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.

Abscess, Psoas


Related Terms

  • Suppurative Peritonitis

Differential Diagnosis

Specialists

  • General Surgeon
  • Infectious Disease Internist
  • Interventional Radiologist

Comorbid Conditions

  • Immune suppressive disorders
  • Infectious disease
  • Metabolic disorders

Factors Influencing Duration

The type of psoas abscess (primary or secondary) may influence the length of disability. Recovery time from secondary abscess may be more extensive because other tissues and organ systems (usually gastrointestinal) are involved. Older individuals may experience longer disability since their recovery time is usually longer. Type of bacteria causing the psoas infection can also be a factor. Certain microbes (e.g., Enterococcus, mycobacterium tuberculosis, Staphylococcus aureus, Streptococcus pneumoniae) have developed resistance to even the most potent antibiotics. Psoas infection caused by drug-resistant bacteria may influence the length of disability.

Medical Codes

ICD-9-CM:
567.31 - Retroperitoneal Infections, Psoas Muscle Abscess

Overview

Psoas abscess is an infection of the psoas muscle that runs from the middle-lower back region into the pelvis and thighs. The psoas muscle is the most powerful flexor of the thigh. It plays a prominent role in walking, running, kicking, and performing sit-ups. Inflammation, thickening, and retention of pus occur when the membranous sheath surrounding the muscle (psoas fascia) becomes infected with bacteria forming a psoas abscess. Psoas infection may occur on either one or both (bilateral) sides, although bilateral incidence occurs in less than 3% of cases.

The two types of psoas abscesses are those that develop from infection of unknown origin (primary) and those that occur as a consequence of infection spreading from an adjacent organ (secondary). A certain type of bacterium (Staphylococcus aureus) is associated with primary psoas abscess 90% of the time, although other bacteria (Escherichia coli, Haemophilus influenza, Proteus mirabilis, Pasteurella multocida, and Salmonella newport) have also been reported. Secondary psoas abscess is usually associated with a mixture of different bacteria (Escherichia coli, bacteroides, staphylococcus, and streptococcus).

Risk factors for primary psoas abscess are not known, however, trauma to the muscle may be an important factor in 18% to 20% of cases. Low socioeconomic class and poor nutrition have also been cited as possible predisposing factors. A major risk factor for secondary psoas abscess is gastrointestinal disease (inflammatory bowel disease, appendicitis, diverticulitis, bowel cancer, and Crohn's disease). The source of secondary psoas abscess is a gastrointestinal infection in 80% of individuals. Other risk factors include tuberculosis, kidney (renal) infection, chronic leukemia, Henoch Schönlein purpura, septic arthritis, pancreatitis, diabetic septicemia, and postoperative infection. In developing countries, cases of psoas abscess are nearly always primary in nature, whereas in the US and Canada almost half of the cases are secondary (Babafemi 4).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Primary psoas abscesses are more common in those under the age of 30, whereas most abscesses that are secondary in nature occur in individuals over the age of 40. These abscesses are rare in the elderly.

Source: Medical Disability Advisor



Diagnosis

History: Individuals complain of fever, chills, loss of appetite (anorexia), night sweats, vague weakness, discomfort, and weight loss. Pain in the abdomen, back, groin, hip, or knee may also be reported. With a more advanced condition, the individual may develop pain while walking.

Physical exam: A fever, increased heart rate (tachycardia), and a general wasted appearance may be evident. Tenderness may occur, and in advanced cases, a mass can be felt (palpated) in the lower abdomen, back, or groin. Skin infection (cellulitis) characterized by local heat, redness, pain, and swelling may be evident. Manipulation of the hip on the side of the infection (ipsilateral) may cause some degree of pain. Individuals with advanced forms of psoas infection develop a limp on the affected side or lateral curvature (scoliosis) in the spine. A deformity while bending at the hip (flexion deformity) may eventually develop.

