Orthopaedic anaesthesia

The last decade has seen many changes in orthopaedic anaesthesia, some within the specialty, some in the wider sphere of orthopaedic surgery, some because of societal and political changes in attitude. Within the profession, the decade has seen orthopaedic anaesthesia become, if not a subspecialty, then at least a special interest. It has seen the foundation of the British Society of Orthopaedic Anaesthetists, which in 2003 ran its Eighth Annual Scientific Meeting and has over 300 members. The Fourth Biennial European Congress of Orthopaedic Anaesthesia held in 2003 attracted delegates from 26 countries, and speakers from the USA as well Europe, This interest both reflects and promotes a growing confidence in orthopaedic anaesthetists as a group and recognition of the importance of the anaesthetist in outcomes for our patients. All the principles of good anaesthetic practice apply here, as they do elsewhere, but the range of procedures and the range of patient ages make the anaesthetic challenges unique. Orthopaedic surgery is often major but seldom life saving. The anaesthetist must be involved in pre-operative assessment and postoperative care to a greater degree than in many other surgical areas, and the ‘First do no harm’ principle must always be borne in mind. The anaesthetist is an essential part of a team, and the anaesthetic part of a process, working towards the rapid, successful rehabilitation of our patients. The last 10 years have seen dramatic changes in the treatment of pain after surgery, following the Report of the Joint Working Party of the Royal College of Surgeons and the College of Anaesthetists [1]. It has seen increasing subspecialisation in orthopaedic surgery, with an increasing number of successful procedures being introduced. Political thinking has moved towards protected elective beds and the creation of elective centres. Orthopaedics outside district general hospitals has always seen the advantage of separating elective orthopaedics and trauma surgery, as a means of ensuring effective management of the elective load, and the efficiency of specialist elective orthopaedic hospitals has been the catalyst for this change in attitude. The decade has seen a steady decline in the number of beds available generally, and orthopaedic surgery is no exception (Table 1). The pressure of long waiting lists has increased the need to shorten hospital stay (Tables 2 and 3), already an important factor in the effort to deal with huge demands, especially for hip and knee arthroplasty. All these bring pressures to bear on the anaesthetist, to ensure that the anaesthetic is not only safe but contributes maximally to the patient's rehabilitation. New procedures, arthoscopic and minimally invasive techniques, mean that the emphasis has changed from short surgical procedures with several days in hospital postoperatively to longer but less traumatic surgery with discharge that day or on the first postoperative day. Discectomies, which used to take 40 min in theatre with a hospital stay of 4 or 5 days, now take 90 min, with surgeons using loops or a microscope, and discharge the next morning. These procedures are often very painful in the immediate postoperative period but settle quickly. Anterior cruciate ligament (ACL) repair is now a day stay or 23-h admission procedure and puts particular onus on anaesthetists to provide good analgesia without interfering with postoperative physiotherapy. At the other end of the scale, spinal fusion surgery for degenerative conditions is more common, and it is a major problem for the anaesthetist and acute pain team. For patients with cerebral palsy, one major episode of surgery in young adolescence has replaced the annual cycle of ‘birthday surgery’ so common a decade ago. While hip and knee arthroplasty remain the most common procedures in any orthopaedic unit, shoulder, elbow wrist and ankle replacements are all growing in frequency. If children are excluded, the population undergoing most orthopaedic surgery is an elderly one. Certain procedures related to sports injuries, such as ACL repair and shoulder stabilisation, are more common in young and early middle-age adults, but the average age of those undergoing major joint replacement is over 70 years. Many patients in their fifth and sixth decades are undergoing the procedures, but so are more of those in their ninth and tenth. This is an age group with a high level of co-morbidity; 40% of those presenting for arthroplasty are on treatment for hypertension or cardiac problems. In my own practice, 14% of patients for primary joint replacements are classed as ASA III or IV, as are 41% of those requiring revision. Patients now often refuse to accept that surgery is not an option. Even after a full explanation of the risks involved, the majority will opt to proceed. While not life threatening, the pain suffered by many patients, and the restriction on their way of life means that they will almost