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SUBARACHNOID SPINAL ANALGESIA
Br. J. Anaesth. (1983), 55, 1141
SUBARACHNOID SPINAL ANALGESIA Changing patterns of practice D. H. ROBERTSON
Although some decrease in the use of subarachnoid spinal analgesia was inevitable following the introduction of neuromuscular blocking agents in the early post-war years, it continued to be used widely throughout the world. Simplicity, effectiveness and low cost guaranteed continuing popularity in poorer countries. However, the technique retained an important place in the practice of anaesthesia in areas where standards are generally considered to be high. The United Kingdom provided an exception to this rule in that medico-legal events culminating in the Wooley and Roe case (Cope, 1954) led to the technique being virtually abandoned because of the fear of neurological complications. The long-term effects of this litigation were demonstrated by an editorial comment in 1975 (Scott and Thorburn, 1975) that use of the technique, at that time, was confined to a few enthusiasts. However, a survey of Scottish consultants in 1976 (Robertson, Lewerentz and Holmes, 1978) appeared to indicate that attitudes were changing with a resultant increase in the number of consultants using spinal analgesia and in the number of cases being undertaken. The authors concluded that a more rational re-appraisal of the technique was taking place and suggested that its use might increase further in the future. Since then, there have been changes in the availability of particular drugs and an increased interest in the technique has been demonstrated in the literaD. H. ROBERTSON, M.B., CH.B., F.F.A.R.C.S.,
Anaesthetics, Royal Infirmary, Stirling.
Department of
ture. Since a widespread increase in the use of subarachnoid blockade would represent a fundamental change in both the approach and practice of British anaesthetists, it seemed appropriate to test the validity of the conclusions drawn from the previous survey. MATERIALS AND METHODS
Five years after the initial survey, questionnaires were sent to each of the 226 consultant anaesthetists practising in Scotland in July, 1981. Questions were asked regarding the use or non-use of spinal analgesia, clinical training in the technique, and the number of years spent in the specialty. Current users were asked to specify the approximate number of subarachnoid spinal blocks administered in a year, their indications, details of any change of frequency of use in the past 5 years, drugs used and details of any personal experience or contact with serious complications. Non-users were asked to specify reasons for not utilizing the technique and all consultants were asked supplementary questions regarding their use or non-use of lumbar extradural analgesia, the relative safety of the two techniques, and their attitude to, and view of, the present status of spinal analgesia in the United Kingdom. RESULTS Results of 1981 survey Replies were received from 169 consultants (74.8%) and 126 (74.6%) stated that they currently used subarachnoid spinal analgesia. No practical © The Macmillan Press Ltd 1983
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The results of a postal enquiry into the current usage of subarachnoid spinal analgesia in Scotland are compared with those obtained in 1976. On each occasion replies were received from more than 70% of those consultants receiving questionnaires. Replies indicating use of the techniques increased from 40% in 1976 to 75% in 1981 and this was accompanied by an increase in the frequency of usage and a decline in medico-legal anxiety. While medical conditions retain their importance, the use of surgical procedures as primary indications has increased. The majority of consultants currently practising extradural techniques also use spinal methods, and there have been changes in attitude regarding the place and safety of both. There is continued minority dissatisfaction with the choice of spinal agents. No major neurological sequelae were reported and replies indicating that subarachnoid spinal analgesia had a useful place in practice increased from 80% in 1976 to more than 90% in 1981.
BRITISH JOURNAL OF ANAESTHESIA
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T A B L E I. The useofsubarachnoid spinalanalgesia of years in the specialty
Number 1981 74 56 39
Years in specialty <16 16-25 >25
169 (total) 1976 49 52 27
Use subarachnoid spinal analgesia 67(90.54%) 38(67.86%) 21(53.95% 126(74.55%)
<16 16-25 >25
128 (total)
related to numbers
Do not use subarachnoid spinal analgesia 7 18 18 43(25.45%)
21 (42.86%) 17(32.69%) 14(51.85%)
28 35 13
52 (40.62%)
76(59.38%)
TABLE II. Analgesic drugs in current us*
Drug
Number of users
1982 Cinchocaine 1:200 Mepivacaine 4% Bupivacaine 0.5% Amethocaine 1% Lignocaine 5% More than one
108 44 18 8 3 49
1976 Cinchocaine 1:200 Prilocaine5% Mepivacaine 4% Amethocaine 1% Procaine crystals More than one
30 21 7 2 1 9
TABLE III. Annual number of cases in which subarachnoid spinal analgesia was used
Number of cases
Number of anaesthetists
1981 <5 5-10 11-20 21-50 51-100 >100 Total
15 17 32 30 15 17 126
11.90 13.49 25.41 23.81 11.90 13.49 100
1976 <5 5-10 11-20 >20 Total
18 12 11 11 52
34.62 23.08 21.15 21.15 100
limb (101); urology (82); anal and rectal (75); gynaecology (62); general surgery (37); obstetrics (30). The various conditions and surgical procedures regarded as indications for the use of the technique are summarized in table IV and reasons for non-use are listed in table V. An increase in frequency of use was reported by 66 (52.4%) for one or more of the following reasons: increased appreciation of clinical value (36); change of appointment or type of cases dealt with (13); greater popularity or acceptability, or both, of technique (11); more rapid onset than extradural analgesia (5); research and teaching (5); availability of better equipment (4); improved medico-legal climate (4). Only six consultants reported a decrease in frequency of use, giving the following reasons: change in types of cases dealt with (4); inadequate assistance (1); increased use of extradural analgesia (1). Fortyone (32.5%) reported no change in frequency of use and nine replies did not specify. Seven users (5.6%) and 11 non-users (25.6%) stated that their practice was affected by medico-legal considerations. No anaesthetist currently using the technique had personal experience or contact with serious neurological complications, although five reported complications attributable to hypotension, including one death. Extradural analgesia was also utilized by 113 users (89.7%), who gave the following clinical indications for using it in preference in subarachnoid block: longer duration of action, including post-operative analgesia (67); catheter technique indicated (52);
