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Anaesthesia for fractured neck of femur
ORTHOPAEDIC ANAESTHESIA
Anaesthesia for fractured neck of femur
Learning objectives After reading this article you should be able to: C list four indications for cardiac consultation C list four patient-related postoperative pulmonary complications C know the advantages of early hip fracture surgery C know the possible benefits of regional anaesthesia compared to general anaesthesia for hip fracture surgery
Michael G Irwin Stanley Sau Ching Wong
Abstract Fracture of the femoral neck is a common injury in the elderly, and many patients have significant co-morbidities. Effective management requires a multidisciplinary approach involving anaesthetists, medical physicians and orthopaedic surgeons. Although early surgery within 24e48 hours is beneficial, there may be medical conditions that need prior optimization. Both general anaesthesia and regional neuroaxial anaesthesia can be used, although it appears regional anaesthesia is preferred by most anaesthetists as it is associated with reduced early postoperative mortality, less deep vein thrombosis, less fatal pulmonary embolism, and fewer pulmonary complications.
co-morbidities. Current evidence suggests that early surgery is beneficial, but sometimes medical optimization or further investigations are required before surgery can proceed safely. Thus a balance needs to be made between optimization/investigations and avoiding unnecessary surgical delay needs. There is great variation in anaesthetic technique for hip fracture surgery, mainly because previous studies have not shown clear benefit with any particular technique. In this article we will review the perioperative management of patients with fractured neck of femur with emphasis on preoperative optimization, minimization of surgical delay, potential consequence of surgical delay, and best anaesthetic technique.
Keywords Femoral neck fracture; fractured hip; fractured neck of femur; general anaesthesia; perioperative management; preoperative assessment; regional anaesthesia
Timing of surgery Guidelines recommend that hip fracture surgery should be performed within 24e48 hours. Early surgery allows quicker mobilization and may reduce deconditioning and muscles wasting. It can also reduce the incidence of complications such as pneumonia and skin breakdown (Table 1). A recent clinical audit performed in the UK showed that time from admission to surgery ranged from 24 to 108 hours, with a median of 47 hours.3 42% of operations were delayed, mostly due to organizational and medical reasons.3 Only 4% of delays were due to anaesthesia.3 Most literature supports early surgery. A recent meta-analysis of prospective observational studies demonstrated that surgery within 24e72 hours significantly reduced mortality at 1 year, but not 1 month or 3e6 months after surgery.4 Even when only analysing studies that adjusted for American Society of Anesthesiology (ASA) score, age, and gender, early surgery was associated with a reduced risk of mortality.4 Another metaanalysis of observational studies showed that delay beyond 48 hours increased risk of 30-day mortality by 41% and 1-year
Introduction Femoral neck fractures are associated with aging and osteoporosis and can occur after relatively trivial trauma in elderly patients. Each year around 75,000 people in the UK suffer from fracture hip.1 The mean age for men is 84 years and women 83 years.1 The incidence worldwide was 1.26 million in 1990 and is expected to increase to 4.5 million by 2050.2 Femoral neck fracture is associated with a 30-day postoperative mortality between 5 to 10%,3 and 1-year mortality of around 30%.1 This mortality rate has remained relatively constant over the past 20 years and it continues to be a major cause for mortality, morbidity and loss of functional activity. Optimal perioperative care emphasizes early optimization and early surgery, effective multimodal analgesia, and use of a multidisciplinary team. The multidisciplinary team should consist of the anaesthetist, orthopaedic surgeon, medical physicians/geriatricians, physiotherapist and nursing staff. Good communication and discussion of patient management between team members is essential. The perioperative management of these patients is challenging as most are elderly with frequent
Advantages of early hip surgery C C
Michael G Irwin MB ChB MD FRCA FANZCA FHKAM is Professor and Head, Department of Anaesthesiology, University of Hong Kong and Honorary Consultant in Anaesthesia at Queen Mary Hospital, Hong Kong, China. Conflicts of interest: none declared.
C C C C C
Stanley Sau Ching Wong MBBS is a Resident in Anaesthesia at Queen Mary Hospital, Hong Kong, China. Conflicts of interest: none declared.
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Y mortality Y length of hospital stay Early mobilization Y muscle loss Y pneumonia Y pressure sores Y severe pain
Table 1
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ORTHOPAEDIC ANAESTHESIA
mortality by 32%.5 Early surgery is associated with less pneumonia, pressure sores,4 and severe pain and also reduces length of hospital stay. Surgical delay is often due to concurrent medical illness or severe co-morbid conditions. Thus, the higher mortality demonstrated from previous studies in patients with delayed surgery may be because they are less healthy generally, and not a result of the delay itself. A prospective case-matched cohort study which defined delay as 24 hours found that there was no difference in mortality and mobility after surgery when patients with a medical reason for delay were removed from analysis. Hip fracture surgery should be performed within 24e48 hours for patients who are medically stable. In patients with unstable medical conditions, optimization is needed first as early surgery without prior stabilization can be harmful.
