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Local anaesthetic infusion for postoperative pain
LOCAL ANAESTHETIC INFUSION FOR POSTOPERATIVE PAIN M. KULKARNI and D. ELLIOT From the Hand Surgery Department, St Andrew’s Centre for Plastic Surgery, Broomfield Hospital, Chelmsford, Essex, UK
The role of continuous bupivacaine infusion either into the wound or as a local nerve block, following hand surgery was investigated in 100 patients. After excluding six patients with complex pain problems in whom neither the bupivacaine infusion nor any other conventional analgesic techniques provided adequate analgesia post-operatively, 86 of 94 (91%) patients were adequately treated for post-operative pain by this system during the first night after surgery, when pain is presumed to be greatest. This system also provided adequate on-going analgesia for up to 1 week after surgery controlling nerve pain and allowing mobilization of tendons after tenolysis. Continuous bupivacaine infusion is of particular use in these two groups of patients and after major hand injuries, when considerable pain can be anticipated. Pain during the first night was not controlled adequately by the bupivacaine infusion system in eight of the 94 patients (8%). All eight had a technical failure of the system, which was rectified in six cases to restore adequate analgesia by the infusion system. Two patients developed infection at the infusion cannula insertion site, which occurred only after 1 week and was successfully treated by removal of the cannula and oral antibiotics. Journal of Hand Surgery (British and European Volume, 2003) 28B: 4: 300–306 Keywords: postoperative pain; neuroma; tenolysis; major hand injury; bupivicaine infusion
administered intermittently, has recently been reported as an effective adjunct to flexor tenolysis (Kirchhoff et al., 2000) but we can find no assessment of the use of continuous infusions of local anaesthetic for the same purpose or for post-operative analgesia in the literature. We have used continous bupavicaine infusion postoperatively for the last 10 years (Sood and Elliot, 1998). This study assesses this technique in 100 patients over a 3 year period in the post-operative management of three groups of hand surgery patients (Table 1). These patient groups were chosen as we felt that they would particularly test the ability of any method of control of pain and would be a good test of the usefulness of the technique more generally in the management of postoperative pain after hand surgery.
INTRODUCTION Post-operative pain relief has been a matter of concern to surgeons and anaesthetists for many years. It was with enthusiasm that we embraced the system of patientcontrolled administration (PCA) of intravenous opiate analgesia a few years ago in our hand surgical practice (Riegler, 1994). Unfortunately, some categories of hand surgery patient require strong analgesia for more than 12–24 h and the side-effects of the opiates often become problematic when PCA administration is continued beyond 12 h, making this system of analgesia unsuitable. In particular, nausea and drowsiness may cause problems (Moote, 1994; Riegler, 1994). Continuous local anaesthetic blockade has been reported in other branches of surgery (Blades and Ford, 1950; Chester et al., 1989; Fenton Lee et al., 1994; Lewis and Thompson, 1953; Tetzlaff et al., 1997; Thomas et al., 1983; Wood et al., 1981) and appears to be an effective and safe technique of post-operative pain control. Although continuous post-operative brachial plexus anaesthesia has been used to effect after hand surgery for some time (Denson et al., 1983), continuous local anaesthesic infusion post-operatively at the site of surgery or immediately proximal to this site as a local nerve block is not commonly used in hand surgery. Although there are passing references to the technique in textbooks and we are aware of its use previously in other units, such use appears to have only been sporadic and this method of achieving post-operative pain relief has not been widely applied or accepted in hand surgery. Use of post-operative local anaesthetic blockade,
PATIENTS AND METHODS Patients Over a 3 year period (1998–2000) continuous bupivicaine infusion was used in 100 patients as the first choice of post-operative analgesia. Three surgical categories of patient were chosen for inclusion in this study (Table 1). Group 1 consisted of 58 patients undergoing neuroma relocation or neurolysis of scar-tethered nerves. These patients usually have considerable post-operative pain. Within this group, we recognized two subgroups: (a) The first and the simpler to treat were 47 patients with a short-term problem who had experienced nerve pain for less than 2 years and who had 300
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Table 1—Clinical Problem Group 1 (n=58) Neuroma relocations Neurolysis Tenolysis with neurolysis
40 9 9
Group 2 (n=28) Extensor tenolysis only Flexor tenolysis only Tenolysis both ext. and flexor
22 4 2
Group 3 (n=14) High-pressure injection injury Crush injury Large haemangioma excisions Complex ganglions Carpal tunnel decompressions after RSD Secondary carpal bone surgery
3 4 2 2 1 2
Fig 1 Post-operative view of a cannula at the proximal end of the wound (arrow) infusing 0.33% bupivacaine locally into the site of extensor tenolysis of the right middle finger. Distally, a Yates drain removes excess local anaesthetic from the wound.
undergone two or less previous operative attempts to cure their pain problem. (b) The second subgroup consisted of 11 patients, many of whom had been referred for tertiary treatment. These had experienced pain for more than 2 years and had often undergone multiple surgical attempts to solve their pain problem. Many of these patients had significant psychological, social and marital problems. Group 2 consisted of 28 patients undergoing tenolysis of flexor or extensor tendons. In these cases, the continuous post-operative local anaesthetic technique was used to allow our therapists to start mobilization within 24 h of surgery without pain at the operative site. Four patients in this group underwent a combined neurolysis and tenolysis, but their predominant clinical problem was loss of tendon mobility and not nerve pain. Group 3 consisted of 14 patients undergoing various hand surgical procedures which, for a variety of reasons including magnitude of injury, multiple nerve injuries, length of operation and/or size of lesion being resected, were expected to have significant post-operative pain. The 100 patients included in the study included 62 men and 38 women, with a male-to-female ratio of 1.8– 1. Their age ranged from 23 to 68 (mean age, 44) years. Technique of continuous bupivacaine infusion Cannula insertion Following surgery and prior to wound closure, an 18 or 20 gauge epidural catheter was placed with its tip in the wound at the site of surgery (Fig 1) or immediately proximal to this site, adjacent to the nerve innervating the site of surgery (Fig 2). In some instances, particularly in group 1, it was possible to place the catheter alongside the regional sensory nerve by passing it proximally from the operative area along the nerve(s). In other cases, a separate incision was made proximally to insert the catheter beside the appropriate nerve. In
Fig 2 Intra-operative view showing a cannula (arrow) infusing 0.33% bupivacaine alongside the superficial radial nerve just proximal to its site of relocation into the underside of the brachioradialis muscle (encircled).
cases in which the operative area was innervated by more than one major nerve, the infusion was either directed into the operative site or an appropriate number of catheters were inserted alongside the involved regional sensory nerves (Fig 3). All catheters were placed alongside nerves under direct vision. The catheters were brought out through separate skin stab incisions close to the operative incisions and anchored securely to the skin by two stay stitches. A small open Yates drain was inserted into the distal end of the main wound and/or any wound made to insert a cannula alongside a nerve to prevent any accumulation of excess local anaesthetic. Within the wound, the proximal end of the drain was placed at a sufficient distance from the tip of the infusion cannula to ensure that the infusion did not escape directly before achieving its analgesic effect. The drain always remained in place until the anaesthetic infusion was discontinued. After catheter and drain insertion and skin closure, the wounds were dressed and the catheter connected to an infusion pump primed with bupivacaine.