always accept the risks described. The 1990s saw a great increase in the provision of pre-operative assessment units, and in postoperative high dependency care for patients. Originally created to reduce the number of patients cancelled after admission, thereby ‘wasting’ a theatre slot, these clinics have several other benefits, each of which is a good reason for their existence. Education is possible at a time when the patient is receptive. Information on the expected procedure and its outcome, anaesthesia and pain relief can be given verbally and in writing in the knowledge that the patient has time to assimilate it. Questions can be answered and views sought. Discharge planning can be started, with both patient and social care staff knowing in advance what will be required once the patient arrives home. All the demographic and other details required by medical and nursing staff can be noted, making the actual admission procedure quicker and smoother. Most important of all, if the patient has concurrent medical problems treatment can be optimised before admission. Patients do not ‘pass or fail’ their pre-operative assessments – they are graded as suitably fit for surgery to proceed on a given date, postponed pending adjustment of current treatment or referred for further investigation after which they will return for surgery. Originally, assessments were arranged 3 or 4 weeks before the patient's expected date of admission, but there is a growing recognition that this does not give sufficient time to make the often necessary alterations in treatment. Discussion as to the compromise between having enough time to optimise the condition of patients who require it, and the assessment being so long before operation that for many elderly patients it has become out of date, is ongoing. It is probable that 6–8 weeks prior to surgery will be better than 3–4 weeks. Over 10% of patients seen at our pre-assessment clinic are deferred for treatment or investigation, almost the same as the number who were cancelled after admission when there was no clinic. The commonest causes of deferment are uncontrolled hypertension and the requirement to have an echocardiogram. Discussion with General Practitioners is starting, so that an early warning system can be created, providing GP's with advance notice and an opportunity to check and correct blood pressure treatment if necessary, improving their condition, and making a ‘successful’ assessment more likely. Access to an echocardiograph either during the clinic or quickly thereafter would substantially reduce the number of postponements. One looks with envy at the Hospital for Special Surgery in New York where facilities for respiratory function testing and echocardiography are available at the assessment clinic. There can be no doubt that the clinics have achieved their first aim – late cancellations and lost theatre time are now fortunately rare. How these clinics are organised varies from trust to trust, from those entirely nurse led, where highly competent senior nurses work with protocols designed by anaesthetic staff, to those with a significant medical, and specifically anaesthetic, input. There must always be ready access to senior anaesthetic staff for difficult or borderline cases, and the number of dedicated consultant anaesthetist sessions allocated to pre-assessment clinics, while still small, is growing. Day of admission surgery is not yet the norm for major orthopaedics, but in America and parts of Europe it is the way the system works. There is no doubt that this will gain popularity here, too, and a properly organised pre-operative assessment clinic, with proper input from anaesthetists, makes it a realistic possibility, saving the patient a largely wasted 12–24 h in hospital. It does, however, require a change in work pattern for anaesthetists, with dedicated rather than grace and favour time in the clinic, and an acceptance that seeing patients on the evening before surgery is neither the only, nor necessarily the best, way for anaesthetists to spend their time. Particularly in dedicated elective orthopaedic units, extended recovery and high dependency areas are of enormous value. Regrettably, there is difficulty in convincing Commissioners, and some managers, that consultant sessions in high dependency care rather than in theatre are value for money. While the creation of these units over the last decade was a major step forward in quality of care, a challenge for the immediate future is to ensure the provision of adequate senior medical cover. The expertise and knowledge acquired by our nursing colleagues who work in these units is impressive. Highly skilled and highly motivated, they have contributed enormously to successful outcomes [2] and patient satisfaction. The quality of care delivered in HDU has facilitated the use of central and peripheral regional analgesia and other sophisticated methods of pain relief, allowing such methods to be introduced safely and