Annals of the Royal College of Surgeons of England (1992) vol. 74, 89-94
prospective audit for hand surgery A
of
regional anaesthesia
J M Porter
MS FRCS Fellow in Hand Surgery
Plastic Surgery and Burns Unit, Aberdeen Royal Infirmary
Key words: Axillary block; Anaesthesia; Intravenous regional anaesthesia; Peripheral
A prospective audit has been carried out of 153 consecutive regional anaesthetics for hand surgery, using intravenous regional anaesthesia (IVRA), axillary block or multiple peripheral nerve blocks in the upper limb. Surgery was carried out successfully in 147 patients. Apart from two patients, who complained of paraesthesia after regional nerve blocks, there were no side-effects. A total of 13 patients said that they would have preferred a general anaesthetic. Regional anaesthesia was found to be suitable for use by members of the surgical staff, but success was only assured by meticulous attention to detail and by careful safety precautions. Regional anaesthesia should not be attempted by inexperienced, unsupervised hand surgeons.
Regional anaesthesia for hand
surgery has been used for alternative to general anaesthesia. Techniques of regional anaesthesia have been discussed extensively in the anaesthetic literature but less frequently in surgical journals. More recently surgeons have described a variety of regional anaesthetic techniques associated with high success rates and few adverse effects (1-4). An extensive correspondence in response to these publications questioned whether the methods described were safe and appropriate for surgeons to attempt (5,6). At the Aberdeen Royal Infirmary, plastic surgery provides an emergency hand service for the accident and emergency department, in co-operation with orthopaedic surgery. Approximately 350 new patients are referred to the plastic surgery service each year, and a large proportion of the operations last for less than 1 h. To expedite emergency hand operations, the plastic surgery staff have, for a number of years, used regional anaesthesia in selected patients. This practice obviates the need to queue with other specialties for the duty emergency anaesthetist. many years as an
Correspondence to: Mr J M Porter, The Wessex Centre for Plastic and Maxillo-Facial Surgery, Odstock Hospital, Salisbury, Wiltshire SP2 8BJ
nerve
block
A prospective audit of regional anaesthesia in the plastic surgery hand service has been undertaken to investigate the success rate, to document the incidence of side-effects or complications and to ascertain if the patients were satisfied with the service being given. Safety precautions before, during and after the administration of regional anaesthesia were reviewed in collaboration with the Department of Anaesthesia, and these were in line with previously published recommendations.
Patients and methods A total of 154 regional anaesthetics for hand or forearm surgery were performed during a period of 6 months. All the blocks were given by members of the plastic surgery staff. A large majority of the operations were for injuries. The details of the patients are summarised in Table I. During the study period, 77 IVRAs, 41 axillary brachial plexus blocks and 35 multiple peripheral nerve blocks were performed. The block was administered by the operating surgeon in 57 out of 77 operations under IVRA, in 37 out of 41 operations under axillary block and in 24 out of 35 operations under regional nerve block. The patients were fasted for 4 h before surgery,
Table I. Details of patients submitted to regional anaesthesia
Patient numbers Mean age (years)
(range) Sex Anaesthesia by operating surgeon
Axillary
Peripheral
IVRA
block
nerve block
77 36.2 (17-86) 13F 64M
41 31.8 (17-77) SF 36M
35 38.6 (16-64) 2F 33M
57
37
24
90
J M Porter
but every effort was made to ensure that the period of fasting was not longer. Peroperative sedation was avoided if at all possible and was only used in two patients. The preoperative assessment of patients for regional anaesthesia was similar to the assessment undertaken before general anaesthesia. The patients selected were in good general health and not excessively apprehensive; those selected for IVRA were for operations which were not expected to last more than 45 min, and those selected for axillary block were scheduled for operations which were expected to last for more than 1 h and less than 3 h. If the diagnosis was in doubt and the operating time was unpredictable, an axillary block was used. Axillary blocks were not attempted in patients in whom the axillary artery could not easily be palpated. Patients were also excluded from regional anaesthesia if they were unable to co-operate, if bilateral surgery was required, if significant preoperative blood loss had taken place, or if there was a need to cut skin grafts from a site other than the anaesthetised upper limb. The blocks were assessed by pinprick before starting surgery. Axillary and regional nerve blocks were classified as complete if all the skin innervated by the blocked nerves was numb to pinprick. If sensate skin remained the block was classified as incomplete, and if there was insufficient analgesia for the operation to proceed the block was classified as a failure. The grades of the surgeons performing the blocks are shown in Table II and the types of operations performed in Table III. The local anaesthetic agents used are summarised in Table IV.
Technique of IVRA The IVRAs were administered in the operating theatre, with the arm resting on a wide hand table. An 18G intravenous cannula was inserted into a vein on the dorsum of both hands. A well-padded double tourniquet was placed on the upper arm and both the cuffs were inflated briefly to ensure that a steady pressure could be maintained and that the radial pulse became impalpable. The arm was then exsanguinated by elevation and using an Esmarch bandage, taking care that the Esmarch bandage did not damage the skin by shearing. The proximal cuff was inflated to a pressure 50 mmHg above systolic arterial pressure and the arm was returned to the table. After a final check that the radial pulse was Table II. Grades of the surgeons administering regional anaesthesia
Consultant Hand Fellow SR equivalent Registrar SHO
IVRA
Axillary block
6
1
21 23 27
35 4 1
Peripheral nerve block
11 22 2
Table III. Range of operations performed under regional anaesthesia
Repair of digital nerve Extensor tendon repair Flexor tendon repair Reduction of finger fractures/dislocations Skin grafting Terminalisation of fingers Cross-finger flap Wound exploration Local skin flap Dupuytren's contracture Tattoo removal Removal of foreign body Other operation
IVRA
Axillary block
Regional nerve block
10 17 2
2 7 13
1 9
3 6
6
12 1 9 3 3
1 10
5 4 6 1 4
1 2 9
1
5
Table IV. Local anaesthetic agents used for regional anaesthesia IVRA Prilocaine Lignocaine/bupivacaine Bupivacaine Lignocaine
77
Peripheral
Axillary block
nerve block
22 16 3
2 4 25 4
impalpable, 30-40 ml of 1% prilocaine (approximately 6 mg/kg) was injected through the cannula. After an interval of 10 min, the distal cuff was inflated, the proximal cuff deflated, and the operation commenced. At the conclusion of the surgery, the dressing was applied, the arm was elevated and the tourniquet was deflated. Great care was taken to ensure that elevation of the arm was maintained continuously during transfer from the operating theatre to the ward and on the ward thereafter. At no point after the release of the tourniquet was the arm lowered, until a minimum period of 2 h had elapsed. IVRA has been described as being a simple technique (3). In practice the method requires a large number of separate steps and success can only be assured by meticulous attention to detail. A number of important points should be emphasised. 1 Moving the patient while the block is in progress can lead to deflation of the tourniquet. 2 Arterial blood may leak into the arm if the elbow is allowed to bend during the anaesthetic. 3 A nurse assistant, sitting on the opposite side of the patient to the surgeon, must observe the pressure dial of the tourniquet throughout the anaesthetic
Regional anaesthesia for hand surgery and maintain the tourniquet pressure as necessary. She should be instructed to maintain verbal contact with the patient and eye contact with the surgeon. 4 A bicycle pump was used to inflate the tourniquet; an automatic tourniquet was never used. There are a number of accounts of this technique in the recent literature (4,7,8).
