Anaesthesia, 2010, 65, pages 443–452 doi:10.1111/j.1365-2044.2010.06248.x .....................................................................................................................................................................................................................
ORIGINAL ARTICLE
Litigation related to regional anaesthesia: an analysis of claims against the NHS in England 1995–2007* K. Szypula,1 K. J. Ashpole,2 D. Bogod,3 S. M. Yentis,4 R. Mihai,5 S. Scott5 and T. M. Cook6 1 Specialist Trainee and 3 Consultant, City Hospital Campus, Nottingham University Hospitals NHS Trust, Nottingham, UK 2 Locum Consultant and 4 Consultant, Magill Department of Anaesthesia, Chelsea and Westminster Hospital NHS Foundation Trust, London, UK 5 Consultant, Department of Anaesthesia, John Radcliffe Hospital, Oxford, UK 6 Consultant, Department of Anaesthesia, Royal United Bath Hospital, Bath, UK Summary
We analysed 366 claims related to regional anaesthesia and analgesia from the 841 anaesthesiarelated claims handled by the National Health Service Litigation Authority between 1995 and 2007. The majority of claims (281 ⁄ 366, 77%) were closed at the time of analysis. The total cost of closed claims was £12 724 017 (34% of the cost of the anaesthesia dataset) with a median (IQR [range]) of £4772 (£0–28 907 [£0–2 070 092]). Approximately half of the claims (186 ⁄ 366; 51%) were related to obstetric anaesthesia and analgesia and of the non-obstetric claims, the majority (148 ⁄ 180; 82%) were related to neuraxial block. The total cost for obstetric closed claims was £5 433 920 (median (IQR [range]) £5678 (£0–27 690 [£0–1 597 565]) while that for nonobstetric closed claims was £7 290 097 (£3337 (£0–31 405 [£0–2 070 062]). Non-obstetric claims were more likely to relate to severe outcomes than obstetric ones. The maximum values of claims were higher for claims related to neuraxial blocks and eye blocks than for peripheral nerve blocks. Despite many limitations, including lack of clinical detail for each case, the dataset provides a useful overview of the extent, patterns and cost associated with the claims. . ......................................................................................................
Correspondence to: Dr K. Szypula E-mail:
[email protected] *Presented in part at the Regional Anaesthesia Great Britain and Ireland Annual Meeting, London, May 2008; the Obstetric Anaesthetists’ Association Annual Meeting, Belfast, May 2008; and the European Society of Regional Anaesthesia Annual Meeting, Genoa, September 2008. Accepted: 28 December 2009
The use of regional anaesthesia and analgesia (both central neuraxial and peripheral techniques) has become routine practice, both for surgical and obstetric procedures. Such techniques may be associated with multiple benefits whether used as an alternative or in addition to general anaesthesia, including superior postoperative analgesia and potentially reduced morbidity and mortality [1–5]. Complications resulting from various regional techniques have been well described [6–9], and studies of insurance 2010 The Authors Journal compilation 2010 The Association of Anaesthetists of Great Britain and Ireland
claims related to regional anaesthesia in Canada, Finland and the USA have been published, with detailed analysis of specific patterns of injury and legal liability [10–13]. Similar information regarding UK practice is lacking, and to the best of our knowledge the pattern of litigation related to regional anaesthesia and analgesia in the UK has not been reported before. The National Health Service Litigation Authority (NHSLA) is a Special Health Authority responsible for 443
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handling both clinical and non-clinical negligence claims on behalf of the NHS bodies in England. Their Clinical Negligence Scheme for Trusts (CNST) is a voluntary risk pooling scheme to which all NHS Trusts in England currently belong. The NHSLA database contains details of clinical claims where the allegedly negligent incident took place on or after 1 April 1995, although before 2002 some minor claims were managed by hospitals locally without notification to the NHSLA. This study analyses all claims from the NHSLA database related to regional anaesthesia and analgesia that occurred between 1995 and March 2007. The aims of the analysis were to highlight areas of high litigation risk and to report the financial impact of the claims. We also briefly compare the differences between neuraxial blocks placed for obstetric and non-obstetric indications. Methods
Data on negligence claims related to anaesthesia were requested and obtained from the NHSLA in May 2007, via their ‘freedom of information’ portal. These included all clinical negligence claims notified to the CNST that occurred between April 1995 and March 2007 filed under ‘anaesthesia’. A detailed description of the data review and classification process has been previously reported [14]. In brief, the data returned were in the form of an anonymous spreadsheet that included information on the financial year of the incident and the claim, whether the case was open (ongoing) or closed (settled or withdrawn), a brief clinical description of the case, the cost to the NHS of the claim, and the specialties involved in the claim. The dataset also contained a classification of the cause of the incidents, the injury type and the location of the incident, but these were found to be inconsistent and therefore unreliable so were not used in sorting or subsequent analyses. The clinical details available for each claim were very limited. Further clinical information was requested from the NHSLA, but was not available for any claim. The cost associated with a closed claim as described in the NHSLA database is the cost of defending a claim, including legal fees (both claimant and defence) and the cost of any settlement, but excluding the cost of the NHSLA itself. The dataset did not contain the information required to determine the proportions of claims successfully defended, or settled in or out of court. Neither were the proportions of claim cost allocated to legal fees and patient settlement available. All financial settlements, unless stated otherwise, were adjusted using the Retail Price Index to 2006 monetary values (the year of the most recent closed claim in the dataset) so that
