Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Chronic Obstructive Pulmonary Disease


Related Terms

  • Asthma
  • CAO
  • Chronic Airway Obstruction
  • Chronic Bronchitis
  • Chronic Obstructive Lung Disease
  • COPD
  • Emphysema

Differential Diagnosis

Specialists

  • Internal Medicine Physician
  • Pulmonologist

Comorbid Conditions

  • Allergies
  • Asthma
  • Heart disease
  • Poor nutrition

Factors Influencing Duration

Factors include type of COPD, severity of the underlying disease when treatment began, severity of COPD exacerbation, individual's compliance with treatment protocols, age of the individual, existence of other chronic medical conditions or complications, frequency of flare-ups, and individual's working and living environments. Exposure to secondhand smoke, occupational exposure to irritants, air pollution levels, and physical condition may all influence disability and the ability to recover.

Disability duration will be determined by the specific diagnosis. Disability is more likely to occur with acute exacerbations.

Medical Codes

ICD-9-CM:
496 - Chronic Airway Obstruction, Not Elsewhere Classified; Chronic Nonspecific Lung Disease; Chronic Obstructive Lung Disease; Chronic Obstructive Pulmonary Disease [COPD] NOS

Overview

Chronic obstructive pulmonary disease (COPD) is defined by the guidelines of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) as a chronic disease characterized by airway/alveolar/systemic inflammation with measured airflow obstruction that is partially reversible with bronchodilator therapy (Fromer 1219). COPD includes two main components: chronic bronchitis, a partially reversible component, and emphysema with fibrosis, which together are an irreversible component. Chronic bronchitis and emphysema often occur together and overlap, resulting in chronic inflammation, airflow limitations, and tissue damage.

Chronic obstructive bronchitis is the most prevalent COPD; about 10% of individuals with COPD have emphysema (Doherty). COPD due to chronic bronchitis is characterized by enlarged, inflamed mucus glands that block the airways (bronchi and bronchioles) with excessive mucus, resulting in a frequent, productive cough. COPD secondary to emphysema is caused by damaged lung capillaries and the destruction of the air sacs at the ends of bronchioles (lung alveoli) where oxygen exchange occurs, resulting in shortness of breath and an infrequent, nonproductive cough. Asthma, although not considered a true form of COPD, is another obstructive pulmonary disease in which chronically inflamed airways become sensitized to certain triggers (pollution, smoke, stress, exertion, allergens), resulting in an accumulation of exudative debris that temporarily blocks airflow. The inflammation and muscle spasm (bronchospasm) that occur with asthma are reversible, however.

Airway obstruction from COPD is progressive, but respiratory limitations once considered by clinicians to be irreversible are now believed to be partially reversible, although not to normal airflow status. Due to the similarity of COPD and asthma symptoms, certain individuals with COPD may be able to partially reverse airway obstruction with medication that opens constricted airways (bronchodilators), similar to that used by asthmatics. Conversely, those with asthma may develop true COPD if repeated airway inflammation leads to scarring and permanent airway constriction.

The most common cause of COPD is inhalation of tobacco smoke and other noxious chemicals, particles, or gases. Another well-established but rare cause of COPD is the deficiency of a liver protein called alpha-1 antitrypsin (AAT). AAT deficiency is an inherited disorder that accounts for less than 5% of COPD in the United States ("Chronic"). Normal lung function depends on elastic fibers surrounding the airways and within the walls of lung alveoli where gas exchange takes place. These elastic fibers are composed of a protein called elastin. In normal individuals, AAT protects lung elastin from breakdown by the enzyme elastase, which typically functions to digest and remove old or damaged cells from the lung. With AAT deficiency, liver does not release enough AAT, and the AAT released is abnormal, which may allow elastase to destroy lung tissues.