Tests: Tests may include a complete blood count (CBC) with differential, red blood cell (erythrocyte) sedimentation rate, and blood and urine cultures. Plain abdominal x-rays, x-rays with a barium enema or taken after injection of a radiopaque dye (intravenous pyelogram), and an upper gastrointestinal series may be useful in diagnosis. The abscess is usually visualized best using high-frequency sound waves (abdominal ultrasonography) or CT. Low-energy radio waves (MRI) may also be helpful.

Source: Medical Disability Advisor



Treatment

Conservative treatment includes broad-spectrum antibiotics (triple antibiotic therapy) followed by conversion to a single antistaphylococcal agent for abscesses infected with Staphylococcus aureus only. Aggressive treatment for primary psoas infection involves antibiotic treatment in combination with drainage of the abscess using a needle and syringe. Secondary psoas abscess is also treated with drainage and antibiotics. Aspiration and drainage of the abscess may be done by directly placing a needle through the skin into the abscess (percutaneous), if the individual is not a surgical candidate. The percutaneous approach usually requires CT scanning to guide exact placement of the needle. If there is gastrointestinal involvement, surgery to correct the bowel condition (removal of a bowel segment) may be warranted.

Source: Medical Disability Advisor



Prognosis

Left untreated, a psoas abscess is nearly always fatal. The outcome is generally good with more aggressive therapy that combines drainage and antibiotics.

Source: Medical Disability Advisor



Rehabilitation

Individual may perform light exercise under the supervision of a physician to stretch and strengthen muscles in the back, hips, and thighs. Initial activities may also include limited walking, range of motion, and treadmill exercises to be performed 2 to 3 times a day for 5 to 20 minutes a session.

If gastrointestinal surgery is used as treatment, intermittent positive pressure breathing exercises may be necessary to prevent pulmonary complications. Exercises that reduce postoperative pain and speed recovery include progressive relaxation and deep breathing techniques. These are performed several times a day until pain from inhalation/exhalation is less noticeable. Physical therapists instruct individuals to splint the abdomen when walking, coughing, or laughing. The individual may also be instructed in abdominal and trunk strengthening exercises, as well as lower extremity range of motion exercises to help increase circulation and make walking easier. These are especially valuable during the first 48 hours after surgery and should be performed 3 to 5 times a day during this time. Individuals may continue these exercises for 4 to 6 weeks until recovery from surgery is complete and pain is no longer noticeable while walking or breathing.

Source: Medical Disability Advisor



Complications

Possible complications of psoas abscess include destruction of the psoas muscle and spread of the infection to other tissues. Delayed or inadequate therapy can result in general infection (sepsis) and death.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Following drainage, the individual with psoas abscess continues medical therapy for approximately 3 weeks. Return to work in a limited capacity may be possible during this time if restrictions are made on heavy lifting, climbing, and walking long distances.

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:

  • What type of psoas abscess does individual have? Primary or secondary?
  • Was Staphylococcus aureus the primary cause of the abscess?
  • Does individual have fever, chills, vague weakness or other symptoms?
  • Was there tenderness or a mass in the lower abdomen, back, or groin?
  • Does individual have a skin infection?
  • Were other conditions with similar symptoms ruled out?

Regarding treatment:

  • Did treatment include triple antibiotic therapy?
  • Was abscess successfully drained?
  • Was surgical intervention required?
  • Did removal of bowel segment present additional problems?

Regarding prognosis:

  • Would current therapy be enhanced if combined with antibiotics, drainage, or surgery?
  • Would individual benefit from consultation with a specialist?
  • Has the psoas infection spread into other vital organ systems? If so, how is this being addressed?
  • Has individual experienced complications that may impact recovery?
  • Does individual have an underlying condition that may impact recovery?

Source: Medical Disability Advisor



References

Cited

Babefemi, T. "Psoas Abscess: A Primer for the Internist." Southern Medical Journal 94 1 (2001): 2-5. Medscape. 2001. WebMD, LLC. 22 Oct. 2004 <http://www.medscape.com/viewarticle/410693?src=search>.

Source: Medical Disability Advisor






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