INTRODUCTION
Primary care is coordinated, comprehensive, and personal care, available on both a first-contact and a continuous basis. It can be defined by several tasks: (1) medical diagnosis and treatment; (2) psychological diagnosis and treatment; (3) personal support of patients of all backgrounds; (4) communication of information about diagnosis, treatment, prevention, and prognosis; (5) maintenance of patients with chronic illness; and (6) prevention of disability and disease through detection, education, behavioral change, and preventive treatment.
This chapter addresses the common clinical problems encountered by physiatrists in office practice of adult patients with disability. In this setting, the physician’s responsibilities and tasks extend beyond the narrow technological confines of medical diagnosis and treatment. As the number of patients requiring rehabilitation increases, the medical problems of those with physical disabilities become more complex, and the availability of primary care physicians who understand the needs of chronically ill patients become relatively less available, it becomes more important for physiatrists to understand the tasks that comprise the clinical work of physicians providing primary care for patients with such problems.
Historically, there has been little coordination across the multiple settings, providers, and treatments encompassed in the care of chronically ill patients. The treatments for chronic diseases are often complicated, making it difficult for patients to comply with treatment protocols. Effective medical care usually requires longer visits to the physician’s office than is common in acute care. Moreover, in treating chronic illnesses, effectiveness of the same intervention, whether medical or behavioral, may differ depending on when in the course of the illness the intervention is suggested. Fragmentation of care is a risk for patients with chronic diseases, because frequently multiple chronic diseases coexist. Physiatrists, because of their broad scope of practice, are ideally positioned to assume the role of gatekeeper in the overall medical management of patients with chronic illness and disability.
Preventive screenings are an important part of health promotion efforts. Many preventive screenings have been recognized as a cost-effective way to identify and treat potential health problems before they develop or worsen. However, it can be challenging to keep up with the latest scientific thinking regarding screenings. Age- and gender-specific preventive screening recommendations exist for dozens of health concerns, but the recommendations may vary from organization to organization and are frequently changed as new information becomes available.
Physicians must acknowledge their primary role in prevention as that of educators. Accurate information regarding risk factors is most likely to reinforce health-enhancing behavior and alter self-destructive behavior. The physician must appreciate the potential for behavior modification and familiarize himself or herself with local resources. Routine screening for specific diseases, the maintenance activity most closely identified with the physician, should be performed selectively. The limits of screening tests as well as their potential health benefits should be clearly understood by every physician, especially those who are managing patients with chronic disabling conditions.
Screening tests are performed to identify asymptomatic disease. The alternative is to wait until patients present with symptoms and then make the diagnosis. The practicalobjective of screening is prevention of morbidity and mortality—not simply early diagnosis. There is little benefit to the patient, and perhaps considerable harm, in advancing the time of diagnosis of a disease for which earlier treatment does not influence outcome.
Several official entities have recommended or published screening protocols and guidelines aimed at improving early detection and hence prevention of common diseases (Table 42–1). Among the most commonly performed screening measures in the general population are those developed to identify risks for hypertension, heart disease, breast cancer, prostate cancer, and colon cancer.
| Screening Measure | Description |
|---|---|
| Obesity/Weight control | Check weight annually if body mass index (BMI) is within normal range. Check more frequently if patient is participating in a weight-loss management program. |
| Blood pressure | Check annually with each medical history review and physical examination if blood pressure is < 120/80 mm Hg. Check more frequently if blood pressure is higher. |
| Breast disease | Monthly self-breast examinations. Annual mammogram and clinical breast examination for all women aged 40–69 years or younger if high risk. After age 70 years, examinations and screenings at provider or patient discretion |
| Colon cancer | Colonoscopy at age 50 years and then every 10 years. Or, sigmoidoscopy or barium enema every 3–5 years plus annual stool test for blood. Check more frequently if patient is at high risk. |
| Prostate cancer | Digital rectal examination annually for all men aged 50 years and older. Prostate-specific antigen (PSA) test is inconclusive.a |
| Vision/Glaucoma | Every 2–4 years until age 65, then every 1–2 years. Annually if at high risk (diabetes). |
| Audiology/Hearing | As needed. |
| Dental examination | Annually. |
| Osteoporosis/Bone density | Dual-energy X-ray absorptiometry (DEXA) scan for postmenopausal women aged 65 years and older and for men aged 70 years and older, or younger if at risk. |
| Mental health | Discuss mood and memory concerns at each visit. |
| Smoking cessation | At each visit. |
Immunizations are an effective and important means of controlling many communicable diseases through primary prevention. Their underuse stems, in large part, from a failure of public education and access to health care delivery. In general, live attenuated vaccines provide more complete and longer lasting immunity than inactivated agents. However, because live vaccines can produce serious disseminated disease in the immunosuppressed host, these preparations should be avoided in patients who are immunologically deficient.