with uncontrolled ventricular rate, newly recognized ventricular tachycardia, symptomatic ventricular arrhythmia). Significant cardiac risk factors include ischaemic heart disease, heart failure (prior/compensated), cerebrovascular disease, and renal insufficiency. Functional status is useful in predicting perioperative and long term cardiac outcomes, and an asymptomatic patient with a metabolic equivalent of four or more (e.g. able to walk two flight of stairs, walk uphill) is unlikely to require preoperative cardiac intervention. Most patients with hip fracture do not require cardiac consultation. Presence of active cardiac conditions mentioned earlier requires cardiac assessment (Table 2). Patients with medical assistance devices like pacemakers and automatic implantable cardioverter defibrillator also require cardiac consultation to evaluate battery life and mode adjustment if necessary. Also, cardiac evaluation may be needed when there is an unexplained cardiac symptom to ascertain a diagnosis. Finally patients with poor functional capacity and presence of clinical risk factors may benefit from cardiac assessment in order to determine if anything can be done to improve it. The need for echocardiography is controversial. The anaesthetist needs to balance the benefit of thorough preoperative work up with the potential disadvantage of surgical delay. Patients with known cardiac murmur and previous echocardiography do not require a repeat examination. A UK national survey conducted amongst 155 trauma anaesthetists by SandbyThomas et al showed that only 20.4% of anaesthetists would insist on a preoperative echocardiogram after detecting a new cardiac murmur.2 Most of the anaesthetists (53.6%) would only ask for an echocardiogram if the patient also had suspicious symptoms or signs.2 There are arguments for and against preoperative echocardiography. The 2001 National Confidential Enquiry into Perioperative Death report recommended that echocardiogram should be performed in all patients with cardiac murmurs. Cardiac murmurs are, however, common in the elderly, most are sclerotic and a study showed that 70% of elderly patients with detected murmur were subsequently found to have valvular heart disease. Presence of valvular heart lesions, particularly aortic stenosis increases the risk of perioperative morbidity and mortality after non-cardiac surgery, although this was not demonstrated in a study involving hip fracture patients.7 While clinical detection of causes for abnormal systolic murmurs is accurate when performed by a cardiologist, accuracy with a non-cardiologist is not
Preoperative assessment A clinical audit of 1195 patients in the UK showed that patients had a median ASA grade of 3.3 The most common co-morbidities are cardiovascular disease, chronic obstructive airway disease, cerebrovascular disease, diabetes mellitus and renal impairment. Another study showed that 35% of the patients had at least one co-morbidity and 17% had two.6 The purpose of preoperative assessment is to identify high-risk patients, optimize conditions that make surgery potentially life threatening, and to help formulate an anaesthetic plan. Clinical assessment and general risk stratification A thorough history and physical examination is an essential part of the preoperative assessment. Often information from a witness/carer is important, especially in patients with cognitive impairment. It is also important to ask for symptoms suggesting acute cardiac or cerebral events that may have precipitated the injury. Assessment for other possible associated injuries especially head injuries should also be performed. Comorbidities are a predictor of mortality and rehabilitation potential. Various scoring systems are available to predict outcome, such as the Charlson co-morbidity index, geriatrics index of co-morbidity, and cumulative illness rating scale. However, many of these systems are complicated and difficult to use in practice. More recently, the Nottingham hip fracture score has been introduced to predict 30-day mortality. Predictors of mortality from that scoring system include: age (66e85, over 86 years), male gender, two or more co-morbidities, mini-mental test score 6 or less out of 10, malignancy, living in an institution and anaemia (admission haemoglobin concentration 10 g/dl). Other predictive factors include preoperative mobility, cognitive state, preoperative residence, abnormal sodium and renal dysfunction.
Indications for cardiac consultation C
Cardiac assessment and preoperative echocardiography Cardiac evaluation involves assessment for active cardiac disease, functional capacity of the patient, and clinical risk factors. Conditions requiring special attention include unstable coronary syndromes (severe or unstable angina, acute or recent myocardial infarction), decompensated heart failure, severe valvular diseases (severe aortic stenosis, symptomatic mitral stenosis), and significant arrhythmia (symptomatic bradycardia, high degree atrioventricular block, supraventricular tachycardia
ANAESTHESIA AND INTENSIVE CARE MEDICINE 13:3
C
C
Active cardiac conditions Unstable coronary syndromes Decompensated heart failure Severe valvular heart disease Significant arrhythmia Medical assistance devices Pacemakers Automatic implantable cardioverter defibrillator Unexplained cardiac symptom
Table 2
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ORTHOPAEDIC ANAESTHESIA
well established. Relying only on clinical examination may miss significant valvular diseases. The American College of Cardiology and the American Heart Association guideline in 2007 opposes the routine use of additional investigations. Echocardiography has been shown to cause significant delays to hip fracture surgery and was unlikely to alter management.8 Delaying surgery is potentially hazardous to patients, and thus waiting for echocardiogram may in fact cause more harm. The use of chest X-ray may act as a useful screening tool, as patients with normal chest X-ray are likely to have normal ventricular function, and thus are unlikely to require change in medical or anaesthetic management.2 Introduction of clinical pathways can provide early cardiac screening and echocardiogram may be performed without delaying surgery.
Respiratory consultation is not commonly required. It should be considered if room air oxygen saturation is below 90%, when there is acute chest infection or acute exacerbation of chronic obstructive pulmonary disease, when there is worsening of chronic symptoms and if there are unexplained symptoms or signs. Chest infections and exacerbation of chronic lung diseases commonly occur. Delaying surgery and prolonged immobility may not improve the chest condition. Prolonged immobility may instead further worsen the chest condition. The decision on whether to proceed, therefore, depends on the individual patient’s lung reserve and availability of postoperative ventilator support and monitoring.
