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American Medical Association and recommendations of the committee. Journal of the American Medical Association, 82, 876. 4. WOODS, L.A., MCMAHON, F.G. & SEEVERS, M.H. (1951) Distribution and metabolism of cocaine in the dog and rabbit. Journal of Pharmacology and Experimental Therapeutics, 101, 200. 5 . WOODS,L.A., COCHIN, J., FORMEFELD, E.H., MCMAHON, F.G. & SEEVERS, M.H. (1951) The estimation of amines in biological materials with critical data for cocaine and mescaline. Journal of Pharmacology and Experimental Therapeutics, 101, 188. 6. CAMPBELL, D. & ADRIANI, J. (1958) Absorption of local anesthetics. Journal of the American Medical Association, 168, 873. 7. CAMPBELL, D. & ADRIANI, J. (1956) Fatalities following the topical application of local anesthetics to mucous membranes. Journal of the American Medical Association, 162, 1527. 8 . LEE,J.A. & ATKINSON, R.S.(1973) Synopsis of Anaesthesia, 7th edn, p. 338. Wright, Bristol. 9. HOPKIN, D.A.B. (1970) Anaesthesia: Recovery and Intensive Care, 1st edn, p. 169. English Universities Press, London. 10. PRYOR J.W. &BUSH,D.C.T. (1973) A Manualof Anaesthetic Techniques, 4th edn, p. 92. Wright, Bristol. 11. British National Formulary, 1974-6, p. 89. 12. MARTINDALE, W. (1972) The Extra Pharmacopoeia (Ed. by N.W. Blacow), 26th edn, p. 1029. The Pharmaceutical Press, London. 13. GOODMAN, L.S. & GILMAN, A. (1970) The Pharmacological Basis of Therapeutics, 4th edn, p. 379. MacmilIan, New York. 14. ORR,D. &JONES, 1. (1968) Anaesthesia for laryngoscopy. A comparison of the cardiovascular effects of cocaine and lignocaine. Anaesthesia, 23, 194. 15. MOORE, D.C. & BRIDENBAUGH, D.L. (1960) Oxygen-The antidote for systemic toxic reactions from local anesthetics drugs. Journal of the American Medical Association, 174, 842. 16. MUSCHOLL, E. (1961) Effect of cocaine and related drugs on the uptake of noradrenaline by heart and spleen. British Journal of Pharmacology and Chemotherapy, 16, 352. 17. STEINHAUS, J.E. (1952) A comparative study of the experimental toxicity of local anaesthetic agents. Anesthesiology, 13, 577. 18. STEINHAUS, J.E. & TATUM, A.L. (1950) An experimental study of cocaine intoxication and its treatment. Journal of Pharmacology and Experimental Therapeutics, 100, 351. Anaesthesia, 1975, Volume 30, pages 817-822
Intravenous regional analgesia using bupivacaine R . J. Ware, MB, BS Registrar, Department of Anaesthetics, King’s College Hospital, London S.E.5 The technique of intravenous regional analgesia was first described by August Bier in 1908 using procaine as the local anaesthetic agent. HolmesZ subsequently repopularized the method in 1963 using lignocaine. A number of workers, 3-5 have since confirmed the effectiveness and usefulness of the technique and other drugs including p r i l ~ c a i n echlorprocaine’ ,~ and mepivacaine7 have been employed. Lignocaine, however, has remained the most widely used local anaesthetic in the United Kingdom for intravenous regional analgesia, although adversereactions occur in a significantnumber of patients due to the large dosages r e q ~ i r e d . ~ ~ ’ Bupivacaine (Marcain) is a more recently introduced local anaesthetic agent which has achieved wide popularity for extradural and direct nerve blocking techniques. Its toxicity when compared with lignocaine is said to be similar in equipotent dosage” but its relative lack of toxicity when given as an intravenous infusion has been commented on by several worker^.'^''^ In view of this relative lack of toxicity of bupivacaine, it was decided to investigate its use for intravenous regional analgesia.