Patients who are chronically ill should be evaluated to determine their immunization status, and whether they would benefit from additional immunizations, including those described below. As noted, vaccines that contain a live virus are generally contraindicated in immunocompromised individuals. Rarely, individuals with allergies can have reactions to components of individual vaccines. Specific cautions and exclusions relating to routinely administered vaccines can be found on the Center for Disease Control and Prevention’s vaccine and immunization web pages (see www.cdc.gov/vaccines/vpd-vac/should-not-vacc.htm#mmr).
The vaccine is effective against 23 serotypes of S pneumonia, and is recommended for individuals with asplenia, sickle cell disease, or any debilitating disease, as well as those older than 65 years of age. The dose should be repeated in 5–6 years.
The influenza vaccine given seasonally is an inactivated vaccine containing two type A and one (or two) type B strains of the influenza virus that have been identified as most likely to cause illness in a given year. The vaccine is generally effective within 2 weeks and must be readministered each year. The Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention (CDC) currently recommends universal vaccination of all individuals older than 6 months of age. High-risk groups (ie, those with chronic illness or immunocompromising conditions, pregnant women, health care professionals, and those in contact with high-risk persons), and older adults should receive priority vaccination. Trivalent inactivated vaccine is contraindicated in persons with severe egg allergy, and it should be used with caution in patients with Guillain-Barré syndrome.
Children in the United States usually receive the live-virus vaccine against measles in combination with mumps and rubella (German measles) as part of the standard childhood immunizations. MMRV is a combination vaccine that adds protection against varicella. Because this is a live-virus vaccine, it should not be administered to immunocompromised patients. In addition, some patients with allergies may have reactions to components of the vaccine.
The live-virus measles vaccine (Attenuvax) is recommended for all susceptible people older than 12 months of age (ie, anyone who does not have documented immunity against measles). Although usually given as part of the MMR vaccination, measles vaccine may be administered separately to individuals who are at risk for contracting infection because of incomplete or missed childhood vaccinations. Persons born before 1956 are considered immune. Individuals born after 1956 should have received two doses of live measles vaccine, given not less than 1 month apart. However, some adults born after 1956 may have received only the first dose as a child. These individuals should be given a second dose of the vaccine to ensure complete protection against the virus. The same cautions listed earlier for MMR administration apply to measles vaccination.
Varicella vaccine (Varivax) is recommended for all older individuals who are not known to be immune to the varicella virus. A past history of chicken pox is sufficient for assuming immunity. If an adult patient is unsure whether he or she had a prior infection, immune status should be evaluated before administering the vaccine as up to 91% of patients so tested are immune.
Unless otherwise contraindicated, inactivated hepatitis A vaccine (Havrix, VAQTA) is recommended in persons 2 years of age or older who are at increased risk of infection with hepatitis A virus, including those with chronic liver disease and travelers outside the United States (except for northern and western Europe, New Zealand, Australia, Canada and Japan).
Hepatitis B vaccine is recommended for all individuals who are or may be at increased risk for infection with hepatitis B virus, including all adolescents. Booster doses can be given every 7 years but are not currently recommended. If an individual’s antibody level is greater than 10 IU/mL, a booster dose is not needed. If a patient has been exposed to hepatitis B and has had the complete vaccination series but the antibody level is unknown, hepatitis B immune globulin (HBIG) should be administered along with a booster dose.
Many children and young adults in the United States have been vaccinated against tetanus and diphtheria as part of the standard childhood vaccinations. Tetanus booster is recommended once every 10 years after the primary series. The booster may be given at 5 years for “dirty” wound management.
Adults 55 years of age and younger who require meningococcal vaccination should receive the quadrivalent meningococcal polysaccharide vaccine. Individuals without a functioning spleen and those with persistent complement deficiencies should routinely receive a two-dose series with 2 months between doses, then booster doses every 5 years. Persons infected with HIV do not require booster doses after the initial two-dose series. Other adults who are at increased risk of infection (eg, college students living in dormitories, laboratory personnel at risk of exposure) should receive a single dose of vaccine; revaccination is not required unless the first dose was given before 16 years of age.