Perioperative management Fluid resuscitation Optimization of fluid status is important, reduces length of hospital stay and shortens postoperative recovery. Many patients with hip fracture are dehydrated. This is due to poor oral intake after injury, effects of opioids, and fasting in preparation for surgery. Fluid replacement is important and should be started immediately after assessment. It should take into account the deficit since injury in addition to the necessary ongoing maintenance replacement. One recommendation is to give the calculated fluid deficit from the time of injury in addition to the maintenance requirement over 6 hours. Fluid status may be difficult to assess in elderly patients, and some may be more prone to fluid overload. Recently the idea of aggressive fluid resuscitation with invasive haemodynamic monitoring has been introduced, although it is used in few hospitals because it is expensive and the efficacy is unproven.10
Pulmonary assessment Major surgery is associated with increased oxygen demand, and various factors after surgery reduce the patient’s ability to deliver oxygen and remove carbon dioxide. The anaesthetist is required to assess pulmonary risk, determine whether the patient can maintain adequate respiratory effort, and whether there is likely to be a need for postoperative ventilator support. Postoperative complications (PPC) increase length of hospital stay, morbidity and mortality9; and have been shown to affect 4% of patients after hip fracture surgery.9 PPCs include atelectasis, pneumonia, pulmonary thromboembolism, exacerbation of chronic lung disease, respiratory failure with prolonged mechanical ventilation, and acute respiratory distress syndrome (Table 3). Patientrelated risk factors for PPC include poor general health status (impaired sensorium and functional dependence, ASA class 2), age 60 and over years, smoking, lower respiratory tract infection, chronic obstructive pulmonary disease (COPD), obstructive sleep apnoea, congestive heart failure, low albumin level, and poorly controlled asthma. The presence of these risk factors may indicate the need for early anaesthetic consultation. Procedure-related risk factors are emergency surgery, operation duration 3 hours or more, general anaesthesia and long-acting neuromuscular blockade. Spirometry, chest X-ray and arterial blood gas should not be ordered as routine investigations. It was shown in a meta-analysis that only 0.1% of chest X-rays revealed unexpected abnormality that altered management. Chest X-rays are indicated when there are unexplained respiratory symptoms or clinical suspicion of lower respiratory tract infection. There is no good evidence to support the use of preoperative spirometry for risk stratification, which was not useful in predicting pulmonary complications.
Respiratory interventions Lung expansion techniques such as deep breathing exercises and incentive spirometry reduce the risk of postoperative pulmonary complications. These techniques can reduce risk of pulmonary complications, and are more effective when taught preoperatively. Nutrition Unfortunately, malnutrition is common in the elderly. Perioperative nutritional supplements can improve nutrition, decrease complications, increase muscle strength, shorten rehabilitation time, and reduce bed sores. Nutritional supplement is recommended, especially for patients with a serum albumin level 3 g/dl or lower. Where possible the enteral route is preferred. Antibiotic prophylaxis Elderly patients are at high risk for infection, and this risk is further enhanced if they have reduced mobility. Antibiotic prophylaxis should be given as it significantly reduces incidence of deep and superficial wound infection, chest infections and urinary tract infections.
Postoperative pulmonary complications after hip surgery C C C C C C
Atelectasis Pneumonia Pulmonary thromboembolism Exacerbation of chronic lung disease Respiratory failure and prolonged mechanical ventilation Acute respiratory distress syndrome
Thromboembolic prophylaxis Patients with fractured neck of femur are at high risk of deep vein thrombosis and pulmonary embolism, and this is one of the most common causes of mortality. Thromboembolic prophylaxis for 10e35 days is recommended by the 2008 American College of Chest Physicians guideline for patients with femoral neck
Table 3
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ORTHOPAEDIC ANAESTHESIA
death are myocardial infarction, pneumonia, congestive heart failure and pulmonary embolism, most of which are probably more likely to occur with general anaesthesia. Another factor that can be considered when deciding between regional versus general anaesthesia is the cost. A recent cost analysis study demonstrated that the cost of spinal anaesthesia was significantly less than general anaesthesia, and would save around £80 per case. Based on the results from the Cochrane review, the National Institute for Health and Clinical Excellence guideline recommends that both spinal and general anaesthesia should be offered after discussing risks and benefits.1 However, regional anaesthesia may be the preferable technique in the majority of the patients, although a definitive conclusion cannot be made based on the evidence currently available. Ultimately, choice of anaesthetic technique needs to be based on each individual patient’s comorbidities, potential complications, and patient preference.
