Close co-operation between obstetricians and obstetric anaesthesia providers is crucial for the safety and comfort of parturients, particularly in low-resource environments. Maternal and foetal mortality is unacceptably high, and the practice of obstetric anaesthesia has an important influence on outcome. Well-conducted national audits have identified the contributing factors to anaesthesia-related deaths. Spinal anaesthesia for caesarean section is the method of choice in the absence of contraindications, but is associated with significant morbidity and mortality. Minimum requirements for safe practice are adequate skills, anaesthesia monitors, disposables and drugs and relevant management protocols for each level of care. The importance of current outreach initiatives is emphasised, and educational resources and the available financial sources discussed. The difficulties of efficient procurement of equipment and drugs are outlined. Guiding principles for the practice of analgesia for labour, anaesthesia for caesarean section and the management of obstetric emergencies, where the anaesthetist also has a central role, are suggested.
The role of the obstetric anaesthetist
Closer co-operation between obstetricians and obstetric anaesthetists is crucial if we are to improve maternal health and reduce maternal mortality by 75% between 1990 and 2015, as in the Millennium Development Goal 5. Obstetricians should appreciate that a well-trained obstetric anaesthetist not only provides safe analgesia and anaesthesia for labour and caesarean section, but also brings a detailed knowledge of the physiology of pregnancy and makes a crucial contribution in maternal and neonatal resuscitation and critical care, including training of obstetric colleagues. In low-resource settings, where workload is high, the anaesthetist has a vital role in identifying co-morbidities that often affect outcome. Together with the obstetrician, the anaesthetist contributes to decisions regarding referral of critically ill patients to the appropriate level of care. Obstetric anaesthesia has become a highly sophisticated subspecialty in the developed world. However, in low-resource settings, maternal and foetal morbidity and mortality remain extremely high. This review examines the principles of interventions required to improve obstetric anaesthesia practice in limited-resource settings, which would greatly improve maternal and foetal outcome. There is little level-one evidence emanating from the developing world upon which to base recommendations, and it is difficult to extrapolate from the enormous volume of literature generated in the developed world. Some randomised trials, surveys, observational studies and expert opinion do however provide a reasonable basis for suggested interventions.
The review focusses on sub-Saharan Africa, the world’s most poverty-stricken area, where nearly 50% of people subsist on less than $1 per day, and the Human Development Index is less than 0.5.
Maternal mortality
The World Health Organization estimates that 515 000 women die every year from pregnancy-related causes, predominantly in developing countries. The lifetime risk of dying during pregnancy is one in six in the poorest parts of the world, due to a high incidence of severe pre-eclampsia, cardiac disease and infectious diseases such as tuberculosis, malaria and HIV/AIDS.
After the first significant reductions in maternal mortality in the late 19th century in Europe and USA, there were still 441 maternal deaths per 100 000 births by 1934. This was reduced to 87 per 100 000 by 1950. Currently, in the USA, United Kingdom, Western Europe and Australia, maternal mortality is low (7–9.8 per 100 000 births). Current mortality per 100 000 births is 150 in South Africa, 600 in the severely under-resourced areas of West Africa and 740 in Nepal. Effectively, there is a 150-fold difference in maternal mortality between Sierra Leone and the United Kingdom. Obstetric haemorrhage is the most common cause of maternal death worldwide, causing 166 000 deaths per annum, with half of these in sub-Saharan Africa.
Hypertensive disorders, obstructed labour and infection, including post-abortion, are the other major causes of death, most of which are preventable. There is a strong relationship between maternal death and poverty: in Indonesia, 33% of deaths occur among women from the poorest quintile of the population. In summary, the current global maternal mortality is approximately 400 per 100 000 deliveries, with a range of 7–740 deaths per 100 000, demonstrating the inequality between the rich and poor countries.
