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).
Table 62–4. Predictors of Increased Perioperative Cardiac Risk. ||Download (.pdf)
Table 62–4. Predictors of Increased Perioperative Cardiac Risk.
- Major predictors
- Recent myocardial infarction (<30 days)
- Unstable or severe angina
- Poorly compensated congestive heart failure
- Significant arrhythmias
- Severe valvular disease
- Intermediate predictors
- Mild angina
- Prior myocardial infarction by history or pathologic Q waves
- Compensated or prior congestive heart failure
- Diabetes mellitus
- Minor predictors
- Advanced age
- Abnormal ECG
- Rhythm other than sinus
- Low functional capacity
- Prior stroke
- Poorly controlled hypertension
- Prior cardiac revascularization, currently asymptomatic
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.
Other Cardiovascular Conditions
The prevalence of hypertension in the perioperative setting is 20%. Its association with coronary artery disease secures it as a risk factor for adverse outcome after surgery. Indeed, it has been shown to be 1 of 5 independent predictors of postoperative myocardial ischemia and 1 of 3 predictors of postoperative mortality. Despite these associations, clinical experience suggests that the magnitude of risk conferred by blood pressure elevations alone appears small, and generally surgery need not be postponed in patients with mild to moderate elevations in blood pressure.
Dysfunction of the cardiac valves is a relatively common manifestation of the connective tissue diseases. There are the Libman-Sacks vegetations of systemic lupus erythematosus, regurgitation of the mitral valve in rheumatoid arthritis, and the aortic valve disease (particularly aortic insufficiency) that accompanies HLA-B27–associated spondyloarthropathies. In addition to these associations, there is the high prevalence of aortic and aortic valve involvement in the systemic vasculitides, including granulomatous disorders, systemic vasculitis, giant cell arteritis, and Takayasu arteritis. Along with perioperative prothrombotic issues, antiphospholipid antibodies in systemic lupus erythematosus are associated with mitral valve nodules and significant mitral regurgitation, possibly due to valvular endothelial cell activation.
Surgical risks in patients with valvular heart disease depend on the valve affected as well as the nature and severity of the valvular lesion. The greatest perioperative risk is associated with hemodynamically significant aortic stenosis, a relatively uncommon valvular lesion in the connective tissue diseases. Mitral valve disease and aortic insufficiency, unless severe, are well tolerated in the surgical setting. Therefore, patients with a significant cardiac murmur, especially if accompanied by signs or symptoms of left ventricular dysfunction, should undergo an echocardiographic assessment preoperatively, particularly if a major procedure is planned. Invasive hemodynamic monitoring perioperatively may also be indicated in patients at higher risk.
While cardiac arrhythmias and conduction system disease are frequently a marker for underlying cardiac or pulmonary disease, metabolic abnormalities, or drug toxicity, they are also more frequently seen in patients with the connective tissue diseases. This is especially true in scleroderma where myocardial fibrosis compromises the cardiac conduction system, resulting in heart block and other electrocardiographic abnormalities and arrhythmias. Therefore, when patients with this and other connective tissue diseases present preoperatively with conduction system problems such as high degrees of heart block or cardiac arrhythmias, the clinician should search for such conditions and institute corrective action, if possible, before surgery.
A common problem is the management of patients with chronic atrial fibrillation who receive long-term anticoagulation. In patients with chronic atrial fibrillation who do not have prosthetic valves or hypercoagulable states and who do not receive anticoagulation therapy, the risk of embolic stroke is low. Therefore, it is safe to temporarily discontinue warfarin preoperatively to allow for normalization of the prothrombin time and international normalized ratio (INR). Five days before surgery is generally sufficient and reinstitution on the night of surgery is safe and appropriate. Newer agents, including the direct thrombin inhibitors (dabigatran etexilate mesylate [Pradaxa]) as well as agents that inhibit Factor Xa (rivaroxaban [Xarelto]), will be increasingly seen in the preoperative setting. Based on a 17 hour half-life, Dabigatran should be stopped at least 2 days prior to surgery. Rivaroxaban, with its shorter (9 hour) half-life, should be stopped at least 1 full day before the procedure. Recent clinical trials focused on venous thrombosis prophylaxis suggest that both agents can started safely immediately after surgery. However, given their rapid onset of action, surgeons may prefer to wait until hemostasis has been achieved.
