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.

Shock


Related Terms

  • Anaphylactic Shock
  • Cardiogenic Shock
  • Circulatory Collapse
  • Hypovolemic Shock
  • Septic Shock
  • Toxic Shock Syndrome
  • Vascular Collapse

Differential Diagnosis

  • Anaphylactic shock
  • Cardiogenic shock
  • Hypovolemic shock
  • Neurogenic shock
  • Septic shock

Specialists

  • Critical Care Internist
  • Critical Care Surgeon
  • Emergency Medicine Physician
  • General Surgeon
  • Internal Medicine Physician

Comorbid Conditions

Factors Influencing Duration

Factors that might influence disability include advanced age, any underlying conditions, duration and severity of the shock, and response to treatment interventions. Duration depends on cause and treatment.

Medical Codes

ICD-9-CM:
785.50 - Shock; Unspecified, Failure of Peripheral Circulation
785.52 - Septic Shock; Endotoxic; Gram-negative
785.59 - Shock without Mention of Trauma; Other; Shock: Hypovolemic
995.0 - Other Anaphylactic Reaction

Overview

Shock is a condition in which the blood pressure is inadequate to deliver oxygenated blood to vital organs (brain, heart, lungs, kidneys, and liver). The amount of blood flowing to the organs and their tissues is inadequate to meet the demand of the organs and tissues for oxygen. When shock persists, impaired organ function is followed by irreversible cell damage and death.

Shock may be caused by any condition that dangerously reduces blood flow, including heart problems such as heart attack or heart failure (cardiogenic shock), changes in blood vessels, decreased blood volume (hypovolemic shock), and injuries. Related factors include bleeding, vomiting, diarrhea, inadequate fluid intake, diabetes (hyperglycemic hyperosmolar shock), allergic reactions (anaphylactic shock), and spinal cord injury (neurogenic shock caused by damage to the nervous system). In contrast, overwhelming infection (such as septic shock or toxic shock syndrome) is associated with increased blood flow.

While the overall effect (lack of oxygen to tissues and organs) is the same in each of these conditions, the underlying cause and treatment varies. Consequently, shock is categorized according to the underlying pathology, following three broad classifications. Hypovolemic shock is caused by a reduction in the volume of blood, cardiogenic shock results from a decline in cardiac output that occurs as a result of serious heart disease, and distributive shock is caused by poor distribution of blood flow as a result of enlargement (vasodilation) of the veins.

In general, shock occurs when the blood pressure drops below the critical level needed for organ perfusion (usually a mean blood pressure of 60mmHg). However, the exact degree of systemic hypotension necessary to cause shock varies and often is related to pre-existing vascular disease. For example, a modest degree of hypotension may be well tolerated by a young, relatively healthy person, yet cause severe cerebral, cardiac, or renal dysfunction in an older individual with significant arteriosclerosis.

As a result of inadequate perfusion to the brain, heart, lungs, kidney, and other organs and tissues, sudden physical symptoms develop. The most obvious clinical manifestations of shock include mental status changes, changes in blood pressure and heart rate, development of chest pain, shortness of breath and rapid respiratory rate, decreased urine output, and cool, pale, moist skin.

Despite advances in medicine and medical technology, mortality from most forms of shock is significant.

Individuals with diabetes mellitus, malnutrition, cancer, or alcoholism are at increased risk for developing septic shock. Menstruating women who use hyperabsorbent tampons are at increased risk for toxic shock syndrome.

Incidence and Prevalence: Incidence of cardiogenic shock in the US for individuals with acute myocardial infarction is 5% to 10% (Goldberg; Hostetler). European incidence of cardiogenic shock following acute myocardial infarction is 7% (Sharma). Sepsis accounts for 2% to 3% of all US hospital admissions. Incidence of septic shock is 500 per 100,000 Americans per year (Neeley), and is increasing at a rate of 1.5% per year (Balk). Incidence of fatalities due to anaphylactic shock following allergy injections is 1 per 2,540,000 (Bernstein). International incidence of anaphylactic shock among hospitalized individuals is 1 per 5,100 (Neeley). The US incidence rate of toxic shock syndrome is 10 to 20 per 100,000 (Salandy); 77% to 93% of cases occur in menstruating women (Tolan).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Cardiogenic shock is more common among older females. Non-white males appear to have an increased risk for developing septic shock.