successfully so that they are now standard through out the service. In the early 1990s, regional anaesthesia for hip and knee arthroplasty was already well established. Though there was no firm evidence of its superiority over general anaesthesia, the stability of patients intra-operatively and their comfort during recovery was sufficient to convince many that spinals or epidurals were the anaesthetics of choice. Over the last decade, evidence, a large part of which was gathered from outcomes in orthopaedics, has accumulated to show that regional anaesthesia reduces mortality and morbidity [3–6]. Sharrock [2] in 1995 in the Hospital for Special Surgery in New York showed that over a 10-year period the steadily increasing use of regional anaesthesia, invasive monitoring and high dependency care after surgery was reflected by a steadily decreasing mortality rate. By 1999, even the surgeons had recognised the benefits of regional anaesthesia, and recommended in the British Orthopaedic Association document ‘Good Practice in Total Hip Replacement’[7] that it was the anaesthetic of choice. However, a decade ago, and to a lesser extent even now, postoperative pain relief was provided by an opioid, with intravenous patient controlled analgesia taking over from intramuscular injections as the route of choice as the decade progressed. The trend for shorter and shorter hospital stays, combined with an increasing focus on the disadvantages of opioids has made those who work in orthopaedics seek alternative methods of providing pain relief. An early audit in this unit showed that almost half of our patients were still nauseated, sometimes still vomiting at discharge 4 or 5 days after surgery. An audit of Postoperative Pain Relief in Musgrave Park Hospital, involving 2000 patients in 2001, showed that intrathecal diamorphine caused 30% of patients to suffer from some degree of postoperative nausea and vomiting. Without intrathecal but using intravenous opioids, 20% of patients suffer. As the possibility of day stay hip replacements comes nearer, and when discharge on the second postoperative day is a reality, prolonged side-effects of opioids are even less acceptable. Nausea and urinary retention are likely to become major factors in delaying physiotherapy and discharge. Early discharge means intensive physiotherapy during the short time patients are in hospital. It is important therefore that the patient be as pain free as possible, with as much motor power as possible. It was against this background that orthopaedic anaesthetists began to examine the use of peripheral nerve blocks to provide anaesthesia and postoperative analgesia. Dahl et al.[8] in 1998 and Serpell et al.[9] in 1991 highlighted the advantages of femoral and sciatic nerve blocks over central blockade inpatients who had undergone knee replacements. Over the next few years femoral and sciatic nerve blocks, providing good analgesia for 18–24 h, became the technique of choice for patients undergoing knee replacement. Preferred by patients and nursing staff, they provide analgesia as good as or better than central blockade, with fewer complications. Improved equipment, with finer catheters (Fig. 1) has allowed the placement of catheters into the nerve sheath, giving the ability to provide prolonged analgesia. Newer local anaesthetics like ropivacaine and levobupivacaine provide pain relief without loss of muscle power. The recent introduction of catheters through which a nerve stimulator can be used should increase the success rate in catheter placement, and enhance the analgesia provided. A stimulating needle with catheter. For patients undergoing total hip arthroplasty, psoas compartment or lumber plexus block has been investigated. First suggested by Winnie et al.[10] in 1974, and described by Chayen et al.[11] in 1976, the psoas block remained an interesting but little used technique. The last decade, for the same reasons as those described above, has seen a steady increase in its use until it is now routine in centres in America and Europe. Capdevila et al.[12] and his colleagues in the South of France describe it as a reliable block which provides ‘optimal analgesia at rest and during physiotherapy after total hip arthroplasty’. Using a 2 mg.ml−1 solution of ropivacaine via a catheter into the psoas compartment, analgesia was maintained for 48 h. Orthopaedic surgery lends itself to regional anaesthetic techniques, and brachial plexus blocks have become widely used. The approach used depends on the area of surgery, with an interscalene approach being chosen for shoulder surgery, subclavian and axillary approaches for surgery to the elbow and forearm. All approaches have been used to site a catheter, enabling analgesia to be continued for several days. For less major surgery more peripheral blocks are employed. Single shot blocks of the radial, median and ulnar nerves at the wrist for hand surgery, the sciatic nerve in the popliteal fossa for operations on