Postoperative pulmonary complications are frequent and important adverse events in the postoperative period. One large study (1055 patients) reported a 2.7% incidence of pulmonary complications in patients thought to be at low to moderate risk; patients in whom pulmonary complications developed had a significantly longer length of hospital stay (27.9 vs 4.5 days). Complications such as atelectasis, pneumonia, aspiration pneumonia, respiratory failure, and exacerbation of chronic obstructive pulmonary disease (COPD) may have more severe consequences than cardiac disease and have been shown to be more predictive of long-term mortality. Smoking is associated with a 1.4- to 4.3-fold risk of postoperative pulmonary complications. COPD is the most important patient-related factor predicting postoperative complications. Such patients have a 6–28% risk for the development of pulmonary complications after surgery. Patients with asthma are also at increased risk if the disease is not well controlled preoperatively. The increased prevalence of cardiovascular disease in these patients further heightens the perioperative risk of these patients.
Chronic pulmonary disease can be divided into three categories: asthma, obstructive lung disease, and restrictive lung disease. COPD (chronic bronchitis, emphysema) and asthma are the most prevalent and account for most of the pulmonary problems arising in the postoperative setting. Minor pulmonary complications (atelectasis, bronchitis) are increased in patients who smoke, who have a chronic cough, or have abnormal spirometry. The risk of severe postoperative pulmonary complications (pneumonia, respiratory failure) is increased mainly in patients with marked impairment in lung function (forced expiratory volume in 1 second [FEV1] <1.5 L).
Restrictive lung disease, while generally less common, deserves mention owing to its prevalence in the connective tissue diseases. Defined by a symmetric decrease in FEV1 and forced vital capacity (FVC), with a reduction in the total lung capacity (TLC), restrictive patterns of lung spirometry are characteristic of the functional abnormality seen in such conditions as rheumatoid arthritis, polymyositis/dermatomyositis, and systemic lupus erythematosus.
Patient- and procedure-related risk factors for postoperative pulmonary complications are recognized. Patient-related risk factors include age, existing COPD, cigarette use, congestive heart failure, comorbidities, functional capacity, obesity, sleep apnea, and cognitive impairment. In contrast, procedure-related risk factors include surgical site (increased complication rate in procedures near the diaphragm), duration of surgery, anesthetic technique, and emergency surgery. While attempts to develop a pulmonary predictive risk index similar to the Goldman Cardiac Risk index (or its descendants) have been unsuccessful, two complication-specific pulmonary risk indices have been published, one for the prediction of postoperative pneumonia and another for respiratory failure occurring after surgery.
Two other pulmonary-related conditions make important contributions to postoperative risk: sleep apnea and chronic pulmonary arterial hypertension (PAH). Sleep apnea syndrome is defined as ≥5 apneic events (airflow stops for ≥10 seconds despite continued respiratory effort) or ≥15/hour hypopneic events (airflow lessens >50% for ≥10 seconds) during a 7-hour sleep study. While three types sleep apnea are recognized (ie, obstructive, central, and mixed), it is the obstructive form that most often comes to light in the postoperative period. Typically, while morbidly obese patients with no documented history of the condition are observed in the recovery room, they demonstrate signs of upper airway obstruction, suggesting the presence of the condition. Other physical characteristics associated with obstructive sleep apnea include a neck circumference of 17 inches, craniofacial abnormalities affecting the airway, anatomic nasal obstruction, and tonsils touching in the midline. The preoperative interview is an efficient means of screening patients; the Berlin questionnaire, comprising 10 questions that pertain to risk factors for sleep apnea (snoring, wake time sleepiness/fatigue, hypertension), has been shown to be predictive of the condition. A number of management difficulties are present in patients with sleep apnea, including a difficult to manage airway; challenging intubation; and postoperative complications, such as hypoxemia, hypertension, atrial fibrillation, and heart failure.
