Perioperative Management of the Patient with Rheumatic Disease: Introduction
Since patients with rheumatic disease often require surgery, rheumatologists may be required to evaluate and care for patients in the perioperative setting. The goals of the preoperative medical consultation and perioperative management include the following: (1) identifying the nature, severity, and stability of all comorbid conditions affecting perioperative clinical decision-making; (2) optimizing treatment of all active medical problems; (3) assessing the risks associated with anesthesia and surgery; (4) anticipating, identifying, and managing postoperative complications; (5) educating patients and families about the perioperative experience; (6) motivating patients to adopt preoperative preventive practices (ie, smoking cessation, weight loss, medication compliance, and adherence to care plans preoperatively and postoperatively).
The Preoperative Evaluation
The needs of the patient in the perioperative setting depends on a number of considerations, notably age, functional capacity, comorbidity, the type of anesthesia to be used, and the surgery to be performed. A complete history and physical examination remains the bedrock of the evaluation because it provides the clinical context upon which informed management decisions can be made. Patients should be asked about their prior experience with surgery and anesthesia, and the presence, severity, and stability of all comorbid conditions should be established. All medications (including over-the-counter preparations, herbs, and supplements) as well as the use of tobacco, alcohol, and other drugs should be documented.
The preoperative examination should be thorough yet focused on patient characteristics that might adversely impact the patient’s postoperative course. In addition to the vital signs, body mass index should be calculated because obesity is not only associated with various chronic diseases, it is a risk factor for surgery. Careful auscultation of the heart is important to rule out the presence of third and fourth heart sounds, which may indicate congestive heart failure. Further cardiac murmurs denote the presence of valvular heart disease, problems that may compromise cardiac function at times of physiologic stress (such as surgery). Obesity, large neck circumference, and hypertension predict obstructive sleep apnea, an important but underappreciated problem in the postoperative setting.
The benefit of preoperative laboratory testing has been examined in many studies and its benefit (or lack thereof) continues to be debated. When there are no clinical indications, laboratory studies rarely provide useful information. Thus, routine preoperative laboratory testing appears unnecessary for healthy patients undergoing minor procedures. Table 62–1 lists laboratory tests that may be considered for patients undergoing major surgical procedures.
| Test | Incidence of Abnormalities that Influence Management | Positive Likelihood Ratio | Negative Likelihood Ratio | Indications |
|---|---|---|---|---|
| Hemoglobin | 0.1% | 3.3 | 0.90 | Anticipated major blood loss or symptoms of anemia |
| White blood cell count | 0.0% | 0.0 | 1.00 | Symptoms suggest infection, myeloproliferative disorder, or myelotoxic medications |
| Platelet count | 0.0% | 0.0 | 1.00 | History of bleeding diathesis, myeloproliferative disorder, or myelotoxic medications |
| Prothrombin time | 0.0% | 0.0 | 1.01 | History of bleeding diathesis, chronic liver disease, malnutrition, recent or long-term antibiotic use |
| Partial thromboplastin time | 0.1% | 1.7 | 0.86 | History of bleeding diathesis |
| Electrolytes | 1.8% | 4.3 | 0.80 | Known renal insufficiency, congestive heart failure, medications that affect electrolytes |
| Renal function | 2.6% | 3.3 | 0.81 | Age >50 years, hypertension, cardiac disease, major surgery, medications that may affect renal function |
| Glucose | 0.5% | 1.6 | 0.85 | Obesity or known diabetes |
| Liver function tests | 0.1% | No indication. Consider albumin measurement for major surgery or chronic illness | ||
| Urinalysis | 1.4% | 1.7 | 0.97 | No indication |
| Electrocardiogram | 2.6% | 1.6 | 0.96 | Men >40 years, women >50 years, known CAD, diabetes, or hypertension |
| Chest radiograph | 3.0% | 2.5 | 0.72 | Age >50 years, known cardiac or pulmonary disease, symptoms or examination suggest cardiac or pulmonary disease |
While the history and physical examination remain the primary method for detecting conditions likely to affect surgical outcome, rating systems that are useful in identifying patients in whom postoperative complications are most likely to develop have been created.
The most widely used rating system is the American Society of Anesthesiologist (ASA) Physical Status Scale, which has a high correlation with the patient’s postoperative course. This scale consists of 5 levels of risk, which are based on the presence of a systemic disturbance (Table 62–2). Although criticized for the vagueness of its criteria, the ASA classification has proven a highly durable and useful predictive tool.
| Level of Risk | Extent of Systemic Diseasea |
|---|---|
| I | Absent (0.2%) |
| II | Mild (0.5%) |
| III | Severe/non-incapacitating (1.9%) |
| IV | Incapacitating/threat to life (4.9%) |
| V |
|
For preoperative assessment of cardiac risk, a revision (Revised Cardiac Risk Index) of the original index of Goldman is now widely used (Table 62–3). One point is assigned for each of the 6 independent risk factors for major cardiac complications in patients undergoing noncardiac surgery. The incidence of such complications in patients with 0, 1, 2, or 3 risk factors is 0.4%, 0.9%, 7%, and 11%, respectively.