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settlements in different years could be directly compared with each other [15]. Each claim was initially analysed independently by three investigators (TC, RM, and SS), in order to classify cases according to clinical category and severity. Claims that were clearly not related to anaesthesia, and those that were related purely to intensive care or management in a pain clinic, were excluded from further analysis. Claims with too little clinical detail for any useful interpretation were also excluded. The remaining claims were subdivided into a number of non-exclusive categories including obstetric anaesthesia (including analgesia), regional anaesthesia, inadequate anaesthesia, drug-related excluding allergy, drug allergy, central venous cannulation, peripheral venous cannulation, consent problems, positioning problems and miscellaneous. Each case was also assigned a severity score, based on the NPSA tool for grading severity of patient incidents (Appendix 1) [16]. Due to lack of detail in clinical descriptions, two intermediate severity categories were added: mild ⁄ moderate and moderate ⁄ severe. The results of the independent assessments by the three investigators were then combined. If there was disagreement regarding inclusion, category or severity score, the case was discussed further until agreement was reached. Further investigators were recruited to analyse individual clinical categories, and a final dataset was agreed in April 2008. It is important to appreciate that the NHSLA database is not a clinical or risk database, but was set up for claim and financial management, with very limited clinical detail available. The detailed examination of each claim and exclusions as described aimed to improve the quality and robustness of the data available to us. The type of regional block involved and the basis of the claim were obtained from the brief description of the incident. The authors sorted the claims into clinical categories according to the major ‘damaging event’ as described in the clinical description (Appendix 2). In cases where two or more ‘damaging events’ were evident, the claim was categorised under the most serious complaint. Claims in the regional anaesthesia category, obstetric and non-obstetric, were analysed both quantitatively and qualitatively. The quantitative analysis was performed to determine the cost associated with regional anaesthesia claims. The qualitative assessment was performed in an attempt to highlight areas of clinical practice that might be considered of high medicolegal risk. MICROSOFT EXCEL (Version 5.0; Microsoft Corporation, Redmond, WA, USA) was used throughout the project, and data were analysed using simple descriptive statistical tests.
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Results
The NHSLA database contained 1067 reports. In total 226 cases were removed from further analysis, because they were clearly not anaesthesia-related or contained inadequate information (n = 196), or were related purely to intensive care (n = 13) or pain clinics (n = 17). The final dataset contained 841 anaesthetic claims. Regional anaesthesia was the single largest clinical category in the dataset with 366 (44%) claims, of which 186 (51%) were obstetric and 180 (49%) non-obstetric. Of the 366 cases included in this analysis, 281 ⁄ 366 (77%) were closed at the time when the data were provided. The severity of claimed outcome and cost of the claims is reported in Table 1. Compared to the whole anaesthesia dataset regional anaesthesia contains a somewhat higher percentage of claims of severe outcome, but fewer claims of a fatal outcome [14]. Table 2 shows the types of regional block cited in claims relating to regional anaesthesia and analgesia. The maximum cost of claims was higher for those related to neuraxial and eye blocks compared with peripheral nerve blocks. The total cost associated with regional anaesthesia was £12 724 017, with a median (IQR [range]) of £4772
(£0–28 907 [£0–2 070 092]). Fatal outcome was associated with the highest median cost, but the maximum cost of a claim relating to a severe outcome was more than 10 times the highest cost of a fatal outcome (Table 1). Closed claims associated with a severe outcome accounted for fewer than 20% of closed claims but almost half their cost. There were 28 claims with an associated cost above £100 000 (Table 3); 26 followed neuraxial blockade, of which 9 (35%) were obstetric and 17 (64%) non-obstetric. Table 4 demonstrates trends in the cost of claims per year. Ninety-two percent of cases (338) were notified to the NHSLA within 3 years of the incident and 99% (362) within 4 years. Table 5 shows the frequency of the ‘damaging events’ for the 366 regional anaesthesia claims. Of the 326 neuraxial claims, 264 (81%) were related to epidurals. Overall, the most frequent ‘damaging event’ was nerve damage (76 claims), followed by inadequate block with resulting pain (24 claims), and back pain (24 claims). Other ‘damaging events’ included: injury related to sensory block, such as burns and pressure sores (23 claims); dural tap (18 claims); epidural haematoma (eight claims); drug error (eight claims); and high block ⁄ hypotension (eight claims). There were 17 claims related to infection, including epidural abscess (seven claims), spinal abscess
Table 1 Distribution of severity in claims reported to the NHSLA (1995–2007) relating to regional anaesthesia or analgesia. Values are number (proportion) or median (IQR [range]).
