Medical Care When You Have Orthopaedic Surgery

1. Definition
2. Components of a Preoperative Medical Evaluation
3. Management of Existing Medical Conditions Before and After Surgery
4. Management of Specific Clinical Problems
5. Outcomes After Surgery
6. Annotated Bibliography

I. Definition

Surgical correction for disorders or injury to the bones and joints (the musculoskeletal system) is a common need among people who have arthritis and other chronic rheumatologic diseases. Although such surgery is performed by the orthopedic surgeon, your rheumatologist, internist, or primary care physician is usually asked to provide a medical evaluation before surgery and to participate in your care after surgery. This is commonly referred to as pre- and post-operative consultation and care - and the whole process before, during and after surgery process is called perioperative. The purpose such perioperative medical management is:

• identification of pre-existing medical conditions (called co-morbidities) that may affect your doctors' decisions about your treatment;
• assessment of the potential risks of surgery for you; and
• identification and management of potential complications that may arise after surgery, the risk of which might be reduced if considered (and possibly treated) before surgery.

II. Components of a Preoperative Medical Evaluation

A. Timing

The preoperative evaluation should take place, whenever possible, in the doctor's office several weeks before surgery. This is not always possible, for instance, if you have a sudden injury requiring surgical correction (i.e. fracture). However, such an advance evaluation allows time for:

• discussion with other physicians' involved in your care,
• additional consultation and further investigation, and
• if necessary, the initiation of therapy to improve your medical condition prior to surgery.

The preoperative evaluation's findings should serve as the focus of communication among all those involved in your care.

B. Guidelines

No consensus exists regarding what constitutes the ideal preoperative medical evaluation. Your needs depend on such factors as: age, general health and overall functioning, pre-existing medical conditions, and the type of anesthesia and surgery to be performed. However, general guidelines can provide a useful framework for such evaluations.

Except in young patients and those having minor surgical procedures, most patients should have a complete medical history and physical examination prior to surgery. Although some research studies have not shown the value of routine preoperative testing, most physicians recommend a number of evaluations prior to major orthopaedic surgery.

Depending on a variety of factors (including the nature of your orthopaedic problem, the magnitude of surgery required to correct it, and the presence of co-existing diseases), such testing might include: a complete blood count, an analysis of the urine, a urine culture (for patients having total joint replacement), and complete blood chemistries. However, in patients who use or will be taking blood thinners (anticoagulants) after surgery, measurement of the blood's clotting capacity may also be performed. A tracing of your heart (EKG) and chest X-ray may also be required, particularly in the elderly and those undergoing major joint or spine surgery.

C. Assessment of Your Surgical Risk

One of the primary purposes of the preoperative medical evaluation is the identification of patients at higher risk for complications after surgery. The standard clinical examination is the principle screening method for the detection of conditions likely to affect surgical outcome. Your doctor is likely to measure any problems you have against a scoring system developed 30 years ago by anesthesiologists, and Your doctors will use the results to plan your medical and surgical care more effectively.

III. Management of Existing Medical Conditions Before and After Orthopedic Surgery

The following discussion addresses existing medical conditions roughly in order of their frequency in people who have surgery.

A. Coronary Artery Disease (Angina, Heart Attack, Blocked Arteries in the Heart)

The contribution of cardiovascular disease to the risk of non-cardiac surgery is important. As such, it is the most thoroughly researched area of perioperative medicine - and can be managed when identified, monitored for and, in some instances, appropriate therapy provided.

The value of the routine clinical assessment, including the medical history, physical examination, laboratory testing, electrocardiogram and chest X-ray is well established, at least with respect to the identification of the presence of pre-existing cardiac disease. However it is also important to define disease severity, stability and prior treatment. In concert with other clinical characteristics such as age, functional capacity, pre-existing medical conditions (particularly diabetes, peripheral vascular disease, chronic pulmonary disease) and type of surgery to be performed, these factors ultimately define the overall risk of surgery.

A series of factors may increase the risk of postoperative heart attack (myocardial infarction), heart failure, or death after orthopaedic surgery.

The major predictors of increased risk due to heart disease include:

• recent (< 30 days) heart attack (myocardial infarction);
• unstable or severe angina;
• poorly controlled congestive heart failure;
• certain disturbances of the heart rhythm;
• severe abnormalities of the heart valves.