Technique of axiliary block Axillary blocks were performed using the perivascular method and an immobile needle technique (9,10). At the start of the investigation, a mixture of 20 ml of 0.5% bupivacaine and 20 ml of 1% lignocaine with 1/200 000 adrenaline was used in 15 blocks; 0.5% bupivacaine alone was used in three patients. After the first 18 blocks, 1% prilocaine was used in all patients, the dose being the same as for IVRA. The technique of axillary block has been well described in recent publications (8-10), but various important points in the method used in the present investigation should be emphasised. 1 The blocks were administered in the anaesthetic room with an ECG monitor and an automatic blood pressure cuff attached and recording. 2 Venous access was established in the contralateral upper limb. 3 The injection was given using a short bevel needle, attached to a plastic extension tube (Plexufix®, Braun Co). 4 While the local anaesthetic was being injected, distal spread of the anaesthetic solution was prevented by firm digital pressure on the axillary sheath, distal to the point of injection. Application of a tourniquet distal to the point of injection has been shown to be ineffective (11). 5 An intercostobrachial block was performed after the axillary injection and before the needle was withdrawn. 6 After surgery, the arm was elevated in an appropriate sling and the patient was confined to bed until the motor and sensory effects of the block had totally disappeared. The nurses were carefully advised that the arm was paralysed and would remain so until the effect of the local anaesthetic disappeared.
Technique of upper limb nerve blocks A combination of nerve blocks was selected, appropriate to the intended operation. The ulnar nerve was most commonly blocked at the elbow and the median and radial nerves at the wrist. The techniques for these blocks have been well-described in the recent literature
(8). If the axillary or the regional nerve blocks had failed to anaesthetise the area to be operated on after 45 min, a
small amount of local anaesthetic was administered, either as a nerve block in the arm or as a local infiltration.
Results Sufficient analgesia for surgery to take place was achieved in 71 out of 77 IVRAs; four failures were due to errors in technique. In one block the arm was not fully exsanguinated. The tourniquet did not retain the local anaesthetic in three blocks; one of these patients was moved during the anaesthetic and in two the leak was probably due to incorrect positioning of the elbow. Two of these patients were subsequently operated on under local infiltration, one had an axillary block and one had a general anaesthetic. Two failures, in the same patient on two different occasions, occurred when an apparently functioning cuff failed to keep the local anaesthetic in the arm. This patient had an exceptionally thin upper arm. She was subsequently operated on under a peripheral nerve block. Ten patients were found to have residual sensation at the commencement of surgery and required a few millilitres of local infiltration before the operation could start. The mean tourniquet time for IVRA was 46.7 min (range 25-90 min). This time is inclusive of the time taken for the anaesthetic to take effect and the time taken to perform the operation. When questioned at the conclusion of surgery, 23 patients (32.4%) said that they had experienced some discomfort from the tourniquet but none of these patients experienced enough discomfort to disrupt the progress of the operation. Surgery was completed successfully in all the patients who underwent an axillary block. The mean time from the commencement of the block to the start of the operation was 40 min (range 20-70 min). The mean operating time was 51 min (range 7-130 min). A complete block was achieved in 32 out of the 41 axillary blocks (78%). In the 9 incomplete blocks, either local infiltration of a few millilitres of anaesthetic or a regional nerve block in the arm provided enough extra analgesia for the operation to proceed. A further six blocks were supplemented after 45 min, either because they were thought to be incomplete or to expedite the start of the surgery; these blocks were found to be complete at the conclusion of the operation. One block was supplemented with an ulnar nerve block at the elbow at the commencement of the anaesthetic, due to uncertainty as to whether the axillary block had been correctly placed; this block proved to be satisfactory. A total of 9 out of the 15 blocks in which the lignocaine/bupivacaine was used required supplementing with a further injection of local anaesthetic, whereas extra local anaesthetic was only used in 6 out of 23 blocks in which 1% prilocaine was given. The mean time between administration of the block and the commencement of the operation was 33.3 min after prilocaine and 45 min after lignocaine/bupivacaine. A tourniquet was used in 39 of the operations performed under axillary block. Fourteen patients said they
92
J M Porter
Table V. Results IVRA Patient numbers Surgery completed Block time (min)*
77 71
(range) Tourniquet time (min) (range) Operating time (min) (range) Tourniquet discomfort Further LA injection Complete block
48
(25-90) 38
(15-80) 27 10 71
Axillary block
Peripheral block
nerve
41 41 40
35 35 45
(25-70)
(10-135)
51 (7-130) 51 (7-130) 14 16 32
26
(9-50) 25
(9-50) 8 6 27
The block time is the time in minutes between the administration of the block and the start of the operation LA = Local anaesthetic
*
experienced some discomfort due to the tourniquet (37%), but none of these patients experienced pain severe enough to interrupt the operation. Peripheral nerve blocks were used in 35 patients. The block was complete in 27 patients and six required a further injection of local anaesthetic. The mean time between administration of the block and the commencement of surgery was 45.2 min (range 10-135 min). A tourniquet was used in 30 patients, of whom eight complained of tourniquet pain. The mean tourniquet time was 26 min (range 9-50 min). Two patients complained of paraesthesiae after peripheral nerve blocks, one after ulnar nerve block at the elbow and one after median nerve block at the wrist. After surgery, 13 patients who received a satisfactory block expressed dissatisfaction, seven after IVRA, three after axillary block and three after peripheral nerve block. The only patient in the series to experience successful IVRA and brachial plexus block on different occasions, emphatically preferred IVRA. The results are summarised in Table V.