Materials and methods Patients were drawn from the general and orthopaedic surgical operating lists and from the Accident and Emergency Department. The technique described below was employed when
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upper limb surgery was proposed, local analgesia was considered the method of choice and the procedure was acceptable to the informed patient. Patients with a history of adverse reactions to local anaesthetic drugs, patients with severe peripheral vascular or neurological disease (where the use of a tourniquet was undesirable), patients with haemolytic diseases including sickle cell states, and patients with a history of epilepsy were excluded from the study. Pilot study
A short pilot study was conducted to determine the optimum dose and concentration of bupivacaine. Dosage was varied between 0.5 and 1.5 mg/kg, with concentrations between 0.125 and 0.25%. It was found that a dose of 1.5 mg/kg at a concentration of 0.2% gave the best results with a convenient and easily calculated injection volume. A 0.2% solution was prepared by adding normal saline to the calculated bupivacaine dosage to achieve the final injection volume (Table 1). If 0.5% bupivacaine is diluted the final injection in ml is conveniently numerically equal to half the dose of bupivacaine in mg calculated at 1.5 mg/kg body weight. Table 1. Bupivacaine dosage and injection volumes for intravenous regional
analgesia
Weight of patient (kg) 80
70 60 50 40
Volume of
-
Bupivacaine dose at 1.5 mg/kg (mg)
bupivacaine (ml)
120 100 90 80 60
24 20 18 16 12
Table 2. Distribution of cases studied using intravenous regional analgesia
Orthopaedic Bone trauma Tendon repair Carpal tunnel release Triggering Removal of internal fixation General surgical Ganglia Skin grafting Foreign bodies Abscess Total
19 2 10 5
2 9 1 1 1 50
0.5%
Final injection volume after dilution with normal saline (ml) 60 50 45
40 30
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Main study
The distribution of 50 cases studied is shown in Table 2. All grades of anaesthetic staff carried out the blocks. Prepared packs containing the necessary drugs, instructions and the above dosage scheme were supplied to ensure uniformity of technique. A questionnaire was also included to record the details of each case. The method used was as follows: A tourniquet cuff was placed on the upper part of the arm over padding, which was used to avoid neurological trauma,I6 and a 21G ‘Butterfly’ indwelling needle (Abbot) was inserted into a distal vein, preferably on the dorsum of the hand. This site has been shown to produce better distribution of the local analgesic agent.5 A double cuff tourniquet” was used for potentially lengthy procedures to obviate the problem of pain due to a single cuff. The limb was exsanguinated using an Esmarch’s bandage, or, in the case of painful lesions, by simple elevation of the arm for 1 minute. The tourniquet cuff was then rapidly inflated to a pressure of 50-100 mmHg above the patient’s systolic blood pressure and the bupivacaine solution injected through the Butterfly needle. Assessment. The time taken for analgesia to pinprick to develop was noted together with the presence or absence of significant muscle relaxation. The clinical success of the block was rated as follows: Excellent. Complete anaesthesia or analgesia with profound muscle relaxation. Good. Complete anaesthesia or analgesia. Fair. Adequate analgesia for procedure without supplementation. Poor. Inadequate or patchy analgesia. Failure. No detectable analgesia. The tourniquet was released without re-inflation after completion of the operation and the patient closely observed and questioned concerning side effects. The total tourniquet time was recorded. Results
The results obtained in 50 patients were analysed. Clinical success was rated as excellent in 21 patients, good in 22 patients, fair in 6 patients and poor in only 1 patient. Thus satisfactory conditions were obtained in 98% (49)of the patients and in approximately half of these cases profound muscle relaxation was produced. Muscle relaxation was, however, always adequate for the successful reduction of the fracture cases. Onset of analgesia was rapid with a’mean injection to analgesia time of 4.4 minutes (range 2-8 minutes) in patients where an Esmarch’s bandage was used (27 patients), and 4.0 minutes (range 2-10) where an Esmarch’s bandage was not used (21 patients). These results were subjected to statistical analysis using Student’s ‘ t ’ test for means of two samples. There was no significant difference between the two groups with respect to the onset of analgesia time. One patient was not included in these calculations because of technical problems with the cuff which allowed the arm to fill with arterial blood, however, even in this case, clinical success was rated as good after a long injection to analgesia time. The use of the Esmarch’s bandage resulted in a greater proportion of cases with profound muscle relaxation (46%) when compared with the non-Esmarch’s group (36%) but the overall success rates were similar. Thus an Esmarch’s bandage need only be used in cases where the surgeon requires a bloodless field. Of the six cases rated as fair four patients noted ‘tingling’ on skin incision, one noted ‘pressure’ and one experienced a slight ache several minutes after the reduction of a Colles’ fracture. The one case rated poor had patchy analgesia and additional local infiltration was necessary. Side effects An 18-year-old, fit West Indian patient became slightly drowsy on cuff release. The total
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tourniquet time, was however, only 8 minutes. No other central nervous system or cardiovascular effects were noted and the patient recovered completely within 3 minutes. Another patient, a nervous girl, mentioned slight 'deafness' 15 minutes or more after cuff release whilst she was drinking a cup of tea in the recovery room. The significance of this is not clear but the deafness did not persist.