Maternal mortality
The World Health Organization estimates that 515 000 women die every year from pregnancy-related causes, predominantly in developing countries. The lifetime risk of dying during pregnancy is one in six in the poorest parts of the world, due to a high incidence of severe pre-eclampsia, cardiac disease and infectious diseases such as tuberculosis, malaria and HIV/AIDS.
After the first significant reductions in maternal mortality in the late 19th century in Europe and USA, there were still 441 maternal deaths per 100 000 births by 1934. This was reduced to 87 per 100 000 by 1950. Currently, in the USA, United Kingdom, Western Europe and Australia, maternal mortality is low (7–9.8 per 100 000 births). Current mortality per 100 000 births is 150 in South Africa, 600 in the severely under-resourced areas of West Africa and 740 in Nepal. Effectively, there is a 150-fold difference in maternal mortality between Sierra Leone and the United Kingdom. Obstetric haemorrhage is the most common cause of maternal death worldwide, causing 166 000 deaths per annum, with half of these in sub-Saharan Africa.
Hypertensive disorders, obstructed labour and infection, including post-abortion, are the other major causes of death, most of which are preventable. There is a strong relationship between maternal death and poverty: in Indonesia, 33% of deaths occur among women from the poorest quintile of the population. In summary, the current global maternal mortality is approximately 400 per 100 000 deliveries, with a range of 7–740 deaths per 100 000, demonstrating the inequality between the rich and poor countries.
The influence of obstetric anaesthesia on maternal mortality
Obstetric anaesthesia practice has had an important influence on maternal mortality. Early awareness of the risks of pulmonary aspiration resulted in widespread acceptance of rapid sequence induction techniques. This initially resulted in an increase in direct anaesthesia-related maternal mortality, reaching 20 per million deliveries in the triennium 1967–1969 in the United Kingdom, due to failed intubation. Subsequent interventions, such as better training, supervision, sub-specialisation and a greater awareness of the particular risks posed by the pregnant woman, resulted in improved safety of general anaesthesia. Since 1985, maternal death rates attributable to anaesthesia in the United Kingdom have fallen to four or less per million deliveries. In the most recent report, anaesthesia was the eighth most common direct cause of death (six deaths from a total of 261). This represents a very low mortality. Indeed, a calculation based upon an assumption of a natural mortality of 1% in the absence of medical care shows that 19 714 lives were saved by the obstetric medical team during the triennium 2000–2002 in the United Kingdom (the difference between the expected maternal deaths (19 975) and the actual deaths (261). In the USA, during the period 1984–2002, the case fatality rate for general anaesthesia has decreased from 32.3 to 6.5 per million, while the rate for regional anaesthesia has increased from 1.9 to 3.8 per million (Hawkins, ASA 2008).
In the developing world, it can be stated with certainty that anaesthesia-related mortality is much higher, despite the fact that the denominator data are often unknown. A retrospective study of anaesthesia mortality in Zimbabwe (1994–2001) reported an avoidable mortality rate of 1:482 anaesthetics, with an operative obstetric mortality of 1:293 cases.
The Confidential Enquiry into Maternal Deaths (CEMD) in South Africa, initiated in 1998, currently constitutes the best evidence for anaesthesia-related mortality in a low-resource environment. During the triennium 1999–2001, there were 56 deaths attributable to anaesthesia (versus two in the United Kingdom). Of these, 31 were related to general and 25 to spinal anaesthesia. In the subsequent triennium (2002–2004), 62 of a total of 3296 maternal deaths were attributable to anaesthesia. Anaesthesia ranked as the seventh most common direct cause of maternal mortality. Accurate denominator data are unavailable. The 74 direct anaesthesia deaths reported in the latest triennium (2005–2007) represent only 0.03% of all maternal deaths. However, since most anaesthesia-related deaths were deemed preventable, anaesthesia contributed 6% of all preventable deaths.