Discussion The results of this investigation have shown that the surgical staff achieved a complete success rate with axillary and with regional nerve blocks, and a 92% success rate with IVRA. Local anaesthetic toxicity was not seen, and the main side-effect observed was discomfort due to the tourniquet. The disadvantages of IVRA have been considerably overstated (1). Venous pooling should not be a problem if the arm is fully exsanguinated before the injection of local anaesthetic. Sudden failure of the tourniquet should not occur if the equipment is kept in good order, if the tourniquet is checked before starting the operation, and
if the pressure dial of the tourniquet is observed continuously throughout surgery. Although the tourniquet cannot be released for haemostasis, any site of venous bleeding is usually obvious, especially if the operation is undertaken under loupe magnification. A haematoma can be prevented by meticulous postoperative elevation of the hand. Onset of anaesthesia is more rapid after IVRA than after an axillary block and, if a correct method is used, complete anaesthesia can nearly always be assured. These are considerable advantages when the emergency service has a large number of relatively minor cases to deal with. Tourniquet discomfort can be minimised if the upper arm is properly padded, if a double cuff tourniquet is used, and if the tourniquet pressure does not exceed the systolic arterial pressure by more than 50 mmHg. A tourniquet time of 45 min was exceeded in 29 IVRAs. Of these patients, 17 (59%) complained of discomfort, whereas only seven patients (12%) complained of discomfort when the tourniquet time was less than 45 min. In retrospect, some of these patients might have been better served with an axillary block, but all of these operations were completed without undue difficulty. In 11 out of the 71 IVRAs, a small amount of local anaesthetic was infiltrated at the site of operation before the surgery commenced. This was considered to be necessary in two out of 27 patients anaesthetised by the consultants or the Hand Fellow, and nine out of 50 patients anaesthetised by the registrars and the SHOs. This problem could have been caused by insufficient exsanguination of the arm leading to the local anaesthetic being diluted in an excessive volume of blood. It is also possible, on some occasions, that further local anaesthetic was injected because the surgeon did not recognise that the patient was feeling movement rather than pain. As the audit progressed, the rate of local infiltration after IVRA decreased, as the more junior members of the staff became more expert. There were six failures of IVRA. Four of these blocks were given by SHOs who were learning the method, and on two of these occasions the surgeon giving the block was unsupervised. It is unwise for novice hand surgeons to carry the extra responsibility of the anaesthetic until confidence in performing the surgery has been acquired. Moreover, allowance should be made for a prolonged learning curve, as IVRA requires attention to many details, and axillary block is by no means a simple technique to teach and learn. Serious complications after IVRA are rare; in one series of 7500 blocks no major complications occurred (3). A series of three fatal accidents caused by IVRA has been reported (12). All these patients were anaesthetised in accident and emergency departments by doctors of SHO grade; two of the patients were children. Bupivacaine was the local anaesthetic agent used and the arms were all kept exsanguinated with an automatic tourniquet. In the present investigation, a simple bicycle pump was used to keep the tourniquet inflated, one person was always delegated to observe the pressure dial
of the tourniquet, children were excluded and a local anaesthetic agent of lesser toxicity than bupivacaine was used (13,14). Axillary block anaesthesia has some disadvantages for a busy emergency hand service. A wait of up to 60 min may be necessary before surgery can commence, and there is a significant incidence of incomplete anaesthesia. However, the anaesthetic lasts for up to 3 h, if prilocaine is used, and for longer if bupivacaine is used, either alone or in a mixture. Axillary block anaesthesia is therefore more suitable than IVRA for operations which last longer than 45 min, although patients may become uncomfortable on the operating table after 2-3 h. The paralysis of the upper limb muscles greatly facilitates the retrieval of divided tendon ends. Axillary block anaesthesia is not a substitute for IVRA or for regional nerve blocks and is properly used to extend the number of operations that can be attempted under regional anaesthesia. Peripheral nerve blocks were found to give effective anaesthesia of the hand in 27 out of 35 patients. The scope of the surgery that can be attempted under these blocks is limited, as the upper arm is not anaesthetised; even with careful padding of the tourniquet, the addition of an intercostobrachial nerve block and the avoidance of overinflation of the tourniquet, tourniquet pain may become a problem after 30 min. However, in the present investigation, the incidence of tourniquet discomfort after peripheral nerve blocks was similar to the incidence after IVRA and axillary block. Peripheral nerve blocks require a smaller dose of local anaesthetic than IVRA or axillary block and the site of the injection is not near any major blood vessel. The anaesthetic can therefore be administered on the ward before the patient is transferred to the operating theatre and it is safe to use bupivacaine. These blocks have the disadvantage that multiple injections are required. There have been two large series of brachial plexus blocks in the recent surgical literature. Rouholamin and Harris (1) described 300 axillary brachial plexus blocks, all of which gave sufficient analgesia for surgery to proceed; only 11 of the blocks required augmenting with a further injection of local anaesthetic. Apart from one case of transient thrombophlebitis of the axilla, no complications or side-effects were observed. Thompson et al. (2) reported a series of 1913 brachial plexus blocks, 1248 administered by the supraclavicular route and 665 by the axillary route. Of these anaesthetics, 80% were carried out by surgical staff. A complete block was obtained in 83.5% of the patients, a further injection of local anaesthetic was required in 11.4%, and in 5.1% insufficient anaesthesia was obtained for the operation to proceed. Neither of these papers stated how many of the regional anaesthetics were performed by the operating surgeon.