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12–60 h, was used to deliver the bupivacaine infusion (Fig 3). This pump is used widely throughout the United Kingdom for continuous intravenous infusions of drugs and is easily available. It has an alarm system which notifies staff of any interruption to the infusion and when the infusion stock is finishing, which was essential to the accuracy of our study. A concentration of 0.375% (3.75 mg/ml) bupivacaine is achieved by loading the IVAC syringe with three 10 ml ampoules of 0.5% (5 mg/ml) and three 10 ml ampoules of 0.25% (2.5 mg/ ml) plain bupivacaine. Weaning off the bupivacaine infusion
Fig 3 Post-operative view of a complex case in which end-neuromata of branches of both the superficial radial nerve and the dorsal branch of the ulnar nerve on the dorso-radial aspect of the wrist were relocated into the brachioradialis and pronator quadratus muscles, respectively. Two cannulae were inserted to block the two nerves proximal to the relocation sites (arrows), and Yates drains (encircled) were inserted distally to drain excess local anaesthetic. The 60 ml syringe of 0.33% bupivacaine connected to the superficial radial nerve cannula is seen in this illustration, with the Ivac pump in the background. The other 60 ml syringe is not seen but is attached to the second cannula, and the two syringes are changed over in the Ivac pump every 2 h to provide analgesia to both relocated nerves. By exchanging the syringes in this way, analgesia of both relocated nerves is achieved without the use of two pumps and with no need for the concentration changes of the bupivacaine which would be necessary if synchronous infusions were used.
Bupivacaine dose Pharmacokinetic studies on patients with chronic pain undergoing continuous perineural bupivacaine infusion have shown no evidence of accumulation of the drug with continuous infusion of doses of up to 30 mg/h (total daily dose of 720 mg) for up to 5 days, both in normal patients and even when total plasma clearance of bupivacaine is reduced by 60% (Denson et al., 1983). Oakley et al. (1998) showed similar safety margins for continuous bupivacaine infusion in a similar group of patients. At the time of carrying out this study, the manufacturers of bupivacaine recommended a maximum dose of 20 mg/h and did not specify an upper limit of total daily dose. This study was set up to comply with the above regulations, using a concentration of 0.375% (3.75 mg/ml) bupivacaine up to a maximum infusion rate of 5 or 18.75 mg/h. This limited the total daily dose possible to 450 mg/24 h which is well within the recommended safety limit of the earlier scientific studies. The infusion pump An ‘‘IVAC’’ volumetric pump( IVAC Medical Systems, Model P7000 variable syringe pump) which holds a 60 ml syringe and can deliver 1–5 ml/h continuously for
The patients were weaned off the bupivacaine infusion by reducing the rate from 5 to 3 to 1 ml/h over a period from 1 to 5 days in most cases and then by removing the cannula. Group 1: These patients always required 48 h and, more often, 72 h of bupivacaine infusion after surgery. In those cases of simpler nerve pain and some of the more complex nerve pain patients, the bupivacaine infusion was replaced by minor oral analgesics on a supply-on-demand basis after 2–4 days. Six of the patients with more complex nerve pain required use of the PCA almost immediately after operation, despite being given bupivacaine at the maximum infusion rate. The bupivacaine infusion was necessary for much longer, up to a maximum of 11 days. These patients also required replacement of the bupivacaine infusion and PCA by specific and stronger pain-relieving drugs, including long-acting opiates, at 3–10 days. Some of the simpler nerve pain patients also needed specific and stronger oral pain-relieving drugs. Group 2: Infusion was routinely maintained in these patients for 3–4 days after surgery to allow pain-free hand therapy. It was then usually possible to reduce the infusion and discontinue it over the next 12 h, with replacement by minor oral analgesics on a supply-ondemand basis. In two cases of teno-neurolysis, it was necessary to continue the infusion for longer because of nerve pain during tendon mobilization: both these patients remained as inpatients for more than 1 week. Group 3: The bupivacaine infusion was reduced and discontinued after 24–72 h, with replacement by minor oral analgesics on a supply-on-demand basis. Other pain relieving management Other analgesics While continuous bupivicaine infusion was the first choice post-operative analgesic technique in this study, all patients also left the operating theatre with an opiate PCA as a back-up for break-through pain. Patients were also written up for dihyrocodeine (DF118) and paracetamol for use if necessary, and these drugs were given in preference to the use of the PCA for break-through pain after the first 24 h. However, if these oral drugs
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were ineffective, the PCA opiate was continued through the second and third days after surgery and was then replaced by either the above drugs or by regular prescription of long-acting oral opiates and specific pain-relieving drugs such as Amitryptalline, Carbamazepine, Gabapentin and Lamotrigine. These were rarely necessary except in Group 1 patients. Generally, patients left hospital soon after weaning off the bupivacaine infusion onto appropriate oral drugs which were then continued as an out-patient. Non-steroidal anti-inflammatory drugs While this group of drugs alone do not provide adequate analgesia in the early post-operative period, they appear to reduce the levels of conventional analgesics necessary and aid early post-operative mobilization. It has been our custom for many years to give hand surgery patients oral diclofenac 50 mg three times a day for a minimum of 5 days whenever there is no respiratory, upper alimentary tract or age contra-indication. In this study, all but 18 patients (in whom the drug was contraindicated) were given oral diclofenac, starting as soon as the patient was drinking post-operatively and continuing throughout and beyond the period of bupivacaine infusion. Splinting In order to reduce the post-operative pain during the first 24 h, all patients in the study left theatre with the appropriate part of the upper limb splinted on a dorsal or palmar plaster slab. Group 1 patients were splinted for as long as the bupivacaine infusion was continued as we believe the absence of movement significantly reduces nerve pain in the early post-operative period after neuroma and neurolysis surgery. These patients also used splints extensively after terminating the bupivacaine infusion. Group 2 patients started active mobilization of the hand on the day after surgery. However, their arm remained in a thermoplastic splint as an aid to analgesia for most of the day during the following 1–2 days, with the splint only being removed every 2–4 h to perform our standard mobilization regimen. This continued until the bupivacaine was discontinued. Thereafter, free movement and less splinting was allowed. Group 3 patients usually retained their upper limb splint for 2–4 days, as an aid to analgesia. Splinting was usually maintained until about the time at which the bupivacaine infusion was discontinued. Assessment PCA use The use of the opiate PCA system by the patient for breakthrough pain during the first night after surgery was used as an indicator that the bupivacaine infusion was not completely controlling the post-operative pain.