Each risk factor is assigned one point.
|
The development of more global indicators of risk remains an important challenge. Holt and Silverman have proposed a resilience score for organ systems compromised by an underlying disease process. An overall resilience score for a given organ system is derived by adding the standard ASA score to a surgical complexity score (rate 1–5). The higher the score, the more likely that a given organ system will suffer injury or fail in the setting of a surgical stress.
Several broad themes relevant to perioperative care have emerged from other recent studies. First, the use of total joint arthroplasty has increased over time, as has the prevalence of hypertension, diabetes mellitus, hypercholesterolemia, obesity, pulmonary disease, and coronary artery disease. Overall complication rates have decreased in spite of a decreasing length of stay except in the case of bilateral procedures. Indeed, among the population undergoing bilateral total joint arthroplasty, procedure-related complication rates were higher than unilateral procedures despite a younger average age and lower comorbidity burden. Mortality after total joint arthroplasty of the hip and knee were most strongly correlated with postoperative pulmonary embolism and stroke. Preoperative risk factors for in-hospital mortality were revision total joint arthroplasty, advanced age (>85 years), and the presence of specific comorbidities (predominately dementia, renal disease, and cerebrovascular disease).
Airway considerations, the site and anticipated duration of surgery, comorbidities, and the patient’s emotional state are important determinants of the type of anesthesia to be used, as well as whether invasive monitoring will be required, and the length of time the patient will spend in the recovery room after surgery.
General and regional anesthesia are commonly used in the surgical treatment of patients with rheumatic disease. Although the debate concerning the relative superiority of these approaches remains unresolved, many surgical procedures, particularly orthopedic surgery, are well suited for regional anesthetic techniques. Regional anesthesia may reduce the incidence of major perioperative complications, including blood loss, deep venous thrombosis and pulmonary embolism, as well as postoperative respiratory events and death. Further, postoperative pain management, a significant problem for patients with a painful rheumatic disease, may be best managed with regional anesthetic approaches. Peripheral nerve blocks using longer acting anesthetics and infusion methods are another consideration since they provide both excellent intraoperative anesthesia and postoperative pain relief.
Patients undergoing major surgical procedures should have continuous electrocardiographic and pulse oximeter monitoring intraoperatively. Arterial line and Swan-Ganz catheter monitoring may be helpful in selected patients, particularly those with chronic cardiopulmonary disease. Such monitoring is also used in patients undergoing bilateral joint replacement surgery.
A number of options exist for the control of postoperative pain, including the traditional intravenous or intramuscular routes versus the use of epidural analgesia. Patient-controlled analgesia via an epidural route of administration is an effective method of pain control after surgery and often facilitates postoperative physical therapy, which is important in the restoration of range of motion in patients undergoing orthopedic surgery. Parenterally administered nonsteroidal anti-inflammatory drugs are a useful alternative to traditional analgesia after surgery and can be used to reduce opioid requirements after major surgery. These drugs should not be given to patients with the common contraindications to nonsteroidal anti-inflammatory drugs, such as peptic ulcer and renal disease.
Perioperative Management of Comorbid Medical Conditions
Cardiovascular disease is the most investigated and well documented problem of perioperative medicine. Practical guidelines intended to guide physicians involved in the assessment and care of patients with cardiac disease are widely recognized and are updated regularly.
With respect to the identification of the presence of preexisting cardiac disease, the predictive value of the routine clinical assessment, the history and physical examination, electrocardiogram, chest radiograph, supplemented by other noninvasive methodologies, is well established. In patients with ischemic heart disease, the postoperative risk is ultimately defined by the estimation of disease severity and stability in concert with age, functional capacity, comorbidity and type of surgery to be performed. A series of factors may predict postoperative myocardial infarction, congestive heart failure, and death after orthopedic surgery (Table 62–4).
|
The American College of Cardiology/American Heart Association Guidelines for the Perioperative Cardiovascular Evaluation for Noncardiac Surgery provides the most extensive discussion of the approach to the preoperative cardiac evaluation. In patients with high exercise tolerance, such testing provides little useful information. In patients with rheumatic disease, however, the evaluation of cardiac function preoperatively may be useful because the chronic illness often limits their activity thereby masking underlying significant cardiac dysfunction. Currently, it remains unclear whether one approach to stress testing is definitively superior to another. Indeed, all approaches may be reasonably good for preoperative risk assessment and which approach is chosen may be related more to the patient’s physical capacity to participate in the stress induction and the local availability of such testing.