Intermediate predictors of increased risk due to heart disease include:

• mild angina;
• prior heart attack (myocardial infarction) by history or EKG;
• well-controlled congestive heart failure;
• diabetes.

Minor predictors of increased risk due to heart disease include:

• advanced age;
• abnormal EKG;
• certain heart rhythm disturbances;
• low functional capacity;
• prior stroke;
• poorly controlled high blood pressure (hypertension);
• prior coronary artery bypass, angioplasty, stenting.

Sometimes exercise stress testing is recommended before surgery. This will depend on your physicians' estimate of the effectiveness, risk, and cost of such testing in the individual patient's case. However, such testing may not be feasible if you have problems with walking quickly due to your arthritis problems or if surgery must be performed relatively urgently (as in the case of the repair of a fractured bone).

The recognition of the protective role of a certain class of medication called beta-blockers in the perioperative setting is perhaps the most significant advance in the treatment of heart patients undergoing surgery. Common examples of this type of medication include Atenolol (Tenormin), Lopressor (Metoprolol), and Inderal (Propranolol). Recent evidence also suggests that beta blockers have an important protective role in the perioperative setting in patients who demonstrate only risk factors for the coronary artery disease. Therefore patients already taking beta-blockers prior to surgery should be advised to continue the medication up to and including the morning of surgery; for those not taking such therapy, a beta-blocker may be recommended before surgery.

Patients taking long-acting nitrates (nitroglycerine) should be given the drug on the morning of surgery as well; nitrate ointments and skin patches can be continued post-operatively until the patient resumes oral intake.

Patients taking ACE inhibitors may be at increased risk of circulatory instability, especially if the medication is taken immediately prior to surgery. Thus, the use of this medication before surgery should be discussed with your cardiologist and coordinated with the anesthesiologist prior to surgery.

If you are taking other types of blood pressure medications, such as diuretics, or drugs known as calcium channel blockers or ACE inhibitors, you should ask the consultant medical doctor whether or not you should continue to take these medications, particularly on the morning of the surgery.

B. Other Cardiovascular Diseases

1. High Blood Pressure (Hypertension)
Although controversy exists about whether mild to moderate hypertension increases the risk of surgery, patients whose blood pressure is poorly controlled may be at greater risk for complications. Therefore, your blood pressure should be treated prior to surgery. Patients who are in satisfactory control should continue their medications, including their use on the morning of surgery. Due to bed rest, fluid losses, and the influences of various medications used after surgery, some patients may temporarily require less (or no) medication for their blood pressure during their recuperation.

2. Conditions involving the Heart Valves (Heart murmurs)
The risk of surgery in patients with abnormalities of the heart valves depends on the valve affected as well as the nature and severity of the valvular abnormality. The risk arises mainly as a result of a thickening of the aortic valve, a condition known as aortic stenosis. Mitral valve disease and leakage of the aortic valve (known as aortic insufficiency), if not severe, are usually not a problem. Therefore, patients with a significant cardiac murmur should have an echocardiographic assessment before surgery, particularly if a major orthopaedic procedure is planned.

3. Cardiomyopathies
Cardiomyopathies are diseases of the heart muscle. The chronic cardiomyopathies are associated with an increased incidence of congestive heart failure after surgery. Some types of cardiomyopathy may affect the type of anesthesia provided.

4. Heart Rhythm Disturbances (Arrhythmias)
In patients who have been on long-term blood thinners for chronic atrial fibrillation, the risk of stroke is low. Therefore, it is safe to temporarily discontinue warfarin (Coumadin) for a sufficient period of time before surgery to allow your blood clotting (coagulation) to return to normal - thus reducing your risk of excessive bleeding during surgery. Five days is generally sufficient. However, all medications taken to control your heart rhythm should continue to be taken, especially on the morning of surgery.

C. Lung Disease

Chronic obstructive lung disease (chronic bronchitis or emphysema) and asthma are the two most common forms of chronic lung (pulmonary) disease. They have also been shown to be important predictors of post-operative complications, which may or may not be related to the lung.

Minor complications related to the lung (atelectasis or bronchitis) are increased in patients who smoke, who have a chronic cough, or who have abnormal lung function studies (spirometry) before surgery. The risk of severe complications (pneumonia or respiratory failure) is increased mainly in patients with marked impairment in lung function. Factors not directly related to the lung that contribute to the risk of complications are age, obesity, and longer duration of anesthesia or over-sedation.