Severity of outcome
Claims
Closed claims
Claims leading to cost
Total cost; £000
Cost per case; £000
Death Severe Moderate ⁄ severe Moderate Mild ⁄ Moderate Mild Unclassified Total
8 68 17 83 74 102 14 366
7 50 9 61 60 85 9 281
6 37 7 46 41 45 6 188
420 6313 651 2190 1262 1015 873 12 724
42 6 3 8 2 1 8 5
(2%) (19%) (5%) (23%) (20%) (28%) (4%) (100%)
(88%) (74%) (53%) (73%) (81%) (83%) (64%) (77%)
(86%) (74%) (78%) (75%) (68%) (53%) (67%) (67%)
(3–99 [0–178]) (0–73 [0–2070]) (1–149 [0–337]) (0–60 [0–184]) (0–21 [0–376]) (0–15 [0–171]) (0–31 [0–782]) (0– 29 [0–2070])
Table 2 Claims reported to the NHSLA (1995–2007) relating to regional anaesthesia or analgesia, according to the type of block. Values are number (proportion) or median (IQR [range]).
Type of block
Claims
Closed claims
Closed claims leading to cost
Total cost; £000
Cost per claim; £000
Epidural Spinal CSE Eye Upper limb Lower limb Paravertebral Splanchnic Unspecified
264 54 8 12 6 4 1 1 16
206 38 8 10 2 4 0 0 13
131 (64%) 26 (68%) 7 (88%) 8 (80%) 2 (100%) 2 (50%) N⁄A N⁄A 12 (92%)
8074 3016 958 361 1 116 N⁄A N⁄A 199
2 (0–23 [0–2070]) 14 (0–41 [0–1598]) 82 (6–269 [0–376]) 24 (7–33 [0–184]) 0.5 [0–1] 6 (0–58 [0–105]) N⁄A N⁄A 7 (3–21 [0–78])
(72%) (15%) (2%) (3%) (2%) (1%)
(4%)
(78%) (70%) (100%) (83%) (33%) (100%)
(81%)
CSE, combined spinal-epidural anaesthesia 2010 The Authors Journal compilation 2010 The Association of Anaesthetists of Great Britain and Ireland
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Table 3 Closed claims with cost exceeding £100 000 in 366 claims reported to the NHSLA (1995–2007) relating to regional anaesthesia or analgesia. Values are actual amounts. Obstetric cases are indicated by *. Year of claim
Cost; £000
Clinical details Spinal haematoma in relation to epidural analgesia for bowel surgery, leading to paraplegia Needle inserted into wrong position during spinal anaesthesia for removal of retained placenta* Neurological damage following epidural for knee replacement Cardiac arrest and brain damage following epidural local anaesthetic overdose Paraplegia following labour epidural analgesia* Neurological damage following CSE* Neurological damage following spinal anaesthesia Pain and weakness in leg and back following damage to nerve roots during epidural via ‘needle through needle technique’* Epidural morphine overdose Spinal cord damage following cervical epidural Globe perforation during peribulbar block Epidural haematoma leading to paraplegia Difficult ⁄ failed spinal Spinal infarct after prophylactic saline infusion for dural puncture following labour epidural* Epidural haematoma leading to paraplegia Epidural analgesia for laparotomy. Pressure sore on heel and permanent nerve lesion Spinal anaesthetic complicated by cord damage, leading to permanent disability* Delay in diagnosis of epidural ‘ulcer’ Pain during hysterectomy under spinal anaesthesia Spinal abscess complicating epidural insertion, leading to permanent disability Labour epidural complicated by dural puncture, leading to ongoing backache and hearing problems* Nerve damage following spinal anaesthetic for elective caesarean section* Temporary paralysis in relation to epidural anaesthesia for hiatus hernia repair Nerve damage during CSE* Nerve root trauma during CSE, resulting in persistent pain and hypersensitivity Nerve damage after femoral ⁄ sciatic block for knee replacement, leading to permanent disability Cervical epidural complicated by dural puncture and cord damage Neurological damage following epidural for arterial bypass
1999 2000 2000 2000 2001 1998 2001 1999
⁄ 2000 ⁄ 2001 ⁄ 2001 ⁄ 2001 ⁄ 2002 ⁄ 1999 ⁄ 2002 ⁄ 2000
2070 1598 782 597 398 376 337 269
2002 1997 2004 2000 1999 1999 2001 1998 1997 2002 2002 1997 2001 1999 1999 2000 2000 1999 2001 2002
⁄ 2003 ⁄ 1998 ⁄ 2005 ⁄ 2001 ⁄ 2000 ⁄ 2000 ⁄ 2002 ⁄ 1999 ⁄ 1998 ⁄ 2003 ⁄ 2003 ⁄ 1998 ⁄ 2002 ⁄ 2000 ⁄ 2000 ⁄ 2001 ⁄ 2001 ⁄ 2000 ⁄ 2002 ⁄ 2003
269 251 184 178 171 166 165 159 143 142 139 133 130 130 129 120 108 105 101 100
CSE, combined spinal-epidural anaesthesia
Table 4 Claims reported to the NHSLA (1995–2007) relating to regional anaesthesia or analgesia, according to the year of the incident. Values are number (proportion) or median (IQR [range]).