If the PCA system was used, the dose and frequency of administration of the intravenous opiate were recorded. Discussion with patients Pain severity was determined by subjective patient selfassessment using the visual analogue scoring system (VAS) on a 100 mm line for pain assessment (Bond and Pilousky, 1966). Zero or position 0, represented no pain and 100 mm, or position 10, was unbearable pain. This chart was completed every 4 h by the nursing staff and the charts examined by us every 24 h. For the purposes of this study, a charting of 20 mm, or level 2 pain, which is described as ‘‘discomfort’’, implied a failure of the bupivacaine infusion system. Patients were questioned with regard to any adverse effects they suffered from the various medications administered and their personal preferences as to the techniques of analgesia used in this study were recorded. Discussion with nurses Patients were advised to call the nurses if level 2 or more pain developed or if there were problems with the bupivacaine pump system. Where a patient developed discomfort or pain, the level of pain and the type of intervention, e.g. increasing the rate of bupivacaine infusion, additional use of the PCA or addition of oral analgesics, were recorded. Where bupivacaine infusion provided inadequate pain relief, the dose and frequency of PCA administration of intravenous opiate were also recorded. Problems encountered in maintaining the bupivacaine infusion on the ward were also noted by the nurses.
RESULTS The results of assessment of the 100 patients in this study are summarized in Figs 4 and 5 and Tables 2–4. Fifty-eight patients required no analgesia other than the bupivacaine infusion during the first 24 h after surgery (Fig 4). Six of the 100 patients with more complex nerve pain, all of whom were from group 1b, required use of the PCA almost immediately after operation, despite being given bupivacaine at the maximum infusion rate from the onset of the post-operative period. In these six cases, use of both the bupivacaine infusion and the PCA were necessary for up to 11 days. These patients also required replacement of the bupivacaine infusion and PCA with oral opiates and other strong pain-relieving drugs from day 3 onwards and all six were eventually discharged with pain which they described as ‘‘moderate’’ (VAS levels 3–6). Although these patients represent a failure of the bupivacaine infusion technique, their inclusion confuses the interpretation of this analgesic method in the remaining 94 patients. For this reason, the
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Table 2—Use of the PCA during the first night after surgery Total number of patients in the study
100
Patients who did not use the PCA at all Patients who used the PCA anticipating pain but who did not actually experience pain or discomfort Patients who used the PCA because of technical failure of the continuous bupivacaine infusion system Patients with complex pain with failure to respond to bupivacaine, PCA opiates or oral opiates
58 28 8 6
Table 3—Technical failures of the continuous bupivacaine infusion system Tube kinked Battery problem Initial infusion rate too low Cannula dislodged
3 1 2 2
Fig 4 Chart showing the post-operative use of bupivacaine and PCA morphine in all 100 patients. Table 4—Complications of the continuous bupivacaine infusion system Localized swelling and itching at the cannula site (after day 6) Cannula infection (after day 8 )
Fig 5 Chart showing the post-operative use of bupivacaine and PCA morphine in the remaining 94 patients after exclusion of six patients with chronic pain, who continued to require bupivacaine infusion and PCA use throughout their hospital stay without full relief of pain.
remaining 94 patients were assessed independently and the results of this analysis are shown in Fig 5. Of the remaining 94 patients in the study, 58 used the bupivacaine system only during the first night after surgery and 36 patients also used the PCA (Fig 5). Of the 36 patients who used the PCA, 28 used it without ever having experienced actual pain (Table 2). Some were frightened of pain suddenly starting during the night, when they presumed that the brachial block anaesthetic would have worn off and others were
3 2
worried about going to sleep and then waking up with pain. These patients used the PCA one, two or three times before settling for the night and did not use it later in the night. Eight of the 94 patients actually developed pain which varied in intensity from discomfort to moderate pain (VAS levels 2–6) during the first night. These eight patients used the PCA between four and 20 times during the first night after surgery. The use of the PCA by these patients was more than by the previous group and the pattern of use of the PCA also differed, with the PCA being used continuously through the night. There was a technical or nursing reason why the bupivacaine had not worked in all eight cases (Table 3) and it was possible to correct the problem in six instances. Thereafter, these six patients stopped using the PCA. Two cannulae had become dislodged and were not replaced as this would have involved re-operation. These two patients used their PCA for 4–5 days as an alternative to the bupivacaine and both developed nausea. Over and above these technical failures, the actual complication rate of use of bupivacaine infusions was very low (Table 4). Two cannulae became infected in patients in whom they had been kept in place into the second week after surgery. These were both complex pain patients in whom the bupivacaine system was ineffective. After removal of the cannulae and change of the antibiotic regimen, both infections settled quickly. A further three patients developed localized swelling and itching around the cannulae after 6–8 days without obvious infection. These also settled after removal of the
LOCAL ANAESTHETIC INFUSION FOR POSTOPERATIVE PAIN
cannulae and treatment of the itching with antihistamines. These complications had no long-term sequelae.
DISCUSSION Opiates given through a PCA system can be very much more effective than the traditional methods of ‘‘on demand’’ administration. However, prolonged PCA administration may lead to drug accumulation and drowsiness and often causes nausea and vomiting (Moote, 1994; Riegler, 1994). Because of these side effects, PCA use is often reduced by the patients who may then suffer increased pain levels, over and above the unpleasantness of the direct side-effects of opiate overdose. Compliance with post-operative treatments, in particular with early hand therapy in our speciality, may also be poor. Single dose local or regional anaesthesia techniques are commonly used, and are very effective, after hand surgery (Kirchhoff et al., 2000) but are limited in their usefulness even when long acting local anaesthetic agents such as bupivacaine are used. Continuous infusion of local anaesthetic at the site of surgery or immediately proximal to this site as a local nerve block has been shown to be effective in other branches of surgery for relieving post-operative pain, and so reduce the need for opiate analgesia. (Blades and Ford, 1950; Chester et al., 1989; Fenton Lee et al., 1994; Gerwig et al., 1951; Lewis and Thompson, 1953; Lutz, 1990; Tetzlaff et al., 1997; Thomas et al., 1983; Wood et al., 1981) but is not used commonly in hand surgery. While many hand surgical procedures do not require prolonged high levels of analgesia post-operatively, some cause significant pain for some time after surgery. It is difficult to achieve complete pain relief by conventional techniques in many patients undergoing surgery for nerve pain and major injuries, especially those with crushing or division of major nerves. It is also often difficult to achieve adequate pain relief by conventional techniques in patients with low pain thresholds. It has been our experience over 10 years that such patients benefit from continuous infusion of local anaesthetic post-operatively and that this is preferable to PCA opiate analgesia, for the reasons given above. This study confirms the usefulness of this post-operative analgesic technique in difficult hand surgical cases. Continuous infusion of local anaesthetic post-operatively is also useful as an adjunct to early mobilization after tenolysis, especially if performed in conjunction with nerve surgery. Some patients requiring such surgery also have a low threshold for pain which may have contributed to their poor co-operation with mobilization after the initial injury, leading to the scar tethering of the tendons and/or nerves. Their co-operation with hand therapy is maximized after the secondary surgery by this analgesic technique.