The risk of complications in the lung after surgery depends, in large part, upon the type of surgery performed. Patients with severe lung impairment can tolerate minor procedures, even under general anesthesia. However, even in the patients with chronic lung disease, the risk of pneumonia following even major orthopaedic surgery on the hip or knee is low.

Patients who have been using bronchodilators before surgery should be given their standard dosage the night before surgery, and bronchodilator therapy should be administered after surgery. Such treatment, as well as the use of an incentive spirometer (a device that forces you to blow air into a bottle device) and getting out of bed as soon as advisable are important in the prevention of lung complications after surgery.

D. Endocrine (Hormonal) Conditions

1. Diabetes Mellitus
Diabetes is the most important endocrine disorder encountered in surgical patients. Diabetics are at slightly greater risk of postoperative death as a result of their greater prevalence of heart disease.

The control of the blood sugar tends to be the focus of medical management after surgery, and numerous approaches have been reported. A common approach for insulin users is the so-called "sliding scale" regimen; one-half to two-thirds of the patient's usual long-acting insulin dose is given on the morning of surgery together with intravenous fluids containing dextrose (a type of sugar). Supplemental short-acting insulin is then given as dictated by finger-stick blood sugar monitoring four times a day. This regimen is continued until the patient resumes eating.

A different regimen is indicated for patients taking pills to control their diabetes. Most of these medications can be taken the day before but not on the morning of surgery. However, chlorpropamide (Diabinese) lasts a long time in your body - so your doctor may want you to stop taking it several days before surgery. Discuss the timing carefully with your doctor.

2. Chronic Corticosteroid Therapy
Corticosteroids (also known as steroids) are frequently taken by people with inflammatory types of rheumatic disease, such as lupus and rheumatoid arthritis. Common steroids include hydrocortisone, prednisone, and methylprednisolone (Medrol). People taking steroids on a chronic basis are at increased risk of problems after surgery if they do not receive sufficient steroid coverage during and immediately after surgery. Patients believed to be at increased risk include those currently taking the equivalent of more than 20 mg hydrocortisone daily, those who have taken such doses for more than two weeks in the preceding year, and those who are receiving replacement corticosteroid therapy for a condition known as adrenal insufficiency. Traditionally, such patients have been given so-called "stress-dose" therapy - extra doses of steroid before, during and after surgery. This will be managed by the medical physician and anesthesiologist.

E. Gastrointestinal Disease

Gastrointestinal problems, both worsening of chronic conditions or new problems arising after surgery, may complicate your recuperation. Peptic ulcer disease, for example, may become active after surgery. This can be particularly problematic if you require blood thinners after surgery, a common prescription for those who have had total hip or knee replacement.

Therefore, patients with a history of ulcers, gastrointestinal bleeding, or dyspepsia (indigestion) should receive preventive therapy after surgery. If your doctor suspects that an active peptic process is ongoing, the surgery should be canceled and you should be evaluated and your gastrointestinal disease treated before it is rescheduled. In patients at risk for the development of gastrointestinal bleeding after surgery, repeated testing of your stool for occult (hidden) blood is a good protective approach.

Development of intestinal problems, mainly a temporary "paralysis" of intestinal function that causes constipation, is a relatively common complication after surgery. The result is you are unable to move your bowels. It can occur in anyone, whether or not you have had chronic gastroenterological problems. The use of narcotic-based pain medication, your relative inactivity after surgery, and an over-zealous reintroduction of food in the early phase of recovery can increase the risk of this problem. Discuss with your doctor when to start eating solid foods. If you have severe constipation at home, call your doctor. It may be possible to eliminate iron supplements that contribute to the problem. In addition, you will be advised to drink lots of fluids. Further, there are many medications that can help with constipation - such as Colace and Senokot - depending on your doctor's advice. Do not take milk of magnesia unless it is recommended by your doctor.

F. Kidney and Bladder Conditions

As a consequence of bed rest, narcotic pain medications, epidural anesthesia, and/or the presence of prostate disease, urinary catheters are frequently placed in patients after major orthopaedic surgery. Unfortunately, such catheters raise the risk of infections in the bladder. In general, such catheters are removed at the earliest possible time after surgery, and a urine culture is then performed to rule out the development of a urinary tract infection. If urinary catheters are removed within 48 hours of surgery and urinary retention is avoided, the risk of urinary tract infection is small.