Factors contributing to anaesthesia mortality
The CEMD in the United Kingdom has clearly shown the factors contributing to anaesthesia mortality in a First World environment. Such valuable audits lead to recommendations and monitoring of their effectiveness; “the audit loop is closed.” Clearly, implicated factors are inexperience of the anaesthetist, failed airway management, obesity and the administration of oxytocin. The increasing proportion of patients managed under regional anaesthesia, together with the reduction of hours worked by trainees, may result in decreased skill levels of anaesthesia providers in the performance of general anaesthesia.
Predisposing factors to anaesthesia mortality may be similar in the developing countries in Africa. In a study in a Nigerian tertiary hospital, 6 of 84 maternal deaths, out of 12 394 deliveries during 10 years, were due to anaesthesia. These were attributable to failed airway management, inadequate supervision of junior anaesthetists and insufficient monitoring. In the CEMD in South Africa for the triennium 1999–2001, the most common cause of death during general anaesthesia was failed intubation. There were four deaths due to pulmonary aspiration. Errors related to the performance of general anaesthesia included repeated attempts at intubation without adequate ventilation, the administration of repeated doses of suxamethonium and the performance of general anaesthesia by inexperienced staff after the prior identification of a Mallampati grade 4 airway. Twenty-one patients died due to haemodynamic instability or high block levels during spinal anaesthesia.
In the rest of sub-Saharan Africa, combined perioperative mortality for caesarean section is high (1–2%). Most deaths are avoidable and one-third of them are attributable to anaesthesia, predominantly due to airway problems.
In the developed world, improvements in obstetric anaesthesia safety have been attributed in part to the increased use of regional anaesthesia. However, the CEMD in South Africa for the latest triennium (2005–2007) reported 74 direct anaesthesia deaths, of which 53 were associated with spinal and 18 with general anaesthesia. Although denominator data are not known, the use of spinal anaesthesia has increased significantly since the previous triennium, and 93% of deaths due to spinal anaesthesia were deemed avoidable. Contributing factors included inappropriate case selection, and inadequate management of hypotension or high motor block, including failed intubation in one case [ http://www.doh.gov.za , accessed July 2009]. Thus, spinal anaesthesia in inexperienced hands is also associated with significant maternal mortality.
Minimum requirements for safe obstetric anaesthesia
In an important recent initiative, a questionnaire explored the problems faced by anaesthetists in low-resource settings. The results are intended to guide national anaesthesia societies and health authorities to improve anaesthesia services, to make better use of limited resources and identify areas requiring support from the World Federation of Societies of Anaesthesiologists (WFSA). Minimum requirements for the provision of safe anaesthesia, including general and spinal anaesthesia for caesarean section, are defined. Key areas investigated in the questionnaire, piloted in Zambia, Malawi and Uganda, include training, access to educational sources, workload, general facilities, drugs and equipment. Severe deficiencies were identified in all areas, to the extent that obstetric anaesthesia could be labelled as frankly unsafe.
A fundamental assumption is that, to reduce maternal mortality, there should be rapid access to effective emergency obstetric and anaesthesia care. The requirements for safe practice of obstetric anaesthesia are as follows:
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Skills, in the form of adequately trained staff and educational resources.
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Appropriate anaesthesia monitors, disposables and drugs.
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Relevant management protocols for each level of care, with supervision and audit.
Level of training of health professionals
Caesarean section rates are less than 1% for the poorest populations in 20 countries, despite the WHO recommendation of a caesarean section rate of 5–10%. This is partly due to inadequate provision of anaesthesia.
In general, very few qualified anaesthetists choose to work in rural areas. In India, for example, only 10% of community health centres and 22% of first-referral units have an anaesthetist on site.
It behoves every government to pass legislation concerning the level of competence required for the particular situation, guided by national anaesthesia societies. In India, there are ”no explicit, detailed written policies, rules or regulations specifying who is allowed to do what level of medical procedures, including obstetrical and anaesthesia procedures.” In the First World, as exemplified by the United Kingdom, recent proposals to change the structure of postgraduate medical training will result in an initial exposure to obstetric anaesthesia at an even more senior level than the present. In South Africa, the demands of under-resourced areas are such that much less experienced physician anaesthesia providers administer obstetric anaesthesia.