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instruction had been received by 40 (23.7%), of whom 25 used spinal techniques. Of the 129 consultants who received practical instruction, 30 (23.3%) were dissatisfied with its adequacy. The numbers of users and non-users of the technique, related to their seniority in the specialty, are shown in table I. The pattern of current drug preference is shown in table II and the approximate number of cases performed annually under subarachnoid spinal analgesia is presented in table III. Forty-eight replies (38.1%) indicated dissatisfaction with the drugs available because of inadequate duration of action (36) or limited choice of drug (12). The surgical specialties and fields in which replies indicated use of spinal analgesia were as follows: lower
SUBARACHNOID SPINAL ANALGESIA
1143
TABLE IV. Specified indications for subarachnoid spinal analgesia. *Twenty-six specified "diabetic" 1981
1976 Number of anaesthetists
Phyiical conditions Pulmonary insufficiency Cardiovascular insufficiency Insulin-dependent diabetes "Poor-risk" patients Advanced age Chronic pain (phenol) Confused mental state
Other Patient preference Teaching and research Situations where extradural excluded because of time factor Difficult intubation
41 16 14 10 9 4 3
Physical conditions Pulmonary insufficiency Cardiovascular insufficiency Insulin-dependent diabetes "Poor-risk" patients Advanced age Chronic pain (phenol) Generalized rheumatoid disease
20 9 7 5 5 2 2
Surgical procedures Amputation Abdomino-perinal resection Major gynaecological surgery Urology Obstetrics Inguinal hernia Orthopaedics (lower limb) Haemorrhoidectomy
8 9 8 8 6 4 3 3
Other Planned hypotension Teaching Patient preference
4 2 1
9 2 2 2 2 3 5 5 2
the younger patient (20); extradural analgesia generally preferred and spinal used only because of limitations of time (4); teaching (3); thoracic surgery (2); previous post-spinal headache (2). Only 17 non-users (39.5%) currently used extradural analgesia. Thirty-three (26.2%) users of subarachnoid spinal analgesia and 10 (23.3%)non-users considered that exfradural analgesia was a safer technique. Opinion, in response to direct questions regarding the present status of spinal analgesia, is shown in table VI. Summary of results of 1976 survey Replies had been received from 128 Consultants (71.5%) and 52 (40.6%) stated that they currently used subarachnoid spinal analgesia. Information derived from this survey is shown for the purpose of comparison in tables I - V I also. Only 17 consultants
(13.3%) had received no practical instructions. A recent increase in frequency of use was reported by nine clinicians (17.3%) as a result of one or more of the following reasons: recent publication of large series with low complication rates (9); rediscovery of the technique (6); preference for subarachnoid to extradural analgesia (2). Twenty-six of those using the technique (50%) reported a decrease since commencing a career in anaesthesia for one or more of the following reasons: fear of litigation (10); improved flexibility of general anaesthesia (9); change of work pattern (8); unpopularity with patients 6r surgeons, or both (5); preference for extradural analgesia (2); lack of time or assistance (1). Seventeen (32.7%) reported no change in frequency of use. Twenty-nine users (56%) and 42 non-users (55%) admitted that their practice was affected by medico—legal considerations. The publication of
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Surgical procedures Amputation* Total hip replacement Abdomino-perineal resection Fracture of femur Prostatectomy Pelvic floor repair Haemorrhoidectomy Transurethral resection of prostate Varicose veins Tngiiinal hemia Surgery of colon Major pelvic surgery
96 50 62 75 60 19 3
Number of anaesthetists
BRITISH JOURNAL OF ANAESTHESIA
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Number of anaesthetists
Reasons 1981 "Not applicable because of nature of work (e.g. paediatrics) Lack of time and assistance Medico—legal implications Patient resistance Frequency of post-spinal headache Lack of training and experience
26 19 11 11 11 9
1976 Preference for extradural analgesia Obsolete because of present standard of general anaesthesia Not applicable because of nature of work (e.g. paediatrics) Lack of time and assistance Medico-legal implications Patient resistance Lack of training and experience Fear of neurological complications Fear of hypotension and post-operative bleeding Lack of suitable analgesic agent Frequency of post-spinal headache Discouragement by colleagues
27 24 18 17 12 12 9
5 3 3 2 1
large series with low complication rates, however, had influenced the practice of 29 users of the technique (55.8%). No anaesthetist currently using subarachnoid block had personal knowledge or experience of serious complications. DISCUSSION The proportion of consultants returning completed questionnaires exceeded 70% in both surveys. How-
T A B L E VI. Present status of subarachnoid spinal analgesia
Opinion 1981 Obsolete Dangerous Medico—legally inadvisable Useful under defined conditions Generally useful 1976 Obsolete Dangerous Medico—legally inadvisable Useful under defined conditions Generally useful
Users 0 0 0 81 (64.28%) 45(35.72%) 0 0 0 28(53.85%) 24(46.15%)
Non-users 4(9.30%) 1 (2.32%) 4(9.30%)
Total 4(2.37%) 1 (0.59%) 4(2.37%)
31 (72.10%) 3 (6.98%)
112(66.27%) 48(28.40%)
8(10.52%) 6(7.89%) 16(21.05%)
8(6.25%) 6(4.69%) 16(12.50%)
52(68.42%) 3 (3.95%)
80(62.50%) 27(21.09%)
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ever, a comparison of the results indicates that the number using the technique has more than doubled, and that the relative percentage has increased from 40% to 75% during the 5-year period from 1976 to 1981. The extent of this increase in popularity was further demonstrated by the numbers of cases undertaken (table III). In 1976, only 11 consultants admitted to attending more than 20 cases in the preceding year, whereas in 1981 this number had increased to 62,17 of whom attended more than 100 annually. Table I shows not only a change in the proportion of younger consultants in the specialty, but demonstrates that the increase in interest in the use of the technique was a feature of this group predominantly. Usage now appears to be inversely related to years in the specialty, those with more than 25 years experience using it least of all. In contrast, the highest proportion of users in the 1976 survey belonged to the group with more than 25 years experience in anaesthesia. A possible explanation of this apparent paradox is the retiral from the profession in the intervening years of a substantial number of those who had trained and gained experience before the events of the post-war era and had retained it as part of their anaesthetic practice. The analgesic drugs in current use (table II) reflect the availability of suitable agents rather than a marked change in drug preference. The withdrawal of heavy cinchocaine (Nupercaine) from the market in 1974 restricted its use to establishments where stocks had been built up, and severely limited choice of agent. A spinal preparation of prilocaine became available in the U.K. at this time, but was withdrawn after only 2 years. Hyperbaric lignocaine, although widely used in Europe, was not accepted