Year 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
⁄ 1996 ⁄ 1997 ⁄ 1998 ⁄ 1999 ⁄ 2000 ⁄ 2001 ⁄ 2002 ⁄ 2003 ⁄ 2004 ⁄ 2005 ⁄ 2006
Claims
Closed claims
Closed claims leading to cost
Total cost; £000
Cost per claim; £000
18 20 20 34 39 37 54 48 51 27 16
17 19 19 33 38 33 45 36 28 11 2
13 17 16 24 30 19 28 23 15 2 2
925 1563 660 2823 3534 1306 1091 413 338 58 15
6 44 9 14 5 2 5 3 1 0 8
(94%) (95%) (95%) (97%) (97%) (89%) (83%) (75%) (55%) (41%) (13%)
(two claims), meningitis (two claims) and other infection (five claims). Of the 54 (17%) claims related to spinal anaesthesia, the three most frequent ‘damaging events’ were inadequate block (21 claims), nerve damage (13 claims), and drug error (three claims). Seven out of the eight claims related to combined spinal-epidural anaesthesia (CSE) were of alleged nerve damage. 446
(76%) (89%) (84%) (73%) (79%) (58%) (62%) (64%) (54%) (18%) (100%)
(0–38 [0–376]) (2–142 [0–269]) (0–47 [0–178]) (0–40 [0–2070]) (0–32 [0–1598]) (0–27 [0–597]) (0–15 [0–337]) (0–14 [0–75]) (0–13 [0–184]) (0–0 [0–42]) ([2–14])
Of the 12 (3%) claims arising from ophthalmic regional anaesthesia, globe perforation was the ‘damaging event’ in 10 cases, with resultant loss of vision and ⁄ or need for further surgery. The six (2%) claims arising from upper limb regional anaesthesia comprised intravenous injection (two claims), pneumothorax (two claims), neurological damage (one 2010 The Authors Journal compilation 2010 The Association of Anaesthetists of Great Britain and Ireland
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claim) and infection from an indwelling axillary catheter (one claim). The four (1%) claims arising from lower limb blocks all related to neurological damage. There were 12 claims in which fatality was recorded as the coded injury sustained. This equates to approximately one claim related to death in this group, each year. Eleven claims cited an epidural and one an eye block. All deaths were related to non-obstetric regional anaesthesia. After consideration of the limited description of the incidents, outcome was classified as ‘death’ only if the investigators considered that the death was a direct consequence of the incident. This resulted in eight of these 12 outcomes classified as ‘death’, three as ‘severe’, and one as ‘mild ⁄ moderate’. The number (proportion) of claims leading to cost was similar for obstetric (103 ⁄ 186; 55%) and non-obstetric (85 ⁄ 180; 47%) claims, respectively. The total cost for obstetric closed claims was £5 433 920 (median (IQR [range]) £5678 (£0–27 690 [£0–1 597 565]) and for non-obstetric closed claims, £7 290 097 (£3337 (£0–31 405 [£0–2 070 062]). Neuraxial block accounted for all of the obstetric claims and 148 ⁄ 180 (82%) non-obstetric claims of claims. In 8 ⁄ 186 (4%) of the obstetric claims the exact type of block involved was indeterminate. Nonobstetric neuraxial claims were more likely to relate to severe outcomes than obstetric ones. Tables 5–7 provide an overview of the differences between the obstetric and non-obstetric claims. The most frequent damaging events for the obstetric neuraxial claims were inadequate block (pain during caesarean section or labour) (57 claims), nerve damage (39 claims) and back pain (19 claims); for the non-obstetric claims these were nerve damage (58 claims), infection (16 claims) and drug error (10 claims).