Following the first two CEMD triennium findings in South Africa, an investigation conducted in a rural area, where mortality was higher than the national average, showed that only 3% of 105 doctors giving obstetric anaesthesia in 2005 were specialist anaesthetists. Most doctors had been trained in anaesthesia for 4 weeks or less, and in 13% of respondents, this did not include obstetric anaesthesia. A significant proportion of doctors were not capable of administering both spinal and general anaesthesia. Subsequently, there has been a marked increase in undergraduate anaesthesia teaching, and legislation has resulted in 2 months of compulsory supervised anaesthesia training as part of a 2-year internship. Only a medical doctor may administer anaesthesia, and a separate practitioner is required for anaesthesia and surgery.
Certified registered nurse anaesthetists performing unsupervised anaesthetics do have a role to play in obstetric anaesthesia in low-resource settings, particularly in remote parts of Africa, where there is no possibility of adequate staffing by medical practitioners. However, inadequate training may result in a high mortality –1 in 150 anaesthetics in one recent report, of which 50% were obstetric. A study of 7150 caesarean sections in Malawi, in which paramedical clinical officers administered anaesthesia, documented a perioperative mortality rate of 0.95%. All available evidence suggests that it is desirable to aim for a physician-anaesthetist-based obstetric service.
Incentives must be created for the retention of doctors in peripheral areas, or medical migration will continue to take its toll.
Availability of educational sources and financial support
Low-resource environments are increasingly dependent on educational support from the developed world. The World Federation of Societies of Anaesthesiologists (WFSA) was established in 1955 and currently comprises 120 National Societies. Its objective is to “make available the highest standard of anaesthesia to all peoples throughout the world.” This is done by facilitating education, encouraging research and establishing safety measures. The influence extends to pain management, trauma and resuscitation via various committees and working parties.
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Outreach to provide regular refresher courses and seminars on basic obstetric anaesthesia topics is essential. An example of the value of outreach visits and personnel exchanges with underprivileged areas is the charitable ‘Mothers of Africa’ project, a link between the departments of anaesthesia in Togo and Benin and the University of Wales. Seminars, lectures, workshops and in-theatre teaching have been provided to 140 nurse anaesthetists, who provide most anaesthesia services, assisted by approximately 15 physician-anaesthetists. Further collaboration between organisations such as the Association of Anaesthetists of Great Britain and Ireland, its International Relations Committee, and WFSA has created valuable outreach opportunities. International non-profit organisations such as Kybele aim to improve childbirth conditions throughout the world by forming medical education partnerships [ http://www.kybeleworldwide.org ]. An example of their work is a recent visit by 12 anaesthetists from the USA, UK, Canada, Belgium and Australia to Croatia, which resulted in significant increases in the use of regional anaesthesia in obstetrics.
‘Health Links’ have been established between northern institutions, such as the Tropical Health and Education Trust, and southern hospitals in some of the poorest countries in the world. When needs have been identified by the southern partner, a long-term programme of staff development is initiated, including anaesthesia services. The Department for International Development of the UK assists poor countries financially by forming partnerships with governments and public health organisations.
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Guidelines appropriate for the specific conditions of the area and type of practice are important for improving safety.
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Educational material has many sources. Textbooks have traditionally been a major source of information for First World anaesthetists. However, these are expensive, rapidly become outdated and the information supplied is often not directly applicable to practice in the developing world. In a recent survey in Africa, only 48% of anaesthesia providers had access to a textbook. Broadband Internet connections in the major centres should improve access to relevant information in low-resource areas. Several books are now available which deal with anaesthesia from the perspective of the developing world. The launching of the World Anaesthesia Society website [ http://www.worldanaesthesia.org ] in January 2007 has provided a means for sharing of information and experience worldwide. Education is facilitated by the online publication of Anaesthesia Tutorial of the Week , and Update in Anaesthesia. Teaching Aids at Low Cost (TALC) [ http://www.talc.org ] is another organisation that provides low-cost teaching materials, including access to seven anaesthesia textbooks.