Source: Medical Disability Advisor



Diagnosis

History: If the individual is alert, he or she will usually complain of being dizzy or "lightheaded." Individuals may report that they "blacked out." Witnesses or family members may provide additional information. They may report circumstances that preceded the individual's loss of consciousness, such as chest pain, injury with significant bleeding, vomiting, high fever, or allergic-type reaction.

Physical exam: The physical examination may reveal symptoms and signs due to shock itself or to the underlying disease process. While thought processes may be preserved, lethargy, confusion, and drowsiness are common. Individuals usually present with cold, moist, and often mottled-blue color (cyanotic) or pale hands and feet. The pulse is usually weak and rapid. However, a slow pulse may occur if there is an underlying heart rhythm disturbance (heart block) or if the shock is at a terminal stage (terminal bradycardia). Sometimes, only femoral or carotid pulses can be felt. A rapid respiratory rate is common in acute shock. In the terminal stage of shock, however, the respiratory center may fail due to inadequate blood flow to the brain (cerebral hypoperfusion) and respirations may cease (apnea). Blood pressure taken by cuff tends to be low (less than 90 mm Hg systolic) or unobtainable, or may decrease further if the individual attempts to stand up (orthostatic hypotension). Fever or low body temperature, and chills may be present in shock due to overwhelming infection (septic shock). Signs of blood loss or fluid loss, such as vomiting, may be associated with hypovolemic shock.

Tests: Tests include electrocardiogram (ECG), blood tests and cultures, urine studies, and prothrombin time. Other x-rays and diagnostic tests may be ordered as appropriate for the underlying cause. For example, a trauma victim with evidence of head, chest, abdominal, or extremity injury will need further x-rays and diagnostic tests. If heart failure is suspected, an echocardiogram and angiography with heart catheterization may be needed.

Source: Medical Disability Advisor



Treatment

Prompt, aggressive treatment, including resuscitation, is paramount to restoring the blood pressure and preventing organ damage or death. Initial treatment should begin at the site of the incident or on arrival of the victim to the emergency department. This involves ensuring the adequacy of airway and breathing, and controlling any obvious bleeding. The individual is kept warm, with the legs raised slightly to help maintain blood flow to the head and heart (Trendelenburg position), unless the shock is caused by congestive heart failure, in which case the head should be elevated. Fluids should not be given by mouth, although a conscious diabetic suspected to be in insulin shock may be given concentrated sugar in paste form or as sugar-sweetened liquid.

Supplemental oxygen by facemask is provided immediately. If severe shock is present or respirations are inadequate, an artificial airway (endotracheal tube) is inserted to begin assisted ventilation. One or more large (16 to 18 gauge) intravenous lines are inserted in large veins (femoral, internal jugular, subclavian, or antecubital) to infuse blood or other fluids and to administer any necessary medications. This is especially needed if bleeding (hemorrhage) is suspected.

Sedatives and pain relievers (narcotics) are generally avoided, but severe pain, such as chest pain associated with a heart attack, may be treated with morphine. Treatment may vary based on the underlying cause of the shock, such as treating the allergic reaction in anaphylactic shock, or using antibiotics in septic shock or toxic shock syndrome. However, all shock victims require intensive-care monitoring with continuous ECG and frequent assessment of blood pressure, respiratory rate and depth, urine flow (usually by indwelling bladder catheter), neurological status, body temperature, and oxygenation. A catheter may be placed through the superior vena cava into the right atrium (central venous pressure catheter) or into the pulmonary artery (pulmonary artery catheter) to continuously measure the pressure in the heart and lungs. This is usually indicated for those with shock of uncertain or mixed cause, or for those with severe shock. This serves to guide fluid administration and use of resuscitative medications (inotropes and vasoactive drugs). A pacemaker may be needed in cardiogenic shock, or other assistive devices may help decrease the workload on the heart, such as intra-aortic balloon counterpulsation or ventricular assist device.

Source: Medical Disability Advisor



Prognosis

All forms of shock carry a high-risk of fatality if there is a delay in treatment or if the shock has progressed to an advanced state. In general, mortality rates range from about 35% to 50% in septic shock to as high as 70% to 90% in cardiogenic shock (Neeley; Hostetler). Outcomes are best in those who do not have comorbid conditions, such as advanced age, heart disease, or immune system compromise, and who are treated appropriately in the very early stages of shock.

Source: Medical Disability Advisor



Rehabilitation

As shock is a life-threatening condition, rehabilitation is not appropriate until the condition is stabilized. At that point, the nature of appropriate rehabilitation varies depending on residual deficits.

