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
  • 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 common preventable and treatable disease, characterized by persistent airflow limitation that is usually progressive and associated with an enhanced chronic inflammatory response in the airways and the lung to noxious particles or gases (Vestbo). COPD includes two main components: chronic bronchitis, which is 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.

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 (dyspnea) and an infrequent, nonproductive cough. Asthma, although not considered a form of COPD, is an obstructive pulmonary disease in which chronically inflamed airways become sensitized to certain triggers (allergens, pollution, smoke, stress, exertion), resulting in an accumulation of exudative debris that temporarily blocks airflow. The inflammation and muscle spasm (bronchospasm) that occur with asthma are reversible.

Airway obstruction from COPD is progressive and not fully reversible. 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, followed much less commonly by 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 2 to 3% of COPD in the United States ("ATS"). 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, the 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 about 15 million American adults self-report a diagnosis of COPD (CDC "What"). This is thought to be an underestimate because over 60% of individuals who have abnormal spirometry results are not diagnosed with COPD even though they meet the criteria. COPD is the third leading cause of death in the United States (ALA). In 20710, death rates for COPD were 47.6 per 100,000 population for men and 36.4 per 100,000 for women (CDC "Data". Between 1999 and 2010, COPD mortality rates have decreased for men and remained steady for women (CDC "Data").

Source: Medical Disability Advisor



Causation and Known Risk Factors

Smoking is the most significant risk factor for COPD. Inhalation of other noxious substances, particles, or gases is also an important 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 occupational dusts and chemicals, do increase the risk of developing COPD (Vestbo). Individuals at risk for this type of occupational pollution include coal miners, construction workers, metalworkers, and cotton processing workers. Other risk factors include age and exposure to second-hand smoke, heredity, a history of childhood respiratory infections, and socioeconomic status. Particulate matter from cigarette smoke and indoor air pollution, including smoke from poorly ventilated wood stoves and the burning of biomass, are related to lung damage (Vestbo).

In one study the fraction of COPD attributable to exposure to occupational pollutants was estimated as 19.2% overall and 31.1% among nonsmokers (Hnizdo).

Source: Medical Disability Advisor



Diagnosis

History: Symptoms may include chronic cough, chronic excess sputum production, worsening dyspnea with exertion, wheezing, and a history of frequent colds or acute bronchitis. A history of exposure to tobacco smoke is often reported when respiratory symptoms of COPD are present. Some individuals may report regular occupational exposure to airborne irritants such as dust, chemicals, 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 (cyanosis). 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 (PFT). 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 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 (Forey). Approximately 85 to 90 percent of COPD deaths are caused by smoking. Female smokers are nearly 13 times as likely to die from COPD compared to women who have never smoked. Male smokers are nearly 12 times as likely to die from COPD compared to men who have never smoked. (Surgeon General).

Traditionally, the individual's age and postbronchodilator forced expiratory volume in 1 second (FEV1) have served as the most important predictors of prognosis. Young individuals and those with an FEV1 greater than 50% were thought to have a better prognosis. A recent study found that in stable COPD patients carbon monoxide transfer factor (TLCO) % predicted, PaO2 and younger age were the only variables associated with survival (Boutou 2013). Staging according to the GOLD criteria, other lung function measures, body measures, and exacerbation history did not add any information to the prediction model. 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 end 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), infections, 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 (Surgeon General).

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.

For more information on risk, capacity, an tolerance, refer to "Work Ability and Return to Work," pages 302, 305-306.

Source: Medical Disability Advisor



Maximum Medical Improvement

90 days.

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 an inherited deficiency of the protein alpha-1 antitrypsin (AAT)?
  • Does individual complain of 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 inhaled corticosteroids administered, as needed?
  • Is individual compliant with the medication regimen?
  • Is individual a candidate for wedge resection of bullae in the lungs?
  • Is individual a candidate for lung resection surgery or transplantation? Would individual benefit from consultation with a 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 cor pulmonale, 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

The Health Consequences of Smoking: A Report of the Surgeon General. Centers for Disease Control and Prevention, 2004.

American Lung Association. "Chronic Obstructive Pulmonary Disease (COPD) Fact Sheet." American Lung Association. May. 2014. 6 May 2014 <http://www.lung.org/lung-disease/copd/resources/facts-figures/COPD-Fact-Sheet.html>.

American Thoracic Society. "Standards for the Diagnosis and Management of Individuals with Alpha-1 Antitrypsin Deficiency." American Journal of Respiratory and Critical Care Medicine 168 (2003): 818-900.

Boutou, A. K. , et al. "Lung Function Indices for Predicting Mortality in Chronic Obstructive Pulmonary Disease." European Respiratory Journal 42 3 (2013): 616-625.

Centers for Disease Control and Prevention. "Chronic Obstructive Pulmonary Disease: Data and Statistics." CDC. 1 May. 2014. Centers for Disease Control and Prevention. 6 May 2014 <http://www.cdc.gov/copd/data.htm>.

Centers for Disease Control and Prevention. "What is COPD?" CDC. 13 Nov. 2013. Centers for Disease Control and Prevention. 6 May 2014 <http://www.cdc.gov/copd/index.htm>.

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.

Forey, B. A. , A. J. Thornton, and P. N. Lee. "Systematic Review with Meta-Analysis of the Epidemiological Evidence Relating Smoking to COPD, Chronic Bronchitis and Emphysema." BMC Pulmonary Medicine 11 36 (2011): None-None.

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. 6 May 2014 <PMID: 18547365>.

Hnizdo, E. , et al. "Association between Chronic Obstructive Pulmonary Disease and Employment by Industry and Occupation in the US Population." American Journal of Epidemiology 156 (2002): 738-746.

Talmage, J. B. , J. M. Melhorn, and M. H. Hyman, eds. Work Ability and Return to Work, AMA Guides to the Evaluation of. Second ed. Chicago: AMA Press, 2011.

Vestbo, J. , S. S. Hurd, and R. Rodriquez-Roisin. "The 2011 Revision of the Global Strategy for the Diagnosis, Management and Prevention of COPD (Gold)--Why and What?" Clinical Respiratory Journal 6 (2012): 208-214.

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. American Journal of Medicine. Aug. 2007. Elsevier, Inc. 6 May 2014 <http://www.amjmed.com/article/S0002-9343(07)00403-2/abstract>.

Source: Medical Disability Advisor






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