the lower leg, and block of all five nerves at the ankle for surgery to the foot are all now everyday practice. While these are usually single shot blocks, a catheter can be placed in the popliteal fossa and, if need be, analgesia extended. These have been shown to reduce dramatically the morphine requirement, with its concomitant side-effects [13]. Spinal surgery is still an area where general anaesthesia remains the standard, but even here regional analgesia may have a place. Patients after spinal surgery of all types have considerable pain, and after multiple level spinal fusion suffer greatly. Surgeons were initially reluctant to agree with epidural analgesia lest it mask cord or nerve damage, but most have accepted the need for better pain relief than is possible with systemic analgesia alone. An epidural catheter is now commonly sited by the surgeon, and an infusion started postoperatively. Unfortunately, this has not brought about the improvement we had hoped, and pain relief remains a problem. Many of these patients have been on weak or even strong opioids for weeks or months before surgery, and a simple infusion of local anaesthetic and opioid is not sufficient to give pain relief. The addition of clondine and ketamine may help, but there is still a considerable way to go. Invasive monitoring is becoming more common. Rare 10 years ago in orthopaedic patients, the techniques are now commonplace. The National Confidential Enquiry into Perioperative Deaths in its 1999 report ‘Extremes of Age’ suggested that central venous monitoring was often useful in the elderly, and over 20% of our patients now have a central venous catheter and an intra-arterial cannula inserted for peri-operative monitoring. For the past 10 years, urinary catheterisation has been carried out routinely for all patients undergoing hip and knee arthroplasty. Introduced in this unit because so many patients required catheterisation urgently during the first night after operation, careful auditing has shown no increase in postoperative infection. Acute renal failure is not uncommon in these patients and hourly measurement of urinary output is a valuable monitor of the patient's state of hydration during the first 24 h. Stays in hospital will get shorter still. Day stay minimally invasive hip replacements, knee replacements and major shoulder surgery are almost here, and are practised already in Europe and America. Patients are going home with nerve sheath catheters in situ, a solution of local anaesthetic delivered by patient controlled boluses providing analgesia for several days. (Nawal R, personal communication; Chelly J, personal communication). Interscalene and subclavicular brachial plexus catheters [14], psoas compartment and femoral nerve catheters can all be used to provide analgesia after discharge and for several days at home. As experience mounts elsewhere, it is almost certain that the technique will gain acceptance here. It will become acceptable to discharge patients before surgical block has worn off, after proper explanation and the provision of a sling or brace, as is already happening in the United States (Urmey W, personal communication). Anaesthetists in orthopaedics will have to be prepared to extend their influence and expertise into the community so that this can be done safely. While the potential benefits are so are the if there is not adequate and with of nerve sheath and epidural will to with patient controlled as well as used to provide analgesia for several days. the of spinal but they are routine in other parts of the The advantages of and peripheral blocks are so great that the from A of the of elective even more so if the unit is an elective is a of medical as to As has already been orthopaedic patients often have concurrent medical problems which require adequate assessment and treatment before surgery, and the majority of problems postoperatively are medical rather than This must be and properly There is for the of peri-operative At the very least there must be adequate in these units, with good access to and respiratory as and orthopaedic anaesthetists must be prepared to accept that their care of patients may not when the patient the or The creation of which patients outside the high dependency unit is but the must have medical as well as nursing to function to the patient's Orthopaedic anaesthesia and orthopaedic anaesthetists have over the last There has been no but rather a steady Postoperative nausea and vomiting remains a problem. use of local anaesthetic to provide nerve blockade out the of analgesia without nausea for more of our patients. have a system which the (Fig. provide regional anaesthesia we reduce and ensure good analgesia allowing physiotherapy and and improving the of our patients, hospital stay and improving of the postoperative The last decade has been interesting and for those of working in orthopaedic anaesthesia, and forward to the challenges of at least some of the next 10 years.