Rouholamin and Harris (1) recommended a method of axillary block in which the injection was administered through a 23G (blue) long bevel needle, with no extension tube. Thompson et al. (2) used a 32G needle but did not otherwise comment on the technique of the injection. In the present series, a short bevel needle on an extension
Regional anaesthesia for hand surgery 93 tube was preferred. The short bevel needle is less likely to pierce a blood vessel or a major nerve than a 23G or 32G needle (15), and the use of the immobile needle technique makes inadvertent movement and consequent penetration of a blood vessel during the injection less likely. Rouholamin and Harris (1) used prilocaine for their axillary blocks and, apart from stating that 'standard resuscitation drugs should be on hand', no mention was made of safety precautions. Thompson et al. (2) used a mixture of lignocaine and bupivacaine and did not mention the safety precautions taken. In the present investigation, prilocaine was the preferred local anaesthetic for IVRA. The rate of incomplete brachial plexus anaesthesia decreased considerably when prilocaine was substituted for the lignocaine/ bupivacaine/adrenaline mixture. Prilocaine is of lower toxicity than either bupivacaine or lignocaine (13). The duration of action is shorter than that of bupivacaine, but the 3 h of anaesthesia obtainable with an axillary block is adequate for the range of operations that were considered suitable. It is clearly imperative that, if regional anaesthesia is to be administered by members of the surgical staff, the least toxic agent should be used. Although local anaesthetic toxicity is unusual after regional anaesthesia of any sort, most serious complications of regional anaesthesia have been reported after the administration of bupivacaine (12,16-18). Although major local anaesthetic toxicity was not observed in any of the previous series quoted or in the present series, every precaution should be taken to minimise the risk of this potentially fatal hazard. Venous access in the contralateral hand, the availability of monitoring equipment and anticonvulsant drugs, the ready availability of oxygen, suction, an operating table with a facility for head-down tilt, and standard procedures in the event of complications are all essential safety precautions. A block administered by the operating surgeon differs from a block administered by an anaesthetist in that a surgeon works within certain constraints. Only medically fit and co-operative patients should be selected. If the patient has a medical condition which may give rise to concern during the progress of the operation, the assistance of an anaesthetist must be sought. It is particularly unwise to administer a large dose of local anaesthetic to a patient who is hypovolaemic, because the compensatory vasoconstriction may divert a large proportion of the local anaesthetic to the heart muscle and the central nervous system (18). We are in full agreement with Rouholamin and Harris (1) that regional anaesthesia is well-suited for use by surgical staff. Patients requiring major hand surgery avoid a general anaesthetic; this is of particular benefit during the recovery period, as the patient is able to cooperate during transfer from the theatre. In more minor hand operations, disruption of the wound by local infiltration can usually be avoided. In the present investigation, a high success rate and a high rate of patient acceptance was achieved by using a variety of techniques,
94
J M Porter
with each block being selected according to the patient's requirements. Although the regional anaesthesia has been shown to have a low complication rate in surgical hands, the potential hazards are serious (5-7,12,14-18). It is absolutely imperative that regional anaesthesia is not attempted by unsupervised, inexperienced surgeons, that the surgical staff take the same safety precautions as the anaesthetic staff and that surgeons are familiar with the pharmacology of local anaesthetic drugs. The circumstances under which surgeons attempt regional anaesthesia and the methods used should be clearly defined. A programme of regional anaesthesia for hand surgery should not be undertaken without the advice and cooperation of the anaesthetic service. I am grateful to Mr C R W Rayner and to Mr 0 M Fenton for permission to study patients under their care. I am especially indebted to Mr Rayner, who showed me the method of performing IVRA and to Mr R H Milner who taught me to perform the axillary brachial plexus block. I would also like to thank my colleagues in the Department of Anaesthesia in Aberdeen for sharing their skills with me and giving advice on the preparation of this paper, and also my colleagues in the Plastic Surgery Unit for filling in the audit proformas.
References I Rouholamin E, Harris D. Axillary block anaesthesia in acute and elective hand surgery: a report on 300 procedures. Ann R Coll Surg Engl 1990;72:90-3. 2 Thompson AM, Newman RJ, Semple JC. Brachial plexus anaesthesia for upper limb surgery: a review of eight years' experience. J Hand Surg 1988;13B: 195-8.
3 Rawlings ID, Staniforth P. Intravenous regional anaesthesia in upper limb trauma. Injury 1979;10:231-4. 4 Wallace WA, Guardini R, Ellis SJ. Standard intravenous regional anaesthesia. Br Med J 1982;285:554-6. 5 Comment. Axillary block anaesthesia in acute and elective surgery: a report on 300 procedures. Ann R Coll Surg Engl 1990;72:274-80. 6 Comment. Standard intravenous regional anaesthesia. Br MedJ3 1982;285:731-2. 7 Goold JE. Intravenous regional anaesthesia. BrJ Hosp Med 1985;33:335-40. 8 Scott DB. Techniques of Regional Anaesthesia. East Norwalk: Appleton and Lange/Mediglobe, 1989. 9 Winnie AP. An 'immobile' needle for nerve blocks. Anesthesiology 1969;31:577-8. 10 Brockway MS, Wildsmith JAW. Axillary brachial plexus block: method of choice? Br J Anaesth 1990;64:224-31. 11 Winnie AP, Radonjic R, Akkineni SR, Durrani Z. Factors influencing distribution of local anaesthetic injected into the brachial plexus sheath. Anesth Analg 1979;58:225-34. 12 Heath ML. Deaths after intravenous regional anaesthesia. Br Med J 1982;285:913-14. 13 Wildsmith JAW. Prilocaine-An underutilised local anaesthetic. Reg Anaesth 1985;10: 155-9. 14 Wildsmith JAW. Intravenous regional analgesia: essential safeguards. Anaesthesia 1982;37:959. 15 Selander D, Dhuner K-G, Lundborg G. Peripheral nerve injury due to injection needles used for regional anaesthesia. An experimental study of the acute effects of needle point trauma. Acta Anaesthesiol Scand 1977;21: 182-8. 16 Scott DB. Toxicity caused by local anaesthetic drugs. BrJ Anaesth 1981;53:553-4. 17 Albright GA. Cardiac arrest following regional anaesthesia with editocaine or bupivacaine. Anesthesiology 1979;51:2857. 18 Scott DB. Toxic effects of local anaesthetic agents on the central nervous system. BrJ7 Anaesth 1986;58:732-5.
