preclude this approach.

Obstetric anaesthetists' workload.

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.

Obstetric epidurals and chronic adhesive arachnoiditis.

It has been suggested that obstetric epidurals lead to chronic adhesive arachnoiditis (CAA). CAA is a nebulous disease entity with much confusion over its symptomatology. This review outlines the pathological, clinical, and radiological features of the disease. The proposed diagnostic criteria for CAA are: back pain that increases on exertion, with or without leg pain; neurological abnormality on examination; and characteristic MRI findings. Using these criteria, there is evidence to show that epidural or subarachnoid placement of some contrast media, preservatives and possibly vasoconstrictors, may lead to CAA. No evidence was found that the preservative-free, low concentration bupivacaine with opioid mixtures or plain bupivacaine currently used in labour lead to CAA.