Source: Medical Disability Advisor



Complications

Shock may be associated with several complications, including lack of oxygen to the brain (cerebral ischemia) causing brain damage, heart attack, respiratory failure (adult respiratory distress syndrome), bleeding disorders (disseminated intravascular coagulation), kidney (renal) failure, multiple organ failure (multisystem organ failure), and death.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Due to the variable nature of the disorder, work restriction and accommodations are made on an individual basis according to the type and extent of residual disability. As shock is a life-threatening condition, individuals are hospitalized for treatment, and therefore cannot work until they are stabilized and discharged. Survivors may be permanently disabled.

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:

  • Has underlying cause of shock been determined?
  • Has individual been evaluated for underlying heart failure or infection?
  • Is there bleeding, vomiting, diarrhea, inadequate fluid intake, allergic reaction (anaphylactic shock), diabetes (hyperglycemic hyperosmolar shock), or spinal cord injury (neurogenic shock) caused by damage to the nervous system?
  • Has individual experienced complications as a result of shock, such as lack of oxygen to the brain causing brain damage, heart attack, respiratory failure, disseminated intravascular coagulation, renal failure, or multiple organ failure?
  • Does individual have an underlying condition that may impact recovery?

Regarding treatment:

  • Is individual responding to treatment (antibiotics, fluids or blood, insulin or blood sugar monitoring, cardiac assistive devices)?
  • Were any complications associated with the central venous pressure catheter or pulmonary artery catheter used to monitor or provide fluids and medications?
  • Were these measures effective in restoration and support of blood pressure?

Regarding prognosis:

  • Was shock state resolved before inadequate circulation led to cell damage, metabolic derangements, or organ failure?
  • Are comorbid conditions present, such as advanced age, heart disease, or immune system compromise?
  • Did individual experience inadequate tissue perfusion as evidenced by altered mental status, low urine output, or accumulation of lactic acid as a result of inadequate tissue circulation?

Source: Medical Disability Advisor



References

Cited

Balk, R. A. "Optimum Treatment of Severe Sepsis and Septic Shock: Evidence in Support of the Recommendations." Disease-A-Month 50 4 (2004): 168-213. MD Consult. Elsevier, Inc. 15 Dec. 2004 <http://home.mdconsult.com/das/journal/view/43285720-2/N/14682720?sid=292899056&source=>.

Bernstein, D. I., et al. "Twelve-Year Survey of Fatal Reactions to Allergen Injections and Skin Testing: 1900-2001." Journal of Allergy and Clinical Immunology 113 6 (2004): 1129-1136. MD Consult. Elsevier, Inc. 15 Dec. 2004 <http://home.mdconsult.com/das/journal/view/43285720-2/N/14790309?sid=292899056&source=MI>.

Goldberg, R. J., et al. "Recent Magnitude of and Temporal Trends (1994-1997) in the Incidence and Hospital Death Rates of Cardiogenic Shock Complicating Acute Myocardial Infarction: The Second National Registry of...." American Heart Journal 141 1 (2001): 65-72. National Center for Biotechnology Information. National Library of Medicine. 15 Dec. 2004 <PMID: 11136488>.

Hostetler, Mark A. "Shock, Cardiogenic." eMedicine. Eds. Daniel J. Dire, et al. 19 Dec. 2004. Medscape. 15 Dec. 2004 <http://emedicine.com/emerg/topic530.htm>.

Neeley, Scott P. "Shock, Distributive." eMedicine. Eds. Cory Franklin, et al. 19 Dec. 2004. Medscape. 15 Dec. 2004 <http://emedicine.com/med/topic2114.htm>.

Salandy, Dane, and Barry Brenner. "Toxic Shock Syndrome." eMedicine. Eds. Theodore Gaeta, et al. 16 Nov. 2004. Medscape. 15 Dec. 2004 <http://emedicine.com/emerg/topic600.htm>.

Sharma, Sat, and Michael E. Zevitz. "Cardiogenic Shock." eMedicine. Eds. Russell F. Kelly, et al. 19 Dec. 2004. Medscape. 15 Dec. 2004 <http://emedicine.com/med/topic285.htm>.

Tolan, Robert W., and Vinod K. Dhawan. "Toxic Shock Syndrome." eMedicine. Eds. David Jaimovich, et al. 29 Oct. 2004. Medscape. 15 Dec. 2004 <http://emedicine.com/ped/topic2269.htm>.

Source: Medical Disability Advisor






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