Received 24 May 1991
prospective audit for hand surgery A
of
regional anaesthesia
J M Porter
MS FRCS Fellow in Hand Surgery
Plastic Surgery and Burns Unit, Aberdeen Royal Infirmary
Key words: Axillary block; Anaesthesia; Intravenous regional anaesthesia; Peripheral
A prospective audit has been carried out of 153 consecutive regional anaesthetics for hand surgery, using intravenous regional anaesthesia (IVRA), axillary block or multiple peripheral nerve blocks in the upper limb. Surgery was carried out successfully in 147 patients. Apart from two patients, who complained of paraesthesia after regional nerve blocks, there were no side-effects. A total of 13 patients said that they would have preferred a general anaesthetic. Regional anaesthesia was found to be suitable for use by members of the surgical staff, but success was only assured by meticulous attention to detail and by careful safety precautions. Regional anaesthesia should not be attempted by inexperienced, unsupervised hand surgeons.
Regional anaesthesia for hand
surgery has been used for alternative to general anaesthesia. Techniques of regional anaesthesia have been discussed extensively in the anaesthetic literature but less frequently in surgical journals. More recently surgeons have described a variety of regional anaesthetic techniques associated with high success rates and few adverse effects (1-4). An extensive correspondence in response to these publications questioned whether the methods described were safe and appropriate for surgeons to attempt (5,6). At the Aberdeen Royal Infirmary, plastic surgery provides an emergency hand service for the accident and emergency department, in co-operation with orthopaedic surgery. Approximately 350 new patients are referred to the plastic surgery service each year, and a large proportion of the operations last for less than 1 h. To expedite emergency hand operations, the plastic surgery staff have, for a number of years, used regional anaesthesia in selected patients. This practice obviates the need to queue with other specialties for the duty emergency anaesthetist. many years as an
Correspondence to: Mr J M Porter, The Wessex Centre for Plastic and Maxillo-Facial Surgery, Odstock Hospital, Salisbury, Wiltshire SP2 8BJ
nerve
block
A prospective audit of regional anaesthesia in the plastic surgery hand service has been undertaken to investigate the success rate, to document the incidence of side-effects or complications and to ascertain if the patients were satisfied with the service being given. Safety precautions before, during and after the administration of regional anaesthesia were reviewed in collaboration with the Department of Anaesthesia, and these were in line with previously published recommendations.
Patients and methods A total of 154 regional anaesthetics for hand or forearm surgery were performed during a period of 6 months. All the blocks were given by members of the plastic surgery staff. A large majority of the operations were for injuries. The details of the patients are summarised in Table I. During the study period, 77 IVRAs, 41 axillary brachial plexus blocks and 35 multiple peripheral nerve blocks were performed. The block was administered by the operating surgeon in 57 out of 77 operations under IVRA, in 37 out of 41 operations under axillary block and in 24 out of 35 operations under regional nerve block. The patients were fasted for 4 h before surgery,
Table I. Details of patients submitted to regional anaesthesia
Patient numbers Mean age (years)
(range) Sex Anaesthesia by operating surgeon
Axillary
Peripheral
IVRA
block
nerve block
77 36.2 (17-86) 13F 64M
41 31.8 (17-77) SF 36M
35 38.6 (16-64) 2F 33M
57
37
24
90
J M Porter
but every effort was made to ensure that the period of fasting was not longer. Peroperative sedation was avoided if at all possible and was only used in two patients. The preoperative assessment of patients for regional anaesthesia was similar to the assessment undertaken before general anaesthesia. The patients selected were in good general health and not excessively apprehensive; those selected for IVRA were for operations which were not expected to last more than 45 min, and those selected for axillary block were scheduled for operations which were expected to last for more than 1 h and less than 3 h. If the diagnosis was in doubt and the operating time was unpredictable, an axillary block was used. Axillary blocks were not attempted in patients in whom the axillary artery could not easily be palpated. Patients were also excluded from regional anaesthesia if they were unable to co-operate, if bilateral surgery was required, if significant preoperative blood loss had taken place, or if there was a need to cut skin grafts from a site other than the anaesthetised upper limb. The blocks were assessed by pinprick before starting surgery. Axillary and regional nerve blocks were classified as complete if all the skin innervated by the blocked nerves was numb to pinprick. If sensate skin remained the block was classified as incomplete, and if there was insufficient analgesia for the operation to proceed the block was classified as a failure. The grades of the surgeons performing the blocks are shown in Table II and the types of operations performed in Table III. The local anaesthetic agents used are summarised in Table IV.
Technique of IVRA The IVRAs were administered in the operating theatre, with the arm resting on a wide hand table. An 18G intravenous cannula was inserted into a vein on the dorsum of both hands. A well-padded double tourniquet was placed on the upper arm and both the cuffs were inflated briefly to ensure that a steady pressure could be maintained and that the radial pulse became impalpable. The arm was then exsanguinated by elevation and using an Esmarch bandage, taking care that the Esmarch bandage did not damage the skin by shearing. The proximal cuff was inflated to a pressure 50 mmHg above systolic arterial pressure and the arm was returned to the table. After a final check that the radial pulse was Table II. Grades of the surgeons administering regional anaesthesia
Consultant Hand Fellow SR equivalent Registrar SHO
IVRA
Axillary block
6
1
21 23 27
35 4 1
Peripheral nerve block
11 22 2
Table III. Range of operations performed under regional anaesthesia
Repair of digital nerve Extensor tendon repair Flexor tendon repair Reduction of finger fractures/dislocations Skin grafting Terminalisation of fingers Cross-finger flap Wound exploration Local skin flap Dupuytren's contracture Tattoo removal Removal of foreign body Other operation
IVRA
Axillary block
Regional nerve block
10 17 2
2 7 13
1 9
3 6
6
12 1 9 3 3
1 10
5 4 6 1 4
1 2 9
1
5
Table IV. Local anaesthetic agents used for regional anaesthesia IVRA Prilocaine Lignocaine/bupivacaine Bupivacaine Lignocaine
77
Peripheral
Axillary block
nerve block
22 16 3
2 4 25 4
impalpable, 30-40 ml of 1% prilocaine (approximately 6 mg/kg) was injected through the cannula. After an interval of 10 min, the distal cuff was inflated, the proximal cuff deflated, and the operation commenced. At the conclusion of the surgery, the dressing was applied, the arm was elevated and the tourniquet was deflated. Great care was taken to ensure that elevation of the arm was maintained continuously during transfer from the operating theatre to the ward and on the ward thereafter. At no point after the release of the tourniquet was the arm lowered, until a minimum period of 2 h had elapsed. IVRA has been described as being a simple technique (3). In practice the method requires a large number of separate steps and success can only be assured by meticulous attention to detail. A number of important points should be emphasised. 1 Moving the patient while the block is in progress can lead to deflation of the tourniquet. 2 Arterial blood may leak into the arm if the elbow is allowed to bend during the anaesthetic. 3 A nurse assistant, sitting on the opposite side of the patient to the surgeon, must observe the pressure dial of the tourniquet throughout the anaesthetic
Regional anaesthesia for hand surgery and maintain the tourniquet pressure as necessary. She should be instructed to maintain verbal contact with the patient and eye contact with the surgeon. 4 A bicycle pump was used to inflate the tourniquet; an automatic tourniquet was never used. There are a number of accounts of this technique in the recent literature (4,7,8).