Table 5 Damaging events (proportion) in 366 claims reported to the NHSLA (1995–2007) relating to regional anaesthesia or analgesia.
Nerve damage Pain* Back pain Injury related to sensory block Dural tap Infection† Drug error Globe perforation Epidural haematoma Injury related to motor block Indeterminate Other
All claims n = 366
Non-obstetric n = 180
Obstetric n = 186
105 63 26 23
(29%) (17%) (7%) (6%)
66 6 7 7
(37%) (3%) (4%) (4%)
39 57 19 16
20 18 13 10 8 7
(5%) (5%) (4%) (3%) (2%) (2%)
9 17 10 10 8 3
(5%) (9%) (6%) (6%) (4%) (2%)
11 (6%) 1 3 (2%) N⁄A 0 4 (2%)
25 (7%) 48 (13%)
7 (4%) 30 (17%)
(21%) (31%) (10%) (9%)
18 (10%) 18 (10%)
*Including intra-operative pain, pain during labour, and postoperative. †Including epidural abscess, spinal abscess, meningitis, sepsis, wound infection and other.
Table 6 Severity of outcome in 334 claims reported to the NHSLA (1995–2007) relating to neuraxial regional anaesthesia or analgesia. Values are number (proportion).
Death Severe Moderate ⁄ severe Moderate Mild ⁄ Moderate Mild Unclassified
Obstetric n = 186
Non-obstetric n = 148
0 19 5 41 49 67 5
8 37 11 31 23 30 8
(10%) (3%) (22%) (26%) (36%) (3%)
(5%) (25%) (7%) (21%) (16%) (20%) (5%)
Discussion
The principal finding of this analysis of claims in the NHSLA dataset relating to regional anaesthesia and analgesia is that they are responsible for 44% of claims and a similar proportion of the cost of the overall anaesthesia dataset. Eighty-nine per cent of the claims involve neuraxial blocks, predominantly epidurals. Our analysis has a number of limitations. A detailed account of these limitations is provided elsewhere [14]. As previously noted, the function of the NHSLA database is to allow financial management of claims, and the clinical information available for each case is therefore severely limited. The clinical information is a very brief account of the alleged incident and lacks verification of actual clinical details and outcome, as well as characteristics of the patient and their ASA and CEPOD status. Inclusion in the database does not mean that the described clinical 2010 The Authors Journal compilation 2010 The Association of Anaesthetists of Great Britain and Ireland
events are accurate. We found the NHSLA coding of type of injury, location and speciality to be of little value; in many cases it did not correlate with the clinical description. More than 10% of cases were misclassified as ‘anaesthesia’, which raises the question of how many claims actually related to anaesthesia were also misclassified and therefore not included in the dataset provided to us. The data available on the cost of claims included the cost of claimant as well as defence legal services, but not the cost of the NHSLA itself, and we were unable to obtain the breakdown of cost into legal fees and patient awards, nor determine the proportion of cases which were settled out of court. The NHSLA database does not contain any denominator data, nor any details of adverse events that did not lead to initiation of a claim. As a result, estimates of risk of litigation for regional anaesthesia in 447
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Table 7 Claims reported to the NHSLA (1995–2007) relating to neuraxial anaesthesia or analgesia, according to the type of block. Values are number (proportion) or median (IQR [range]). Claims with indeterminate type of block (n = 16) have been excluded.