Prostate enlargement can obstruct the outflow of urine in men, particularly after orthopaedic surgery. In men with significant chronic symptoms of obstruction, a urologist should be consulted prior to orthopaedic surgery. In patients with enlarged prostate glands, particularily those who report obstructive symptoms, therapy with agents such as terazosin (Hytrin) and tamsulosin (Flomax) could be instituted before surgery.

In patients with a history of kidney stones, dehydration should be rigorously avoided to help prevent development of further stones.

G. Infectious Complications

The risk of infection in an implanted artificial joint is of utmost importance. The first step is prevention before surgery. During your pre-surgical medical evaluation, your doctor will take care to check for any infection, especially those of the skin and urinary tract. A preoperative urine culture should be routine. In addition, formal dental consultation may be appropriate, especially in patients with poor oral hygiene or chronic dental problems. Further, preventive antibiotic therapy will be given to total joint replacement therapy patients starting a few hours before surgery surgery and continuing for 24 hours afterward.

If you develop a fever after you get home, it is usually unrelated to the surgery. For instance an upper respiratory tract infection or a simple virus may be causing the fever. Should you experience such a fever then you should contact your doctor.

After joint replacement, in the setting of certain procedures or infections, bacteria can circulate through the bloodstream and, rarely, these bacteria can infect your new joint. Antibiotics can help prevent such infection. If osteoarthritis led to the joint replacement, you should take antibiotic precautions for the first two years following the joint replacement. If you have inflammatory arthritis, such as rheumatoid or psoriatic arthritis, or if you have diabetes mellitus, the following precautions apply indefinitely.

1. Dental Work
Any dental procedure that might release bacteria into the blood should be preceded by a prophylactic (preventive) dose of antibiotics one hour before the procedure. Certain dental procedures, like simple cleaning without scaling, may not require antibiotics. Your dentist will make that decision. When your dentist determines that you should use antibiotics before the procedure, the general guidelines are:

1. if you are not allergic to penicillin: amoxicillin, cephalexin, or cephradine (2 grams orally);
   
2. if you are allergic to penicillin: clindamycin (600 mg orally).

2. Diagnostic Procedures
Antibiotic prophylaxis is also needed prior to certain diagnostic procedures, such as urinary tract catheterization, endoscopy involving the stomach or lower intestines, and cystoscopy ("scope" of the bladder). Different antibiotics are used for different procedures. Make sure the doctor is aware that you have an artificial joint when you schedule any invasive procedure.

3. Infections elsewhere in your body:
If you have an infection that might be bacterial, such as a boil or bronchitis, contact your doctor. While viral infections are not a risk for artificial joint infections, any uncontrolled bacterial infection can be a risk. Your doctor can make the decision as to whether a bacterial infection exists and determine the optimal treatment for it. Make sure that your history of having received an artificial joint is known to all of your doctors and dentists - so they can assure that you to take antibiotics in appropriate situations.

H. Neurologic Problems

1. Confusional States
Elderly patients are at significant risk for becoming confused after surgery due to multiple factors, including sedatives, pain killers, anesthesia, fever, metabolic disturbances, and the disorienting effects of an unfamiliar environment. For example, in patients undergoing emergency surgical repair of a fractured hip, 30 to 50% have been reported to develop significant changes in their mental functioning. Fortunately, such problems are usually temporary, correcting on their own without specific treatment.

However, elderly patients and patients with underlying neurological problems (such as alcoholism or Parkinsonism) are at increased risk for postoperative delirium. Sometimes consultation with a neurologist is recommended.

2. Peripheral Nerve Damage (Neuropraxias)
During orthopaedic surgery, the arms/shoulders or legs/hips may be held in an atypical position for a prolonged period of time. This may exert pressure on underlying nerves. Rarely, such nerves may be damaged. Early detection and intervention is critical to the outcome in these circumstances. Therefore, you should report to your doctor any changes in sensation - ranging from numbness to tingling to pain -- in or near the area of surgery.

I. Emotional/Psychiatric Problems

Living with the consequences of chronic rheumatic diseases or orthopaedic problems can be very difficult. Unfortunately, the disease may cause chronic pain, disability, and interfere with your career opportunities and social life. In some people, this may contribute to emotional difficulties - and such problems may be worsened by surgery because it is yet another significant life stress. The result is that you may need additional emotional support before and after surgery.