A single dose of the herpes zoster vaccine (Zostavax) is recommended for adults aged 60 years and older, regardless of their history. Vaccine effectiveness decreases with age; therefore, patients should be immunized as soon as possible after age 60. The vaccine contains a live virus and thus is contraindicated in persons with immunocompromising conditions.
Tobacco use is implicated in one in five deaths in the United States per year. Smoking is considered the most important of the modifiable risk factors for ischemic heart disease and stroke. There are both pharmacologic and nonpharmacologic options to aid in smoking cessation. Nonpharmacologic options include receiving brief advice from a health care provider and participating in behavioral therapy. Options such as acupuncture and hypnotherapy, while anecdotal evidence might prove otherwise, have not been shown to be statistically more effective than placebo. Pharmacologic options, however, are well studied and have been shown to be quite effective. These include bupropion, nortriptyline, varenicline, and nicotine replacement therapy (NRT). NRT has a mild side-effect profile and has proven effective in clinical trials. If patients are unable to adhere to NRT, a trial of bupropion, nortriptyline, or varenicline may be considered next. There are no recommendations at this time as to which is the superior. The physician must consider pricing, patient preference, availability, and potential side effects when prescribing these agents.
CARDIOVASCULAR DISORDERS
ESSENTIALS OF DIAGNOSIS
Hypertension in adults is defined as a systolic blood pressure of at least 140 mm Hg, or a diastolic blood pressure of at least 90 mm Hg, or both.
Screening is the primary method of detection.
Nonmodifiable risk factors include older age, male gender, African-American race, and a family history of hypertension.
Modifiable risk factors include obesity, sedentary lifestyle, excessive alcohol consumption, tobacco use, increased sodium intake, decreased potassium intake, vitamin D deficiency, and stress.
Untreated hypertension may lead to cardiovascular disease, peripheral vascular disease, renal disease, and other end-organ damage.
Hypertension in adults is defined as a systolic blood pressure of at least 140 mm Hg, or a diastolic blood pressure of at least 90 mm Hg, or both (Table 42–2). Screening is the primary method of detecting hypertension. Essential hypertension, also known as idiopathic or primary hypertension, accounts for approximately 90% of cases, has no identifiable cause, and is often asymptomatic. It is an important risk factor for subsequent cardiovascular disease, peripheral vascular disease, and stroke. Secondary hypertension has an identifiable and often treatable or reversible cause; examples include obstructive sleep apnea and use of certain medications (eg, birth control pills and decongestants).
| Initial Drug Therapy | |||||
|---|---|---|---|---|---|
| Blood Pressure Classification | Systolic Blood Pressure (mm Hg) | Diastolic Blood Pressure (mm Hg) | Lifestyle Modification | Without Compelling Indication | With Compelling Indication |
| Normal | < 120 | and < 80 | Encourage | ||
| Prehypertension | 120–139 | or 80–89 | Yes | No antihypertensive drug indicated | |
Stage 1 hypertension | 140–159 | or 90–99 | Yes | Thiazide-type diuretics for most patients. May consider ACEI, ARB, BB, CCB, or combination. | Drug(s) for compelling indications.a Other antihypertensive drugs (diuretics, ACEI, ARB, BB, CCB) as needed. |
Stage 2 hypertension (systolic blood pressure) | > 160 | or > 100 | Yes | Two-drug combination for most patients (usually thiazide-type diuretic and ACEI, or ARB or BB or CCB). | Drug(s) for compelling indications.a Other antihypertensive drugs (diuretics, ACEI, ARB, BB, CCB) as needed. |
Nonmodifiable risk factors include increasing age, male gender, African-American race, and a family history of hypertension. Modifiable risk factors include obesity, sedentary lifestyle, excessive alcohol consumption, tobacco use, increased sodium intake, decreased potassium intake, vitamin D deficiency, and stress.
Hypertension causes increased systemic vascular resistance (afterload), which leads to concentric left ventricular hypertrophy and decreased left ventricular function. Thus, the chamber often dilates, leading to heart failure. Hypertension also accelerates atherosclerosis, leading to a higher incidence of coronary artery disease (CAD).
Most people with hypertension have no signs or symptoms, even when blood pressure readings reach dangerously high levels. A few individuals with early-stage hypertension may have dull headaches, dizziness, or nosebleeds but these findings typically do not occur until blood pressure elevation has reached a severe stage.