fracture. Drugs that can be used include fondaparinux, lowmolecular-weight heparin, low-dose unfractionated heparin and vitamin K antagonists. Although initiation of thromboembolic prophylaxis usually begins before surgery, starting after surgery may be more favourable because it provides similarly effective protection, does not interfere with the use of regional anaesthesia, and does not affect intraoperative bleeding. Mechanical techniques such as pneumatic sequential leg compression or graduated compression stocking should also be used. Anaesthetic technique There has been no definitive conclusion on which is the best anaesthetic technique. Choice is often based on the clinical judgement of the anaesthetist for each individual patient. A total of 75.8% of respondents in the survey by SandbyThomas et al preferred regional anaesthesia (spinal or epidural),2 9.8% preferred general anaesthesia alone, and 14.4% preferred general anaesthesia combined with a regional technique.2 When regional was selected as the sole technique, spinal anaesthesia was preferred 95.5% of the time.2 This was quite different to the clinical audit of White et al who collected data over a 2-month winter period and showed that 51% of the patients received general anaesthesia, and 49% received regional anaesthesia.3 This difference may be due to presence of contraindications to regional anaesthesia in patients, thus precluding its use. The Cochrane review in 2004 comparing regional (spinal and epidural) versus general anaesthesia showed that regional anaesthesia was associated with reduced mortality at 1 month, but this was only marginally significant statistically, and there were no significant differences in mortality at 3 months and 1 year.11 A more recent review by Luger et al analysed 34 randomized controlled trials, 14 observational studies and eight meta-analysis/reviews searched from the PubMed and Cochrane database. It involved 18,715 patients older than 65 years. The review concluded that there was significantly reduced hospital and 1 month mortality.12 However, again this difference was not apparent after 3 months. In both reviews the trials analysed had methodological flaws, and many did not correspond to current anaesthetic practice. Current evidence suggests that regional anaesthesia is associated with reduced morbidity. Regional anaesthesia is associated with significantly reduced incidence of deep vein thrombosis,11,12 but this advantage is less obvious when thromboembolic prophylaxis is used.12 The incidence of acute postoperative confusion is also reduced.11,12 The review by Luger et al concluded that regional anaesthesia was associated with significantly reduced incidence of fatal pulmonary embolism, early postoperative hypoxia, pneumonia, exacerbation of chronic obstructive pulmonary disease, and respiratory failure.12 Incidence of pneumonia and postoperative hypoxia was not shown to be different in the Cochrane review.11 There is a tendency towards reduced incidence of myocardial infarction when using regional anaesthesia, although this has not been shown to be statistically significant.11,12 Regional anaesthesia has been shown to increase the incidence of intraoperative hypotension and use of vasopressors, but how this affects outcome is not well established.12 Incidence of congestive heart failure, cerebrovascular accident and renal failure is not affected by anaesthetic technique.11,12 It should be noted that the most common causes of
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Analgesia Pain both preoperatively and postoperatively can be severe. Effective pain control can reduce incidence of postoperative delirium, and improved mobility thereby reducing the risk of pneumonia and pressure sores. Acute pain teams are being involved earlier in pain management. There is little evidence about best postoperative analgesic regimen for these patients. Postoperative pain 1 hour after surgery has been shown to be less when using spinal anaesthesia instead of general anaesthesia, but no difference was seen after 1 hour.12 In agreement with the recent National Institute for Health and Clinical Excellence guideline,1 almost all anaesthetists surveyed by Sandby-Thomas et al would use paracetamol, and morphine was also a popular option.2 These are effective and easy to administer. Non-steroidal anti-inflammatory drugs should be avoided.1 Nerve blocks, epidural analgesia, and patient-controlled analgesia may also provide effective pain control, although they are not commonly used.2 Any nerve block involving the proximal femur can be used, and no one particular type is superior.1 These include subcostal, lateral cutaneous nerve of the thigh, femoral, fascia iliaca compartmental, psoas (lumbar plexus), and triple (femoral, obturator, sciatic) nerve blocks.1 The use of intrathecal morphine during spinal anaesthesia may improve pain control,2 although the side effects (nausea, pruritus) can be difficult to manage. A
REFERENCES 1 National Clinical Guideline Centre. The management of hip fracture in adults. London: National Clinical Guideline Centre. Also available at: www.ncgc.ac.uk; 2011. 2 Sandby-Thomas M, Sullivan G, Hall J. A national survey into the perioperative anaesthetic management of patients presenting for surgical correction of a fractured neck of femur. Anaesthesia 2008; 63: 250e8. 3 White S, Griffiths R, Holloway J, Shannon A. Anaesthesia for proximal femoral fracture in the UK: first report from the NHS Hip Fracture Anaesthesia Network. Anaesthesia 2010; 65: 243e8. 4 Simunovic N, Devereaux PJ, Sprague S, et al. Effect of early surgery after hip fracture on mortality and complications: systemic review and meta-analysis. Can Med Assoc J 2010; 182: 1606e15.
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5 Shiga T, Wajima Z, Ohe Y. Is operative delay associated with increased mortality of hip fracture patients? Systematic review, meta-analysis, and meta-regression. Can J Anaesth 2008; 55: 146e54. 6 Roche J, Wenn R, Sahota O, Moran C. Effect of comorbidities and postoperative complications on mortality after hip fracture in elderly people: prospective observational cohort study. Br Med J 2005; 331: 1374. doi:10.1136/bmj.38643.663843.55. 7 McBrien M, Heyburn G, Stevenson M, et al. Previously undiagnosed aortic stenosis revealed by auscultation in the hip fracture population e echocardiographic findings, management and outcome. Anaesthesia 2009; 64: 863e70. 8 Ricci W, Della Rocca G, Combs C, Borrelli J. The medical and economic impact of preoperative cardiac testing in elderly patients with hip fractures. Injury 2007; 38(suppl 3): S49e52.
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9 Lawrence V, Hilsenbeck S, Noveck H, Poses R, Carson J. Medical complications and outcomes after hip fracture repair. Arch Intern Med 2002; 162: 2053e7. 10 Price J, Sear J, Venn R. Perioperative fluid optimization following proximal femoral fracture. Cochrane Database Syst Rev 2004; doi: 10.1002/14651858.CD003004.pub2. Issue 1. Art. No.:CD003004. 11 Parker M, Handoll H, Griffiths R. Anaesthesia for hip fracture surgery in adults. Cochrane Database Syst Rev 2004; doi: 10.1002/14651858.CD000521.pub2. Issue 4. Art. No.:CD000521. 12 Luger T, Kammerlander C, Gosch M, et al. Neuroaxial versus general anaesthesia in geriatric patients for hip fracture surgery: does it matter? Osteoporos Int 2010; 21(suppl 4): S555e72. FURTHER READING Osteoporosis International, vol. 21, suppl 4/December 2010.