PAH is also seen in the connective tissue diseases, a consequence of the pulmonary disease associated with such conditions as scleroderma and mixed connective tissue disease. In the surgical setting, PAH is an especially treacherous problem associated with a substantial mortality. A pathophysiologic state characterized by elevated right heart afterload, decreased venous return, reduced cardiac output and deficient oxygen saturation, PAH is categorized as primary (idiopathic) pulmonary hypertension or as secondary PAH arising as a consequence of left heart disease, hypoxic pulmonary disorders (for instance obstructive sleep apnea), or chronic thromboembolic phenomenon. Sustained elevations in pulmonary vascular resistance and pulmonary arterial pressure, coupled with impaired vascular reactivity, may result in systemic hypotension in the setting of anesthesia. The negative inotropic effects of some anesthetic agents may exacerbate this tendency precipitating right heart failure. Thus, the adverse consequences on the left side of the circulation (systemic hypotension) are further exacerbated by concomitant right-sided responses, the pulmonary vessels constrict in response to the resultant hypoxia thereby promoting the development of hypercarbia, acidosis, hypothermia, and the release of catecholamines, a cascade that may result in further hemodynamic deterioration and circulatory collapse. Although new medications (such as endothelin receptor antagonists and prostaglandins) can significantly decrease the pulmonary artery pressures, PAH is an important risk factor for adverse outcomes after surgery.
The degree of perioperative risk imposed by chronic pulmonary dysfunction is significantly influenced by the type of surgery to be performed. Patients with severe lung impairment can tolerate minor procedures, even under general anesthesia. The risk of pneumonia following major peripheral limb surgery (such as hip or knee surgery) is low, even in the patients with chronic lung disease. In contrast, intra-abdominal or intrathoracic procedures are associated with a high risk of atelectasis or pneumonia in patients, particularly in patients with severe COPD. Regional anesthesia for surgery on the extremities circumvents many of these problems with one important caveat. Interscalene block, frequently used in shoulder surgery, may transiently paralyze the ipsilateral diaphragm and reduce the FVC by 30–40%. Therefore, patients with lung disease undergoing shoulder surgery, in which interscalene block is being considered, should have pulmonary function studies performed preoperatively. In patients with severely impaired pulmonary function (FEV1 <1 L), interscalene block should be avoided altogether. Patients with moderate COPD generally fare well with this anesthesia, especially if performed in the sitting position.
Patients using bronchodilators on a long-term basis should receive their standard dosage the night before surgery; bronchodilator therapy should be administered postoperatively usually by nebulizer. Incentive spirometry 10 times daily and early mobilization are helpful in the prevention of postoperative atelectasis.
Diabetes is the most important endocrine disorder encountered in surgical patients and, in the postoperative setting, such patients should be regarded as at risk for complications including myocardial infarction, stroke, infection, and death. Patients who have diabetes mellitus with autonomic insufficiency (manifested by postural hypotension, erectile dysfunction, nocturnal diarrhea) are at risk for sudden cardiopulmonary arrest postoperatively. Given the high prevalence of coronary artery disease, cardiovascular risk assessment is an important concern in diabetic patients; the management approach for diabetic patients is the same as that outlined earlier in the section concerning cardiovascular disease. Otherwise, the primary perioperative consideration is glycemic control.
The maintenance of good glycemic control in the surgical setting is often challenging. Because of a complex interplay of factors, the net effect of anesthesia and surgery is to drive the blood sugars higher. While the value of tight glycemic control in the perioperative setting has not been definitively established, 3 primary observations lend support to this practice. First, diabetes is a common clinical problem in surgical practice; it is estimated that 25% of diabetic patients will require surgery in the course of their lifetime. Second, many diabetic patients are at high risk in the surgical setting and efforts to reduce these risks are justified. Third, good glycemic control may reduce the rate of wound infection, vascular complications, and death in the perioperative setting.
