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.

Aortic Dissection


Related Terms

  • Dissecting Aneurysm
  • Dissecting Hematoma

Differential Diagnosis

Specialists

  • Cardiovascular Internist
  • Pulmonologist
  • Thoracic Surgeon
  • Vascular Surgeon

Comorbid Conditions

Factors Influencing Duration

The individual's age, the extent of surgical repair necessary, the individual's response to surgery and prescribed medications, and the type and severity of symptoms that may not have significantly improved with surgery can influence length of disability.

Medical Codes

ICD-9-CM:
441.00 - Dissection of Aorta, Unspecified Site
441.02 - Dissection of Aorta, Abdominal
441.03 - Dissection of Aorta, Thoracoabdominal

Overview

An aortic dissection is a tear in the inner layer of the aorta (intima) that causes bleeding into and along the wall of the aorta. It can also cause abnormal widening or ballooning of the aorta (aneurysm).

The aorta is the main artery in the body, beginning above the left pumping chamber (ventricle) of the heart (ascending aorta), curving over (aortic arch) and descending down into the chest (descending thoracic aorta) and into the abdomen (abdominal aorta). The aorta is composed of an inner layer (intima), middle layer (media), and outer layer (adventitia).

A dissection of the aorta can occur anywhere along the artery, but the most frequent sites for dissection are the ascending aorta (proximal or type A dissection) and the descending thoracic aorta (distal or type B dissection). A tear in the intima results in blood surging into the media that causes the media to be torn from the adventitia. A false path for blood flow is then formed within the aorta, diminishing the blood flow to any artery fed by the aorta and resulting in failure of the aortic valve to function. If the aorta ruptures due to hemorrhaging into the area around the heart (pericardial cavity) or around the left lung (pleural space), death frequently follows.

Risk factors for aortic dissection include hereditary disorders such as Ehlers-Danlos syndrome, Marfan's syndrome, and pseudoxanthoma elasticum. Other risk factors are cardiac or vascular abnormalities at birth (congenital anomalies), aortic valve disease, high blood pressure (hypertension), pregnancy, atherosclerosis, arteriosclerosis, inflammation of the arteries (arteritis), abdominal aortic aneurysm, and traumatic injury, particularly blunt trauma to the chest (e.g., when the chest hits the steering wheel during a motor vehicle collision). There is also a risk for aortic dissection during cardiovascular surgery.

Incidence and Prevalence: Aortic dissection occurs most commonly in males between the ages of 40 and 70. The prevalence is 2 in 10,000 individuals (Arnaldo).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Individuals who smoke or have a family history of aortic aneurysms are more at risk for the disease.

Source: Medical Disability Advisor



Diagnosis

History: The main symptom associated with an aortic dissection is the sudden onset of very severe, sharp, stabbing, tearing pain, often in the chest, between the shoulder blades, or in the back. The pain may travel to the head, neck, shoulders, arms, jaw, abdomen, hips, and legs as the dissection travels along the aorta. Individuals may also report shortness of breath (dyspnea) and marked difficulty breathing, dizziness and/or fainting, or rapid heart rate (pulse). The individual may report complete or partial inability to move one side of the body (hemiplegia), particularly the lower part of the body, accompanied by decreased sensation.

When rupture or hemorrhaging occurs, effects associated with increased pressure on the surrounding structures such as the lungs, trachea, larynx, esophagus, and spinal nerves may be evident. Hoarseness or loss of voice may be related to compression of the esophagus. Other symptoms can include confusion, disorientation, problems concentrating, anxiety, dry mouth, or nausea and vomiting.

Physical exam: The physician may note profuse sweating, pallor, clammy skin, and an increased pulse rate. Using a stethoscope, a "blowing" sound may be heard in the chest or abdomen and a murmur during rests between heartbeats (diastolic murmur). There may also be intermittent loss of the pulses at the wrist (radial), groin (femoral), inner elbow (brachial), and ankle (pedal). Decreased blood pressure (hypotension) is generally associated with type A dissection, whereas hypertension is often noted with type B dissection.

Tests: An electrocardiogram (ECG) or echocardiogram can determine if an individual is experiencing or has experienced a heart attack. A chest x-ray is taken to note the size of the aorta, determine if fluid has collected in the space around the lungs (pleural effusion), or see if there has been mediastinal widening. A catheter inserted into the aorta from an artery in the arm or leg (aortography) shows where the dissection originated, the extent of the dissection, and the extent of damage done to arteries fed by the aorta.

A procedure for diagnosing aortic dissection that causes no discomfort to the individual uses sound waves to visualize the inside of the chest (transthoracic ultrasonography) or the esophagus (transesophageal ultrasonography). These tests help identify the sections of the aorta that will need surgery. CT and MRI of the chest are also useful diagnostic tests. Blood tests are performed to determine if individual has decreased hemoglobin levels that may indicate blood loss from the aorta. An enzyme analysis is also done to determine if the individual is having a heart attack (creatine kinase).