Obstetric
Non-obstetric
Type of block
Claims
Closed claims
Closed claims leading to cost
Total cost; £000
Cost per claim; £000
Epidural Spinal CSE Total Epidural Spinal CSE Total
139 35 4 178 125 19 4 148
115 23 4 142 91 15 4 110
75 17 4 96 56 9 3 68
2198 2322 822 5342 5876 694 136 6706
3 20 195 5 2 2 14 2
(78%) (20%) (2%) (100%) (84%) (13%) (3%) (100%)
(83%) (66%) (100%) (80%) (73%) (79%) (100%) (74%)
general or for specific regional anaesthesia procedures cannot be made directly from these data. Our analysis is likely to underestimate the number of regional anaesthesia cases in the dataset since, unless there was clear evidence that a case was related to regional anaesthesia, it was excluded from our analysis. Finally, over the 11-year database period, there have been changes in anaesthetic practice and standards. Despite the above limitations, analysis of the NHSLA claims related to regional anaesthesia or analgesia is valuable, by disclosing the type of regional block involved, the severity and the financial risk of such claims in the NHS in England. It is potentially useful at various organisational levels. Firstly, by highlighting areas of apparently high medicolegal risk, it may help professional organisations, including trusts and those who advise them, to direct development of guidelines regarding safe practice and risk avoidance. Secondly, it is potentially very useful to individual clinicians, by demonstrating the type of cases that lead to medicolegal claims, and the nature of those claims. For example, the fact that almost 10% of claims included allegations of lack of consent may act as an impetus to anaesthetists to consider how best to deliver and document information about the risks and benefits of regional blocks [17]. In general terms, there was a tendency for cost to rise with increased severity. This is in keeping with expectations, and suggests that our assessment of severity was not grossly inaccurate for the regional anaesthesia claims [14]. However, caution is needed when assuming a close correlation between cost and severity of damage. While the award to the patient might reasonably be expected to reflect the harm that they have experienced, the far from trivial legal cost component of the overall sum is often related to whether the negligence claim proceeds to a full hearing or is settled out of court. This is more likely to depend on the merits of the claim, specifically whether there is clear failure of duty of care and causation, rather than being related to degree of harm. Overall the NHSLA 448
(65%) (74%) (100%) (68%) (62%) (60%) (75%) (62%)
(0–28 [0–398]) (0–45 [0–1598]) (104-322 [56–376]) (0–28 [0–1598]) (0–35 [0–2070]) (0–37 [0–337]) (14-18 [0–108]) (0–35 [0–2070])
spends slightly more on legal fees (51% in 2007) than on patient settlements (49%) [18]. Regional anaesthesia accounts for the largest number of claims in the full ‘anaesthesia’ dataset (44%), and, of these claims, approximately half are obstetric. Regional anaesthesia is also the group with the highest overall cost. However, it does not have the highest cost per claim; the groups with the highest mean cost per claim are respiratory, central venous cannulation and drug error excluding allergy [14]. These data cannot provide an estimate of risk of litigation due to the lack of denominator data. While it is not known how many anaesthetics are administered in the UK or in England per year it has been estimated that 7.2–8 million surgical procedures are carried out in England each year (http://www.npsa.nhs. uk/corporate/news/safe-surgery-saves-lives/ (accessed 22 ⁄ 04 ⁄ 2009)) [19], and the 3rd National Audit Project of the Royal College of Anaesthetists (NAP3) has established that approximately 700 000 neuraxial blocks are performed in the NHS in the UK each year [6]. These data strongly suggest that the number of claims related to regional anaesthesia is disproportionately high. The results may be taken to suggest that there is a decrease in the number of claims for the years 2003 onwards. However, the time from the incident occurring to claim notification was up to 10 years. Only 10% of claims were registered within 1 year of the incident, and 8% were registered more than 3 years after the incident. Therefore data for the years 2003 onwards are almost certainly incomplete, and very unlikely to reflect a true downward trend. Indeed, the broader NHSLA data suggest that the number of claims is probably increasing [18]. The review of the Canadian Medical Protective Association claims for the period 1990–1997, by Peng and Smedstad, identified 310 cases involving anaesthetists, of which 61 cases (20%) were related to (obstetric and non-obstetric) regional anaesthesia [10]. The authors reported that approximately two thirds of closed claims 2010 The Authors Journal compilation 2010 The Association of Anaesthetists of Great Britain and Ireland
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were related to neuraxial blockade (n = 42), with eye blocks the most commonly cited peripheral nerve block (n = 7 ⁄ 19), accounting for 12% of all regional claims. There were no deaths in the regional anaesthesia group. In a review from the American Society of Anesthesiologists Closed Claims Project (ASACCP), Lee et al. [12] reviewed injuries associated with regional anaesthesia for the period 1980–1999. Of 5047 claims in that period, just under 20% (n = 1005) were related to regional anaesthesia and analgesia, including obstetrics. Of the neuraxial anaesthesia claims, 368 (45%) cases were obstetric and 453 (55%) non-obstetric. Of the 453 non-obstetric neuraxial anaesthesia claims, 143 (32%) led to death ⁄ brain damage, 117 (26%) to permanent nerve injury and 172 (38%) to temporary nerve injury. Peripheral nerve blocks accounted for 13% of all regional anaesthesia claims, and 21% of the non-obstetric claims, while regional anaesthesia of the eye (45 ⁄ 1005) accounted for 4% of all regional anaesthesia claims. In the NHSLA dataset, claims relating to eye blocks represented 3% (12 ⁄ 366) of regional anaesthesia claims, comparable to the ASACCP data, but significantly less than in the Canadian dataset. In the North American reviews retrobulbar and peribulbar blocks had been used in the majority cases. During the period of the NHSLA dataset it is likely that such blocks have decreased with a commensurate increase in sub-Tenon’s blocks and topical (eye-drop) anaesthesia. While these techniques might be anticipated to lead to a reduction in the number of complications and negligence claims [20], with seven of 12 claims occurring in the second half of the dataset there is no evidence of such an effect to date. Compared to these two North American anaesthesia datasets the data presented here have approximately twice the proportion of claims relating to regional anaesthesia. This may reflect a greater reliance on regional blocks in UK practice. Of note, the North American analyses cover an earlier period than the NHSLA data and the use of regional anaesthetic and analgesic techniques has probably increased in the early years of the 21st century, due to greater appreciation of the benefits of these techniques [21] and the development of new techniques for successful siting of regional blocks [22]. The different legal systems might also contribute to this discrepancy: in the USA litigation with low value claims (e.g. < $50 000) is less likely to be encouraged in the ‘no-win no fee’ system, while in England, where all legal costs are sometimes provided by the state, the likelihood of low value claims is perhaps increased [23]. As the regional anaesthesia group contains a relative excess of low severity, low value claims, this group would be most affected by such a trend.