If you are taking any medication for depression or anxiety, make sure your doctors - including your surgeon and anesthesiologist - know what medications you are taking. Rarely, you may need to discontinue the medication before surgery. This is most likely to be the case if you are taking one of a class of drugs known as a monoamine oxidase (MAO) inhibitors, which include bromocriptine (Parlodil) and phenelzine (Nardil). Patients taking these medications are at risk of significant cardiovascular problems when taken in conjunction with general anesthesia and certain narcotic pain medications, e.g., meperidine (Demerol).

IV. Management of Specific Clinical Problems

Clinical problems that may benefit by perioperative management are discussed here roughly in order of how often they are encountered.

A. Blood Clots (Thrombo-embolic Disease)

Prevention of blood clots after orthopaedic surgery is the most thoroughly studied of potential complications. Pulmonary embolism (a blood clot which travels to the lung), perhaps the most dreaded complication of orthopaedic surgery, remains an important cause of death after surgery.

Prevention begins at the time of the procedure. Quick surgery reduces the risk of deep venous thrombosis (clots in the veins) following operations such as total hip replacement. The type of anesthesia employed is also important; epidural anesthesia significantly reduces the risk of deep venous thrombosis following total hip replacement..

Mechanical means of reducing the risk of clots include various compression devices, such as foot pumps and stockings, foot flexion/extension exercises, and getting out of bed and walking as soon as your doctor approves. These maneuvers are safe, effective and do not increase the risk of bleeding.

The mainstay of prevention is blood thinners (anticoagulant medication). Prophylactic anticoagulation is begun immediately following surgery with drugs such as warfarin (Coumadin), Aspirin, or Heparin. Repeated blood tests check their effectiveness.

Despite these precautions against clots, they sometimes occur. In the weeks after surgery, you should also be aware of any signs of possible blood clots. If you develop shortness of breath, call your doctor immediately or go to an emergency room. One possible cause might be a blood clot to the lung. The problem is quite treatable with quick medical attention. Leg swelling after you get home is often due only to "gravity" - with leg swelling from the surgery becoming more visible as you walk more. However, if the swelling is painful or extensive, call your doctor, since on occasion it may reflect phlebitis (vein clot) of the leg.

B. Fat Embolism Syndrome

Fat arising from the bone marrow may be released after a hip or knee is replaced, a condition which may lead to injury of the lung. This problem, known as fat embolism syndrome, is more common when both hip or knee joints are replaced at the same time. It may occur almost right after surgery or develop or more slowly over the next two to three days. Symptoms may include: the development of confusion, particularly in the elderly; abnormalities in your blood; a drop in blood pressure; or severe difficulty breathing (respiratory distress syndrome) that requires aggressive supportive measures (such as placing a tube down the throat, called intubation, to assist with breathing) and may become life-threatening. Treatment is supportive and includes the administration of increased concentrations of inspired oxygen (possibly via ventilator) fluid restriction and the use of diuretics.

C. The Difficult Neck

Some patients with rheumatoid arthritis, generally those very severe disease, may have significant neck (cervical spine) involvement. This presents both important risks to the patient undergoing surgery and significant challenges for the anesthesiologist, particularly if intubation is required. These patients have an increased risk for spinal cord compression during intubation or from uncontrolled neck movement during positioning for surgery.

Neck instability should be ruled out prior to surgery with X-rays in patients who have: neck pain or crepitus (a creaking sound) on range of motion testing, specific symptoms of such instability, or arm and/or leg weakness. If you have neck instability, you will be given a soft cervical collar to wear during surgery - both to stabilize your neck and as a warning to all involved not to over-manipulate your neck. When possible, epidural or spinal anesthesia will be used - rather than general anesthesia.

Additional problems arising from the rheumatoid disease process include involvement of the temporomandibular joint (TMJ), which may limit your ability to open your jaw. Because this also may influence the choice of airway management, the anesthesiologist should be informed before surgery about such a problem.

The rigid cervical spine of the patient with ankylosing spondylitis may also present technical challenges for the anesthesiologist during intubation. A flexible fiberoptic method is often employed in this situation.

D. Immunosuppressive/Anti-Inflammatory Therapy

In rheumatic disease patients, the question often arises as to what, if anything, should be done about their regular regimens of immunosuppressive medications, such as methotrexate. Whether or not such drugs increase the risk of infection or delayed wound healing is uncertain, but it has become common practice to discontinue such therapy one to two weeks prior to surgery and then restart it approximately one to two weeks afterwards. Acute disease flares resulting from the abrupt discontinuation of such therapy for these brief periods are unusual and can usually be managed with steroids.