TABLE V. Reasons for non-use of subarachnoid spinal analgesia
SUBARACHNOID SPINAL ANALGESIA
The physical conditions given as an indication for the use of spinal analgesia (table IV) are very much the same in both surveys: pulmonary and cardiovascular insufficiency, diabetes, "poor-risk" patients and patients of advanced age. There was, however, a surprising difference in the numbers nominating each condition, which was out of all proportion to the increase in users. Examination of the figures shows that, in 1976, most consultants named only one indication, while in 1981 most named three or more, indicating a wider applicability of the technique. The recent appreciation of the importance of the
management of chronic pain, and its acceptance by the specialty, is reflected by the numbers using intrathecal phenol or alcohol, these having increased from 2 to 19 over the period in question. Whereas in 1976 anaesthetists were asked only for "indications", in 1981 they were asked, in addition, whether any specific procedure constituted a primary indication for spinal analgesia and, if so, to specify. The procedures listed in table IV are, therefore, those in which consultants considered subarachnoid spinal analgesia to be the anaesthetic technique of choice, regardless of physical condition. This does not totally apply to amputations, in that a majority of those who specified this procedure qualified it with the word "diabetic". Recent publications suggesting improved oxygenation after operation and a lower mortality rate following surgery of fractured neck of femur (McKenzie et al., 1980), and a lower frequency of deep venous thrombosis after hip replacement (Thorburn, Louden and Vallance, 1980), may have played a part in establishing orthopaedics as the most popular field of application of the technique. Similarly, those using the technique for operations on the colon or rectum may have been influenced by the possiblity of a lower frequency of dehiscence after large bowel anastomosis (Aitkenhead, Wishart and Peebles Brown, 1978). The number using the technique in obstetrics suggest some measure of agreement with Crawford's conclusion (1979) that subarachnoid spinal analgesia should be extensively re-introduced in this field of practice. While the publication of series with low complication rates (Moore et al., 1968; Noble and Murray, 1971) was a major influence on those who reported an increase in usage in 1976, it did not feature in any reply to the 1981 survey. The reasons given in 1981 for the increase in usage seem more related to individual situations in that the majority refer to a greater appreciation of the clinical value of the technique or to change in the type of patient dealt with. In 1976, 50% of users reported a decrease in frequency of use during their anaesthetic careers, compared with 5% in 1981 over the previous 5 years. In the former group, fear of litigation and improved general anaesthesia featured prominently as reasons which are noticeably absent from the replies of the latter. A comparison of the reasons for non-use of spinal analgesia (table V) demonstrates some interesing changes and some remarkable similarities. The number of reasons currently given has decreased
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for use in the United Kingdom at that time. Having returned to the market, heavy cinchocaine is now used by 84% of users followed, some way behind, by heavy mepivacaine and plain bupivacaine. The latter drug did not feature in the 1976 results in spite of published use in Europe at that time (Nolte et al., 1977). Amethocaine is widely used as a spinal agent in North America but, like lignocaine, is not generally available in the U.K. Table II indicates that the obvious difficulties in obtaining supplies are being overcome by a minority of consultants. The prolonged analgesia obtainable with modern extradural techniques may have influenced those who were dissatisfied with the duration of spinal preparations. That no one drug is universally considered appropriate for use in all cases is indicated by the users, 39% of whom used two or more agents. The fact that 24% of the current replies stated that they had received no practical instruction and that, of those who had, 23% were dissatisfied with its adequacy, is an indication that, in some centres, anaesthetic training is not comprehensive. The number using extradural analgesia (130) and those using subarachnoid spinal analgesia (126) are similar and 87% of the extradural group also use subarachnoid analgesia. In a situation where both techniques are practised, largely by the same consultants, it is pertinent to consider whether practical education in the one can be significantly better than the other. In 1976, only 13% of consultants admitted to having received no practical instruction. This does not appear realistic when compared with the 1981 results and is difficult to explain satisfactorily. It is relevant, in this context, to consider the observations of Crawford (1979) who pointed out that trainees during the previous two to three decades had received little guidance on the administration of spinal block because of the prejudice or inexperience of their consultants.
1145
BRITISH JOURNAL OF ANAESTHESIA
1146
ACKNOWLEDGEMENTS
The Author wishes to thank Messrs Duncan Flockhart and the Forth Valley Health Board for their help in the production and distribution of the questionnaire, and the Editors and Publishers
of Anaesthesia for their permission to reproduce the tables relating to the 1976 survey. REFERENCES
Aitkenhead, A.R., Wishart, H. Y., and Peebles Brown, D. A. (1978). High spinal nerve block for large bowel anastomosis. Br.J. Anaesth., SO, 177. Cope, R. W. (1954). The Wooley and Roe Case. Anaesthesia, 9, 249. Crawford, J. S. (1979). Experience with spinal analgesia in a British obstetric unit. Br. J. Anatsth., 51, 531. McKenzie, P. J., Wishart, H. Y., Dewar, K. M. S., Gray, J., and Smith, G. (1980). Comparison of the effects of spinal anaesthesia on postoperative oxygenation and perioperative mortality. Br. J. Anatsth., 52,49. Moore, D. C., Bridgenbaugh, L. D., Bagdi, P. A., Bridenbaugh, P. O., and Stander, H. (1968). The present status of spinal (subarachnoid) and epidural (peridural) block. Anesth. Analg., 47,40. Noble, A. B., and Murray, J. G. (1971). A review of the complications of spinal anaesthesia with experience in Canadian ri-arhing hospitals from 1959 to 1969. Can. Anaesth. So$. 7,18, 5. Nolte, H., Schikor, K., George, P., Mayer, J., and Stark, P. (1977). On spinal anaesthesia with isobaric bupivacaine 0.5%. Anaesthesist, 26, 33. Robertson, D. H., Lewercntz, H., and Holmes, F. (1978). Subarachnoid spinal analgesia. Anaesthesia, 33, 913. Scott, D. B., and Thorburn, J. T. (1975). Spinal anaesthesia. Br. J. Anaesth., AT, A2\.