Hypertension is identified by means of blood pressure readings using an appropriately sized cuff. When warranted, an electrocardiogram can help identify cardiac abnormalities associated with hypertension (eg, left ventricular hypertrophy). A basic metabolic panel can provide evidence of primary and secondary contributors to hypertension, including low potassium level and renal dysfunction (blood urea nitrogen and creatinine).
Most complications of hypertension result from end-organ damage. Hypertension is a major risk factor for CAD, which can result in angina and myocardial infarction. Congestive heart failure with left ventricular hypertrophy is another common result of chronic uncontrolled blood pressure elevation. In addition, hypertension predisposes patients to peripheral vascular disease and is associated with an increased risk of aortic dissection.
Uncontrolled hypertension can lead to intracerebral hemorrhage, transient ischemic attacks, and other stroke subtypes, as well. Severely elevated pressures can cause hypertensive encephalopathy. Kidney disease with eventual renal failure can occur in patients with chronic hypertension as a result of decreased glomerular filtration rate and tubular dysfunction.
Treatment of hypertension is often initially addressed with lifestyle modification techniques, and this alone may be adequate for some patients. Patients should be advised to limit sodium intake and alcohol consumption, lose weight, exercise regularly, stop unnecessary medications that may contribute to hypertension, stop smoking or other use of tobacco products, and engage in stress management practices. Additional risk factors, if identified, should be addressed (eg, low potassium level, contributing to renal problems).
Use of tobacco and alcohol should be questioned and addressed by all health care providers, and the benefits and methods of smoking cessation discussed at every visit. Alcohol consumption should be limited to the equivalent of 30 mL (in men) or 15 mL (in women) of ethanol per day. Some evidence suggests that the cardiovascular benefits of alcohol may be greater for red wine than for other alcoholic drinks. Overweight or obese people need to be advised to lose weight. Consumption of fruits and vegetables is usually sufficient for adequate potassium intake; however, some patients with low potassium levels may benefit from supplementation.
Ambulatory blood pressure self-monitoring should be recommended for patients with prehypertension or hypertension as part of their regular monitoring.
Pharmacologic intervention includes the use of various antihypertensive agents (refer to Tables 42–2 and 42–3). Thiazide diuretics are considered first-line agents in African-American patients as this population often has a type of hypertension that is more “salt-sensitive.” Monitoring for hypokalemia is important while patients are taking these drugs. If patients also have diabetes, however, an angiotensin-converting enzyme (ACE) inhibitor is the initial choice. Angiotensin II receptor blockers (ARBs) also inhibit the renin–angiotensin–aldosterone system. β blockers decrease heart rate, cardiac output, and renin release. Calcium channel blockers cause vasodilation of arteriolar vasculature. Vasodilators such as minoxidil and hydralazine are used often in conjunction with β blockers.
| Compelling Indications | Recommended Drugs | |||||
|---|---|---|---|---|---|---|
| Diuretics | a Blocker | ACEI | ARB | CCB | Aldosterone Antagonist | |
| Heart failure | Yes | Yes | Yes | Yes | Yes | |
| Postmyocardial infarction | Yes | Yes | Yes | |||
| High coronary disease risk | Yes | Yes | Yes | Yes | ||
| Diabetes mellitus | Yes | Yes | Yes | Yes | Yes | |
| Chronic kidney disease | Yes | Yes | ||||
| Recurrent stroke prevention | Yes | Yes | ||||
ESSENTIALS OF DIAGNOSIS
Excess serum cholesterol, especially low-density lipoprotein cholesterol (LDL-C) level > 160 mg/dL, or excess triglycerides (> 250 mg/dL).
Patients are usually asymptomatic; however, rarely symptoms of lipid deposition or pancreatitis may be noted.
LDL-C is considered to be the major contributor to CAD risk; high-density lipoprotein cholesterol (HDL-C) is cardioprotective.
Hyperlipidemia is a group of disorders characterized by an excess of serum cholesterol, especially excess LDL-C, or an excess of triglycerides, or both. On its own it is often asymptomatic. Hyperlipidemia is often genetically determined, but it can be caused or amplified by abnormal diet, drugs, and certain disease conditions. Hyperlipidemia is one of the most important and modifiable risk factors for CAD as it causes accelerated atherosclerosis.