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This study shows that the technique of continuous bupivacaine infusion used was simple, effective and safe. In many cases, it is evident that the bupivacaine infusion was working adequately when patients are reviewed on the first morning after surgery and the PCA was discontinued at this stage, with direct replacement of the bupivacaine infusion by routine oral analgesic drugs as required. Others transferred to oral analgesics fairly quickly during the second, third or fourth day. While the combination of a bupivacaine infusion attached to one arm and a PCA to the other confines the patient to his/her bed or an adjacent chair and is inconvenient, removal of the PCA allows the patient to move more freely and to be ambulant, while remaining comfortable. However, we do not recommend such early removal of the PCA in cases with significant nerve-related pain. In this study, the system of analgesia was used entirely on inpatients as this was suitable for the particular pathological problems which we were treating. However, in other branches of surgery, continuous local anaesthetic infusion has been used as an out-patient following day case surgery (Fenton Lee et al., 1994; Oakley et al., 1998) and the techniques used may be applicable to hand surgery, although we have no experience of such use. The incidence of infection as a result of leaving a bupivacaine cannula in situ for a week was negligible, probably because prophylactic antibiotics were used but, possibly, also because instillation of bupivacaine into wounds has an antimicrobial action (Rosenberg and Renkonin, 1985). There is probably no benefit to leaving the cannula and drain in situ beyond a week: the six patients with complex nerve pain in our study who had this system in place for this length of time had very questionable benefit from bupivacaine infusion. In general, the results of treatment of complex nerve pain patients, with regional surgical methods such as neuroma relocation and neurolysis, with or without wrapping the neurolysed nerve in vein, fascia or muscle, are poorer than in simpler cases of nerve pain. The fact that neither local bupivacaine infusion, PCA use of opiates nor oral analgesics of various types and strengths were effective in this group would support the general impression among hand surgeons and others that there is a central nervous component to their pain problem whether neurological or psychological or both. However, these patients are not common and this technique has proved highly effective in providing simple and effective post-operative analgesia for more straightforward nerve pain patients in our practice. During this study, several patients with nerve pain undergoing repeat surgery expressed a strong preference for use of bupivacaine local infusions post-operatively and completely refused PCA and oral opiates. After removal of the local anaesthetic infusion system they preferred to use other oral analgesics, even if pain relief was only partial, in order to avoid the nausea they had experienced from use of opiates on previous admissions.
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Since completion of this study, the manufacturers have issued new guidelines recommending the same upper limit of hourly infusion of bupivicaine (20 mg/h) but also recommending a maximum total daily dose of 400 mg/24 h. The manufacturers have given no explanation for their choice of this total daily dose limitation and it is very much lower than that shown to be safe in clinical studies (Denson et al., 1983; Oakley et al., 1998). Although we experienced no drug-related complications from the use of bupivacaine up to a maximum total daily dose of 450 mg/24 h during this study, we have now reduced our bupivacaine dose slightly to comply with this manufacturer’s recommendation. We now use a concentration of 0.33% plain bupivacaine, which is achieved by the use of a 60 ml IVAC infusion pump loaded with two 10 ml ampoules of 0.5% and four 10 ml ampoules of 0.25% bupivacaine. This concentration of bupivacaine has been used in a further 100 cases and appears to be equally effective. If used for 24 h at the maximum infusion rate of 5 ml/h, this gives a maximum total daily dose of 397 mg of bupivacaine.
Acknowledgements We would like to thank Dr T. Myint of the anaesthetic staff of the St Andrew’s Centre for Plastic Surgery, Broomfield Hospital, for his advice and assistance. We also wish to thank the nursing staff of Mayflower ward, Broomfield Hospital, for their help in assessing the technique of analgesia and Dr U. Kulkarni for her help with the graphics.
THE JOURNAL OF HAND SURGERY VOL. 28B No. 4 AUGUST 2003 Denson DD, Raj PP, Saldahna F, Finnsson RA, Ritschel WA, Joyce TH, Turner JL (1983). Continuous perineural infusion of bupivacaine for prolonged analgesia: pharmacokinetic considerations. International Journal of Clinical Pharmacology, Therapy and Toxicology, 21: 591–597. Fenton Lee D, Riach E, Cooke T (1994). The use of local anaesthetic wound perfusion device versus oral analgesia – a comparison in day case inguinal herniorraphy. British Journal of Intensive Care, 153–156. Gerwig WH, Thompson CW, Blades B (1951). Pain control following upper abdominal operations. Archives of Surgery, 62: 678–682. Kirchhoff R, Jensen PB, Nielson NS, Boeckstyns MH (2000). Repeated digital nerve block for pain control after tenolysis. Scandinavian Journal of Plastic and Reconstructive Hand Surgery, 34: 257–258. Lewis DL, Thompson WAL (1953). Reduction of post-operative pain. British Medical Journal, 1: 973–974. Lutz LJ (1990). Management of post-operative pain: review of current techniques and methods. Proceedings of the Mayo Clinic, 65: 584–596. Moote CA (1994). The prevention of post-operative pain. Canadian Journal of Anaesthesia, 41: 527–533. Oakley MJ, Smith SJ, Anderson JR, Fenton Lee D (1998). Randomized placebo controlled trial of local anaesthetic infusion in day-case inguinal hernia repair. British Journal of Surgery, 85: 797–799. Riegler FX (1994). Update on perioperative pain management. Clinical Orthopaedics and Related Research, 305: 283–292. Rosenberg PH, Renkonin OV (1985). Antimicrobial activity of bupivicaine and morphine. Anaesthesiology, 62: 178–179. Sood MK, Elliot D (1998). Treatment of painful neuromas of the hand and wrist by relocation into the pronator quadratus muscle. Journal of Hand Surgery, 23B: 214–219. Tetzlaff JE, Andrish J, O Hara J, Dilger J, Yoon HJ (1997). Effectiveness of bupivacaine administered via femoral nerve catheter for pain control after anterior cruciate ligament repair. Journal of Clinical Anaesthesia, 9: 542–545. Thomas DF, Lambert WG, Lloyd Williams K (1983). The direct perfusion of surgical wounds with local anaesthetic solution: an approach to postoperative pain. Annals of the Royal College of Surgeons of England, 65: 226–229. Wood GJ, Lloyd JW, Bullingham RFS, Britton BJ, Finch DRA (1981). Postoperative analgesia for day-case herniorrhaphy patients. Anaesthesia, 36: 603–610.
References Blades B, Ford WB (1950). A method for control of post-operative pain relief. Surgery, Gynecology and Obstetrics, 91: 524–526. Bond MR, Pilousky I (1966). Subjective assessment of pain and its relationship to the administration of analgesics in patients with advanced Cancer. Journal of Psychosomatic Research, 10: 203–208. Chester JF, Kancherla R, White BD, Shanahan D, Taylor R, Williams KL (1989). Wound perfusion with bupivacaine; objective evidence for efficacy in post-operative pain relief. Annals Royal college of Surgeons of England, 71: 394–396.