Thorburn, J., Louden, J.R., and Vallance.R. (1980). Spinal and general anaesthesia in total hip replacement: frequency of deep vein thrombosis. Br. J. Anaesth., 52,1117.
RACHIANESTHESIE La pratique d changi RESUME
Les resultats d'une enquete postale (en Ecosse) sur l'utilisation de la rachianesthesie en pratique courante sont compares a ceux obtenus en 1976. A chaque fois, plus de 70% des consultants qui avaient recu le questionnaire ont repondu. Les reponses traduisant un usage de ces techniques ont augment^ de 40% en 1976 a 75% en 1981, avec une augmenarion de la frequence d'utilisation et une attitude phis detachee vis-4-vis des prpblemes medico legaux. Tandis que les considerations de terrain gardent leur importance, les indications posees d'abord pour (a nature de l'acte chirurgical ont augmented La majorite des consultants qui pratiquent habituellement les techniques de peridurale explorent egalement la rachianesthesie et les attitudes ont change vis-a-vis de la place et de la fiabilite respective* de chacune d'entre elles. II persiste une minorite d'insatisfaiu de l'eventail propose d'anesthesiques locaux. Aucune sequdle neurologique majeure n'a etc rapportee et lei reponses considerant que la rachianesthesie a «a place en pratique ont augment^ de 80% en 1976 a phis 90% en 1981.
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considerably and those most commonly cited in 1976, —preference for extradural analgesia and improved standard of general anaesthesia, no longer feature. The numbers of consultants quoting nonapplicability to current practice, patient resistance, time involved and medico-legal risk, are almost identical in both tables. Although no specific questions regarding the use of extradural analgesia were asked in the 1976 survey, it was considered appropriate to do so on this occasion. The majority of indications given for using extradural in preference to spinal analgesia were consistent with the majority view that it offered no advantage in terms of safety, in that they were related to more prolonged duration of action and the use of catheter techniques for prolonged pain relief. The only complications currently reported were related to hypotension and, with the exception of two possible cases of meningitis in the 1950's, no consultant had personal experience of, or contact with, major neurological sequelae. The reported increase in the use of spinal analgesia has been accompanied by a commensurate decrease in the number who admit to being influenced by medico-legal considerations in their use, or non-use, of the technique. This is demonstrated by the decline from 55% of both users and non-users in 1976 to 6% of users and 26% of non-users in 1981. Similarly, the minority view that it is dangerous or inadvisable has decreased from 17% to less than 3% (table VI) and is confined to non-users of the technique. Speculative consideration of those factors likely to have contributed to this change in attitude and practice would include: repeated demonstration of a low frequency of neurological complications, acceptance of the fact that extradural analgesia has its own sequelae, and the increase in numbers of legal inquiries following the administration of general anaesthesia. The nature of the change in the general status of subarachnoid spinal analgesia is probably better indicated by the number of consultants using the technique rather than the number who thought it useful. Over a 5-year period, a substantial minority of users has become a substantial majority, with relatively little percentage change in opinion as to the usefulness of the technique.
SUBARACHNOID SPINAL ANALGESIA
1147
SUBARACHNOIDALE SPINALANALGESIE Vtrandtrung dtr Anwtndung in der Praxis
ANALGESIA ESPINAL SUBARACNOIDEA Cambios dt mitodos
ZUSAMMHNFASSUNG
Se Ueva a cabo una compmracion de los resultados de una encuesta postal respecto del uso actual de la analgrtifl espinal tubaracnoidea en Escocia con los obtenidos en 1976. En cada ocaai6n, las respuestas fueron manitiHa« por mas del 70% de los consultores que habian recibido el cuesrionario. Las respuestas en que se indicaban el uso de las tecnicas aumentaron desde 40% en 1976 hasta 75% en 1981 y eso se acompano de un aumento de la frecuencia del uso y un descenso de la »ntlit
SUMARIO
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Die Ergebnisse einer postalischen Umfrage uber die allgemeine Verwendung subarachnoidaler Spinalanalgesie in Schottland wurden mit denen aus dem Jahre 1976 verglichen. Beide Male wurden die verwmdten Fragebogcn von uber 70% der Befragten beantwortet. Die Zahl der Antworten, die cine Verwendung der Technik angeben, stieg von 40% 1976 auf 75% 1981, begleitet von einer Hfl\ifigkciTft7"nahTn^ der Anwendung und einer Abnahme der medizinisch-juristischen Bedenken. Wahrend medizinische Indikationen ihre Bedcutung wahren irnnntwij nahm die Haufigkeit cfairurgucfaer Eingrif f e als Primarindikation zu. Die Mehrheit der Befragten, die extradurale Techniken anwenden, machen auch Spinalanalgesien. Eine Anderung bezuglich der Einstellung gegenuber Bedeutung und Sicherheit beider Techniken war festzustellen. Bei einer kleinen Anzahl Befragter besteht weiternin Unzufriedenheit mit der Auswahl an spinalen Wirkstoffen. Es wurden keiner grdfieren neurologiscbcn Spatfolgen beobachtet. Die Zahl der Antworten, die der Spinalanalgesie einen wichtigen Platz in der Praxis einraumen, stieg von 80% 1976 auf fiber 90% 1981.