Discussion Intravenous regional analgesia using lignocaine is a commonly practised and useful technique. The toxic manifestations of lignocaine in various applications have been noted by Bromage'' and toxicity specifically following intravenous regional analgesia is also well documented. In one series described by Kennedy and his colleagues,1° 15% of their patients developed electrocardiographic (ECG) abnormalities including ventricular ectopics, bradycardia, nodal rhythm and one case had an asystolic cardiac arrest; 9% of their patients also became drowsy. The average dose of lignocaine used was 182.5 mg. Bell '' and his colleagues reported a 50% incidence of mild central nervous system reactions after the use of 0.5% lignocaine and Kew & Lowe' (in the Bantu) found a 3 1% incidence of bradycardia using 200 mg of lignocaine. An editorial (1965) in the Journalof the American Medical Association'9 advised against the use of the technique until safer agents were available. Attempts to reduce the toxic effects of local anaesthetic drugs have included pre-injection ischaemia to reduce the dosage necessary for successful analgesia. 1 * 2 0 ~ 2 1This modification of the technique requires that the tourniquet be inflated for 15-30 minutes before the local anaesthetic is injected but this procedure is both uncomfortable for the patient and time consuming for the anaesthetist. Furthermore, the value of pre-injection ischaemia in preventing side effects is questionable' ' unless the local anaesthetic dosage is greatly reduced. Intermittent release and re-inflation of the tourniquet at the end of the procedure, to delay systemic absorption of the local anaesthetic, has been recommended and was employed in a series by Merrifield & Carter.3 Despite this modification, approximately 12% of their patients had transient neurological symptoms such as dizziness on cuff release. Other local anaesthetics have been used in an attempt to improve the method. ThornAlquist6 using prilocaine described good clinical success (923%) with few side effects. Methaemoglobinaemia, however, can occur following the use of large doses of prilocaine, l e Z 2 Dickler' although this phenomenon is probably of little significance in clinical found that chlorprocaine, although successful in producing analgesia, was associated with a high incidence of neurological sequelae (37.5 %) and also local thrombophlebitis. A series reported by Costley & Lorhans using mepivacaine was highly successful (98 %) and had n o apparent side effects. Their dosage scheme of 4.3 mg/kg in 0.6% concentration was, however, rather unwieldy. It can therefore be demonstrated that all the local anaesthetic drugs previously used for intravenous regional analgesia have obvious disadvantages. The results of the present investigation have shown that bupivacaine is a suitable agent for use in this technique and that it offers advantages over the previously used agents. Several features of the use of bupivacaine deserve elaboration. The onset of analgesia was very rapid and patients reported sensations of 'warmth' followed by progressive analgesia and muscle relaxation with the limb becoming subjectively 'heavy'. One patient complained about the paraesthesiae becoming uncomfortable. Injection to analgesia time was usually 3-5 minutes. This is in contrast to the slow onset of action of bupivacaine when used for direct nerve blocks. The degree of exsanguination of the limb (whether gravity or an Esmarch's bandage was used) made no difference to the onset time or degree of analgesia; muscle relaxation, however, was more marked in the Esmarch group, Pre-injection ischaemia was not used in any of the cases and would appear to be unnecessary. The method used in the present series produced an extremely high success rate (98%).