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Ó 2011 Elsevier Ltd. All rights reserved.
Anaesthesia for fractured neck of femur
Learning objectives After reading this article you should be able to: C list four indications for cardiac consultation C list four patient-related postoperative pulmonary complications C know the advantages of early hip fracture surgery C know the possible benefits of regional anaesthesia compared to general anaesthesia for hip fracture surgery
Michael G Irwin Stanley Sau Ching Wong
Abstract Fracture of the femoral neck is a common injury in the elderly, and many patients have significant co-morbidities. Effective management requires a multidisciplinary approach involving anaesthetists, medical physicians and orthopaedic surgeons. Although early surgery within 24e48 hours is beneficial, there may be medical conditions that need prior optimization. Both general anaesthesia and regional neuroaxial anaesthesia can be used, although it appears regional anaesthesia is preferred by most anaesthetists as it is associated with reduced early postoperative mortality, less deep vein thrombosis, less fatal pulmonary embolism, and fewer pulmonary complications.
co-morbidities. Current evidence suggests that early surgery is beneficial, but sometimes medical optimization or further investigations are required before surgery can proceed safely. Thus a balance needs to be made between optimization/investigations and avoiding unnecessary surgical delay needs. There is great variation in anaesthetic technique for hip fracture surgery, mainly because previous studies have not shown clear benefit with any particular technique. In this article we will review the perioperative management of patients with fractured neck of femur with emphasis on preoperative optimization, minimization of surgical delay, potential consequence of surgical delay, and best anaesthetic technique.
Keywords Femoral neck fracture; fractured hip; fractured neck of femur; general anaesthesia; perioperative management; preoperative assessment; regional anaesthesia
Timing of surgery Guidelines recommend that hip fracture surgery should be performed within 24e48 hours. Early surgery allows quicker mobilization and may reduce deconditioning and muscles wasting. It can also reduce the incidence of complications such as pneumonia and skin breakdown (Table 1). A recent clinical audit performed in the UK showed that time from admission to surgery ranged from 24 to 108 hours, with a median of 47 hours.3 42% of operations were delayed, mostly due to organizational and medical reasons.3 Only 4% of delays were due to anaesthesia.3 Most literature supports early surgery. A recent meta-analysis of prospective observational studies demonstrated that surgery within 24e72 hours significantly reduced mortality at 1 year, but not 1 month or 3e6 months after surgery.4 Even when only analysing studies that adjusted for American Society of Anesthesiology (ASA) score, age, and gender, early surgery was associated with a reduced risk of mortality.4 Another metaanalysis of observational studies showed that delay beyond 48 hours increased risk of 30-day mortality by 41% and 1-year
Introduction Femoral neck fractures are associated with aging and osteoporosis and can occur after relatively trivial trauma in elderly patients. Each year around 75,000 people in the UK suffer from fracture hip.1 The mean age for men is 84 years and women 83 years.1 The incidence worldwide was 1.26 million in 1990 and is expected to increase to 4.5 million by 2050.2 Femoral neck fracture is associated with a 30-day postoperative mortality between 5 to 10%,3 and 1-year mortality of around 30%.1 This mortality rate has remained relatively constant over the past 20 years and it continues to be a major cause for mortality, morbidity and loss of functional activity. Optimal perioperative care emphasizes early optimization and early surgery, effective multimodal analgesia, and use of a multidisciplinary team. The multidisciplinary team should consist of the anaesthetist, orthopaedic surgeon, medical physicians/geriatricians, physiotherapist and nursing staff. Good communication and discussion of patient management between team members is essential. The perioperative management of these patients is challenging as most are elderly with frequent
Advantages of early hip surgery C C
Michael G Irwin MB ChB MD FRCA FANZCA FHKAM is Professor and Head, Department of Anaesthesiology, University of Hong Kong and Honorary Consultant in Anaesthesia at Queen Mary Hospital, Hong Kong, China. Conflicts of interest: none declared.
C C C C C
Stanley Sau Ching Wong MBBS is a Resident in Anaesthesia at Queen Mary Hospital, Hong Kong, China. Conflicts of interest: none declared.
ANAESTHESIA AND INTENSIVE CARE MEDICINE 13:3
Y mortality Y length of hospital stay Early mobilization Y muscle loss Y pneumonia Y pressure sores Y severe pain
Table 1
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ORTHOPAEDIC ANAESTHESIA
mortality by 32%.5 Early surgery is associated with less pneumonia, pressure sores,4 and severe pain and also reduces length of hospital stay. Surgical delay is often due to concurrent medical illness or severe co-morbid conditions. Thus, the higher mortality demonstrated from previous studies in patients with delayed surgery may be because they are less healthy generally, and not a result of the delay itself. A prospective case-matched cohort study which defined delay as 24 hours found that there was no difference in mortality and mobility after surgery when patients with a medical reason for delay were removed from analysis. Hip fracture surgery should be performed within 24e48 hours for patients who are medically stable. In patients with unstable medical conditions, optimization is needed first as early surgery without prior stabilization can be harmful.