Anaesthesia trainers themselves require refresher courses, educating them to administer skill courses such as the Advanced Trauma and Life Support (ATLS), and Managing Obstetric Emergencies and Trauma (MOET), which are of enormous benefit for anaesthetists and obstetricians. In South Africa, a current similar initiative is ESMOE (Essential Steps in the Management of Obstetric Emergencies). A recent review examines the components of effective training in obstetric emergencies, and emphasises teamwork training in combination with clinical teaching and the use of simulation models.
Equipment, consumables and drugs
There are no current international standards for the exact requirements for the provision of safe anaesthesia, in terms of equipment, consumables, monitoring and drugs. The most recent recommendations are those of the WFSA in 1993. Anaesthesia equipment must be appropriate for the particular circumstances. The often unsolicited donation of equipment results in an array of common problems, including inadequate training in its use, a lack of maintenance facilities and unavailability of manuals or spare parts. This has contributed to ‘equipment graveyards’ in the developing countries. In environments where compressed gases and/or electricity are not reliably available, continuous-flow anaesthesia cannot be supplied, and therefore draw-over anaesthesia is required. The Oxford Miniature Vaporiser functions reliably in both continuous-flow (plenum) and draw-over modes. However, oxygen supplementation is highly recommended in anaesthesia practice, particularly as many low-resource areas are significantly above sea level. Commercially available oxygen concentrators have reduced dependence upon cylinder gas supplies, and newer concentrators can pressurise air and thus drive a ventilator or rota meter. This facility has been employed in the Glostavent machine, which functions in either draw-over or continuous-flow mode. The machine has an oxygen concentrator, a gas-driven ventilator, a low-resistance vaporiser, a draw-over breathing circuit, an uninterruptible power supply and a reserve oxygen cylinder. In a field trial, 21 machines were distributed in Zambia, Mozambique and Malawi from 2001 to 2003 and were assessed by the users as easy to operate, versatile and safe. Malfunction was rare and of a minor nature. The oxygen concentrator resulted in large savings to the hospitals involved.
Ethical issues arise in donating single-use items, which will be re-used, and date-expired items. A good example is that of spinal needles for caesarean section, where the alternative to using a date-expired needle is general anaesthesia. The WHO has established ‘Guidelines for Healthcare Equipment Donations’.
Atraumatic spinal needles are to be encouraged; in Ghana, an incidence of 33% of mild-to-moderate post-dural puncture headache was found when 22 G Quincke needles were used.
The basic minimum requirement for monitoring in obstetric anaesthesia consists of either electrocardiogram (ECG) or pulse oximetry. Pulse oximetry is highly recommended and may be of greater benefit than ECG in this patient population with its low incidence of ischaemic heart disease. ‘Global oximetry’ is an initiative recently launched in Uganda, the Philippines, India and Vietnam to encourage the use of pulse oximetry and reduce costs in low-resource areas. This is a major objective of the Safety and Quality of Practice Committee of the WFSA. The WHO has launched a pilot study on the effects of pulse oximetry in areas where its use is currently limited.
Blood pressure monitoring is mandatory, preferably using an automated non-invasive device. Capnography is recommended for general anaesthesia during caesarean section to confirm tracheal intubation and maintain normocarbia before delivery. An oxygen analyser is mandatory, and agent monitoring would be an added benefit to avoid awaking during caesarean section.
Table 1 is in line with WFSA ‘basic’ equipment requirements, with some additions specific to obstetric anaesthesia.
| Equipment | Minimum | Optimum |
|---|---|---|
| Major operating theatre |
|
|
| Intravenous (IV) access and infusions |
|
|
| Tracheal intubation |
|
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| Manual ventilation |
| |
| Additional requirements for spinal anaesthesia |
| Atraumatic spinal needles (25 G, 90 and 120 mm), with introducers |
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