Received: 11 January 2002 Accepted: 25 June 2002 Mr D. ELLIOT, MA, FRCS, Hand Surgery Department, St Andrew’s Centre for Plastic Surgery, Broomfield Hospital, Court Road, Chelmsford, Essex CM1 7ET, UK. Tel.: +441621-857-362; Fax: +44-1621-841-127; E-mail; [email protected] r 2003 The British Society for Surgery of the Hand. Published by Elsevier Science Ltd. All rights reserved. doi:10.1016/S0266-7681(03)00015-9 available online at http://www.sciencedirect.com
The role of continuous bupivacaine infusion either into the wound or as a local nerve block, following hand surgery was investigated in 100 patients. After excluding six patients with complex pain problems in whom neither the bupivacaine infusion nor any other conventional analgesic techniques provided adequate analgesia post-operatively, 86 of 94 (91%) patients were adequately treated for post-operative pain by this system during the first night after surgery, when pain is presumed to be greatest. This system also provided adequate on-going analgesia for up to 1 week after surgery controlling nerve pain and allowing mobilization of tendons after tenolysis. Continuous bupivacaine infusion is of particular use in these two groups of patients and after major hand injuries, when considerable pain can be anticipated. Pain during the first night was not controlled adequately by the bupivacaine infusion system in eight of the 94 patients (8%). All eight had a technical failure of the system, which was rectified in six cases to restore adequate analgesia by the infusion system. Two patients developed infection at the infusion cannula insertion site, which occurred only after 1 week and was successfully treated by removal of the cannula and oral antibiotics. Journal of Hand Surgery (British and European Volume, 2003) 28B: 4: 300–306 Keywords: postoperative pain; neuroma; tenolysis; major hand injury; bupivicaine infusion
administered intermittently, has recently been reported as an effective adjunct to flexor tenolysis (Kirchhoff et al., 2000) but we can find no assessment of the use of continuous infusions of local anaesthetic for the same purpose or for post-operative analgesia in the literature. We have used continous bupavicaine infusion postoperatively for the last 10 years (Sood and Elliot, 1998). This study assesses this technique in 100 patients over a 3 year period in the post-operative management of three groups of hand surgery patients (Table 1). These patient groups were chosen as we felt that they would particularly test the ability of any method of control of pain and would be a good test of the usefulness of the technique more generally in the management of postoperative pain after hand surgery.
INTRODUCTION Post-operative pain relief has been a matter of concern to surgeons and anaesthetists for many years. It was with enthusiasm that we embraced the system of patientcontrolled administration (PCA) of intravenous opiate analgesia a few years ago in our hand surgical practice (Riegler, 1994). Unfortunately, some categories of hand surgery patient require strong analgesia for more than 12–24 h and the side-effects of the opiates often become problematic when PCA administration is continued beyond 12 h, making this system of analgesia unsuitable. In particular, nausea and drowsiness may cause problems (Moote, 1994; Riegler, 1994). Continuous local anaesthetic blockade has been reported in other branches of surgery (Blades and Ford, 1950; Chester et al., 1989; Fenton Lee et al., 1994; Lewis and Thompson, 1953; Tetzlaff et al., 1997; Thomas et al., 1983; Wood et al., 1981) and appears to be an effective and safe technique of post-operative pain control. Although continuous post-operative brachial plexus anaesthesia has been used to effect after hand surgery for some time (Denson et al., 1983), continuous local anaesthesic infusion post-operatively at the site of surgery or immediately proximal to this site as a local nerve block is not commonly used in hand surgery. Although there are passing references to the technique in textbooks and we are aware of its use previously in other units, such use appears to have only been sporadic and this method of achieving post-operative pain relief has not been widely applied or accepted in hand surgery. Use of post-operative local anaesthetic blockade,
PATIENTS AND METHODS Patients Over a 3 year period (1998–2000) continuous bupivicaine infusion was used in 100 patients as the first choice of post-operative analgesia. Three surgical categories of patient were chosen for inclusion in this study (Table 1). Group 1 consisted of 58 patients undergoing neuroma relocation or neurolysis of scar-tethered nerves. These patients usually have considerable post-operative pain. Within this group, we recognized two subgroups: (a) The first and the simpler to treat were 47 patients with a short-term problem who had experienced nerve pain for less than 2 years and who had 300
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301
Table 1—Clinical Problem Group 1 (n=58) Neuroma relocations Neurolysis Tenolysis with neurolysis
40 9 9
Group 2 (n=28) Extensor tenolysis only Flexor tenolysis only Tenolysis both ext. and flexor
22 4 2
Group 3 (n=14) High-pressure injection injury Crush injury Large haemangioma excisions Complex ganglions Carpal tunnel decompressions after RSD Secondary carpal bone surgery
3 4 2 2 1 2
Fig 1 Post-operative view of a cannula at the proximal end of the wound (arrow) infusing 0.33% bupivacaine locally into the site of extensor tenolysis of the right middle finger. Distally, a Yates drain removes excess local anaesthetic from the wound.
undergone two or less previous operative attempts to cure their pain problem. (b) The second subgroup consisted of 11 patients, many of whom had been referred for tertiary treatment. These had experienced pain for more than 2 years and had often undergone multiple surgical attempts to solve their pain problem. Many of these patients had significant psychological, social and marital problems. Group 2 consisted of 28 patients undergoing tenolysis of flexor or extensor tendons. In these cases, the continuous post-operative local anaesthetic technique was used to allow our therapists to start mobilization within 24 h of surgery without pain at the operative site. Four patients in this group underwent a combined neurolysis and tenolysis, but their predominant clinical problem was loss of tendon mobility and not nerve pain. Group 3 consisted of 14 patients undergoing various hand surgical procedures which, for a variety of reasons including magnitude of injury, multiple nerve injuries, length of operation and/or size of lesion being resected, were expected to have significant post-operative pain. The 100 patients included in the study included 62 men and 38 women, with a male-to-female ratio of 1.8– 1. Their age ranged from 23 to 68 (mean age, 44) years. Technique of continuous bupivacaine infusion Cannula insertion Following surgery and prior to wound closure, an 18 or 20 gauge epidural catheter was placed with its tip in the wound at the site of surgery (Fig 1) or immediately proximal to this site, adjacent to the nerve innervating the site of surgery (Fig 2). In some instances, particularly in group 1, it was possible to place the catheter alongside the regional sensory nerve by passing it proximally from the operative area along the nerve(s). In other cases, a separate incision was made proximally to insert the catheter beside the appropriate nerve. In
Fig 2 Intra-operative view showing a cannula (arrow) infusing 0.33% bupivacaine alongside the superficial radial nerve just proximal to its site of relocation into the underside of the brachioradialis muscle (encircled).
cases in which the operative area was innervated by more than one major nerve, the infusion was either directed into the operative site or an appropriate number of catheters were inserted alongside the involved regional sensory nerves (Fig 3). All catheters were placed alongside nerves under direct vision. The catheters were brought out through separate skin stab incisions close to the operative incisions and anchored securely to the skin by two stay stitches. A small open Yates drain was inserted into the distal end of the main wound and/or any wound made to insert a cannula alongside a nerve to prevent any accumulation of excess local anaesthetic. Within the wound, the proximal end of the drain was placed at a sufficient distance from the tip of the infusion cannula to ensure that the infusion did not escape directly before achieving its analgesic effect. The drain always remained in place until the anaesthetic infusion was discontinued. After catheter and drain insertion and skin closure, the wounds were dressed and the catheter connected to an infusion pump primed with bupivacaine.
