Why Mothers Die — Report on Confidential Enquiries into Maternal Deaths in the United Kingdom 1994–96

Abstract

This is the fifteenth Report in this series on maternal deaths and is the fourth reporting on deaths in the UK as a whole. Since the first Report included Anaesthesia as an entity in 1952, obstetric anaesthetists in most parts of the world have used the data as benchmarks of safety of anaesthetic and analgesic procedures administered in pregnancy. In those 50-odd years, anaesthesia in pregnancy and the puerperium has undergone a transformation from general anaesthesia with ether, chloroform or cyclopropane to today's low-dose, regional techniques which have minimal impact on maternal mortality. In the ‘Anaesthesia’ section of the Report (Chapter 9), there is one Direct death, which is discussed below. Eight of the nine mortalities associated with anaesthesia received general anaesthesia; all had serious pre-existing medical conditions and, on the data provided, at least two of these could have had regional anaesthesia, which reflects a lack of planning and/or early communication between obstetricians, physicians and anaesthetists. It is most distressing therefore to see an increase in the absolute numbers of Direct and Indirect deaths in this Report. Of the 268 Direct and Indirect deaths in this triennium, 67 are due to improved case ascertainment. The new baseline maternal mortality rate of 12.2 per 100 000 maternities contrasts with 9.8 per 100 000 in the previous Report [1]. The fact remains that substandard care is the real message of this Report. The Report highlights many interesting features of present-day obstetric practice. One is the increasing numbers of Caesarean deliveries, now up to 30% in some specialised units. Ninety-three deaths were associated with Caesarean section compared with 98 in the 1991–93 Report. It is unfortunate therefore that the traditional chapter on Caesarean sections has been omitted. Another is increasing maternal age, and with it the incidence of diseases and complex medical problems, all of which complicate anaesthesia, especially in emergencies. For women 35 years or older, the Caesarean section rate is now 25%. For primiparas it is 33% (Table 1). Recent publicity concerning Caesarean section ‘on demand’ may increase these rates further [2]. Caesarean-hysterectomy is also increasing in frequency in line with the increased prevalence of abdominal delivery, and is often predictable. The chance of hysterectomy increases almost exponentially with the number of previous Caesarean sections [3], so it goes without saying that women at risk of repeat Caesarean section should be cared for by experienced consultants. Management plans, including anaesthesia, should be formulated and documented during the last trimester. With increasing maternal age and intervention rates, such as induction of labour and Caesarean delivery, and rising demands for labour analgesia it is clear that the 20-year-old recommendation for one consultant anaesthetist session per 500 deliveries is no longer adequate [4]. Whilst general anaesthesia has not been directly responsible for any deaths in this triennium, it is associated with many deaths, all of which patients were seriously ill. Although no denominator data for anaesthesia are available for the country as a whole, it is widely recognised that in the UK the use of general anaesthesia for delivery has declined to a small percentage of all obstetric anaesthesia. Indeed, obstetric anaesthetists, exhorted by the recommendations in previous Reports, other audits and studies, have striven successfully to minimise the use of general anaesthesia, which today is largely reserved for only those cases where regional methods are contraindicated or considered to be more hazardous. This Report reflects that trend. It is axiomatic therefore that the sole, Direct anaesthetic death should have been caused by a regional technique. This tragic death, like the epidural death in the previous triennium [1], is yet another reminder that regional techniques, improperly administered, can be as hazardous as any other anaesthetic procedure. Combined spinal-epidural (CSE) anaesthesia was first reported in 1937 [5], and has been extensively researched and developed to the point where it is now in widespread use throughout the world. Along with the use of synergistic, low-dose mixtures of local anaesthetics and opioids, and the introduction of fine-gauge, pencil-point spinal needles, CSE is being increasingly recognised as an important addition to the armamentarium of the anaesthetist. ‘The CSE technique offers many advantages over continuous epidural or subarachnoid methods alone, not the least of which are a reduction in drugs dosage, the ability to eliminate motor blockade and to achieve highly selective sensory blockade and optimal analgesia. These features hold great promise for minimising the hazards and side-effects of traditional epidural or intrathecal catheter techniques’ [6]. In obstetrics, CSE is used for analgesia and anaesthesia, in both the delivery suite and th