with uncontrolled ventricular rate, newly recognized ventricular tachycardia, symptomatic ventricular arrhythmia). Significant cardiac risk factors include ischaemic heart disease, heart failure (prior/compensated), cerebrovascular disease, and renal insufficiency. Functional status is useful in predicting perioperative and long term cardiac outcomes, and an asymptomatic patient with a metabolic equivalent of four or more (e.g. able to walk two flight of stairs, walk uphill) is unlikely to require preoperative cardiac intervention. Most patients with hip fracture do not require cardiac consultation. Presence of active cardiac conditions mentioned earlier requires cardiac assessment (Table 2). Patients with medical assistance devices like pacemakers and automatic implantable cardioverter defibrillator also require cardiac consultation to evaluate battery life and mode adjustment if necessary. Also, cardiac evaluation may be needed when there is an unexplained cardiac symptom to ascertain a diagnosis. Finally patients with poor functional capacity and presence of clinical risk factors may benefit from cardiac assessment in order to determine if anything can be done to improve it. The need for echocardiography is controversial. The anaesthetist needs to balance the benefit of thorough preoperative work up with the potential disadvantage of surgical delay. Patients with known cardiac murmur and previous echocardiography do not require a repeat examination. A UK national survey conducted amongst 155 trauma anaesthetists by SandbyThomas et al showed that only 20.4% of anaesthetists would insist on a preoperative echocardiogram after detecting a new cardiac murmur.2 Most of the anaesthetists (53.6%) would only ask for an echocardiogram if the patient also had suspicious symptoms or signs.2 There are arguments for and against preoperative echocardiography. The 2001 National Confidential Enquiry into Perioperative Death report recommended that echocardiogram should be performed in all patients with cardiac murmurs. Cardiac murmurs are, however, common in the elderly, most are sclerotic and a study showed that 70% of elderly patients with detected murmur were subsequently found to have valvular heart disease. Presence of valvular heart lesions, particularly aortic stenosis increases the risk of perioperative morbidity and mortality after non-cardiac surgery, although this was not demonstrated in a study involving hip fracture patients.7 While clinical detection of causes for abnormal systolic murmurs is accurate when performed by a cardiologist, accuracy with a non-cardiologist is not
Preoperative assessment A clinical audit of 1195 patients in the UK showed that patients had a median ASA grade of 3.3 The most common co-morbidities are cardiovascular disease, chronic obstructive airway disease, cerebrovascular disease, diabetes mellitus and renal impairment. Another study showed that 35% of the patients had at least one co-morbidity and 17% had two.6 The purpose of preoperative assessment is to identify high-risk patients, optimize conditions that make surgery potentially life threatening, and to help formulate an anaesthetic plan. Clinical assessment and general risk stratification A thorough history and physical examination is an essential part of the preoperative assessment. Often information from a witness/carer is important, especially in patients with cognitive impairment. It is also important to ask for symptoms suggesting acute cardiac or cerebral events that may have precipitated the injury. Assessment for other possible associated injuries especially head injuries should also be performed. Comorbidities are a predictor of mortality and rehabilitation potential. Various scoring systems are available to predict outcome, such as the Charlson co-morbidity index, geriatrics index of co-morbidity, and cumulative illness rating scale. However, many of these systems are complicated and difficult to use in practice. More recently, the Nottingham hip fracture score has been introduced to predict 30-day mortality. Predictors of mortality from that scoring system include: age (66e85, over 86 years), male gender, two or more co-morbidities, mini-mental test score 6 or less out of 10, malignancy, living in an institution and anaemia (admission haemoglobin concentration 10 g/dl). Other predictive factors include preoperative mobility, cognitive state, preoperative residence, abnormal sodium and renal dysfunction.
Indications for cardiac consultation C
Cardiac assessment and preoperative echocardiography Cardiac evaluation involves assessment for active cardiac disease, functional capacity of the patient, and clinical risk factors. Conditions requiring special attention include unstable coronary syndromes (severe or unstable angina, acute or recent myocardial infarction), decompensated heart failure, severe valvular diseases (severe aortic stenosis, symptomatic mitral stenosis), and significant arrhythmia (symptomatic bradycardia, high degree atrioventricular block, supraventricular tachycardia
ANAESTHESIA AND INTENSIVE CARE MEDICINE 13:3
C
C
Active cardiac conditions Unstable coronary syndromes Decompensated heart failure Severe valvular heart disease Significant arrhythmia Medical assistance devices Pacemakers Automatic implantable cardioverter defibrillator Unexplained cardiac symptom
Table 2
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ORTHOPAEDIC ANAESTHESIA
well established. Relying only on clinical examination may miss significant valvular diseases. The American College of Cardiology and the American Heart Association guideline in 2007 opposes the routine use of additional investigations. Echocardiography has been shown to cause significant delays to hip fracture surgery and was unlikely to alter management.8 Delaying surgery is potentially hazardous to patients, and thus waiting for echocardiogram may in fact cause more harm. The use of chest X-ray may act as a useful screening tool, as patients with normal chest X-ray are likely to have normal ventricular function, and thus are unlikely to require change in medical or anaesthetic management.2 Introduction of clinical pathways can provide early cardiac screening and echocardiogram may be performed without delaying surgery.
Respiratory consultation is not commonly required. It should be considered if room air oxygen saturation is below 90%, when there is acute chest infection or acute exacerbation of chronic obstructive pulmonary disease, when there is worsening of chronic symptoms and if there are unexplained symptoms or signs. Chest infections and exacerbation of chronic lung diseases commonly occur. Delaying surgery and prolonged immobility may not improve the chest condition. Prolonged immobility may instead further worsen the chest condition. The decision on whether to proceed, therefore, depends on the individual patient’s lung reserve and availability of postoperative ventilator support and monitoring.
