Whose distress is it anyway? ‘Fetal distress’ and the 30‐minute rule

There can be few situations in obstetric anaesthesia as stressful as the request for anaesthesia to allow immediate delivery by Caesarean section of a severely stressed fetus. With the Caesarean section rate relentlessly increasing [1], it is important that the indications for surgery are continuously scrutinised; nowhere is this more the case than Caesarean section for fetal distress. To the anaesthetist, perhaps the most obvious manifestation of fetal distress is the prolonged, profound fetal bradycardia that strikes chill into the most hardy obstetric anaesthetic heart. However, defining fetal distress according to a severely abnormal fetal heart is not foolproof. First, what is meant by ‘severely abnormal’? Second, a normal fetal heart pattern may be associated with a poor neonatal outcome, whilst an abnormal fetal heart pattern may be associated with a good neonatal outcome [2]. Perhaps, then, we should take a step back and define fetal distress as severe fetal hypoxia or acidosis. But here, too, there are problems, as the link between fetal biochemistry and ‘birth asphyxia’ is artificial, and not only do most acidotic babies have Apgar scores greater than 7, but the neonatal pH is normal in most depressed babies [3, 4]. We are left, then, with rather less precise definitions of fetal distress, for example ‘whatever leads to a depressed neonate’– but there are many causes of neonatal depression other than acute intrapartum events, and not all can be identified antepartum [5]. Even defining fetal distress as merely an ill-defined indication for Caesarean section does not help; for example, in West Sussex between 1980 and 1999, over 80% of babies delivered by Caesarean section for ‘fetal distress’ had 1-min Apgar scores over 5, whilst 74% of those with scores under 5 did not have this diagnosis [6]. We are left with one possibility: fetal distress is really obstetric distress, and this exists whenever the obstetrician says so. Furthermore, obstetricians appear to be getting more distressed: in 1980 in West Sussex, ‘fetal distress’ was the indication for 6.4% of Caesarean sections whereas in 1999 it had risen to 13%[6], and in the national Sentinel survey of Caesarean sections carried in the UK in 2001, fetal distress – or rather, obstetric distress – accounted for 20–24%[7]. Apart from the possibility that Caesarean section may be unnecessary, fetal/obstetric distress has implications for anaesthesia and the anaesthetist. First, the apparent need for rapid delivery may result in use of general anaesthesia, with all its attendant risks, when a regional technique may have sufficed – and many of these may be done out of hours by trainees, working on their own [8]. Second, anaesthetists may contribute to delay in delivering the baby; for example, in a 3-year audit cycle in Bradford, anaesthetic delay was judged responsible for delivery times exceeding 50 min in 15 out of 721 cases overall (2.1%) [9]. In the Confidential Enquiry into Stillbirths and Deaths in Infancy (CESDI)'s report for 1994–95, delay of anaesthetic personnel or of anaesthesia was judged to have occurred in 21 out of 25 cases in which anaesthetists were involved [10]. The figure of 30 min for delivery of a distressed fetus (or rather, delivery of a fetus by a distressed obstetrician) is oft bandied about, even though it is well accepted that this interval is not useful, arising as it does from animal experiments in the 1969s, our love of round numbers, and consensus based on actual practice [11]. Indeed, even 10 min may be too long for some babies, e.g. in the presence of severe abruption. Despite this, and despite the superiority of clinical definitions over time-based descriptions of urgency [12], the obsession with meeting this arbitrary 30-min ‘standard’ continues. An aspect of the ‘golden half-hour’ that is rarely touched upon is nicely highlighted by O'Regan in this issue [13]– that is, when does the important interval actually start and finish? According to studies done by obstetricians and by CESDI, it is from the time the decision for Caesarean section is made to the time the baby is delivered [9–11, 14]. According to anaesthetists, at least anecdotally, it is from when the anaesthetist is informed to the time of delivery. Clearly, the argument goes: anaesthetists cannot be held responsible for delay that occurs before they have been made aware of the case – notwithstanding anaesthetists' duty to be available to receive such information and to be involved in improving communication in the maternity suite. The Obstetric Anaesthetists' Association and the Association of Anaesthetists of Great Britain & Ireland go one step further: 30 min should be the maximum between informing the anaesthetist and starting surgery[15], removing delay arising from difficult surgery. The pedant might suggest a more relevant ‘anaesthetic time’ as ending when the mother is in the operating theatre, ready for surgery, eliminating delay caused by a less than keen surgeon. Such chronological nit-picking has two harmful consequences. First, it reinforces the divisive ‘your fault not mine’ culture that so easily exists on the labour ward, and detracts from efforts to improve what is, after all, a team activity. Second, it increases the confusion that already exists over the ideal interval to delivery of a stressed fetus, and lends weight to reliance on meaningless and arbitrary ‘standards’. As O'Regan has shown, even in developing countries it is possible to improve teamworking and communication, and O'Regan should be congratulated for her excellent work in that environment. For audits of this type, time to surgery/delivery (however, defined) is a reasonable outcome to use – though measuring the actual times and then aiming to shorten them would be better than looking at the proportion of cases that meet an arbitrary target. But it would be better still to look at the entire process of care, including before the decision for surgery was formally made, and analysing areas where delays arose or decisions could have been improved. One thing is certain: continued use of the 30-min rule leaves everybody distressed.