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Claims arising from obstetric neuraxial regional anaesthesia were associated with a lower proportion of severe injuries and death than non-obstetric claims and more mild-moderate injuries (Table 6). Despite similar numbers of claims in the two subsets, the total cost was lower in the obstetric group, due to a larger number of claims related to lower severity harm. A similar picture is seen in the obstetric claims in the ASACCP, where the majority of claims were also less severe [13]. This highlights the importance of tackling relatively small events ⁄ incidents as well as major ones in order to reduce the financial burden of obstetric anaesthetic claims on the NHS. The distribution of the type of regional anaesthesia involved was similar in the obstetric and non-obstetric groups. Inadequate regional anaesthesia leading to pain during surgery or labour was the most common ‘damaging event’ in the obstetric group with 57 (31%) claims; in comparison there were only two cases with intra-operative pain as the main ‘damaging event’ in the non-obstetric group. Pain during caesarean section under regional anaesthesia was classified as ‘mild’ or ‘moderate’ (where post-traumatic stress disorder was cited) harm and these cases in particular contribute to the high frequency of low severity claims seen with obstetric anaesthesia. The relatively large proportion of claims relating to pain during caesarean section suggests a need to improve intra-operative management of regional anaesthesia for these. The cost (and, we speculate, the settlements) associated with the second most frequent damaging event, nerve injury, was considerably greater than the cost associated with inadequate anaesthesia. There was a wide spectrum of claimed injury, from paraesthesia and mild injuries to cases of paraplegia. Nerve injury (most being temporary and ⁄ or non-disabling) is now the most frequent damaging event in the ASACCP for obstetric anaesthesia [13], having previously been the third commonest cause [24]. Notably only a third of ASACCP claims relating to nerve injury received payments, compared with over three-quarters of similar NHSLA closed claims. In the ASACCP, the most frequent cause of maternal death between 1990 and 2003 was high neuraxial block, accounting for 22% of maternal deaths in the obstetric dataset overall and 37% of deaths related to regional anaesthesia [11]. The majority (80%) were epidural related (10 accidental intrathecal catheters and two high blocks). The NHSLA dataset included no deaths associated with high obstetric regional anaesthetic blocks, though in the last four Confidential Enquiries into Maternal Deaths triennial reports there were two direct anaesthetic deaths related to high neuraxial blocks: one following a CSE in the 1994–1996 report and one epidural in the 1997–1999 report [25–28].