Hyperlipidemia is usually asymptomatic. In rare cases, patients may experience recurrent abdominal pain as a result of pancreatitis secondary to very high triglyceride levels of greater than 1000 mg/dL. Similarly, although there are often no signs associated with hyperlipidemia, at extremely high levels, as occurs in familial hypercholesterolemia, lipid deposition may produce masses that are observable on physical examination. Patients may present with xanthomas, which appear as hard yellowish masses on the extensor tendons of the hands, the Achilles tendons, plantar tendons, and at the insertion of the patella tendon. Xanthelasmas can also be seen and are described as yellowish plaques on eyelids, but these are not specific for hypercholesterolemia or hyperlipidemia.
Cholesterol and triglyceride levels are routinely evaluated in primary care visits. The determination of what constitutes “ideal,” “low,” and “high” cholesterol continues to be refined as epidemiologic studies provide evidence about long-term consequences relating to these values.
Ideal total cholesterol is currently equated with a level less than 200 mg/dL, but some evidence suggests that levels between 60 and 200 mg/dL may be associated with an increased risk of CAD. A borderline level is considered to be 200–240 mg/dL, and high total cholesterol is deemed to be any level greater than 240 mg/dL. High total cholesterol is associated with a severe increased risk of CAD and requires medical intervention.
LDL is considered to be the major contributor to CAD risk because it is the most atherogenic of all lipoproteins. It is a calculated measurement derived from the total cholesterol value. Ideal LDL is currently considered to be a level less than 130 mg/dL; borderline is 130–160 mg/dL; and high is greater than 160 mg/dL.
An ideal triglyceride level is considered to be less than 125 mg/dL; borderline is 125–250 mg/dL; and high is greater than 250 mg/dL.
HDL has a protective effect as it removes excess cholesterol from arterial walls. For every 10 mg/dL increase in HDL levels, the CAD risk is decreased by 50%. A low HDL level of less than 35 mg/dL is a major independent risk factor for CAD, whereas high HDL of greater than 60 mg/dL counteracts risk to some degree (see later discussion).
Treatment goals are based on absolute serum levels of lipids in combination with risk stratification of patients. Evidence shows that effective therapy to lower serum LDL-C is associated with dramatic benefits in terms of short-term morbidity and mortality in patients with CAD, and long-term morbidity and mortality even in low-risk patients The short-term goal is to reduce LDL levels, while the long-term goal of treatment is to reduce the risk of atherosclerosis and CAD.
The patient’s risk for CAD events is determined, based on the Framingham score for 10-year risk of developing myocardial infarction or death, to aid in planning specific treatment interventions. In tabulating this score, major risk factors are giving one point each; these include hypertension (blood pressure > 140/90 mm Hg, or treatment for hypertension), cigarette smoking (any within the past month, HDL-C level < 40 mg/dL), male gender and age greater than 45 years, female gender and age greater than 55 years, and family history of premature CAD (clinical disease or sudden death in a first-degree male relative before age 55, or first-degree female relative before age 65). If HDL-C level is 60 mg/dL or greater, one point is subtracted from the total.
Updated recommendations from the National Cholesterol Education Program Adult Treatment Panel (NCEP-ATP) III define target levels for treatment based on the Framingham score and include optional, more aggressive, lower target LDL-C goals in patients at higher risk. The target LDL-C levels defined by NCEP are listed in Table 42–4.
| Target Patient | LDL-C Treatment Goal |
|---|---|
| Low-risk patients with < 2 major risk factors and a 10-year risk < 10% | < 160 mg/dL |
| Moderate-risk patients with ≥ 2 major risk factors and a 10-year risk of < 10% | < 130 mg/dL |
| Moderately high-risk patients with ≥ 2 risk factors and a 10-year risk of 10–20 | < 130 mg/dL Optional: < 100 mg/dL |
| High-risk patients with clinical coronary heart disease or equivalent risk factors and a 10-year risk > 20% | < 100 mg/dLb |
| Very high-risk patients with severe, poorly controlled risk factors, including continued smoking, multiple other major risk factors for coronary heart disease (eg, diabetes), multiple risk factors for metabolic syndrome, and patients with acute coronary syndromes | < 100 mg/dL Optional: < 70 mg/dL |
Many of the measures previously described for prevention of hypertension and hyperlipidemia are included in the treatment recommendations for lifestyle modifications to improve LDL and HDL levels. In particular, exercise is beneficial in increasing HDL-C level.