SUBARACHNOID SPINAL ANALGESIA Changing patterns of practice D. H. ROBERTSON
Although some decrease in the use of subarachnoid spinal analgesia was inevitable following the introduction of neuromuscular blocking agents in the early post-war years, it continued to be used widely throughout the world. Simplicity, effectiveness and low cost guaranteed continuing popularity in poorer countries. However, the technique retained an important place in the practice of anaesthesia in areas where standards are generally considered to be high. The United Kingdom provided an exception to this rule in that medico-legal events culminating in the Wooley and Roe case (Cope, 1954) led to the technique being virtually abandoned because of the fear of neurological complications. The long-term effects of this litigation were demonstrated by an editorial comment in 1975 (Scott and Thorburn, 1975) that use of the technique, at that time, was confined to a few enthusiasts. However, a survey of Scottish consultants in 1976 (Robertson, Lewerentz and Holmes, 1978) appeared to indicate that attitudes were changing with a resultant increase in the number of consultants using spinal analgesia and in the number of cases being undertaken. The authors concluded that a more rational re-appraisal of the technique was taking place and suggested that its use might increase further in the future. Since then, there have been changes in the availability of particular drugs and an increased interest in the technique has been demonstrated in the literaD. H. ROBERTSON, M.B., CH.B., F.F.A.R.C.S.,
Anaesthetics, Royal Infirmary, Stirling.
Department of
ture. Since a widespread increase in the use of subarachnoid blockade would represent a fundamental change in both the approach and practice of British anaesthetists, it seemed appropriate to test the validity of the conclusions drawn from the previous survey. MATERIALS AND METHODS
Five years after the initial survey, questionnaires were sent to each of the 226 consultant anaesthetists practising in Scotland in July, 1981. Questions were asked regarding the use or non-use of spinal analgesia, clinical training in the technique, and the number of years spent in the specialty. Current users were asked to specify the approximate number of subarachnoid spinal blocks administered in a year, their indications, details of any change of frequency of use in the past 5 years, drugs used and details of any personal experience or contact with serious complications. Non-users were asked to specify reasons for not utilizing the technique and all consultants were asked supplementary questions regarding their use or non-use of lumbar extradural analgesia, the relative safety of the two techniques, and their attitude to, and view of, the present status of spinal analgesia in the United Kingdom. RESULTS Results of 1981 survey Replies were received from 169 consultants (74.8%) and 126 (74.6%) stated that they currently used subarachnoid spinal analgesia. No practical © The Macmillan Press Ltd 1983
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The results of a postal enquiry into the current usage of subarachnoid spinal analgesia in Scotland are compared with those obtained in 1976. On each occasion replies were received from more than 70% of those consultants receiving questionnaires. Replies indicating use of the techniques increased from 40% in 1976 to 75% in 1981 and this was accompanied by an increase in the frequency of usage and a decline in medico-legal anxiety. While medical conditions retain their importance, the use of surgical procedures as primary indications has increased. The majority of consultants currently practising extradural techniques also use spinal methods, and there have been changes in attitude regarding the place and safety of both. There is continued minority dissatisfaction with the choice of spinal agents. No major neurological sequelae were reported and replies indicating that subarachnoid spinal analgesia had a useful place in practice increased from 80% in 1976 to more than 90% in 1981.
BRITISH JOURNAL OF ANAESTHESIA
1142
T A B L E I. The useofsubarachnoid spinalanalgesia of years in the specialty
Number 1981 74 56 39
Years in specialty <16 16-25 >25
169 (total) 1976 49 52 27
Use subarachnoid spinal analgesia 67(90.54%) 38(67.86%) 21(53.95% 126(74.55%)
<16 16-25 >25
128 (total)
related to numbers
Do not use subarachnoid spinal analgesia 7 18 18 43(25.45%)
21 (42.86%) 17(32.69%) 14(51.85%)
28 35 13
52 (40.62%)
76(59.38%)
TABLE II. Analgesic drugs in current us*
Drug
Number of users
1982 Cinchocaine 1:200 Mepivacaine 4% Bupivacaine 0.5% Amethocaine 1% Lignocaine 5% More than one
108 44 18 8 3 49
1976 Cinchocaine 1:200 Prilocaine5% Mepivacaine 4% Amethocaine 1% Procaine crystals More than one
30 21 7 2 1 9
TABLE III. Annual number of cases in which subarachnoid spinal analgesia was used
Number of cases
Number of anaesthetists
1981 <5 5-10 11-20 21-50 51-100 >100 Total
15 17 32 30 15 17 126
11.90 13.49 25.41 23.81 11.90 13.49 100
1976 <5 5-10 11-20 >20 Total
18 12 11 11 52
34.62 23.08 21.15 21.15 100
limb (101); urology (82); anal and rectal (75); gynaecology (62); general surgery (37); obstetrics (30). The various conditions and surgical procedures regarded as indications for the use of the technique are summarized in table IV and reasons for non-use are listed in table V. An increase in frequency of use was reported by 66 (52.4%) for one or more of the following reasons: increased appreciation of clinical value (36); change of appointment or type of cases dealt with (13); greater popularity or acceptability, or both, of technique (11); more rapid onset than extradural analgesia (5); research and teaching (5); availability of better equipment (4); improved medico-legal climate (4). Only six consultants reported a decrease in frequency of use, giving the following reasons: change in types of cases dealt with (4); inadequate assistance (1); increased use of extradural analgesia (1). Fortyone (32.5%) reported no change in frequency of use and nine replies did not specify. Seven users (5.6%) and 11 non-users (25.6%) stated that their practice was affected by medico-legal considerations. No anaesthetist currently using the technique had personal experience or contact with serious neurological complications, although five reported complications attributable to hypotension, including one death. Extradural analgesia was also utilized by 113 users (89.7%), who gave the following clinical indications for using it in preference in subarachnoid block: longer duration of action, including post-operative analgesia (67); catheter technique indicated (52);