Source: Medical Disability Advisor



Treatment

Emergency surgery is typically performed on individuals with an aortic dissection. Goals are to stabilize the individual prior to surgery and prevent complications. Stabilization includes intravenous (IV) administration of fluids and medications to lower an elevated blood pressure (antihypertensive) or to maintain blood pressure in a low-to-normal range. Medication is also administered to decrease vessel contraction force, keep the heart rate slow, and relieve pain (narcotic analgesics). Oxygen is administered for breathing problems, and if necessary, blood transfusions may also be required. Cardiac beta-blocking medications may help reduce some symptoms.

Surgical repair of a type A (proximal) dissection is done as quickly as possible. The surgery involves repairing or removing the damaged part of the aorta (aortic resection) and restoring blood flow using a replacement synthetic graft. If there is aortic valve insufficiency, treatment also includes valve repair (commissurotomy) or replacement with a mechanical (prosthesis) or human valve. Valve repair or replacement surgery is similar in magnitude to open-heart surgery. Most individuals with a type A dissection will also need their coronary arteries re-implanted.

Type B (distal) dissection also requires surgery (aortic resection) with synthetic graft replacement if it poses life-threatening complications such as lack of blood flow to the kidneys (resulting in renal failure), the arms or legs (limb ischemia), or other organs of the body, particularly the abdomen (visceral ischemia). Type B also requires aortic resection surgery if the dissection causes blood to leak out of the aorta or if the individual has symptoms of a "ballooning" of the aorta (aneurysm) that could rupture.

Source: Medical Disability Advisor



Prognosis

The mortality rate for aortic dissection is very high, with 75% of individuals who receive no treatment dying within 2 weeks. For those who undergo surgery, mortality is approximately 15% for type A dissections and slightly higher than 15% for type B dissections (Beers).

Individuals who survive surgery and take medications as prescribed have a survival rate of about 40% at 10 years (Beers). Some individuals may live as long as 25 years.

Source: Medical Disability Advisor



Rehabilitation

A gradual increase in physical activity may be accomplished through a hospital-based cardiac rehabilitation program. The amount and type of exercise the individual can tolerate is determined by the doctor. The cardiac rehabilitation specialist then designs a program geared toward the individual's abilities. As the individual progresses, monitoring decreases until the exercise regimen can be completed at home. The individual is instructed to inform the doctor if any change in ability to exercise is noticed.

Source: Medical Disability Advisor



Complications

Possible complications include stroke, partial or complete paralysis, bleeding into the pericardium that causes compression of the heart due to increased pressure in the chest cavity (cardiac tamponade), redissection, aneurysm because of weakened walls, and worsening of aortic valve insufficiency.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Individual tolerance for physical exercise after surgery will dictate the level of physical activity possible. Underlying conditions, effects of surgical repair, or use of postoperative medications may require individual to be reassigned to a position that is not physically demanding.

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 type A or B dissection?
  • Did individual have sudden onset of very severe, sharp, stabbing, tearing pain in the chest, between the shoulder blades, or in the back?
  • Was individual's mental state altered?
  • Does individual have a dry mouth? Nausea and vomiting?
  • Did individual notice hoarseness?
  • Does individual feel anxious?
  • Was ECG or echocardiogram performed? Chest x-ray? Blood tests?
  • Were transthoracic or transesophageal ultrasound, CT, or MRI performed?
  • Does individual have any conditions that may affect the ability to recover?

Regarding treatment:

  • Did individual have emergency surgery?
  • Was aortic valve insufficiency found? Was it repaired?
  • Is individual on permanent medication therapy?

Regarding prognosis:

  • Is individual active in rehabilitation?
  • Is individual's employer able to accommodate any necessary restrictions?
  • Does individual have any conditions that could affect the ability to recover?
  • Did individual have any postoperative complications such as heart attack, stroke, pericardial bleeding, or redissection?

Source: Medical Disability Advisor



References

Cited

Arnaldo, Fabian. "Aortic Dissection." MedlinePlus. National Library of Medicine. 23 Sep. 2004 <http://www.nlm.nih.gov/medlineplus/ency/article/000181.htm>.

Beers, Mark H., and Robert Berkow, eds. "Aortic Dissection." The Merck Manual of Diagnosis and Therapy. 17th ed. Whitehouse Station, NJ: Merck and Company, Inc., 1999. Merck. Merck & Co., Inc. 23 Sep. 2004 <http://www.merck.com/mrkshared/mmanual/sections.jsp>.

Source: Medical Disability Advisor






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