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12–60 h, was used to deliver the bupivacaine infusion (Fig 3). This pump is used widely throughout the United Kingdom for continuous intravenous infusions of drugs and is easily available. It has an alarm system which notifies staff of any interruption to the infusion and when the infusion stock is finishing, which was essential to the accuracy of our study. A concentration of 0.375% (3.75 mg/ml) bupivacaine is achieved by loading the IVAC syringe with three 10 ml ampoules of 0.5% (5 mg/ml) and three 10 ml ampoules of 0.25% (2.5 mg/ ml) plain bupivacaine. Weaning off the bupivacaine infusion
Fig 3 Post-operative view of a complex case in which end-neuromata of branches of both the superficial radial nerve and the dorsal branch of the ulnar nerve on the dorso-radial aspect of the wrist were relocated into the brachioradialis and pronator quadratus muscles, respectively. Two cannulae were inserted to block the two nerves proximal to the relocation sites (arrows), and Yates drains (encircled) were inserted distally to drain excess local anaesthetic. The 60 ml syringe of 0.33% bupivacaine connected to the superficial radial nerve cannula is seen in this illustration, with the Ivac pump in the background. The other 60 ml syringe is not seen but is attached to the second cannula, and the two syringes are changed over in the Ivac pump every 2 h to provide analgesia to both relocated nerves. By exchanging the syringes in this way, analgesia of both relocated nerves is achieved without the use of two pumps and with no need for the concentration changes of the bupivacaine which would be necessary if synchronous infusions were used.
Bupivacaine dose Pharmacokinetic studies on patients with chronic pain undergoing continuous perineural bupivacaine infusion have shown no evidence of accumulation of the drug with continuous infusion of doses of up to 30 mg/h (total daily dose of 720 mg) for up to 5 days, both in normal patients and even when total plasma clearance of bupivacaine is reduced by 60% (Denson et al., 1983). Oakley et al. (1998) showed similar safety margins for continuous bupivacaine infusion in a similar group of patients. At the time of carrying out this study, the manufacturers of bupivacaine recommended a maximum dose of 20 mg/h and did not specify an upper limit of total daily dose. This study was set up to comply with the above regulations, using a concentration of 0.375% (3.75 mg/ml) bupivacaine up to a maximum infusion rate of 5 or 18.75 mg/h. This limited the total daily dose possible to 450 mg/24 h which is well within the recommended safety limit of the earlier scientific studies. The infusion pump An ‘‘IVAC’’ volumetric pump( IVAC Medical Systems, Model P7000 variable syringe pump) which holds a 60 ml syringe and can deliver 1–5 ml/h continuously for
The patients were weaned off the bupivacaine infusion by reducing the rate from 5 to 3 to 1 ml/h over a period from 1 to 5 days in most cases and then by removing the cannula. Group 1: These patients always required 48 h and, more often, 72 h of bupivacaine infusion after surgery. In those cases of simpler nerve pain and some of the more complex nerve pain patients, the bupivacaine infusion was replaced by minor oral analgesics on a supply-on-demand basis after 2–4 days. Six of the patients with more complex nerve pain required use of the PCA almost immediately after operation, despite being given bupivacaine at the maximum infusion rate. The bupivacaine infusion was necessary for much longer, up to a maximum of 11 days. These patients also required replacement of the bupivacaine infusion and PCA by specific and stronger pain-relieving drugs, including long-acting opiates, at 3–10 days. Some of the simpler nerve pain patients also needed specific and stronger oral pain-relieving drugs. Group 2: Infusion was routinely maintained in these patients for 3–4 days after surgery to allow pain-free hand therapy. It was then usually possible to reduce the infusion and discontinue it over the next 12 h, with replacement by minor oral analgesics on a supply-ondemand basis. In two cases of teno-neurolysis, it was necessary to continue the infusion for longer because of nerve pain during tendon mobilization: both these patients remained as inpatients for more than 1 week. Group 3: The bupivacaine infusion was reduced and discontinued after 24–72 h, with replacement by minor oral analgesics on a supply-on-demand basis. Other pain relieving management Other analgesics While continuous bupivicaine infusion was the first choice post-operative analgesic technique in this study, all patients also left the operating theatre with an opiate PCA as a back-up for break-through pain. Patients were also written up for dihyrocodeine (DF118) and paracetamol for use if necessary, and these drugs were given in preference to the use of the PCA for break-through pain after the first 24 h. However, if these oral drugs
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were ineffective, the PCA opiate was continued through the second and third days after surgery and was then replaced by either the above drugs or by regular prescription of long-acting oral opiates and specific pain-relieving drugs such as Amitryptalline, Carbamazepine, Gabapentin and Lamotrigine. These were rarely necessary except in Group 1 patients. Generally, patients left hospital soon after weaning off the bupivacaine infusion onto appropriate oral drugs which were then continued as an out-patient. Non-steroidal anti-inflammatory drugs While this group of drugs alone do not provide adequate analgesia in the early post-operative period, they appear to reduce the levels of conventional analgesics necessary and aid early post-operative mobilization. It has been our custom for many years to give hand surgery patients oral diclofenac 50 mg three times a day for a minimum of 5 days whenever there is no respiratory, upper alimentary tract or age contra-indication. In this study, all but 18 patients (in whom the drug was contraindicated) were given oral diclofenac, starting as soon as the patient was drinking post-operatively and continuing throughout and beyond the period of bupivacaine infusion. Splinting In order to reduce the post-operative pain during the first 24 h, all patients in the study left theatre with the appropriate part of the upper limb splinted on a dorsal or palmar plaster slab. Group 1 patients were splinted for as long as the bupivacaine infusion was continued as we believe the absence of movement significantly reduces nerve pain in the early post-operative period after neuroma and neurolysis surgery. These patients also used splints extensively after terminating the bupivacaine infusion. Group 2 patients started active mobilization of the hand on the day after surgery. However, their arm remained in a thermoplastic splint as an aid to analgesia for most of the day during the following 1–2 days, with the splint only being removed every 2–4 h to perform our standard mobilization regimen. This continued until the bupivacaine was discontinued. Thereafter, free movement and less splinting was allowed. Group 3 patients usually retained their upper limb splint for 2–4 days, as an aid to analgesia. Splinting was usually maintained until about the time at which the bupivacaine infusion was discontinued. Assessment PCA use The use of the opiate PCA system by the patient for breakthrough pain during the first night after surgery was used as an indicator that the bupivacaine infusion was not completely controlling the post-operative pain.