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instruction had been received by 40 (23.7%), of whom 25 used spinal techniques. Of the 129 consultants who received practical instruction, 30 (23.3%) were dissatisfied with its adequacy. The numbers of users and non-users of the technique, related to their seniority in the specialty, are shown in table I. The pattern of current drug preference is shown in table II and the approximate number of cases performed annually under subarachnoid spinal analgesia is presented in table III. Forty-eight replies (38.1%) indicated dissatisfaction with the drugs available because of inadequate duration of action (36) or limited choice of drug (12). The surgical specialties and fields in which replies indicated use of spinal analgesia were as follows: lower
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TABLE IV. Specified indications for subarachnoid spinal analgesia. *Twenty-six specified "diabetic" 1981
1976 Number of anaesthetists
Phyiical conditions Pulmonary insufficiency Cardiovascular insufficiency Insulin-dependent diabetes "Poor-risk" patients Advanced age Chronic pain (phenol) Confused mental state
Other Patient preference Teaching and research Situations where extradural excluded because of time factor Difficult intubation
41 16 14 10 9 4 3
Physical conditions Pulmonary insufficiency Cardiovascular insufficiency Insulin-dependent diabetes "Poor-risk" patients Advanced age Chronic pain (phenol) Generalized rheumatoid disease
20 9 7 5 5 2 2
Surgical procedures Amputation Abdomino-perinal resection Major gynaecological surgery Urology Obstetrics Inguinal hernia Orthopaedics (lower limb) Haemorrhoidectomy
8 9 8 8 6 4 3 3
Other Planned hypotension Teaching Patient preference
4 2 1
9 2 2 2 2 3 5 5 2
the younger patient (20); extradural analgesia generally preferred and spinal used only because of limitations of time (4); teaching (3); thoracic surgery (2); previous post-spinal headache (2). Only 17 non-users (39.5%) currently used extradural analgesia. Thirty-three (26.2%) users of subarachnoid spinal analgesia and 10 (23.3%)non-users considered that exfradural analgesia was a safer technique. Opinion, in response to direct questions regarding the present status of spinal analgesia, is shown in table VI. Summary of results of 1976 survey Replies had been received from 128 Consultants (71.5%) and 52 (40.6%) stated that they currently used subarachnoid spinal analgesia. Information derived from this survey is shown for the purpose of comparison in tables I - V I also. Only 17 consultants
(13.3%) had received no practical instructions. A recent increase in frequency of use was reported by nine clinicians (17.3%) as a result of one or more of the following reasons: recent publication of large series with low complication rates (9); rediscovery of the technique (6); preference for subarachnoid to extradural analgesia (2). Twenty-six of those using the technique (50%) reported a decrease since commencing a career in anaesthesia for one or more of the following reasons: fear of litigation (10); improved flexibility of general anaesthesia (9); change of work pattern (8); unpopularity with patients 6r surgeons, or both (5); preference for extradural analgesia (2); lack of time or assistance (1). Seventeen (32.7%) reported no change in frequency of use. Twenty-nine users (56%) and 42 non-users (55%) admitted that their practice was affected by medico—legal considerations. The publication of
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Surgical procedures Amputation* Total hip replacement Abdomino-perineal resection Fracture of femur Prostatectomy Pelvic floor repair Haemorrhoidectomy Transurethral resection of prostate Varicose veins Tngiiinal hemia Surgery of colon Major pelvic surgery
96 50 62 75 60 19 3
Number of anaesthetists
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Number of anaesthetists
Reasons 1981 "Not applicable because of nature of work (e.g. paediatrics) Lack of time and assistance Medico—legal implications Patient resistance Frequency of post-spinal headache Lack of training and experience
26 19 11 11 11 9
1976 Preference for extradural analgesia Obsolete because of present standard of general anaesthesia Not applicable because of nature of work (e.g. paediatrics) Lack of time and assistance Medico-legal implications Patient resistance Lack of training and experience Fear of neurological complications Fear of hypotension and post-operative bleeding Lack of suitable analgesic agent Frequency of post-spinal headache Discouragement by colleagues
27 24 18 17 12 12 9
5 3 3 2 1
large series with low complication rates, however, had influenced the practice of 29 users of the technique (55.8%). No anaesthetist currently using subarachnoid block had personal knowledge or experience of serious complications. DISCUSSION The proportion of consultants returning completed questionnaires exceeded 70% in both surveys. How-
T A B L E VI. Present status of subarachnoid spinal analgesia
Opinion 1981 Obsolete Dangerous Medico—legally inadvisable Useful under defined conditions Generally useful 1976 Obsolete Dangerous Medico—legally inadvisable Useful under defined conditions Generally useful
Users 0 0 0 81 (64.28%) 45(35.72%) 0 0 0 28(53.85%) 24(46.15%)
Non-users 4(9.30%) 1 (2.32%) 4(9.30%)
Total 4(2.37%) 1 (0.59%) 4(2.37%)
31 (72.10%) 3 (6.98%)
112(66.27%) 48(28.40%)
8(10.52%) 6(7.89%) 16(21.05%)
8(6.25%) 6(4.69%) 16(12.50%)
52(68.42%) 3 (3.95%)
80(62.50%) 27(21.09%)
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ever, a comparison of the results indicates that the number using the technique has more than doubled, and that the relative percentage has increased from 40% to 75% during the 5-year period from 1976 to 1981. The extent of this increase in popularity was further demonstrated by the numbers of cases undertaken (table III). In 1976, only 11 consultants admitted to attending more than 20 cases in the preceding year, whereas in 1981 this number had increased to 62,17 of whom attended more than 100 annually. Table I shows not only a change in the proportion of younger consultants in the specialty, but demonstrates that the increase in interest in the use of the technique was a feature of this group predominantly. Usage now appears to be inversely related to years in the specialty, those with more than 25 years experience using it least of all. In contrast, the highest proportion of users in the 1976 survey belonged to the group with more than 25 years experience in anaesthesia. A possible explanation of this apparent paradox is the retiral from the profession in the intervening years of a substantial number of those who had trained and gained experience before the events of the post-war era and had retained it as part of their anaesthetic practice. The analgesic drugs in current use (table II) reflect the availability of suitable agents rather than a marked change in drug preference. The withdrawal of heavy cinchocaine (Nupercaine) from the market in 1974 restricted its use to establishments where stocks had been built up, and severely limited choice of agent. A spinal preparation of prilocaine became available in the U.K. at this time, but was withdrawn after only 2 years. Hyperbaric lignocaine, although widely used in Europe, was not accepted