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The one case rated poor had patchy analgesia and this could probably have been made complete by the injection of a further small quantity of intravenous bupivacaine. Significant side effects were limited to one young fit patient and were probably associated with the very brief tourniquet time (8 minutes). With the exception of one case, no attempt was made to reduce the dose of bupivacaine for reasons such as the age or physical condition of patients but despite this, toxic symptoms were not observed even in the older patients in the series. One patient had overt hepatic dysfunction; an excellent block resulted and no side effects were seen. Seven patients were obese and received relatively large intravenous dosages (120 mg) of bupivacaine with good results and no side effects. Bupivacaine is normally a long acting local analgesic but in this series paraesthesiae were experienced when the cuff was released and sensation returned within a further 10 or 15 minutes. It would appear that bupivacaine is an eminently suitable local anaesthetic agent for intravenous regional analgesia. A standardised dose regime is possible for all cases (1.5 mg/kg in 0.2% solution); analgesia and muscle relaxation develop rapidly in the majority of patients few side effects are seen at the recommended dosage. There is no need to subject the patient to pre-injection ischaemia, an Esmarch’s bandage or intermittent release and re-inflation of the cuff at the end of the procedure. Summary Intravenous regional analgesia using bupivacaine (Marcain) was employed as the anaesthetic technique in a series of 50 cases undergoing a variety of surgical procedures on the upper limb. A short pilot study was undertaken to determine the optimal dosage and concentration of bupivacaine. This was found to be 1.5 mgikg in 0.2% concentration and proved suitable for all patients regardless of age or physical condition. The use of bupivacaine produced highly successful results in 98% of cases. Onset of analgesia was very rapid (3-5 minutes) and profound muscular relaxation occurred in approximately half of the cases. The degree of muscle relaxation was, however, always adequate for the successful reduction of fractures. Only one patient exhibited an adverse reaction to the dose of bupivacaine used and this was limited to a brief period of slight drowsiness. The results of this series suggest that bupivacaine may provide advantages over previously used local analgesic agents for intravenous regional analgesia and that it may be the agent of choice for this useful technique.
Acknowledgments The author would like to express his sincere thanks to his anaesthetic and surgical colleagues at King’s College Hospital for their help with this study, to Dr Leo Strumin for encouragement and advice and to Miss Rosemary Nimmo and Miss Amanda Shaw for their capable secretarial assistance.
References 1. BIER,A. (1908) Uber einen neuen Weg Localanaesthesie an den Gleidmassen zu erzeugen. Archiv fur Klinische Chirurgie, 86, 1007. 2. HOLMES, C.McK. (1963) Intravenous regional anaesthesia: a useful method of producing analgesia of the limbs. Lancet, i, 245. 3. ADAMS, J.P., DEALY, E.J. & KENMORE, P.I. (1964) Intravenous regional anesthesia in hand surgery. Journal of Bone and Joint Surgery, &A, 811. 4. MERRIFIELD, A.J. & CARTER, S.J. (1965) Intravenous regional analgesia: lignocaine blood levels. Anaesthesia, 20, 287.
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C. & CHACHA, P. (1965) Regional anaesthesia by the intravenous route. British Medical 5. SORBIE, Journal, i, 957. A.-M. (1971) Intravenous regional anaesthesia. Acta Anaesthesiologica Scandi6. THORN-ALQUIST, navica, Supplement, 40. P.L. & SUSMAN, I.C. (1965) Intravenous regional anesthesia with 7. DICKLER,D.J., FRIEDMAN, chloroprocaine. Anesthesiology, 26,244. D.O. & LORHAN, P.H. (1971) Intravenous regional anesthesia. Archives of Surgery, 103, 8. COSTLEY, 34. 9. Cox, J.M.R. (1964) Intravenous regional anaesthesia. Canadian Anaesthetists' Society Journal, 11, 503. B.R., DUTHIE,A.M., PARBROOK, G.D. & CARR,T.L. (1965) Intravenous regional 10. KENNEDY, analgesia: an appraisal. British Medical Journal, i, 954. E.M. & HARRIS,W.H. (1963) Regional anaesthesia with intravenous lido11. BELL,H.M., SLATER, caine. Journal of the American Medical Association, 186, 544. 12. KEW, M.C. & LOWE,J.P. (1971) The cardiovascular complications of intravenous regional anaesthesia. British Journal of Surgery, 58, 179. 