Technique of axiliary block Axillary blocks were performed using the perivascular method and an immobile needle technique (9,10). At the start of the investigation, a mixture of 20 ml of 0.5% bupivacaine and 20 ml of 1% lignocaine with 1/200 000 adrenaline was used in 15 blocks; 0.5% bupivacaine alone was used in three patients. After the first 18 blocks, 1% prilocaine was used in all patients, the dose being the same as for IVRA. The technique of axillary block has been well described in recent publications (8-10), but various important points in the method used in the present investigation should be emphasised. 1 The blocks were administered in the anaesthetic room with an ECG monitor and an automatic blood pressure cuff attached and recording. 2 Venous access was established in the contralateral upper limb. 3 The injection was given using a short bevel needle, attached to a plastic extension tube (Plexufix®, Braun Co). 4 While the local anaesthetic was being injected, distal spread of the anaesthetic solution was prevented by firm digital pressure on the axillary sheath, distal to the point of injection. Application of a tourniquet distal to the point of injection has been shown to be ineffective (11). 5 An intercostobrachial block was performed after the axillary injection and before the needle was withdrawn. 6 After surgery, the arm was elevated in an appropriate sling and the patient was confined to bed until the motor and sensory effects of the block had totally disappeared. The nurses were carefully advised that the arm was paralysed and would remain so until the effect of the local anaesthetic disappeared.
Technique of upper limb nerve blocks A combination of nerve blocks was selected, appropriate to the intended operation. The ulnar nerve was most commonly blocked at the elbow and the median and radial nerves at the wrist. The techniques for these blocks have been well-described in the recent literature
(8). If the axillary or the regional nerve blocks had failed to anaesthetise the area to be operated on after 45 min, a
small amount of local anaesthetic was administered, either as a nerve block in the arm or as a local infiltration.
Results Sufficient analgesia for surgery to take place was achieved in 71 out of 77 IVRAs; four failures were due to errors in technique. In one block the arm was not fully exsanguinated. The tourniquet did not retain the local anaesthetic in three blocks; one of these patients was moved during the anaesthetic and in two the leak was probably due to incorrect positioning of the elbow. Two of these patients were subsequently operated on under local infiltration, one had an axillary block and one had a general anaesthetic. Two failures, in the same patient on two different occasions, occurred when an apparently functioning cuff failed to keep the local anaesthetic in the arm. This patient had an exceptionally thin upper arm. She was subsequently operated on under a peripheral nerve block. Ten patients were found to have residual sensation at the commencement of surgery and required a few millilitres of local infiltration before the operation could start. The mean tourniquet time for IVRA was 46.7 min (range 25-90 min). This time is inclusive of the time taken for the anaesthetic to take effect and the time taken to perform the operation. When questioned at the conclusion of surgery, 23 patients (32.4%) said that they had experienced some discomfort from the tourniquet but none of these patients experienced enough discomfort to disrupt the progress of the operation. Surgery was completed successfully in all the patients who underwent an axillary block. The mean time from the commencement of the block to the start of the operation was 40 min (range 20-70 min). The mean operating time was 51 min (range 7-130 min). A complete block was achieved in 32 out of the 41 axillary blocks (78%). In the 9 incomplete blocks, either local infiltration of a few millilitres of anaesthetic or a regional nerve block in the arm provided enough extra analgesia for the operation to proceed. A further six blocks were supplemented after 45 min, either because they were thought to be incomplete or to expedite the start of the surgery; these blocks were found to be complete at the conclusion of the operation. One block was supplemented with an ulnar nerve block at the elbow at the commencement of the anaesthetic, due to uncertainty as to whether the axillary block had been correctly placed; this block proved to be satisfactory. A total of 9 out of the 15 blocks in which the lignocaine/bupivacaine was used required supplementing with a further injection of local anaesthetic, whereas extra local anaesthetic was only used in 6 out of 23 blocks in which 1% prilocaine was given. The mean time between administration of the block and the commencement of the operation was 33.3 min after prilocaine and 45 min after lignocaine/bupivacaine. A tourniquet was used in 39 of the operations performed under axillary block. Fourteen patients said they
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Table V. Results IVRA Patient numbers Surgery completed Block time (min)*
77 71
(range) Tourniquet time (min) (range) Operating time (min) (range) Tourniquet discomfort Further LA injection Complete block
48
(25-90) 38
(15-80) 27 10 71
Axillary block
Peripheral block
nerve
41 41 40
35 35 45
(25-70)
(10-135)
51 (7-130) 51 (7-130) 14 16 32
26
(9-50) 25
(9-50) 8 6 27
The block time is the time in minutes between the administration of the block and the start of the operation LA = Local anaesthetic
*
experienced some discomfort due to the tourniquet (37%), but none of these patients experienced pain severe enough to interrupt the operation. Peripheral nerve blocks were used in 35 patients. The block was complete in 27 patients and six required a further injection of local anaesthetic. The mean time between administration of the block and the commencement of surgery was 45.2 min (range 10-135 min). A tourniquet was used in 30 patients, of whom eight complained of tourniquet pain. The mean tourniquet time was 26 min (range 9-50 min). Two patients complained of paraesthesiae after peripheral nerve blocks, one after ulnar nerve block at the elbow and one after median nerve block at the wrist. After surgery, 13 patients who received a satisfactory block expressed dissatisfaction, seven after IVRA, three after axillary block and three after peripheral nerve block. The only patient in the series to experience successful IVRA and brachial plexus block on different occasions, emphatically preferred IVRA. The results are summarised in Table V.