If the PCA system was used, the dose and frequency of administration of the intravenous opiate were recorded. Discussion with patients Pain severity was determined by subjective patient selfassessment using the visual analogue scoring system (VAS) on a 100 mm line for pain assessment (Bond and Pilousky, 1966). Zero or position 0, represented no pain and 100 mm, or position 10, was unbearable pain. This chart was completed every 4 h by the nursing staff and the charts examined by us every 24 h. For the purposes of this study, a charting of 20 mm, or level 2 pain, which is described as ‘‘discomfort’’, implied a failure of the bupivacaine infusion system. Patients were questioned with regard to any adverse effects they suffered from the various medications administered and their personal preferences as to the techniques of analgesia used in this study were recorded. Discussion with nurses Patients were advised to call the nurses if level 2 or more pain developed or if there were problems with the bupivacaine pump system. Where a patient developed discomfort or pain, the level of pain and the type of intervention, e.g. increasing the rate of bupivacaine infusion, additional use of the PCA or addition of oral analgesics, were recorded. Where bupivacaine infusion provided inadequate pain relief, the dose and frequency of PCA administration of intravenous opiate were also recorded. Problems encountered in maintaining the bupivacaine infusion on the ward were also noted by the nurses.
RESULTS The results of assessment of the 100 patients in this study are summarized in Figs 4 and 5 and Tables 2–4. Fifty-eight patients required no analgesia other than the bupivacaine infusion during the first 24 h after surgery (Fig 4). Six of the 100 patients with more complex nerve pain, all of whom were from group 1b, required use of the PCA almost immediately after operation, despite being given bupivacaine at the maximum infusion rate from the onset of the post-operative period. In these six cases, use of both the bupivacaine infusion and the PCA were necessary for up to 11 days. These patients also required replacement of the bupivacaine infusion and PCA with oral opiates and other strong pain-relieving drugs from day 3 onwards and all six were eventually discharged with pain which they described as ‘‘moderate’’ (VAS levels 3–6). Although these patients represent a failure of the bupivacaine infusion technique, their inclusion confuses the interpretation of this analgesic method in the remaining 94 patients. For this reason, the
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Table 2—Use of the PCA during the first night after surgery Total number of patients in the study
100
Patients who did not use the PCA at all Patients who used the PCA anticipating pain but who did not actually experience pain or discomfort Patients who used the PCA because of technical failure of the continuous bupivacaine infusion system Patients with complex pain with failure to respond to bupivacaine, PCA opiates or oral opiates
58 28 8 6
Table 3—Technical failures of the continuous bupivacaine infusion system Tube kinked Battery problem Initial infusion rate too low Cannula dislodged
3 1 2 2
Fig 4 Chart showing the post-operative use of bupivacaine and PCA morphine in all 100 patients. Table 4—Complications of the continuous bupivacaine infusion system Localized swelling and itching at the cannula site (after day 6) Cannula infection (after day 8 )
Fig 5 Chart showing the post-operative use of bupivacaine and PCA morphine in the remaining 94 patients after exclusion of six patients with chronic pain, who continued to require bupivacaine infusion and PCA use throughout their hospital stay without full relief of pain.
remaining 94 patients were assessed independently and the results of this analysis are shown in Fig 5. Of the remaining 94 patients in the study, 58 used the bupivacaine system only during the first night after surgery and 36 patients also used the PCA (Fig 5). Of the 36 patients who used the PCA, 28 used it without ever having experienced actual pain (Table 2). Some were frightened of pain suddenly starting during the night, when they presumed that the brachial block anaesthetic would have worn off and others were
3 2
worried about going to sleep and then waking up with pain. These patients used the PCA one, two or three times before settling for the night and did not use it later in the night. Eight of the 94 patients actually developed pain which varied in intensity from discomfort to moderate pain (VAS levels 2–6) during the first night. These eight patients used the PCA between four and 20 times during the first night after surgery. The use of the PCA by these patients was more than by the previous group and the pattern of use of the PCA also differed, with the PCA being used continuously through the night. There was a technical or nursing reason why the bupivacaine had not worked in all eight cases (Table 3) and it was possible to correct the problem in six instances. Thereafter, these six patients stopped using the PCA. Two cannulae had become dislodged and were not replaced as this would have involved re-operation. These two patients used their PCA for 4–5 days as an alternative to the bupivacaine and both developed nausea. Over and above these technical failures, the actual complication rate of use of bupivacaine infusions was very low (Table 4). Two cannulae became infected in patients in whom they had been kept in place into the second week after surgery. These were both complex pain patients in whom the bupivacaine system was ineffective. After removal of the cannulae and change of the antibiotic regimen, both infections settled quickly. A further three patients developed localized swelling and itching around the cannulae after 6–8 days without obvious infection. These also settled after removal of the
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cannulae and treatment of the itching with antihistamines. These complications had no long-term sequelae.
DISCUSSION Opiates given through a PCA system can be very much more effective than the traditional methods of ‘‘on demand’’ administration. However, prolonged PCA administration may lead to drug accumulation and drowsiness and often causes nausea and vomiting (Moote, 1994; Riegler, 1994). Because of these side effects, PCA use is often reduced by the patients who may then suffer increased pain levels, over and above the unpleasantness of the direct side-effects of opiate overdose. Compliance with post-operative treatments, in particular with early hand therapy in our speciality, may also be poor. Single dose local or regional anaesthesia techniques are commonly used, and are very effective, after hand surgery (Kirchhoff et al., 2000) but are limited in their usefulness even when long acting local anaesthetic agents such as bupivacaine are used. Continuous infusion of local anaesthetic at the site of surgery or immediately proximal to this site as a local nerve block has been shown to be effective in other branches of surgery for relieving post-operative pain, and so reduce the need for opiate analgesia. (Blades and Ford, 1950; Chester et al., 1989; Fenton Lee et al., 1994; Gerwig et al., 1951; Lewis and Thompson, 1953; Lutz, 1990; Tetzlaff et al., 1997; Thomas et al., 1983; Wood et al., 1981) but is not used commonly in hand surgery. While many hand surgical procedures do not require prolonged high levels of analgesia post-operatively, some cause significant pain for some time after surgery. It is difficult to achieve complete pain relief by conventional techniques in many patients undergoing surgery for nerve pain and major injuries, especially those with crushing or division of major nerves. It is also often difficult to achieve adequate pain relief by conventional techniques in patients with low pain thresholds. It has been our experience over 10 years that such patients benefit from continuous infusion of local anaesthetic post-operatively and that this is preferable to PCA opiate analgesia, for the reasons given above. This study confirms the usefulness of this post-operative analgesic technique in difficult hand surgical cases. Continuous infusion of local anaesthetic post-operatively is also useful as an adjunct to early mobilization after tenolysis, especially if performed in conjunction with nerve surgery. Some patients requiring such surgery also have a low threshold for pain which may have contributed to their poor co-operation with mobilization after the initial injury, leading to the scar tethering of the tendons and/or nerves. Their co-operation with hand therapy is maximized after the secondary surgery by this analgesic technique.