0. (1971) Physical and chemical data on anaesthetics. Acta Anaesthesiologica Scandin13. SECHER, avica, Supplement, 42. L., LOFSTROM, B., PERNOW, B., PERSSON, F., WARHEN, J. & WIDMAN, B. (1966) The 14. JORFELDT, intravenous toxicity of LAC 43 in dog and man evaluated by physiological methods. Proceedings of the III World Congress of Anaesthesiology, Sao Paulo, September I964 (Ed. by P. R. Bromage et a/.),vol. 1, p. 340. Springer, Berlin. B. (1966) Some circulatory and respiratory effects of intravenously infused local anaes15. WIDMAN, thetics. Acta Anaesthesiologica Scandinavica, Supplement, 25, 34. 16. MONTY,C.P. & DELLER,C.R. (1965) Experiences with intravenous regional anaesthesia. Proceedings of the Royal Society of Medicine, 58, 338. 17. HOYLE,J.R. (1964) Tourniquet for intravenous regional analgesia. Anaesthesia, 19, 294. P.R. & ROBSON, J.G. (1961) Concentrations of lignocaine in the blood after intravenous, 18. BROMAGE, intramuscular. euidural and endotracheal administration. Anaesthesia., 16.461. , 19. Journal of the American Medical Association (1965) Editorial-regional intravenous anesthesia. Journal of the American Medical Association, 193, 300. 20. HARRIS, W.H., SLATER, E.M. &BELL,H.M. (1965) Regional anesthesia by the intravenous route. Journal of the American Medical Association, 194, 1273. 21. HARRIS, W.H. (1969) Choice of anesthetic agents for intravenous regional anesthesia. Acta Anaesthesiologica Scandinavica, Supplement, 36,47. 22. HARRIS,W.H., COLE,D.W., MITAL,M. & LAVER,M.B. (1968) Methemoglobin formation and oxygen transport following intravenous regional anesthesia using prilocaine. Anesthesiology, 29, 65. I
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817
American Medical Association and recommendations of the committee. Journal of the American Medical Association, 82, 876. 4. WOODS, L.A., MCMAHON, F.G. & SEEVERS, M.H. (1951) Distribution and metabolism of cocaine in the dog and rabbit. Journal of Pharmacology and Experimental Therapeutics, 101, 200. 5 . WOODS,L.A., COCHIN, J., FORMEFELD, E.H., MCMAHON, F.G. & SEEVERS, M.H. (1951) The estimation of amines in biological materials with critical data for cocaine and mescaline. Journal of Pharmacology and Experimental Therapeutics, 101, 188. 6. CAMPBELL, D. & ADRIANI, J. (1958) Absorption of local anesthetics. Journal of the American Medical Association, 168, 873. 7. CAMPBELL, D. & ADRIANI, J. (1956) Fatalities following the topical application of local anesthetics to mucous membranes. Journal of the American Medical Association, 162, 1527. 8 . LEE,J.A. & ATKINSON, R.S.(1973) Synopsis of Anaesthesia, 7th edn, p. 338. Wright, Bristol. 9. HOPKIN, D.A.B. (1970) Anaesthesia: Recovery and Intensive Care, 1st edn, p. 169. English Universities Press, London. 10. PRYOR J.W. &BUSH,D.C.T. (1973) A Manualof Anaesthetic Techniques, 4th edn, p. 92. Wright, Bristol. 11. British National Formulary, 1974-6, p. 89. 12. MARTINDALE, W. (1972) The Extra Pharmacopoeia (Ed. by N.W. Blacow), 26th edn, p. 1029. The Pharmaceutical Press, London. 13. GOODMAN, L.S. & GILMAN, A. (1970) The Pharmacological Basis of Therapeutics, 4th edn, p. 379. MacmilIan, New York. 14. ORR,D. &JONES, 1. (1968) Anaesthesia for laryngoscopy. A comparison of the cardiovascular effects of cocaine and lignocaine. Anaesthesia, 23, 194. 15. MOORE, D.C. & BRIDENBAUGH, D.L. (1960) Oxygen-The antidote for systemic toxic reactions from local anesthetics drugs. Journal of the American Medical Association, 174, 842. 16. MUSCHOLL, E. (1961) Effect of cocaine and related drugs on the uptake of noradrenaline by heart and spleen. British Journal of Pharmacology and Chemotherapy, 16, 352. 17. STEINHAUS, J.E. (1952) A comparative study of the experimental toxicity of local anaesthetic agents. Anesthesiology, 13, 577. 18. STEINHAUS, J.E. & TATUM, A.L. (1950) An experimental study of cocaine intoxication and its treatment. Journal of Pharmacology and Experimental Therapeutics, 100, 351. Anaesthesia, 1975, Volume 30, pages 817-822