At the preoperative evaluation, it is important to characterize the type of diabetes (type 1 or 2), determine the specifics of the patient’s treatment (medications, timing of and adherence to therapy), and estimate the degree of glycemic control. The occurrence and frequency of hypoglycemia should also be ascertained. An understanding of the nature and magnitude of the type of surgery to be performed is also necessary.
In general, the goal of therapy is to maintain the glucose level between 150 mg/dL and 200 mg/dL during surgery in order to protect against hypoglycemia. Numerous regimens have been recommended to achieve this end; management approaches are dictated by the type and severity of the patient’s diabetes. Regardless of the severity of the disease, however, management should be proactive as opposed to reactive. Whenever possible, diabetic patients should undergo surgery early in the day, thereby avoiding prolonged periods of fast on the day of surgery. For patients treated with oral agents, such medications are usually given on the day before surgery and then held in the early postoperative period. For insulin-dependent patients, the patient’s usual insulin regimen should be continued. Patients with type 1 diabetes mellitus should take a fractional amount (one third to one-half their usual dosage) of their long-acting insulin on the morning of surgery. Patients with type 2 diabetes mellitus should take none to one third of their dosage, and those patients treated with an insulin pump should continue at their basal rate of insulin infusion.
In the early postoperative period, blood sugars may be difficult to control. Divided doses of intermediate-acting (twice daily) or short-acting insulin (usually 4–6 times/daily) can be supplemented by the subcutaneous administration according to a predetermined algorithm (ie, sliding scale). Continuous insulin infusions are occasionally used postoperatively in the patient with severe, brittle disease. This approach is maintained until the patient’s oral intake is reestablished. Oral hypoglycemic agents can be resumed when the patient is eating.
Long-Term Glucocorticoid Therapy
Since many patients with rheumatic disease take glucocorticoids, the management of the patient’s glucocorticoid therapy in the perioperative setting is a common problem. Five to 7.5 mg daily of prednisone approximates the normal daily adrenal output of cortisol (30 mg). Patients believed to be at increased risk for adrenal insufficiency include (1) those currently taking >20 mg prednisone daily for >3 weeks, (2) those who have taken such doses for more than 2 weeks in the preceding year, and (3) those who are receiving replacement glucocorticoid therapy for known adrenal insufficiency. While surgery may produce sufficient “stress” to provoke adrenal insufficiency, surgeries vary in the amount of stress they produce and the circulating cortisol concentration usually normalize within 24–48 hours in most patients after surgery. Thus, supplementation should depend on the degree of stress (a function of the duration and severity of the surgical procedure) and the long-term daily glucocorticoid dose. Table 62–5 provides recommendations for perioperative glucocorticoid coverage according to the magnitude of the surgery to be performed.
Table 62–5. Recommendations for Perioperative Glucocorticoid Coverage. ||Download (.pdf)
Table 62–5. Recommendations for Perioperative Glucocorticoid Coverage.
|Surgical Stress||Target Hydrocortisone Equivalent||Preoperative Dose||Intraoperative Dose||Postoperative Dosea||Postoperative Dose Day 1a||Postoperative Dose Day 2a|
|Minor (eg, inguinal herniorrhaphy)||25 mg/d for 1 day||Usual daily dose||Noneb||Noneb||Usual daily doseb|
|Moderate (eg, colon resection, total joint replacement, lower extremity revascularization)||50–75 mg/day for 1–2 days||Usual daily dose||50 mg hydrocortisone||20 mg hydrocortisone every 8 h||20 mg hydrocortisone every 8 h|
|Major (eg, pancreatoduodenectomy, esophagectomy)||100–150 mg/d for 2–3 days||Usual daily dose||50 mg hydrocortisone||50 mg hydrocortisone every 8 h||50 mg hydrocortisone every 8 h||50 mg hydrocortisone every 8 h|
Gastrointestinal problems may complicate the postoperative period and produce significant morbidity. Postoperative nausea and vomiting arises in 20–30% of patients after surgery and is perhaps the most frequently encountered management problem. Risk factors include female sex, use of opioids for postoperative pain, a history of motion sickness, or postoperative nausea and vomiting with prior surgery. The presence of 0, 1, 2, 3, or 4 these risk factors is associated with an incidence of 10%, 21%, 39%, 61% or 79%, respectively. Nausea, abdominal distention and pain, and vomiting often herald the onset of more significant problems, specifically that of postoperative abdominal ileus.