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Recently, NAP3 has helped to define the risks of neuraxial blockade and has also provided robust denominator data on the number of neuraxial blocks performed in the NHS in the UK [6]. The results of NAP3 have been described, by its authors (one also an author of this paper), as ‘largely reassuring’. Out of the 700 000 cases, the ‘pessimistic’ point estimate of incidence of permanent injury was 1 in 24 000 and of paraplegia or death was 1 in 55 000. Of note, peri-operative epidurals were associated with the highest incidence of adverse sequelae (with point estimates of between 1 in 6000 and 1 in 12 000). In the NHSLA dataset, epidural block was responsible for more than two-thirds of all claims; but, due to limited clinical data, we were unable to determine the proportion of claims related to permanent nerve damage or paraplegia. It is also possible that the term ‘epidural’ has been used generically for other procedures such as spinal, caudal or CSE techniques: this would artificially increase the proportion of claims filed under ‘epidural’. Spinals accounted for over 40% of neuraxial blocks in NAP3, and yet there were only 54 (15%) claims related to spinal anaesthesia in the current dataset. This suggests that spinal anaesthesia is a procedure associated with a relatively low risk of litigation. There is much current interest in wrong-route errors in neuraxial block and their potential solutions. NAP3 highlighted nine cases (six in obstetrics) of wrong-route injection errors, where a drug planned for neuraxial administration was accidentally injected intravenously, or vice versa. There was one clear wrong-route error involving the wrong drug administered into an epidural catheter (in obstetric theatre recovery) and three others that may have been wrong-dose or wrong-route errors (one theatre based and two ward-based, all non-obstetric) [29]. There were no claims relating to accidental intravenous administration of epidural drugs, nor of the wrong drug given intrathecally. This small number of wrong-route claims contrasts markedly with recent reports [6, 30]. Surveys of lead obstetric anaesthetists in the UK suggest that drug errors are relatively common [30, 31], with almost one in four UK obstetric units surveyed in September 2006 having knowledge of a recent wrong-route error in their department [30]. This mismatch between errors and litigation may be explained by incorrect classification of claims but, if this is not so, other possibilities are that few patients involved in such incidents are harmed or that disproportionately few proceed to litigation. Recent events make this unlikely to be sustained. The current dataset highlights some high medicolegal risk areas where claims may be avoidable, but, with the limited clinical data, a detailed analysis of system and human factors is not possible. However, in many areas it 450
is evident there are potential solutions to reduce risk of patient harm and litigation. Examples include: appropriate informed consent for regional anaesthesia with documentation of the risks discussed; improved intra-operative care to eliminate pain from inadequate regional anaesthesia (particularly in obstetric practice); and perhaps improved postoperative surveillance to prevent, or allow early active management of, sequelae. Drug errors may be reduced by improvements both in design of delivery systems and systems for drug checking. While analysis of the present data has enabled documentation of the broad patterns of litigation in this area, the quality of the data on which the analysis is based prevents both genuine closed claim analysis and root cause analysis. A communication pathway between the NHSLA (and other UK-based bodies) and anaesthetists that improved the extent and quality of review of these cases would enable detailed analysis of claims and better identification of patterns resulting from system error, and enable resultant change in practice to minimise patient harm and litigation. This would logically be beneficial for clinicians, the NHSLA itself and ultimately for patients. In conclusion, we have examined the existing data held by the NHSLA on claims related to regional anaesthesia in England. The dataset provides an overview of the extent, patterns and cost associated with the claims. The data suggest that claims associated with regional anaesthesia are proportionately more likely in England than North America. Non-obstetric claims appear to be of greater severity and are associated with higher cost than obstetric claims. Factors frequently associated with litigation include epidurals, nerve injury, inadequate anaesthesia, obstetrics and, to a lesser extent, ophthalmic blocks. However, the data analysed have considerable limitations and the potential lessons that might be learnt from a genuine closed claims analysis are not achievable from these data. Introduction of a UK-wide closed claims analysis system would overcome many of the limitations of the NHSLA dataset, and would be beneficial to the NHS, anaesthetists and patients. Acknowledgement
We are grateful to Ms Ruth Symons of the National Health Service Litigation Authority for assistance with the dataset. References 1 Ballantyne JC, Carr DB, deFerranti S, et al. The comparative effects of postoperative analgesic therapies on pulmonary outcome: cumulative meta-analysis of randomised controlled trials. Anesthesia and Analgesia 1998; 86: 598–612. 2010 The Authors Journal compilation 2010 The Association of Anaesthetists of Great Britain and Ireland
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Appendix 1
Appendix 2
National Patient Safety Agency severity of outcome scale, for patient safety incidents. Severity grade
Description
None
No harm (whether lack of harm was due to prevention or not) Minimal harm necessitating extra observation or minor treatment* Significant, but not permanent harm, or moderate increase in treatment† Permanent harm due to the incident‡ Death due to the incident
Low Moderate Severe Death
*First aid, additional therapy or additional medication. Excludes extra stay in hospital, return to surgery or readmission. †Return to surgery, unplanned re-admission, prolonged episode of care as in or out patient or transfer to another area such as intensive care unit. ‡Permanent lessening of bodily functions, sensory, motor, physiologic or intellectual.
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Types of ‘damaging events’ in the regional anaesthesia claims. Allergy
Infection (other)
Awareness Back pain Bladder damage Cardiac arrest Child injury Consent Drug error Dural tap Epidural abscess Epidural haematoma Foreign body Globe perforation Headache High block with EFL Hypotension Inappropriate block Indeterminate
Injury related to failure of block* Injury related to motor block Injury related to sensory block Iv injection Meningitis Nerve damage Pain Pain during CS Pain with EFL Pain intra-operative Pneumothorax Psychological Spinal abscess Spinal cord ischaemia Total spinal Wrong site of block
*Injury related to general anaesthesia following failed regional anaesthesia. CS, caesarean section; EFL, epidural for labour.
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