HMG-CoA reductase inhibitors (statins) are the medication of choice for patients at high risk of CAD. These agents have been shown to reduce mortality from cardiovascular events and significantly reduce total mortality by lowering LDL-C. They are also indicated as secondary stroke prophylaxis. Statins are considered to be more effective than other medications in reducing LDL-C; however, they are less effective than fibrates for reducing triglycerides and raising HDL-C. Liver function tests should be monitored at first monthly for 3 months, and then every 6 months, in all patients taking these drugs.
Niacin is a second-line agent in the treatment of hyperlipidemia. It lowers triglyceride and LDL levels and increases HDL levels but should be avoided in diabetic patients, in whom it may worsen glycemic control. At levels prescribed for antilipemic treatment, niacin is often poorly tolerated. The most common side effect, cutaneous flushing, can be reduced by taking aspirin 30 minutes prior.
Bile acid–binding resins lower LDL but increase triglyceride level. They are often effective when used in combination with statins or niacin to treat severe disease in high-risk patients. However, these agents are often poorly tolerated because of side effects, including gastrointestinal discomfort.
Fibrates are used when all the other pharmacologic options fail. They lower very low-density lipoprotein (VLDL) and triglyceride levels while increasing HDL. Side effects include gastrointestinal distress and, less commonly, gynecomastia, gallstones, weight gain, and myopathies.
ESSENTIALS OF DIAGNOSIS
May present as stable angina pectoris, unstable angina, myocardial infarction, or sudden cardiac death, or be completely asymptomatic.
Stable angina produces chest pain or a substernal pressure sensation (heaviness, pressure, or squeezing), usually lasts 1–5 minutes, is brought on by exertion or emotion and relieved with rest or nitroglycerin.
Classic symptoms are crushing substernal chest pain, radiating to the left neck, jaw, or arm, and a sensation similar to gastroesophageal reflux.
Atypical symptoms are common in women and in the elderly.
Coronary artery disease (CAD) is the clinical manifestation of the pathologic features seen in atherosclerosis of the coronary arteries. It is the most common type of heart disease and is the leading cause of death for both men and women in the United States. Every year, more than 400,000 Americans die from CAD.
Nonmodifiable risk factors include age, gender, and family history of CAD. In premenopausal women, estrogen has cardioprotective properties. Modifiable factors account for more than 90% of the population-attributable risk of a first myocardial infarction and include smoking, dyslipidemia, hypertension, diabetes mellitus, abdominal obesity, psychosocial factors, regular alcohol consumption, and lack of regular physical activity. Controlling risk factors often can lessen genetic influences and help prevent CAD, even in older adults.
CAD can present as stable angina pectoris, unstable angina, myocardial infarction, or sudden cardiac death, yet for some individuals can be completely asymptomatic. Stable angina appears as chest pain or a sensation of substernal pressure (often described as heaviness, pressure, or squeezing) that usually lasts for 1–5 minutes, is brought on by exertion or emotion, and is relieved with rest or nitroglycerin. The classic picture is crushing substernal chest pain, radiating to the left neck, jaw, or arm, and a sensation similar to gastroesophageal reflux. Up to one third of patients are asymptomatic or have other symptoms, such as dyspnea, syncope, diaphoresis, weakness, nausea, and vomiting. This atypical presentation is more common in patients who are diabetic, female, elderly, or postoperative.
Diagnosis of CAD relies on findings obtained primarily from electrocardiographic studies. One or more of the following diagnostic studies may be ordered: electrocardiogram, exercise stress test, echocardiography, Holter monitoring, and cardiac catheterization. In patients with unstable angina, the diagnostic workup needs to exclude a myocardial infarction; these patients should be stabilized with medical management prior to undergoing stress testing or catheterized initially. (Additional information about cardiac evaluation of at-risk patients appears in Chapter 23.)
Patients should be educated about risk factors for CAD and actions they can take to decrease their risk of disease. Smoking cessation is paramount; patients often require assistance in identifying options and methods that will increase their chances of quitting successfully. Blood pressure control is likewise crucial, and measures aimed at reaching a goal of less than 130/60 mm Hg may include use of pharmacologic agents, if necessary (see Hypertension, earlier). Hyperlipidemia should be addressed with lifestyle modifications, including regular exercise and decreased intake of saturated fat and cholesterol. Medications such as HMG-CoA reductase inhibitors (statins) may be prescribed to help to reduce LDL level (see Hyperlipidemia, earlier).