The impairment of gastrointestinal motility after surgery is a common postoperative complication. Postoperative ileus is generally a self-limited condition lasting 3–5 days and is characterized by constipation, the accumulation of gas and fluids in the bowel with the development of abdominal distention and intolerance to enteral feeding. Perturbations in gastrointestinal motility after surgery result from a number of adverse influences arising after surgery. External risk factors include opioid analgesia and anesthesia, the fasting state, and the reintroduction of oral feeding. Internal or physiologic responses to surgery also play an important role and include increases in sympathetic tone, the hypothalamic release of corticotropin-releasing factor, and the release of nitric oxide each of which negatively influence gastrointestinal motility. In order to counteract these influences, careful consideration should be given to the optimal timing for the resumption of oral intake (both liquid and solid), and potent opioid therapy should be tapered and discontinued as quickly as possible. Early mobilization is also an effective preventive strategy. In more severe cases, medications that act on the autonomic nervous system (eg, bethanechol, carbachol, methacholine) or cholinesterase inhibitors (eg, neostigmine) may be required. Neostigmine is generally reserved for severe cases of adynamic ileus with massive dilatation of the colon in the absence of mechanical obstruction (Ogilvie syndrome), a highly threatening complication with an attendant mortality of 50%. For the motility problems arising as a consequence of postoperative opioid therapy, the mu-opioid-receptor antagonist methylnaltrexone may be useful in the postoperative setting. Last, a simple and novel preventive approach is the use of chewing gum as a stimulant of gastrointestinal motility in the postoperative setting.
Other gastrointestinal conditions, such as intestinal volvulus (which is usually seen in patients with a history of abdominal surgery), diverticular disease (chronic disease may flare in the postoperative setting), and colon cancer, may present in the postoperative period. All 3 may mimic abdominal ileus. Another important consideration is the development of Clostridium difficile–induced colitis. As a result of an increasing prevalence of this organism in the population and the widespread colonization of hospitals, severe infectious colitis has been increasingly seen in the postoperative period. C difficile–induced colitis may be asymptomatic, present with diarrhea alone (without colitis), or as acute pseudomembranous colitis progressing to life-threatening toxic megacolon. Treatment requires aggressive fluid support and the institution of oral antibiotic therapy, either metronidazole (250 mg four times daily) or vancomycin (125 mg four times daily). Resistant cases have become more frequent. Surgery including total colectomy may be required in the most severe cases.
Peptic ulcer disease is a relatively common problem among patients with orthopedic or rheumatic disease because of long-term use of nonsteroidal anti-inflammatory agents and glucocorticoids. Should peptic ulcer disease become active after surgery, it poses a particular challenge in patients who require anticoagulation prophylaxis, such as those who have undergone total joint arthroplasty. Therefore, patients with a history of peptic ulcer disease, gastrointestinal bleeding, or active dyspepsia should receive a prophylactic proton pump inhibitor or H2-blocker throughout the postoperative period. Elective surgery should be cancelled when there is an active peptic process. In patients at risk for the development of gastrointestinal bleeding after surgery, serial monitoring using stool guaiac tests are a satisfactory approach.
Urinary catheters, which are frequently used in patients undergoing major surgery, should be removed as early as possible postoperatively. If the catheter is removed within 48 hours of surgery, urinary retention is avoided and the risk of urinary tract infection is small. There are simple questionnaires that are useful in predicting in whom postoperative urinary retention is likely to develop.