Strategies to reduce cardiac risk in noncardiac surgery may involve (1) medical therapy or invasive cardiac interventions performed preoperatively, (2) alterations in anesthetic technique, or (3) aggressive management of adverse hemodynamic developments before and after surgery. For the internist-rheumatologist who evaluates the patient preoperatively, the relevant approach includes medical management, specifically the use of β-blockers, antiplatelet agents, and statin therapy. Managing antiplatelet therapy in patients who have cardiac stents can be challenging (see below). On occasion, coronary revascularization prior to the noncardiac surgery is considered.
Theoretically, β-blockers can protect the heart in the perioperative period by improving myocardial oxygen balance by slowing the heart rate and reducing contractility. In addition, slowing of the heart rate improves diastolic filling while decreasing myocardial oxygen consumption. Studies on the impact of β-blocker use on perioperative morbidity and mortality have yielded conflicting results. In one study, patients with coronary artery disease or a significant risk factor profile were randomized to receive atenolol or placebo starting 7 days before surgery and continuing for 1 month after surgery. A significant reduction in cardiac events was noted postoperatively, a benefit that remained significant for 2 years. Some subsequent studies confirmed these results; however, a large randomized control trial showed that while prophylactic β-blockade significantly decreased the incidence of postoperative myocardial infarction, this benefit was negated by the higher incidence of death (3.1% vs 2.3%), stroke (1.0% vs 0.5%), clinically significant hypotension (15% vs 9.7%), and bradycardia (6.6% vs 2.4%). While controversy remains, the most prudent approach to the use of perioperative β-blockade is to use them only in selected circumstances, such as high-risk patients who currently take β-blockers.
Long-term aspirin therapy for the primary and secondary prevention of atherosclerotic cardiovascular disease is highly prevalent, and the use of aspirin and other antiplatelet agents in the perioperative setting is commonplace. In the past, these agents were usually discontinued before surgery whenever possible because of their perceived bleeding risk. As the protective role of aspirin has been better appreciated, the practice of discontinuing aspirin prior to surgery has been called into question. A meta-analysis has demonstrated that aspirin withdrawal preceded up to 10% of all acute cardiovascular events and that while aspirin-related bleeding complications increased, the bleeding tended to be mild and of little significance (except in intracranial surgery and transurethral resection of the prostate). A related problem is the management of antiplatelet therapy in patients with intracoronary stents who are undergoing noncardiac surgery. Reports of perioperative stent thrombosis in patients who have discontinued antiplatelet therapy preoperatively have raised concern about the attendant risks. Such thrombosis is associated with high rates of myocardial infarction (up to 50%). Two major classes of stents are currently used: bare metal stents (BMS) and drug-eluting stents (DES). The latter contain drugs that prevent endothelialization of the stent and hence restenosis. Since antiplatelet agents (usually dual antiplatelet therapy) significantly reduce the incidence of stent thrombosis, the protective influence of such medication is important. Further, the risk of stent thrombosis varies with the type of stent used. The BMS have a lower risk of thrombosis than DES when antiplatelet therapy is discontinued. The heightened risk of thrombosis associated with DES is believed to persist for upwards of 1 year. According to a recent advisory statement, for patients who require surgery and have had a DES placed in the preceding 12 months, clopidogrel should not be discontinued for an elective procedure.
The statins have both lipid-lowering and anti-inflammatory activity, stabilizing coronary plaque, improving endothelial function, and inhibiting platelet aggregation. As a consequence of these benefits and a number of clinical trial suggesting a cardioprotective effect in the perioperative setting, statin therapy should be continued during the perioperative period.
While fewer patients with rheumatoid arthritis and spondyloarthropathies are undergoing orthopedic surgery due to modern treatment strategies, some patients require surgical intervention and their cardiovascular risks need to be appreciated. Rheumatoid arthritis results in premature development of atherosclerosis, myocardial infarction, and arterial stiffening. Congestive heart failure is likewise independently related to rheumatoid arthritis, possibly because of impaired left ventricular diastolic filling. Although effective control of disease activity may be beneficial in ameliorating vascular and myocardial disease, patients with severe disease are the most likely to have subclinical coronary disease. Like rheumatoid arthritis, systemic lupus erythematosus results in premature development of atherosclerosis, myocardial infarction, and arterial stiffening. Left ventricular hypertrophy develops in systemic lupus erythematosus unrelated to traditional stimuli to hypertrophy and may be due to inflammation-related arterial stiffening. All cyclooxygenase-2 selective and traditional nonsteroidal anti-inflammatory drugs increase the risk for ischemic heart disease and should be factored into the perioperative risk assessment.