Incidence and Prevalence: The Centers for Disease Control and Prevention report that COPD affects about 10 million adults who self-report the diagnosis, and that 24 million have lung disease that may actually be COPD but has not been diagnosed by a physician (Doherty). Among these, 120,000 deaths due to COPD are recorded annually; it is the fourth leading cause of death in the United States (Doherty). In 2001, of 12.1 million COPD patients, approximately 9.2 million individuals had chronic bronchitis, 2 million had emphysema, and 0.9 million had both conditions (Doherty). Between 50,000 and 100,000 Americans have chronic lung disease due to AAT deficiency (“Chronic”). It is believed that COPD incidence may be significantly underestimated because not all individuals who have abnormal spirometry results are diagnosed with COPD. The prevalence of COPD has increased, and among the top 5 causes of death in the United States, COPD is the only disease whose mortality rate has increased (Doherty).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Smoking is the most significant risk factor for COPD. Although not all cigarette smokers develop COPD, an estimated 15% to 20% will develop it rapidly, and up to 70% to 90% will ultimately be diagnosed with COPD (Doherty). Smokers experience more frequent respiratory symptoms such as coughing and shortness of breath, and more deterioration in lung function than nonsmokers or ex-smokers. The effects of passive smoking or secondhand smoke on the lungs are not well quantified, but inhalation of tobacco smoke increases the risk. Smoking is responsible for up to 90% of COPD in the United States (“Chronic”).

Inhalation of other noxious substances, particles, or gases is also a major risk factor. Air pollution can result in airway inflammation and respiratory limitations in individuals with lung disease, but it is unclear whether air pollution alone contributes to the development of COPD. Some occupational pollutants, such as cadmium and silica, do increase the risk of developing COPD. Individuals at risk for this type of occupational pollution include coal miners, construction workers, metal workers, and cotton workers. Exposure to occupational pollutants is responsible for 19% of COPD cases (“Chronic”).

Although COPD is often thought of as a disease of elderly adults, the mean age at which a first cigarette is smoked (less than 10 years of age) has lowered the age of COPD diagnosis. A 20-year history of smoking could therefore be reached by age 30, placing even younger adults age 30 to 40 at risk (Doherty). Females have nearly twice the rate of chronic bronchitis as males, with 7.5 million females and 3.7 million males affected (Doherty). Conversely, among individuals with emphysema, 57% are male, and 43% are female (Doherty). The incidence of and deaths from emphysema are increasing among women, which is believed to be due to the greater susceptibility of women to tobacco smoke and to an increase in the number of female smokers in response to peer pressure and the idea that stopping smoking may result in weight gain or depression (Doherty).

Source: Medical Disability Advisor



Diagnosis

History: Individuals with COPD present with a combination of signs and symptoms of chronic bronchitis, emphysema, and asthma. Symptoms may include chronic cough, excess sputum production, worsening shortness of breath (dyspnea) with exertion, wheezing, and a history of frequent colds or acute bronchitis. A history of smoking tobacco is often reported when respiratory symptoms of COPD are present. Some individuals may report regular exposure to airborne irritants such as dust, particles, and gases.

Physical exam: The evaluation for individuals with emphysema usually reveals a chest resembling the shape of a barrel (barrel chest), rapid and labored breathing, rapid heart rate (tachycardia), and normal skin color. Breath sounds are faint. Individuals with chronic bronchitis have less distressed breathing, but the skin may appear blue. Unique breath sounds with a musical-type pitch (rhonchi) indicate secretions or inflammation in the airways.

Tests: Chronic obstructive pulmonary disease is specifically diagnosed by pulmonary function tests (PFTs). Simple measurement of airflow (spirometry) can be done in the doctor's office to confirm COPD. The diagnosis, classification of severity, prognosis, and guidance of treatment are determined by a complete PFT done in a standardized PFT laboratory, including forced expiratory volume (FEV) and forced vital capacity (FVC). Blood gas analysis (oxygen, carbon dioxide) is another indicator of severity of disease. Serum chemistries and a complete blood count (CBC) may also be performed. A chest x-ray can also provide information on the severity of COPD and help rule out other conditions such as pneumonia or lung cancer.