Prostatic hypertrophy leading to urinary obstruction is a common problem in men after surgery. In patients with significant chronic symptoms, urologic consultation should be obtained prior to surgery and therapy (including transurethral prostatectomy) instituted. In patients who have a predisposition for urinary retention and those with enlarged prostate glands and obstructive symptoms, treatment with terazosin and tamsulosin may be started before or at the time of surgery. In patients with a history of nephrolithiasis, dehydration should be rigorously avoided to help prevent acute renal colic.
Prevention of Postoperative Infection
Efforts to prevent and detect infectious processes before and after surgical procedures, such as total joint arthroplasty, are of utmost importance. The skin and urinary tract are sites of particular concern, and infection can be ruled out by a careful physical examination and routine preoperative urine culture. Dental consultation may be appropriate in patients with poor oral hygiene.
Prophylactic antibiotic therapy for total joint arthroplasty patients should begin <2 hours before surgery and continue for 24 hours. A recommended protocol involves cefazolin 1 g every 8 hours (total of three doses) or, in penicillin-allergic patients, vancomycin 1 g every 12 hours (total of two doses).
Acute confusional states frequently arise during the postoperative period, particularly in the elderly. Delirium is characterized by an alteration in the level of consciousness, a diminished ability to maintain and focus attention, hallucinations, delusions, and agitation. While its onset may occur during the day, it may become more severe at night (sundowning). The duration of delirium is unpredictable. Patients are at increased risk for the development of delirium after surgery due to a such risk factors as acute infections, drug (psychoactive, analgesia, anesthetic) and alcohol toxicity or withdrawal, dehydration, fluid/electrolyte/metabolic disturbances, and states of low perfusion (heart failure and shock). The incidence of this problem is high in some postoperative settings. For example, postoperative delirium reportedly developed in 37% of nondemented patients following hip fracture repair. The significance of this finding is underscored by the observation that among those who experienced delirium after surgery, frank dementia developed in 69% over a subsequent 5-year period of follow-up (compared with a 20% incidence in those without postoperative delirium). Further, patients with postoperative cognitive dysfunction at discharge have been reported to die within the first year after surgery.
Although usually a transient phenomenon, clinicians should focus on the detection and treatment of correctable causes of acute delirium arising postoperatively. These include metabolic disturbances (hyponatremia, hypoxemia), medications (which might be discontinued), infection, and various acute conditions (eg, respiratory failure, myocardial infarction, cardiac arrhythmias, congestive heart failure, pulmonary embolism, and fat embolism syndrome). Likewise, elderly patients and patients with underlying neurologic conditions (eg, parkinsonism) should be considered a high risk population. Formal neurologic consultation and work-up is generally unrevealing. The incidence of postoperative delirium can be reduced by proactive geriatric consultation.
Peripheral Nerve Injuries
Peripheral nerve injuries arise more often after upper and lower extremity surgery, most often a consequence of excessive traction on the nerve, direct compression on the nerve due to prolonged intraoperative positioning of the extremity or subsequently as a result of a cast. Early detection and intervention is critical to the ultimate outcome in these circumstances. Patients with antecedent neurologic disease (such as neuropathies associated with diabetes mellitus or spinal stenosis) are at increased risk for nerve injury.
Patients living with a chronic rheumatic disease or disabling orthopedic condition may experience emotional difficulties due to chronic pain, disability, impaired social interactions and personal relationships, and constrained career opportunities. Because surgery is a significant life stress, such individuals may require additional emotional support perioperatively. Further, some patients may be taking or require antidepressant or anti-anxiolytic medication. In general, these medications may be continued throughout the perioperative period; however, monoamine oxidase inhibitors must be discontinued 10–14 days before surgery. Monoamine oxidase inhibitors may cause circulatory instability in patients receiving general anesthesia or certain opioids, especially meperidine.