Perioperative management Fluid resuscitation Optimization of fluid status is important, reduces length of hospital stay and shortens postoperative recovery. Many patients with hip fracture are dehydrated. This is due to poor oral intake after injury, effects of opioids, and fasting in preparation for surgery. Fluid replacement is important and should be started immediately after assessment. It should take into account the deficit since injury in addition to the necessary ongoing maintenance replacement. One recommendation is to give the calculated fluid deficit from the time of injury in addition to the maintenance requirement over 6 hours. Fluid status may be difficult to assess in elderly patients, and some may be more prone to fluid overload. Recently the idea of aggressive fluid resuscitation with invasive haemodynamic monitoring has been introduced, although it is used in few hospitals because it is expensive and the efficacy is unproven.10
Pulmonary assessment Major surgery is associated with increased oxygen demand, and various factors after surgery reduce the patient’s ability to deliver oxygen and remove carbon dioxide. The anaesthetist is required to assess pulmonary risk, determine whether the patient can maintain adequate respiratory effort, and whether there is likely to be a need for postoperative ventilator support. Postoperative complications (PPC) increase length of hospital stay, morbidity and mortality9; and have been shown to affect 4% of patients after hip fracture surgery.9 PPCs include atelectasis, pneumonia, pulmonary thromboembolism, exacerbation of chronic lung disease, respiratory failure with prolonged mechanical ventilation, and acute respiratory distress syndrome (Table 3). Patientrelated risk factors for PPC include poor general health status (impaired sensorium and functional dependence, ASA class 2), age 60 and over years, smoking, lower respiratory tract infection, chronic obstructive pulmonary disease (COPD), obstructive sleep apnoea, congestive heart failure, low albumin level, and poorly controlled asthma. The presence of these risk factors may indicate the need for early anaesthetic consultation. Procedure-related risk factors are emergency surgery, operation duration 3 hours or more, general anaesthesia and long-acting neuromuscular blockade. Spirometry, chest X-ray and arterial blood gas should not be ordered as routine investigations. It was shown in a meta-analysis that only 0.1% of chest X-rays revealed unexpected abnormality that altered management. Chest X-rays are indicated when there are unexplained respiratory symptoms or clinical suspicion of lower respiratory tract infection. There is no good evidence to support the use of preoperative spirometry for risk stratification, which was not useful in predicting pulmonary complications.
Respiratory interventions Lung expansion techniques such as deep breathing exercises and incentive spirometry reduce the risk of postoperative pulmonary complications. These techniques can reduce risk of pulmonary complications, and are more effective when taught preoperatively. Nutrition Unfortunately, malnutrition is common in the elderly. Perioperative nutritional supplements can improve nutrition, decrease complications, increase muscle strength, shorten rehabilitation time, and reduce bed sores. Nutritional supplement is recommended, especially for patients with a serum albumin level 3 g/dl or lower. Where possible the enteral route is preferred. Antibiotic prophylaxis Elderly patients are at high risk for infection, and this risk is further enhanced if they have reduced mobility. Antibiotic prophylaxis should be given as it significantly reduces incidence of deep and superficial wound infection, chest infections and urinary tract infections.
Postoperative pulmonary complications after hip surgery C C C C C C
Atelectasis Pneumonia Pulmonary thromboembolism Exacerbation of chronic lung disease Respiratory failure and prolonged mechanical ventilation Acute respiratory distress syndrome
Thromboembolic prophylaxis Patients with fractured neck of femur are at high risk of deep vein thrombosis and pulmonary embolism, and this is one of the most common causes of mortality. Thromboembolic prophylaxis for 10e35 days is recommended by the 2008 American College of Chest Physicians guideline for patients with femoral neck
Table 3
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death are myocardial infarction, pneumonia, congestive heart failure and pulmonary embolism, most of which are probably more likely to occur with general anaesthesia. Another factor that can be considered when deciding between regional versus general anaesthesia is the cost. A recent cost analysis study demonstrated that the cost of spinal anaesthesia was significantly less than general anaesthesia, and would save around £80 per case. Based on the results from the Cochrane review, the National Institute for Health and Clinical Excellence guideline recommends that both spinal and general anaesthesia should be offered after discussing risks and benefits.1 However, regional anaesthesia may be the preferable technique in the majority of the patients, although a definitive conclusion cannot be made based on the evidence currently available. Ultimately, choice of anaesthetic technique needs to be based on each individual patient’s comorbidities, potential complications, and patient preference.