Source: Medical Disability Advisor



Treatment

The general treatment goals for COPD are to optimize lung function, maintain airflow, slow down or stop disease progression, prevent acute flare-ups and complications, and maintain quality of life. The use of bronchodilator medications is the foundation of treatment, specifically long-acting ß2 agonists that offer improvement in lung function. Inhaled drugs are preferred because they work more quickly to open the airways. Anticholinergic drugs that relax the smooth muscle in the airways may also be given, and sometimes inhaled corticosteroids are used to control the inflammatory process. Combination therapies are sometimes employed when their different effects may lead to greater improvement in lung function. Specific treatments also include smoking cessation, antibiotics, supplemental oxygen, and pulmonary rehabilitation. Certain treatments may be long term, and others may be added only during acute episodes.

Exacerbations are usually caused by infective organisms, and treatment involves antibiotic therapy (Wise).

Acute exacerbations may require immediate intervention, either through outpatient medical treatment or hospitalization.

Some individuals with advanced COPD may be candidates for surgical removal (wedge resection) of large bubble-like structures (bullae) in the lung, lung volume reduction surgery, or lung transplantation.

Source: Medical Disability Advisor



Prognosis

If smoking is stopped during the early stages of COPD, some of the damaged small airways may return to normal, improving the prognosis even though lost lung function may not be fully recovered. Individuals with mild COPD treated early may be free of disability. Individuals with severe COPD will continue to have progressively deteriorating lung function despite treatment and usually become permanently disabled. Individuals with COPD who continue to smoke have higher death rates than those who quit the habit (Doherty). Individuals who smoke are 10 times more likely to die from COPD than nonsmokers (Doherty).

The individual's age and postbronchodilator forced expiratory volume in 1 second (FEV1) are the most important predictors of prognosis. Young individuals and those with an FEV1 greater than 50% have a better prognosis (Doherty). Older individuals and those with more advanced lung disease are subject to exacerbations and have a poor prognosis; the mortality rates for hospitalized patients with exacerbations of COPD is 2.5%; it is 25% in patients requiring intensive care (Wise). Supplemental oxygen (when indicated) has been shown to increase survival (Wise). Increase in size (hypertrophy) of the right ventricle in the heart (cor pulmonale), abnormally increased arterial carbon dioxide tension (hypercapnia), rapid heartbeat (tachycardia), and malnutrition are associated with a poor prognosis.

Source: Medical Disability Advisor



Rehabilitation

Pulmonary rehabilitation combines exercise training with behavioral and educational programs designed to help individuals with COPD control symptoms and improve day-to-day activities. It involves a team approach, with individuals working closely with their doctors; nurses; respiratory, physical, and occupational therapists; psychologists; exercise specialists; and dietitians. The main goals of pulmonary rehabilitation are to help individuals improve their day-to-day lives and restore their ability to function independently. Pulmonary rehabilitation can help reduce the number and length of hospital stays and increase the chances of living longer. Pulmonary rehabilitation involves exercise training of the lower body, the upper body, and ventilatory muscle training. It also includes psychosocial support and educational programs.

Since smoking is well known to be the primary risk factor for the onset and progression of COPD, many pulmonary rehabilitation programs provide educational sessions and counseling to help individuals stop smoking.

Source: Medical Disability Advisor



Complications

The two most serious complications of COPD are right-sided heart failure (cor pulmonale) and respiratory failure. If the impairment is severe enough, the individual may succumb to respiratory failure. Individuals with COPD are often able to recover from their first few episodes of respiratory failure. However, increasing frequency of respiratory failure episodes is a sign of the last stages of this chronic disease.

Some individuals with COPD develop single or multiple, large, irregular-shaped air spaces in the lungs, called bullae. These bullae can be large enough to compromise unaffected portions of the lung by crowding and compressing them. They can also break, causing an accumulation of air in the chest cavity (pneumothorax) that further compromises pulmonary function. Increased blood pressure in the lung (pulmonary hypertension) and malnutrition are sometimes complications of COPD.

Decreased bone mineralization and increased fracture risk are linked to COPD; individuals with COPD are at increased risk of developing osteopenia and osteoporosis (Doherty).