Discussion The results of this investigation have shown that the surgical staff achieved a complete success rate with axillary and with regional nerve blocks, and a 92% success rate with IVRA. Local anaesthetic toxicity was not seen, and the main side-effect observed was discomfort due to the tourniquet. The disadvantages of IVRA have been considerably overstated (1). Venous pooling should not be a problem if the arm is fully exsanguinated before the injection of local anaesthetic. Sudden failure of the tourniquet should not occur if the equipment is kept in good order, if the tourniquet is checked before starting the operation, and
if the pressure dial of the tourniquet is observed continuously throughout surgery. Although the tourniquet cannot be released for haemostasis, any site of venous bleeding is usually obvious, especially if the operation is undertaken under loupe magnification. A haematoma can be prevented by meticulous postoperative elevation of the hand. Onset of anaesthesia is more rapid after IVRA than after an axillary block and, if a correct method is used, complete anaesthesia can nearly always be assured. These are considerable advantages when the emergency service has a large number of relatively minor cases to deal with. Tourniquet discomfort can be minimised if the upper arm is properly padded, if a double cuff tourniquet is used, and if the tourniquet pressure does not exceed the systolic arterial pressure by more than 50 mmHg. A tourniquet time of 45 min was exceeded in 29 IVRAs. Of these patients, 17 (59%) complained of discomfort, whereas only seven patients (12%) complained of discomfort when the tourniquet time was less than 45 min. In retrospect, some of these patients might have been better served with an axillary block, but all of these operations were completed without undue difficulty. In 11 out of the 71 IVRAs, a small amount of local anaesthetic was infiltrated at the site of operation before the surgery commenced. This was considered to be necessary in two out of 27 patients anaesthetised by the consultants or the Hand Fellow, and nine out of 50 patients anaesthetised by the registrars and the SHOs. This problem could have been caused by insufficient exsanguination of the arm leading to the local anaesthetic being diluted in an excessive volume of blood. It is also possible, on some occasions, that further local anaesthetic was injected because the surgeon did not recognise that the patient was feeling movement rather than pain. As the audit progressed, the rate of local infiltration after IVRA decreased, as the more junior members of the staff became more expert. There were six failures of IVRA. Four of these blocks were given by SHOs who were learning the method, and on two of these occasions the surgeon giving the block was unsupervised. It is unwise for novice hand surgeons to carry the extra responsibility of the anaesthetic until confidence in performing the surgery has been acquired. Moreover, allowance should be made for a prolonged learning curve, as IVRA requires attention to many details, and axillary block is by no means a simple technique to teach and learn. Serious complications after IVRA are rare; in one series of 7500 blocks no major complications occurred (3). A series of three fatal accidents caused by IVRA has been reported (12). All these patients were anaesthetised in accident and emergency departments by doctors of SHO grade; two of the patients were children. Bupivacaine was the local anaesthetic agent used and the arms were all kept exsanguinated with an automatic tourniquet. In the present investigation, a simple bicycle pump was used to keep the tourniquet inflated, one person was always delegated to observe the pressure dial
of the tourniquet, children were excluded and a local anaesthetic agent of lesser toxicity than bupivacaine was used (13,14). Axillary block anaesthesia has some disadvantages for a busy emergency hand service. A wait of up to 60 min may be necessary before surgery can commence, and there is a significant incidence of incomplete anaesthesia. However, the anaesthetic lasts for up to 3 h, if prilocaine is used, and for longer if bupivacaine is used, either alone or in a mixture. Axillary block anaesthesia is therefore more suitable than IVRA for operations which last longer than 45 min, although patients may become uncomfortable on the operating table after 2-3 h. The paralysis of the upper limb muscles greatly facilitates the retrieval of divided tendon ends. Axillary block anaesthesia is not a substitute for IVRA or for regional nerve blocks and is properly used to extend the number of operations that can be attempted under regional anaesthesia. Peripheral nerve blocks were found to give effective anaesthesia of the hand in 27 out of 35 patients. The scope of the surgery that can be attempted under these blocks is limited, as the upper arm is not anaesthetised; even with careful padding of the tourniquet, the addition of an intercostobrachial nerve block and the avoidance of overinflation of the tourniquet, tourniquet pain may become a problem after 30 min. However, in the present investigation, the incidence of tourniquet discomfort after peripheral nerve blocks was similar to the incidence after IVRA and axillary block. Peripheral nerve blocks require a smaller dose of local anaesthetic than IVRA or axillary block and the site of the injection is not near any major blood vessel. The anaesthetic can therefore be administered on the ward before the patient is transferred to the operating theatre and it is safe to use bupivacaine. These blocks have the disadvantage that multiple injections are required. There have been two large series of brachial plexus blocks in the recent surgical literature. Rouholamin and Harris (1) described 300 axillary brachial plexus blocks, all of which gave sufficient analgesia for surgery to proceed; only 11 of the blocks required augmenting with a further injection of local anaesthetic. Apart from one case of transient thrombophlebitis of the axilla, no complications or side-effects were observed. Thompson et al. (2) reported a series of 1913 brachial plexus blocks, 1248 administered by the supraclavicular route and 665 by the axillary route. Of these anaesthetics, 80% were carried out by surgical staff. A complete block was obtained in 83.5% of the patients, a further injection of local anaesthetic was required in 11.4%, and in 5.1% insufficient anaesthesia was obtained for the operation to proceed. Neither of these papers stated how many of the regional anaesthetics were performed by the operating surgeon.