TABLE V. Reasons for non-use of subarachnoid spinal analgesia
SUBARACHNOID SPINAL ANALGESIA
The physical conditions given as an indication for the use of spinal analgesia (table IV) are very much the same in both surveys: pulmonary and cardiovascular insufficiency, diabetes, "poor-risk" patients and patients of advanced age. There was, however, a surprising difference in the numbers nominating each condition, which was out of all proportion to the increase in users. Examination of the figures shows that, in 1976, most consultants named only one indication, while in 1981 most named three or more, indicating a wider applicability of the technique. The recent appreciation of the importance of the
management of chronic pain, and its acceptance by the specialty, is reflected by the numbers using intrathecal phenol or alcohol, these having increased from 2 to 19 over the period in question. Whereas in 1976 anaesthetists were asked only for "indications", in 1981 they were asked, in addition, whether any specific procedure constituted a primary indication for spinal analgesia and, if so, to specify. The procedures listed in table IV are, therefore, those in which consultants considered subarachnoid spinal analgesia to be the anaesthetic technique of choice, regardless of physical condition. This does not totally apply to amputations, in that a majority of those who specified this procedure qualified it with the word "diabetic". Recent publications suggesting improved oxygenation after operation and a lower mortality rate following surgery of fractured neck of femur (McKenzie et al., 1980), and a lower frequency of deep venous thrombosis after hip replacement (Thorburn, Louden and Vallance, 1980), may have played a part in establishing orthopaedics as the most popular field of application of the technique. Similarly, those using the technique for operations on the colon or rectum may have been influenced by the possiblity of a lower frequency of dehiscence after large bowel anastomosis (Aitkenhead, Wishart and Peebles Brown, 1978). The number using the technique in obstetrics suggest some measure of agreement with Crawford's conclusion (1979) that subarachnoid spinal analgesia should be extensively re-introduced in this field of practice. While the publication of series with low complication rates (Moore et al., 1968; Noble and Murray, 1971) was a major influence on those who reported an increase in usage in 1976, it did not feature in any reply to the 1981 survey. The reasons given in 1981 for the increase in usage seem more related to individual situations in that the majority refer to a greater appreciation of the clinical value of the technique or to change in the type of patient dealt with. In 1976, 50% of users reported a decrease in frequency of use during their anaesthetic careers, compared with 5% in 1981 over the previous 5 years. In the former group, fear of litigation and improved general anaesthesia featured prominently as reasons which are noticeably absent from the replies of the latter. A comparison of the reasons for non-use of spinal analgesia (table V) demonstrates some interesing changes and some remarkable similarities. The number of reasons currently given has decreased
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for use in the United Kingdom at that time. Having returned to the market, heavy cinchocaine is now used by 84% of users followed, some way behind, by heavy mepivacaine and plain bupivacaine. The latter drug did not feature in the 1976 results in spite of published use in Europe at that time (Nolte et al., 1977). Amethocaine is widely used as a spinal agent in North America but, like lignocaine, is not generally available in the U.K. Table II indicates that the obvious difficulties in obtaining supplies are being overcome by a minority of consultants. The prolonged analgesia obtainable with modern extradural techniques may have influenced those who were dissatisfied with the duration of spinal preparations. That no one drug is universally considered appropriate for use in all cases is indicated by the users, 39% of whom used two or more agents. The fact that 24% of the current replies stated that they had received no practical instruction and that, of those who had, 23% were dissatisfied with its adequacy, is an indication that, in some centres, anaesthetic training is not comprehensive. The number using extradural analgesia (130) and those using subarachnoid spinal analgesia (126) are similar and 87% of the extradural group also use subarachnoid analgesia. In a situation where both techniques are practised, largely by the same consultants, it is pertinent to consider whether practical education in the one can be significantly better than the other. In 1976, only 13% of consultants admitted to having received no practical instruction. This does not appear realistic when compared with the 1981 results and is difficult to explain satisfactorily. It is relevant, in this context, to consider the observations of Crawford (1979) who pointed out that trainees during the previous two to three decades had received little guidance on the administration of spinal block because of the prejudice or inexperience of their consultants.
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ACKNOWLEDGEMENTS
The Author wishes to thank Messrs Duncan Flockhart and the Forth Valley Health Board for their help in the production and distribution of the questionnaire, and the Editors and Publishers
of Anaesthesia for their permission to reproduce the tables relating to the 1976 survey. REFERENCES
Aitkenhead, A.R., Wishart, H. Y., and Peebles Brown, D. A. (1978). High spinal nerve block for large bowel anastomosis. Br.J. Anaesth., SO, 177. Cope, R. W. (1954). The Wooley and Roe Case. Anaesthesia, 9, 249. Crawford, J. S. (1979). Experience with spinal analgesia in a British obstetric unit. Br. J. Anatsth., 51, 531. McKenzie, P. J., Wishart, H. Y., Dewar, K. M. S., Gray, J., and Smith, G. (1980). Comparison of the effects of spinal anaesthesia on postoperative oxygenation and perioperative mortality. Br. J. Anatsth., 52,49. Moore, D. C., Bridgenbaugh, L. D., Bagdi, P. A., Bridenbaugh, P. O., and Stander, H. (1968). The present status of spinal (subarachnoid) and epidural (peridural) block. Anesth. Analg., 47,40. Noble, A. B., and Murray, J. G. (1971). A review of the complications of spinal anaesthesia with experience in Canadian ri-arhing hospitals from 1959 to 1969. Can. Anaesth. So$. 7,18, 5. Nolte, H., Schikor, K., George, P., Mayer, J., and Stark, P. (1977). On spinal anaesthesia with isobaric bupivacaine 0.5%. Anaesthesist, 26, 33. Robertson, D. H., Lewercntz, H., and Holmes, F. (1978). Subarachnoid spinal analgesia. Anaesthesia, 33, 913. Scott, D. B., and Thorburn, J. T. (1975). Spinal anaesthesia. Br. J. Anaesth., AT, A2\.