Intravenous regional analgesia using bupivacaine R . J. Ware, MB, BS Registrar, Department of Anaesthetics, King’s College Hospital, London S.E.5 The technique of intravenous regional analgesia was first described by August Bier in 1908 using procaine as the local anaesthetic agent. HolmesZ subsequently repopularized the method in 1963 using lignocaine. A number of workers, 3-5 have since confirmed the effectiveness and usefulness of the technique and other drugs including p r i l ~ c a i n echlorprocaine’ ,~ and mepivacaine7 have been employed. Lignocaine, however, has remained the most widely used local anaesthetic in the United Kingdom for intravenous regional analgesia, although adversereactions occur in a significantnumber of patients due to the large dosages r e q ~ i r e d . ~ ~ ’ Bupivacaine (Marcain) is a more recently introduced local anaesthetic agent which has achieved wide popularity for extradural and direct nerve blocking techniques. Its toxicity when compared with lignocaine is said to be similar in equipotent dosage” but its relative lack of toxicity when given as an intravenous infusion has been commented on by several worker^.'^''^ In view of this relative lack of toxicity of bupivacaine, it was decided to investigate its use for intravenous regional analgesia.
Materials and methods Patients were drawn from the general and orthopaedic surgical operating lists and from the Accident and Emergency Department. The technique described below was employed when
818
Forum
upper limb surgery was proposed, local analgesia was considered the method of choice and the procedure was acceptable to the informed patient. Patients with a history of adverse reactions to local anaesthetic drugs, patients with severe peripheral vascular or neurological disease (where the use of a tourniquet was undesirable), patients with haemolytic diseases including sickle cell states, and patients with a history of epilepsy were excluded from the study. Pilot study
A short pilot study was conducted to determine the optimum dose and concentration of bupivacaine. Dosage was varied between 0.5 and 1.5 mg/kg, with concentrations between 0.125 and 0.25%. It was found that a dose of 1.5 mg/kg at a concentration of 0.2% gave the best results with a convenient and easily calculated injection volume. A 0.2% solution was prepared by adding normal saline to the calculated bupivacaine dosage to achieve the final injection volume (Table 1). If 0.5% bupivacaine is diluted the final injection in ml is conveniently numerically equal to half the dose of bupivacaine in mg calculated at 1.5 mg/kg body weight. Table 1. Bupivacaine dosage and injection volumes for intravenous regional
analgesia
Weight of patient (kg) 80
70 60 50 40
Volume of
-
Bupivacaine dose at 1.5 mg/kg (mg)
bupivacaine (ml)
120 100 90 80 60
24 20 18 16 12
Table 2. Distribution of cases studied using intravenous regional analgesia
Orthopaedic Bone trauma Tendon repair Carpal tunnel release Triggering Removal of internal fixation General surgical Ganglia Skin grafting Foreign bodies Abscess Total
19 2 10 5
2 9 1 1 1 50
0.5%
Final injection volume after dilution with normal saline (ml) 60 50 45
40 30
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Main study
The distribution of 50 cases studied is shown in Table 2. All grades of anaesthetic staff carried out the blocks. Prepared packs containing the necessary drugs, instructions and the above dosage scheme were supplied to ensure uniformity of technique. A questionnaire was also included to record the details of each case. The method used was as follows: A tourniquet cuff was placed on the upper part of the arm over padding, which was used to avoid neurological trauma,I6 and a 21G ‘Butterfly’ indwelling needle (Abbot) was inserted into a distal vein, preferably on the dorsum of the hand. This site has been shown to produce better distribution of the local analgesic agent.5 A double cuff tourniquet” was used for potentially lengthy procedures to obviate the problem of pain due to a single cuff. The limb was exsanguinated using an Esmarch’s bandage, or, in the case of painful lesions, by simple elevation of the arm for 1 minute. The tourniquet cuff was then rapidly inflated to a pressure of 50-100 mmHg above the patient’s systolic blood pressure and the bupivacaine solution injected through the Butterfly needle. Assessment. The time taken for analgesia to pinprick to develop was noted together with the presence or absence of significant muscle relaxation. The clinical success of the block was rated as follows: Excellent. Complete anaesthesia or analgesia with profound muscle relaxation. Good. Complete anaesthesia or analgesia. Fair. Adequate analgesia for procedure without supplementation. Poor. Inadequate or patchy analgesia. Failure. No detectable analgesia. The tourniquet was released without re-inflation after completion of the operation and the patient closely observed and questioned concerning side effects. The total tourniquet time was recorded. Results
