The hidden cost of neuraxial anaesthesia?

In this month’s Anaesthesia, Syzpula and colleagues report on litigation related to regional anaesthesia over the period 1995–2007 [1]. Their study indicates that there was a total cost from litigation to the National Health Service of just over £1 million per year for the twelve-year period up to 2007. This may be compared with 62 claims involving drug administration errors over the same period that cost £4.3 million [2]. Unfortunately, as the authors recognise, the relative safety of regional anaesthesia cannot be determined from reports of this type because we do not know how many blocks were performed during the period examined, or the total number of complications arising from those blocks; we know only the number of complications that led to successful claims. Closed-claim analysis will tend to underestimate the true incidence of complications because not all patients who suffer complications will sue [3]. Furthermore, we cannot accurately establish the real severity of the complications, but must deal with only the Courts’ assessment of the financial impact of injuries. The costs awarded for obstetric regional anaesthesia claims (median £5 678) were higher than those awarded for non-obstetric regional anaesthesia claims (median £3 337). Neuraxial block accounted for all of the obstetric claims and 82% of the non-obstetric claims. The interpretation of these figures must be in the light of how the Courts determine the amount of money awarded in damages. Sums are awarded to compensate loss of earnings and requirement for ongoing care; thus, complications resulting in the death of a patient may not receive as great an award as those causing issues requiring ongoing, expensive care. However, the eight deaths that were recorded were awarded a median award of £42 000 (with a largest payment of £178 000), whereas the 68 severe complications received only £6 000 (but with a largest payment of £2 070 000); this may have been influenced by care needs for a child who may also have been injured. Interestingly, it may be observed that the severity of non-fatal complication did not correlate well with the amounts awarded, with the cost per case greater for moderate complications than for moderate/severe ones as assessed by the authors. When one turns to the type of regional anaesthesia performed, the results may be interpreted as sobering or encouraging, depending on which type of anaesthesia one practises. The total cost of damages following complications of neuraxial regional anaesthesia was £12 million, the cost for ophthalmic regional anaesthesia claims was £0.36 million and the cost for all other peripheral blocks excluding ‘unspecified’ was £0.12 million. This is partly related (see Table 3 in the authors’ manuscript) to the catastrophic complications that may occur following neuraxial anaesthesia. Perhaps surprisingly, damages awarded following lower limb blocks (£116 000) far exceeded those awarded following upper limb blocks (£1 000). The cost of awards related to central neuraxial blockade amounted to 89% of all regional anaesthesia claims. Of these, 81% were for complications related to epidurals (72% of all claims). One can only speculate on the reasons for these findings; perhaps, a greater number of epidurals are performed, complications occur more frequently and/or are more likely to be successfully settled following neuraxial blockade, or more simply, complications are less frequent following peripheral nerve blockade. The worrying possibility is that epidural anaesthesia is not as safe as we once thought. The Third National Audit Project of the Royal College of Anaesthetists on major complications following neuraxial block estimated the incidence of adverse sequelae following peri-operative epidural block at between 1 in 6000 and 1 in 12 000 and the incidence of paraplegia or death at approximately 1 in 100 000, which the authors of the report found reassuring [4]. The size of the awards presented by Szypula et al. serve as a reminder that although severe complications after neuraxial block are rare, when they do occur they have a major impact on patients’ lives. Brull and colleagues reviewed 32 studies primarily investigating neurological complications of regional anaesthesia [5]. The rate of both temporary and permanent neuropathy after spinal and epidural anaesthesia was 3.78:10 000 (95% CI 1.06–13.50:10 000) and 2.19:10 000 (95% CI 0.88–5.44:10 000), respectively. For peripheral nerve blocks, the rate of neuropathy after interscalene brachial plexus block, axillary brachial plexus block, and femoral nerve block was 2.84:100 (95% CI 1.33–5.98:100), 1.48:100 (95% CI 0.52–4.11:100), and 0.34:100 (95% CI 0.04–2.81:100), respectively. This might suggest that there is less risk of neurological complications following central neuraxial than peripheral blocks. However, they also stated that the rates of permanent neurological injury after spinal and epidural anaesthesia were 0–4.2:10 000 and 0–7.6:10 000, respectively, with only one case of permanent neuropathy reported in 16 studies of neurological complications after peripheral nerve blockade. This second statement probably reflects both the rare but serious sequelae following central neuraxial blockade and a high incidence of temporary neurological symptoms with very rare permanent neurological damage following peripheral block. This may have more relevance to patients and also in relation to successful damage claims. What conclusions should we draw from Szypula and colleagues’ report? Caution is certainly advisable, given the afore-mentioned lack of a denominator to lend context to the numerator provided. Caution is also advisable given that the real severity of claims is skewed to the Courts’ view of financial impact. However, we feel that it is wise to bear in mind the potentially major impact on patients’ lives of the complications related to regional, and in particular, epidural, anaesthesia. A large multi-centre Australian study of epidural analgesia following major surgery did not show the 20% reduction in mortality and morbidity it was powered to find, and patients in both the treatment and control (non-epidural) groups demonstrated low pain scores [6]. This may have influenced a reduction in epidural usage in Australia and New Zealand [7]. One cannot dispute the excellent dynamic analgesia that regional analgesia can provide postoperatively. However, now that epidural analgesia is routinely administered on the open ward, hypotension and failure are frequently encountered and its success relies on the presence of an efficient, on-site acute pain service to deal swiftly with these problems and other complications that occur. The paucity of clear evidence of benefit and risk relating to the use of peri-operative epidural analgesia means that anaesthetists should still make risk-benefit calculations for each patient. We should also perhaps be encouraged that the amount of damages awarded following peripheral regional anaesthetic blockade was so small. The evidence is limited here in much the same way as was discussed regarding epidurals: the lack of a denominator makes firm conclusions inadvisable. However, this evidence may provide further encouragement that peripheral nerve blocks result in few significant injuries. Finally, we would also emphasise the importance of informed consent before the performance of regional anaesthetic techniques and the recording of clear and detailed notes of any procedure performed. In the eyes of the Courts, it is not the occurrence of a complication that determines fault and the award of damages, but the failure to demonstrate that a responsible and appropriately cautious technique was employed. JGH provides medicolegal reports that sometimes concern regional anaesthesia.