Treatment involves risk-factor modification for all patients with CAD, as previously discussed. Medical therapy for patients with stable angina includes aspirin, as it decreases morbidity and reduces the risk of a myocardial infarction. β Blockers decrease cardiac workload and have been shown to reduce the frequency of coronary events. Nitrates reduce preload through generalized vasodilation and also offer the benefit of symptom relief. Revascularization may be preferred in high-risk patients.
Patients with unstable angina should be admitted to the hospital for continuous cardiac monitoring. Aggressive medical management is warranted, as well as oxygen therapy and pain relief with nitrates and morphine. (See Chapter 23 for further details.)
The exercise prescription for a patient with CAD needs to address type, intensity, duration, and frequency of exercise. There should be a particular emphasis on aerobic, isotonic exercises that involve larger muscle groups. Some patients with CAD, including those with congestive heart failure, severe valvular disease, and uncontrolled arrhythmias, should avoid resistive and isometric exercises. It is common to use a target heart rate to assess exercise intensity. For detailed discussion of exercise in a post–myocardial infarction patient, refer to Chapter 23 on cardiac rehabilitation.
PULMONARY DISORDERS
ESSENTIALS OF DIAGNOSIS
Cessation of airflow for > 10 seconds during sleep.
Oxygen saturation usually decreases by > 4% during the apneic episodes.
Diagnosis is confirmed by polysomnography.
Sleep apnea is defined as a cessation of airflow for greater than 10 seconds during sleep. It becomes clinically significant at 10–15 episodes per hour, and in severe cases patients may have more than 40 episodes per hour. Oxygen saturation usually decreases by more than 4% during the apneic episodes. Two classes of sleep apnea are differentiated: central and obstructive.
Diagnosis is confirmed by polysomnography (sleep study). Presence or absence of inspiratory effort during the apneic episode differentiates between obstructive and central apnea. Oxygen desaturation of less than 85% or a change of greater than 4% are significant. The frequency of hypoxic apneic episodes determines the severity of the disease.
Obstructive sleep apnea (OSA) occurs despite continuing ventilatory effort. The obstructive episode is usually followed by a loud snore. Patients have daytime hypersomnolence, snoring, and may have headaches, recent weight gain, and hypertension. OSA is frequently associated with an abnormal airway, myxedema, and obesity.
Treatment of persistent and significant OSA involves either nasal continuous positive airway pressure (nCPAP) or bilevel positive airway pressure (BiPAP). With nCPAP, air at constant pressure (5–15 mm H2O) is supplied by means of a well-sealed nose mask. This acts like a “splint” to the pharynx to keep it open at night and is a very effective measure to prevent nocturnal hypoxemia. BiPAP is similar but can be used with a nasal or full-face mask and allows independent adjustment for inspiratory and expiratory pressures. This improves comfort and compliance.
Mild to moderate OSA can be successfully treated with weight loss; avoidance of alcohol, sedatives, and hypnotics; and not sleeping in the supine position. Nasal and intraoral patency devices may also be helpful. For moderate OSA, treatments include uvulopalatopharyngoplasty, nCPAP, BiPAP, or a combination of these measures.
CSA occurs in less than 5% of sleep apnea patients. Although usually observed in neurologically impaired patients (eg, those with Cheyne–Stokes breathing), it frequently is seen in healthy patients at high altitudes for the first time and in patients suffering from congestive heart failure. Treatment mainly involves avoidance of central nervous system depressants such as alcohol, sedatives, and hypnotics. Weight loss and avoidance of sleep deprivation are also helpful.
ESSENTIALS OF DIAGNOSIS
A group of diseases that includes emphysema, chronic bronchitis, and peripheral airway disease.
Primary cause is long-term exposure to inhaled lung irritants, especially cigarette smoke.
Lack of abnormal lung fibrosis is a distinguishing feature (in contrast to interstitial airway disease).
Chest radiographs are preferable to spirometry for diagnosis of exacerbations.
Chronic obstructive pulmonary disease (COPD) is a progressive disease that usually involves components of emphysema and chronic bronchitis, often with predominance of one or the other condition. Peripheral airway disease, previously considered a distinct entity, is now thought to represent an early form of emphysema or early chronic bronchitis, and hence is encompassed within this group as well. In COPD, there is no abnormal fibrosis in the lung, a finding that distinguishes COPD from interstitial lung disease. COPD is usually treated with bronchodilators and anticholinergics.