The results obtained in 50 patients were analysed. Clinical success was rated as excellent in 21 patients, good in 22 patients, fair in 6 patients and poor in only 1 patient. Thus satisfactory conditions were obtained in 98% (49)of the patients and in approximately half of these cases profound muscle relaxation was produced. Muscle relaxation was, however, always adequate for the successful reduction of the fracture cases. Onset of analgesia was rapid with a’mean injection to analgesia time of 4.4 minutes (range 2-8 minutes) in patients where an Esmarch’s bandage was used (27 patients), and 4.0 minutes (range 2-10) where an Esmarch’s bandage was not used (21 patients). These results were subjected to statistical analysis using Student’s ‘ t ’ test for means of two samples. There was no significant difference between the two groups with respect to the onset of analgesia time. One patient was not included in these calculations because of technical problems with the cuff which allowed the arm to fill with arterial blood, however, even in this case, clinical success was rated as good after a long injection to analgesia time. The use of the Esmarch’s bandage resulted in a greater proportion of cases with profound muscle relaxation (46%) when compared with the non-Esmarch’s group (36%) but the overall success rates were similar. Thus an Esmarch’s bandage need only be used in cases where the surgeon requires a bloodless field. Of the six cases rated as fair four patients noted ‘tingling’ on skin incision, one noted ‘pressure’ and one experienced a slight ache several minutes after the reduction of a Colles’ fracture. The one case rated poor had patchy analgesia and additional local infiltration was necessary. Side effects An 18-year-old, fit West Indian patient became slightly drowsy on cuff release. The total
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tourniquet time, was however, only 8 minutes. No other central nervous system or cardiovascular effects were noted and the patient recovered completely within 3 minutes. Another patient, a nervous girl, mentioned slight 'deafness' 15 minutes or more after cuff release whilst she was drinking a cup of tea in the recovery room. The significance of this is not clear but the deafness did not persist.
Discussion Intravenous regional analgesia using lignocaine is a commonly practised and useful technique. The toxic manifestations of lignocaine in various applications have been noted by Bromage'' and toxicity specifically following intravenous regional analgesia is also well documented. In one series described by Kennedy and his colleagues,1° 15% of their patients developed electrocardiographic (ECG) abnormalities including ventricular ectopics, bradycardia, nodal rhythm and one case had an asystolic cardiac arrest; 9% of their patients also became drowsy. The average dose of lignocaine used was 182.5 mg. Bell '' and his colleagues reported a 50% incidence of mild central nervous system reactions after the use of 0.5% lignocaine and Kew & Lowe' (in the Bantu) found a 3 1% incidence of bradycardia using 200 mg of lignocaine. An editorial (1965) in the Journalof the American Medical Association'9 advised against the use of the technique until safer agents were available. Attempts to reduce the toxic effects of local anaesthetic drugs have included pre-injection ischaemia to reduce the dosage necessary for successful analgesia. 1 * 2 0 ~ 2 1This modification of the technique requires that the tourniquet be inflated for 15-30 minutes before the local anaesthetic is injected but this procedure is both uncomfortable for the patient and time consuming for the anaesthetist. Furthermore, the value of pre-injection ischaemia in preventing side effects is questionable' ' unless the local anaesthetic dosage is greatly reduced. Intermittent release and re-inflation of the tourniquet at the end of the procedure, to delay systemic absorption of the local anaesthetic, has been recommended and was employed in a series by Merrifield & Carter.3 Despite this modification, approximately 12% of their patients had transient neurological symptoms such as dizziness on cuff release. Other local anaesthetics have been used in an attempt to improve the method. ThornAlquist6 using prilocaine described good clinical success (923%) with few side effects. Methaemoglobinaemia, however, can occur following the use of large doses of prilocaine, l e Z 2 Dickler' although this phenomenon is probably of little significance in clinical found that chlorprocaine, although