Anti-inflammatory therapy, particularly aspirin, should be discontinued five days before surgery because their anti-platelet effects may increase the risk of bleeding. This does not appear to be necessary with the new COX-2 inhibitors, such as celecoxib (Celebrex), rofecoxib (Vioxx), and valdecoxib (Bextra) because they do not interfere with platelet function.

E. The Skin

Skin integrity may be compromised before and after surgery because of long-term therapy with steroids or immunosuppressive drugs or as a manifestation (i.e. decubitus ulceration) of the debilitating consequences of underlying rheumatic disease. In addition, delayed wound healing and a tendency toward infection may result from the same influences. The early institution of preventive measures to combat the development of decubitus ulcers (particularly of the heels and buttocks) is vital to an uncomplicated post-operative course.

F. The Eye

Patients taking eye medication should have their eye drops instilled prior to surgery, especially if a prolonged procedure is anticipated. This is particularly important for patients with Sjogren's syndrome who need artificial tears to prevent injury to the eye from dryness. The one exception to this recommendation involves the use of one type of glaucoma drug called phosphodiesterase inhibitors; these agents, which may prolong the action of the neuromuscular blocker succinylcholine used by anesthesiologists, should not be used on the day of surgery.

Patients who are lying flat, especially face down, are at risk for injury to their eyes due to external pressure. Patients with underlying vasculitis of the blood vessels of the eye are at particular risk of injury to the eye due to an inadequate blood supply. Thus, in these situations, the anesthesiologist will take particular care to position you carefully, avoiding excessive pressure on the eye and providing appropriate eye protection.

V. Outcomes after Surgery

The ultimate purpose of the preoperative medical evaluation and perioperative care in general is to improve patient outcome. Through the preoperative identification of pre-existing diseases and other relevant problems, treatments that improve your capacity to withstand the rigors of surgery and its aftermath can be implemented early, often before the surgery takes place. As perioperative medicine has become a field of research in its own right, the clinical characteristics that predict who will be at risk have become increasingly better defined. Research on interventions to reduce complications after surgery have become more frequent, leading to significant reductions in postoperative crises. Perhaps no group of patients has benefited more from these advances than functionally compromised patients suffering from rheumatic disease or an orthopedic problem and patients who are elderly and frail. Thus, despite all these potential problems, most patients have a smooth post-operative course.

VI. Annotated Bibliography

1. Questions To Ask Your Doctor Before You Have Surgery. Prepared by the U.S. government's Agency for Health Care Research and Quality. http://www.ahcpr.gov/consumer/surgery.htm
2. Quick Tips-When Planning for Surgery. Prepared by the U.S. government's Agency for Health Care Research and Quality.
   http://www.ahcpr.gov/consumer/quicktips/tipsurgery.htm
3. Vandam, LD, Desai,Sukumar PD. Evaluation of the Patient and Preoperative Preparation. In. Clinical Anesthesia, Ed. Barash PG, Cullen BF, Stoelting RK. Philadelphia: J.B. Lippincott Co., 1989. Chapter 15, pg. 407-438. This contains the American Society of Anesthesiologist (ASA) Physical Status Scale for preoperative risk evaluation.
4. Mangano DT, Layug EL, Wallace A, Tateo I. Effect of atenolol on mortality and cardiovascular morbidity after noncardiac surgery. Multicenter Study of Perioperative Ischemia Research Group. N Engl J Med. 1996 Dec 5;335(23):1713-20. This was the first study to demonstrate the cardio-protective effects of beta-blockers in the non-cardiac surgical setting. Largely a result of this study, the use of beta-blockers in such circumstances has become standard medical practice.
5. Fleisher LA, Eagle KA. Clinical practice. Lowering cardiac risk in noncardiac surgery. N Engl J Med. 2001 Dec 6; 345(23):1677-82. This is a succinct review of current strategies for reducing the risk of cardiac complications in patients undergoing non-cardiac surgery. It covers the identification of patients at risk, prophylactic interventions, the role of monitoring, and potential therapies. The paper concludes with a review of current guidelines and recommendations.
6. Geerts WH, Heit JA, Clagett GP, Pineo GF, Colwell CW, et al. Prevention of venous thromboembolism. Chest. 2001 Jan;119(1 Suppl):132S-175S. This is an exhaustive review of the clinical problem of venous thromboembolism and its prevention.