fracture. Drugs that can be used include fondaparinux, lowmolecular-weight heparin, low-dose unfractionated heparin and vitamin K antagonists. Although initiation of thromboembolic prophylaxis usually begins before surgery, starting after surgery may be more favourable because it provides similarly effective protection, does not interfere with the use of regional anaesthesia, and does not affect intraoperative bleeding. Mechanical techniques such as pneumatic sequential leg compression or graduated compression stocking should also be used. Anaesthetic technique There has been no definitive conclusion on which is the best anaesthetic technique. Choice is often based on the clinical judgement of the anaesthetist for each individual patient. A total of 75.8% of respondents in the survey by SandbyThomas et al preferred regional anaesthesia (spinal or epidural),2 9.8% preferred general anaesthesia alone, and 14.4% preferred general anaesthesia combined with a regional technique.2 When regional was selected as the sole technique, spinal anaesthesia was preferred 95.5% of the time.2 This was quite different to the clinical audit of White et al who collected data over a 2-month winter period and showed that 51% of the patients received general anaesthesia, and 49% received regional anaesthesia.3 This difference may be due to presence of contraindications to regional anaesthesia in patients, thus precluding its use. The Cochrane review in 2004 comparing regional (spinal and epidural) versus general anaesthesia showed that regional anaesthesia was associated with reduced mortality at 1 month, but this was only marginally significant statistically, and there were no significant differences in mortality at 3 months and 1 year.11 A more recent review by Luger et al analysed 34 randomized controlled trials, 14 observational studies and eight meta-analysis/reviews searched from the PubMed and Cochrane database. It involved 18,715 patients older than 65 years. The review concluded that there was significantly reduced hospital and 1 month mortality.12 However, again this difference was not apparent after 3 months. In both reviews the trials analysed had methodological flaws, and many did not correspond to current anaesthetic practice. Current evidence suggests that regional anaesthesia is associated with reduced morbidity. Regional anaesthesia is associated with significantly reduced incidence of deep vein thrombosis,11,12 but this advantage is less obvious when thromboembolic prophylaxis is used.12 The incidence of acute postoperative confusion is also reduced.11,12 The review by Luger et al concluded that regional anaesthesia was associated with significantly reduced incidence of fatal pulmonary embolism, early postoperative hypoxia, pneumonia, exacerbation of chronic obstructive pulmonary disease, and respiratory failure.12 Incidence of pneumonia and postoperative hypoxia was not shown to be different in the Cochrane review.11 There is a tendency towards reduced incidence of myocardial infarction when using regional anaesthesia, although this has not been shown to be statistically significant.11,12 Regional anaesthesia has been shown to increase the incidence of intraoperative hypotension and use of vasopressors, but how this affects outcome is not well established.12 Incidence of congestive heart failure, cerebrovascular accident and renal failure is not affected by anaesthetic technique.11,12 It should be noted that the most common causes of
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Analgesia Pain both preoperatively and postoperatively can be severe. Effective pain control can reduce incidence of postoperative delirium, and improved mobility thereby reducing the risk of pneumonia and pressure sores. Acute pain teams are being involved earlier in pain management. There is little evidence about best postoperative analgesic regimen for these patients. Postoperative pain 1 hour after surgery has been shown to be less when using spinal anaesthesia instead of general anaesthesia, but no difference was seen after 1 hour.12 In agreement with the recent National Institute for Health and Clinical Excellence guideline,1 almost all anaesthetists surveyed by Sandby-Thomas et al would use paracetamol, and morphine was also a popular option.2 These are effective and easy to administer. Non-steroidal anti-inflammatory drugs should be avoided.1 Nerve blocks, epidural analgesia, and patient-controlled analgesia may also provide effective pain control, although they are not commonly used.2 Any nerve block involving the proximal femur can be used, and no one particular type is superior.1 These include subcostal, lateral cutaneous nerve of the thigh, femoral, fascia iliaca compartmental, psoas (lumbar plexus), and triple (femoral, obturator, sciatic) nerve blocks.1 The use of intrathecal morphine during spinal anaesthesia may improve pain control,2 although the side effects (nausea, pruritus) can be difficult to manage. A
REFERENCES 1 National Clinical Guideline Centre. The management of hip fracture in adults. London: National Clinical Guideline Centre. Also available at: www.ncgc.ac.uk; 2011. 2 Sandby-Thomas M, Sullivan G, Hall J. A national survey into the perioperative anaesthetic management of patients presenting for surgical correction of a fractured neck of femur. Anaesthesia 2008; 63: 250e8. 3 White S, Griffiths R, Holloway J, Shannon A. Anaesthesia for proximal femoral fracture in the UK: first report from the NHS Hip Fracture Anaesthesia Network. Anaesthesia 2010; 65: 243e8. 4 Simunovic N, Devereaux PJ, Sprague S, et al. Effect of early surgery after hip fracture on mortality and complications: systemic review and meta-analysis. Can Med Assoc J 2010; 182: 1606e15.
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5 Shiga T, Wajima Z, Ohe Y. Is operative delay associated with increased mortality of hip fracture patients? Systematic review, meta-analysis, and meta-regression. Can J Anaesth 2008; 55: 146e54. 6 Roche J, Wenn R, Sahota O, Moran C. Effect of comorbidities and postoperative complications on mortality after hip fracture in elderly people: prospective observational cohort study. Br Med J 2005; 331: 1374. doi:10.1136/bmj.38643.663843.55. 7 McBrien M, Heyburn G, Stevenson M, et al. Previously undiagnosed aortic stenosis revealed by auscultation in the hip fracture population e echocardiographic findings, management and outcome. Anaesthesia 2009; 64: 863e70. 8 Ricci W, Della Rocca G, Combs C, Borrelli J. The medical and economic impact of preoperative cardiac testing in elderly patients with hip fractures. Injury 2007; 38(suppl 3): S49e52.
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9 Lawrence V, Hilsenbeck S, Noveck H, Poses R, Carson J. Medical complications and outcomes after hip fracture repair. Arch Intern Med 2002; 162: 2053e7. 10 Price J, Sear J, Venn R. Perioperative fluid optimization following proximal femoral fracture. Cochrane Database Syst Rev 2004; doi: 10.1002/14651858.CD003004.pub2. Issue 1. Art. No.:CD003004. 11 Parker M, Handoll H, Griffiths R. Anaesthesia for hip fracture surgery in adults. Cochrane Database Syst Rev 2004; doi: 10.1002/14651858.CD000521.pub2. Issue 4. Art. No.:CD000521. 12 Luger T, Kammerlander C, Gosch M, et al. Neuroaxial versus general anaesthesia in geriatric patients for hip fracture surgery: does it matter? Osteoporos Int 2010; 21(suppl 4): S555e72. FURTHER READING Osteoporosis International, vol. 21, suppl 4/December 2010.
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