successful in producing analgesia, was associated with a high incidence of neurological sequelae (37.5 %) and also local thrombophlebitis. A series reported by Costley & Lorhans using mepivacaine was highly successful (98 %) and had n o apparent side effects. Their dosage scheme of 4.3 mg/kg in 0.6% concentration was, however, rather unwieldy. It can therefore be demonstrated that all the local anaesthetic drugs previously used for intravenous regional analgesia have obvious disadvantages. The results of the present investigation have shown that bupivacaine is a suitable agent for use in this technique and that it offers advantages over the previously used agents. Several features of the use of bupivacaine deserve elaboration. The onset of analgesia was very rapid and patients reported sensations of 'warmth' followed by progressive analgesia and muscle relaxation with the limb becoming subjectively 'heavy'. One patient complained about the paraesthesiae becoming uncomfortable. Injection to analgesia time was usually 3-5 minutes. This is in contrast to the slow onset of action of bupivacaine when used for direct nerve blocks. The degree of exsanguination of the limb (whether gravity or an Esmarch's bandage was used) made no difference to the onset time or degree of analgesia; muscle relaxation, however, was more marked in the Esmarch group, Pre-injection ischaemia was not used in any of the cases and would appear to be unnecessary. The method used in the present series produced an extremely high success rate (98%).
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The one case rated poor had patchy analgesia and this could probably have been made complete by the injection of a further small quantity of intravenous bupivacaine. Significant side effects were limited to one young fit patient and were probably associated with the very brief tourniquet time (8 minutes). With the exception of one case, no attempt was made to reduce the dose of bupivacaine for reasons such as the age or physical condition of patients but despite this, toxic symptoms were not observed even in the older patients in the series. One patient had overt hepatic dysfunction; an excellent block resulted and no side effects were seen. Seven patients were obese and received relatively large intravenous dosages (120 mg) of bupivacaine with good results and no side effects. Bupivacaine is normally a long acting local analgesic but in this series paraesthesiae were experienced when the cuff was released and sensation returned within a further 10 or 15 minutes. It would appear that bupivacaine is an eminently suitable local anaesthetic agent for intravenous regional analgesia. A standardised dose regime is possible for all cases (1.5 mg/kg in 0.2% solution); analgesia and muscle relaxation develop rapidly in the majority of patients few side effects are seen at the recommended dosage. There is no need to subject the patient to pre-injection ischaemia, an Esmarch’s bandage or intermittent release and re-inflation of the cuff at the end of the procedure. Summary Intravenous regional analgesia using bupivacaine (Marcain) was employed as the anaesthetic technique in a series of 50 cases undergoing a variety of surgical procedures on the upper limb. A short pilot study was undertaken to determine the optimal dosage and concentration of bupivacaine. This was found to be 1.5 mgikg in 0.2% concentration and proved suitable for all patients regardless of age or physical condition. The use of bupivacaine produced highly successful results in 98% of cases. Onset of analgesia was very rapid (3-5 minutes) and profound muscular relaxation occurred in approximately half of the cases. The degree of muscle relaxation was, however, always adequate for the successful reduction of fractures. Only one patient exhibited an adverse reaction to the dose of bupivacaine used and this was limited to a brief period of slight drowsiness. The results of this series suggest that bupivacaine may provide advantages over previously used local analgesic agents for intravenous regional analgesia and that it may be the agent of choice for this useful technique.
Acknowledgments The author would like to express his sincere thanks to his anaesthetic and surgical colleagues at King’s College Hospital for their help with this study, to Dr Leo Strumin for encouragement and advice and to Miss Rosemary Nimmo and Miss Amanda Shaw for their capable secretarial assistance.
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