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Individuals with COPD should avoid inhaled irritants in the workplace, such as gases, fumes, and dust. Very cold or hot air temperatures should also be avoided. Work at higher altitudes may be discouraged with moderate or severe COPD. Tolerance for physical exertion may be limited with COPD. If individuals with an asthmatic component to their COPD have an acute attack while working, they should be given time to take inhaled medication and rest, and then be evaluated for their ability to continue working.

Source: Medical Disability Advisor



Failure to Recover

If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case.

Regarding diagnosis:

  • Does individual have a history of smoking? If so, how much has individual smoked and for how long?
  • Was individual exposed to noxious substances, particles, or gases, especially cadmium or silica, while engaged in coal mining, construction work, or metal or cotton work?
  • Does individual have a deficiency of the protein alpha-1 antitrypsin (AAT)?
  • Does individual complain of shortness of breath (dyspnea) with exertion, progressive exercise limitation, or alteration in mental status? Is there coughing, wheezing, or excessive mucus production?
  • Does individual have a barrel-shaped chest?
  • Were pulmonary function tests (PFTs) and/or spirometry done? Were arterial blood gases (ABGs), blood chemistries, and a complete blood count (CBC) performed? Was a chest x-ray obtained? What did all test results reveal?
  • Was diagnosis of COPD confirmed?

Regarding treatment:

  • Has individual completely stopped smoking? If not, was individual urged to participate in a smoking cessation program?
  • Has individual participated in a pulmonary rehabilitation program?
  • Were bronchodilators, antibiotics, supplemental oxygen, and corticosteroids administered, as needed?
  • Is individual compliant with the medication regimen?
  • Is individual a candidate for surgical removal (wedge resection) of large bubble-like structures (bullae) in the lungs?
  • Is individual a candidate for lung resection surgery or transplantation? Would individual benefit from consultation with a specialist (transplant surgeon)?

Regarding prognosis:

  • How advanced is the disease?
  • Has individual completely stopped smoking? Was smoking stopped and treatment begun during the early stages of COPD?
  • Is individual's postbronchodilator forced expiratory volume in 1 second (FEV1) better, worse, or the same?
  • Has individual developed right-sided heart failure (cor pulmonale), abnormally increased arterial carbon dioxide tension (hypercapnia), malnutrition, or respiratory failure?
  • Is this the first episode of respiratory failure, or is it a recurrence, suggesting late-stage disease?
  • Has pneumothorax occurred, further compromising pulmonary function? How severely is pulmonary function compromised? How will this affect the ability of individual to function?
  • Has individual developed increased blood pressure in the lung (pulmonary hypertension)?

Source: Medical Disability Advisor



References

Cited

"Chronic Obstructive Pulmonary Disease (COPD) Fact Sheet." American Lung Association. Jun. 2009. 29 Jul. 2009 <http://www.lungusa.org/site/apps/nlnet/content3.aspx?c=dvLUK9O0E&b=2058829&content_id={EE451F66-996B-4C23-874D-BF66586196FF}¬oc=1>.

Doherty, Dennis E., and Dick D. Briggs. "Chronic Obstructive Pulmonary Disease: Epidemiology, Pathogenesis, Disease Course, and Prognosis." Clinical Cornerstone 6 Suppl. 2 (2004): S5-16. MD Consult. Elsevier, Inc. 23 Jun. 2009 <www.mdconsult.com/das/article/body/145796129-3/html>.

Fromer, L., and C. B. Cooper. "A Review of the GOLD Guidelines for the Diagnosis and Treatment of Patients with COPD." International Journal of Clinical Practice 62 8 (2008): 1219-1236. PubMed. 23 Jun. 2009 <PMID: 18547365>.

Wise, Robert A., and Donald P. Tashkin. "Optimizing Treatment of Chronic Obstructive Pulmonary Disease: An Assessment of Current Therapies." American Journal of Medicine 120 8A (2007): S4-13. MD Consult. Elsevier, Inc. 27 Feb. 2014 <www.mdconsult.com/das/article/body/145796129-3/html>.

Source: Medical Disability Advisor






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