Rouholamin and Harris (1) recommended a method of axillary block in which the injection was administered through a 23G (blue) long bevel needle, with no extension tube. Thompson et al. (2) used a 32G needle but did not otherwise comment on the technique of the injection. In the present series, a short bevel needle on an extension
Regional anaesthesia for hand surgery 93 tube was preferred. The short bevel needle is less likely to pierce a blood vessel or a major nerve than a 23G or 32G needle (15), and the use of the immobile needle technique makes inadvertent movement and consequent penetration of a blood vessel during the injection less likely. Rouholamin and Harris (1) used prilocaine for their axillary blocks and, apart from stating that 'standard resuscitation drugs should be on hand', no mention was made of safety precautions. Thompson et al. (2) used a mixture of lignocaine and bupivacaine and did not mention the safety precautions taken. In the present investigation, prilocaine was the preferred local anaesthetic for IVRA. The rate of incomplete brachial plexus anaesthesia decreased considerably when prilocaine was substituted for the lignocaine/ bupivacaine/adrenaline mixture. Prilocaine is of lower toxicity than either bupivacaine or lignocaine (13). The duration of action is shorter than that of bupivacaine, but the 3 h of anaesthesia obtainable with an axillary block is adequate for the range of operations that were considered suitable. It is clearly imperative that, if regional anaesthesia is to be administered by members of the surgical staff, the least toxic agent should be used. Although local anaesthetic toxicity is unusual after regional anaesthesia of any sort, most serious complications of regional anaesthesia have been reported after the administration of bupivacaine (12,16-18). Although major local anaesthetic toxicity was not observed in any of the previous series quoted or in the present series, every precaution should be taken to minimise the risk of this potentially fatal hazard. Venous access in the contralateral hand, the availability of monitoring equipment and anticonvulsant drugs, the ready availability of oxygen, suction, an operating table with a facility for head-down tilt, and standard procedures in the event of complications are all essential safety precautions. A block administered by the operating surgeon differs from a block administered by an anaesthetist in that a surgeon works within certain constraints. Only medically fit and co-operative patients should be selected. If the patient has a medical condition which may give rise to concern during the progress of the operation, the assistance of an anaesthetist must be sought. It is particularly unwise to administer a large dose of local anaesthetic to a patient who is hypovolaemic, because the compensatory vasoconstriction may divert a large proportion of the local anaesthetic to the heart muscle and the central nervous system (18). We are in full agreement with Rouholamin and Harris (1) that regional anaesthesia is well-suited for use by surgical staff. Patients requiring major hand surgery avoid a general anaesthetic; this is of particular benefit during the recovery period, as the patient is able to cooperate during transfer from the theatre. In more minor hand operations, disruption of the wound by local infiltration can usually be avoided. In the present investigation, a high success rate and a high rate of patient acceptance was achieved by using a variety of techniques,
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with each block being selected according to the patient's requirements. Although the regional anaesthesia has been shown to have a low complication rate in surgical hands, the potential hazards are serious (5-7,12,14-18). It is absolutely imperative that regional anaesthesia is not attempted by unsupervised, inexperienced surgeons, that the surgical staff take the same safety precautions as the anaesthetic staff and that surgeons are familiar with the pharmacology of local anaesthetic drugs. The circumstances under which surgeons attempt regional anaesthesia and the methods used should be clearly defined. A programme of regional anaesthesia for hand surgery should not be undertaken without the advice and cooperation of the anaesthetic service. I am grateful to Mr C R W Rayner and to Mr 0 M Fenton for permission to study patients under their care. I am especially indebted to Mr Rayner, who showed me the method of performing IVRA and to Mr R H Milner who taught me to perform the axillary brachial plexus block. I would also like to thank my colleagues in the Department of Anaesthesia in Aberdeen for sharing their skills with me and giving advice on the preparation of this paper, and also my colleagues in the Plastic Surgery Unit for filling in the audit proformas.
References I Rouholamin E, Harris D. Axillary block anaesthesia in acute and elective hand surgery: a report on 300 procedures. Ann R Coll Surg Engl 1990;72:90-3. 2 Thompson AM, Newman RJ, Semple JC. Brachial plexus anaesthesia for upper limb surgery: a review of eight years' experience. J Hand Surg 1988;13B: 195-8.
3 Rawlings ID, Staniforth P. Intravenous regional anaesthesia in upper limb trauma. Injury 1979;10:231-4. 4 Wallace WA, Guardini R, Ellis SJ. Standard intravenous regional anaesthesia. Br Med J 1982;285:554-6. 5 Comment. Axillary block anaesthesia in acute and elective surgery: a report on 300 procedures. Ann R Coll Surg Engl 1990;72:274-80. 6 Comment. Standard intravenous regional anaesthesia. Br MedJ3 1982;285:731-2. 7 Goold JE. Intravenous regional anaesthesia. BrJ Hosp Med 1985;33:335-40. 8 Scott DB. Techniques of Regional Anaesthesia. East Norwalk: Appleton and Lange/Mediglobe, 1989. 9 Winnie AP. An 'immobile' needle for nerve blocks. Anesthesiology 1969;31:577-8. 10 Brockway MS, Wildsmith JAW. Axillary brachial plexus block: method of choice? Br J Anaesth 1990;64:224-31. 11 Winnie AP, Radonjic R, Akkineni SR, Durrani Z. Factors influencing distribution of local anaesthetic injected into the brachial plexus sheath. Anesth Analg 1979;58:225-34. 12 Heath ML. Deaths after intravenous regional anaesthesia. Br Med J 1982;285:913-14. 13 Wildsmith JAW. Prilocaine-An underutilised local anaesthetic. Reg Anaesth 1985;10: 155-9. 14 Wildsmith JAW. Intravenous regional analgesia: essential safeguards. Anaesthesia 1982;37:959. 15 Selander D, Dhuner K-G, Lundborg G. Peripheral nerve injury due to injection needles used for regional anaesthesia. An experimental study of the acute effects of needle point trauma. Acta Anaesthesiol Scand 1977;21: 182-8. 16 Scott DB. Toxicity caused by local anaesthetic drugs. BrJ Anaesth 1981;53:553-4. 17 Albright GA. Cardiac arrest following regional anaesthesia with editocaine or bupivacaine. Anesthesiology 1979;51:2857. 18 Scott DB. Toxic effects of local anaesthetic agents on the central nervous system. BrJ7 Anaesth 1986;58:732-5.
Received 24 May 1991