Thorburn, J., Louden, J.R., and Vallance.R. (1980). Spinal and general anaesthesia in total hip replacement: frequency of deep vein thrombosis. Br. J. Anaesth., 52,1117.
RACHIANESTHESIE La pratique d changi RESUME
Les resultats d'une enquete postale (en Ecosse) sur l'utilisation de la rachianesthesie en pratique courante sont compares a ceux obtenus en 1976. A chaque fois, plus de 70% des consultants qui avaient recu le questionnaire ont repondu. Les reponses traduisant un usage de ces techniques ont augment^ de 40% en 1976 a 75% en 1981, avec une augmenarion de la frequence d'utilisation et une attitude phis detachee vis-4-vis des prpblemes medico legaux. Tandis que les considerations de terrain gardent leur importance, les indications posees d'abord pour (a nature de l'acte chirurgical ont augmented La majorite des consultants qui pratiquent habituellement les techniques de peridurale explorent egalement la rachianesthesie et les attitudes ont change vis-a-vis de la place et de la fiabilite respective* de chacune d'entre elles. II persiste une minorite d'insatisfaiu de l'eventail propose d'anesthesiques locaux. Aucune sequdle neurologique majeure n'a etc rapportee et lei reponses considerant que la rachianesthesie a «a place en pratique ont augment^ de 80% en 1976 a phis 90% en 1981.
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considerably and those most commonly cited in 1976, —preference for extradural analgesia and improved standard of general anaesthesia, no longer feature. The numbers of consultants quoting nonapplicability to current practice, patient resistance, time involved and medico-legal risk, are almost identical in both tables. Although no specific questions regarding the use of extradural analgesia were asked in the 1976 survey, it was considered appropriate to do so on this occasion. The majority of indications given for using extradural in preference to spinal analgesia were consistent with the majority view that it offered no advantage in terms of safety, in that they were related to more prolonged duration of action and the use of catheter techniques for prolonged pain relief. The only complications currently reported were related to hypotension and, with the exception of two possible cases of meningitis in the 1950's, no consultant had personal experience of, or contact with, major neurological sequelae. The reported increase in the use of spinal analgesia has been accompanied by a commensurate decrease in the number who admit to being influenced by medico-legal considerations in their use, or non-use, of the technique. This is demonstrated by the decline from 55% of both users and non-users in 1976 to 6% of users and 26% of non-users in 1981. Similarly, the minority view that it is dangerous or inadvisable has decreased from 17% to less than 3% (table VI) and is confined to non-users of the technique. Speculative consideration of those factors likely to have contributed to this change in attitude and practice would include: repeated demonstration of a low frequency of neurological complications, acceptance of the fact that extradural analgesia has its own sequelae, and the increase in numbers of legal inquiries following the administration of general anaesthesia. The nature of the change in the general status of subarachnoid spinal analgesia is probably better indicated by the number of consultants using the technique rather than the number who thought it useful. Over a 5-year period, a substantial minority of users has become a substantial majority, with relatively little percentage change in opinion as to the usefulness of the technique.
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SUBARACHNOIDALE SPINALANALGESIE Vtrandtrung dtr Anwtndung in der Praxis
ANALGESIA ESPINAL SUBARACNOIDEA Cambios dt mitodos
ZUSAMMHNFASSUNG
Se Ueva a cabo una compmracion de los resultados de una encuesta postal respecto del uso actual de la analgrtifl espinal tubaracnoidea en Escocia con los obtenidos en 1976. En cada ocaai6n, las respuestas fueron manitiHa« por mas del 70% de los consultores que habian recibido el cuesrionario. Las respuestas en que se indicaban el uso de las tecnicas aumentaron desde 40% en 1976 hasta 75% en 1981 y eso se acompano de un aumento de la frecuencia del uso y un descenso de la »ntlit
SUMARIO
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Die Ergebnisse einer postalischen Umfrage uber die allgemeine Verwendung subarachnoidaler Spinalanalgesie in Schottland wurden mit denen aus dem Jahre 1976 verglichen. Beide Male wurden die verwmdten Fragebogcn von uber 70% der Befragten beantwortet. Die Zahl der Antworten, die cine Verwendung der Technik angeben, stieg von 40% 1976 auf 75% 1981, begleitet von einer Hfl\ifigkciTft7"nahTn^ der Anwendung und einer Abnahme der medizinisch-juristischen Bedenken. Wahrend medizinische Indikationen ihre Bedcutung wahren irnnntwij nahm die Haufigkeit cfairurgucfaer Eingrif f e als Primarindikation zu. Die Mehrheit der Befragten, die extradurale Techniken anwenden, machen auch Spinalanalgesien. Eine Anderung bezuglich der Einstellung gegenuber Bedeutung und Sicherheit beider Techniken war festzustellen. Bei einer kleinen Anzahl Befragter besteht weiternin Unzufriedenheit mit der Auswahl an spinalen Wirkstoffen. Es wurden keiner grdfieren neurologiscbcn Spatfolgen beobachtet. Die Zahl der Antworten, die der Spinalanalgesie einen wichtigen Platz in der Praxis einraumen, stieg von 80% 1976 auf fiber 90% 1981.