305
This study shows that the technique of continuous bupivacaine infusion used was simple, effective and safe. In many cases, it is evident that the bupivacaine infusion was working adequately when patients are reviewed on the first morning after surgery and the PCA was discontinued at this stage, with direct replacement of the bupivacaine infusion by routine oral analgesic drugs as required. Others transferred to oral analgesics fairly quickly during the second, third or fourth day. While the combination of a bupivacaine infusion attached to one arm and a PCA to the other confines the patient to his/her bed or an adjacent chair and is inconvenient, removal of the PCA allows the patient to move more freely and to be ambulant, while remaining comfortable. However, we do not recommend such early removal of the PCA in cases with significant nerve-related pain. In this study, the system of analgesia was used entirely on inpatients as this was suitable for the particular pathological problems which we were treating. However, in other branches of surgery, continuous local anaesthetic infusion has been used as an out-patient following day case surgery (Fenton Lee et al., 1994; Oakley et al., 1998) and the techniques used may be applicable to hand surgery, although we have no experience of such use. The incidence of infection as a result of leaving a bupivacaine cannula in situ for a week was negligible, probably because prophylactic antibiotics were used but, possibly, also because instillation of bupivacaine into wounds has an antimicrobial action (Rosenberg and Renkonin, 1985). There is probably no benefit to leaving the cannula and drain in situ beyond a week: the six patients with complex nerve pain in our study who had this system in place for this length of time had very questionable benefit from bupivacaine infusion. In general, the results of treatment of complex nerve pain patients, with regional surgical methods such as neuroma relocation and neurolysis, with or without wrapping the neurolysed nerve in vein, fascia or muscle, are poorer than in simpler cases of nerve pain. The fact that neither local bupivacaine infusion, PCA use of opiates nor oral analgesics of various types and strengths were effective in this group would support the general impression among hand surgeons and others that there is a central nervous component to their pain problem whether neurological or psychological or both. However, these patients are not common and this technique has proved highly effective in providing simple and effective post-operative analgesia for more straightforward nerve pain patients in our practice. During this study, several patients with nerve pain undergoing repeat surgery expressed a strong preference for use of bupivacaine local infusions post-operatively and completely refused PCA and oral opiates. After removal of the local anaesthetic infusion system they preferred to use other oral analgesics, even if pain relief was only partial, in order to avoid the nausea they had experienced from use of opiates on previous admissions.
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Since completion of this study, the manufacturers have issued new guidelines recommending the same upper limit of hourly infusion of bupivicaine (20 mg/h) but also recommending a maximum total daily dose of 400 mg/24 h. The manufacturers have given no explanation for their choice of this total daily dose limitation and it is very much lower than that shown to be safe in clinical studies (Denson et al., 1983; Oakley et al., 1998). Although we experienced no drug-related complications from the use of bupivacaine up to a maximum total daily dose of 450 mg/24 h during this study, we have now reduced our bupivacaine dose slightly to comply with this manufacturer’s recommendation. We now use a concentration of 0.33% plain bupivacaine, which is achieved by the use of a 60 ml IVAC infusion pump loaded with two 10 ml ampoules of 0.5% and four 10 ml ampoules of 0.25% bupivacaine. This concentration of bupivacaine has been used in a further 100 cases and appears to be equally effective. If used for 24 h at the maximum infusion rate of 5 ml/h, this gives a maximum total daily dose of 397 mg of bupivacaine.
Acknowledgements We would like to thank Dr T. Myint of the anaesthetic staff of the St Andrew’s Centre for Plastic Surgery, Broomfield Hospital, for his advice and assistance. We also wish to thank the nursing staff of Mayflower ward, Broomfield Hospital, for their help in assessing the technique of analgesia and Dr U. Kulkarni for her help with the graphics.
THE JOURNAL OF HAND SURGERY VOL. 28B No. 4 AUGUST 2003 Denson DD, Raj PP, Saldahna F, Finnsson RA, Ritschel WA, Joyce TH, Turner JL (1983). Continuous perineural infusion of bupivacaine for prolonged analgesia: pharmacokinetic considerations. International Journal of Clinical Pharmacology, Therapy and Toxicology, 21: 591–597. Fenton Lee D, Riach E, Cooke T (1994). The use of local anaesthetic wound perfusion device versus oral analgesia – a comparison in day case inguinal herniorraphy. British Journal of Intensive Care, 153–156. Gerwig WH, Thompson CW, Blades B (1951). Pain control following upper abdominal operations. Archives of Surgery, 62: 678–682. Kirchhoff R, Jensen PB, Nielson NS, Boeckstyns MH (2000). Repeated digital nerve block for pain control after tenolysis. Scandinavian Journal of Plastic and Reconstructive Hand Surgery, 34: 257–258. Lewis DL, Thompson WAL (1953). Reduction of post-operative pain. British Medical Journal, 1: 973–974. Lutz LJ (1990). Management of post-operative pain: review of current techniques and methods. Proceedings of the Mayo Clinic, 65: 584–596. Moote CA (1994). The prevention of post-operative pain. Canadian Journal of Anaesthesia, 41: 527–533. Oakley MJ, Smith SJ, Anderson JR, Fenton Lee D (1998). Randomized placebo controlled trial of local anaesthetic infusion in day-case inguinal hernia repair. British Journal of Surgery, 85: 797–799. Riegler FX (1994). Update on perioperative pain management. Clinical Orthopaedics and Related Research, 305: 283–292. Rosenberg PH, Renkonin OV (1985). Antimicrobial activity of bupivicaine and morphine. Anaesthesiology, 62: 178–179. Sood MK, Elliot D (1998). Treatment of painful neuromas of the hand and wrist by relocation into the pronator quadratus muscle. Journal of Hand Surgery, 23B: 214–219. Tetzlaff JE, Andrish J, O Hara J, Dilger J, Yoon HJ (1997). Effectiveness of bupivacaine administered via femoral nerve catheter for pain control after anterior cruciate ligament repair. Journal of Clinical Anaesthesia, 9: 542–545. Thomas DF, Lambert WG, Lloyd Williams K (1983). The direct perfusion of surgical wounds with local anaesthetic solution: an approach to postoperative pain. Annals of the Royal College of Surgeons of England, 65: 226–229. Wood GJ, Lloyd JW, Bullingham RFS, Britton BJ, Finch DRA (1981). Postoperative analgesia for day-case herniorrhaphy patients. Anaesthesia, 36: 603–610.
References Blades B, Ford WB (1950). A method for control of post-operative pain relief. Surgery, Gynecology and Obstetrics, 91: 524–526. Bond MR, Pilousky I (1966). Subjective assessment of pain and its relationship to the administration of analgesics in patients with advanced Cancer. Journal of Psychosomatic Research, 10: 203–208. Chester JF, Kancherla R, White BD, Shanahan D, Taylor R, Williams KL (1989). Wound perfusion with bupivacaine; objective evidence for efficacy in post-operative pain relief. Annals Royal college of Surgeons of England, 71: 394–396.
Received: 11 January 2002 Accepted: 25 June 2002 Mr D. ELLIOT, MA, FRCS, Hand Surgery Department, St Andrew’s Centre for Plastic Surgery, Broomfield Hospital, Court Road, Chelmsford, Essex CM1 7ET, UK. Tel.: +441621-857-362; Fax: +44-1621-841-127; E-mail; [email protected] r 2003 The British Society for Surgery of the Hand. Published by Elsevier Science Ltd. All rights reserved. doi:10.1016/S0266-7681(03)00015-9 available online at http://www.sciencedirect.com