Complex regional pain syndrome (CRPS), also known as reflex sympathetic dystrophy, is characterized by pain and sensory changes in an upper or lower extremity, typically after a noxious event, such as trauma, surgery, or myocardial ischemia (CRPS type 1) or with known injury to a nerve innervating the extremity (CRPS type 2). The key to early diagnosis is the identification of autonomic changes, such as edema, skin mottling, sweating, or temperature change of the affected area. Skin thickening and motion restriction occur later in the disease course. MRI or a bone scan can help to confirm the diagnosis by revealing patchy bone demineralization and other changes characteristic of CRPS. Autonomic testing may also be helpful.

CRPS can be differentiated from soft-tissue injury by findings of autonomic changes of the affected area.

CRPS must be differentiated from a peripheral neuropathy or radiculopathy, which manifests with deficits that conform to distribution of a particular nerve or nerve root.

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Caused by resuscitation-related bowel edema and fluid sequestration or retroperitoneal hemorrhage causing a mass effect.






  • Organ dysfunction due to increased abdominal pressure which compromises perfusion to vital organs
  • Can be thought of as Perfusion Pressure in that while normally, perfusion to organs within the abdominal compartment is MAP-RAP, when abdominal compartment pressure increases, perfusion pressure becomes MAP-Abdominal pressure
  • Normal intraabdominal pressure in adults is about 5 mmHg
  • Intraabdominal Hypertension in adults is >12 mmHg
  • Abdominal Compartment Syndrome in adults is defined as an intraabdominal pressure of >20 mmHg with evidence of organ dysfunction. In reality, a more relevant definition may be an elevated intraabdominal pressure with evidence of organ dysfunction. 
  • There are no clear values for intraabdominal hypertension or compartment syndrome in children
  • Increased abdominal wall compliance that develops over time (ie chronic cirrhosis with ascites) may be protective against abdominal compartment syndrome1

Consequence of intraabdominal hypertension resulting in symptomatic organ dysfunction.

Increased intraabdominal pressure directly decreases visceral perfusion and results in organ dysfunction and respiratory compromise.






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Abdominal decompression when abdominal pressure exceeds 20–25 mm Hg.


Complications of Injecting Drug Use

  • Local problems—Abscess (Figures 240-2 
    Image not available.

    A 32-year-old woman with type 1 diabetes developed large abscesses all over her body secondary to injection of cocaine and heroin. Her back shows the large scars remaining after the healing of these abscesses. (Courtesy of ­Richard P. Usatine, MD.)

    and 240-3; Abscess), cellulitis, septic thrombophlebitis, local induration, necrotizing fasciitis, gas gangrene, pyomyositis, mycotic aneurysm, compartmental syndromes, and foreign bodies (e.g., broken needle parts) in local areas.2
    • IDUs are at higher risk of getting methicillin-resistant Staphylococcus aureus(MRSA) skin infections that the patient may think are spider bites (Figure 240-4).
    • Some IDUs give up trying to inject into their veins and put the cocaine directly into the skin. This causes local skin necrosis that produces round atrophic scars (Figure 240-5).
  • IDUs are at risk for contracting systemic infections, including HIV and hepatitis B or hepatitis C.
    • Injecting drug users are at risk of endocarditis, osteomyelitis (Figures 240-6and 240-7), and an abscess of the epidural region. These infections can lead to long hospitalizations for intravenous antibiotics. The endocarditis that occurs in IDUs involves the right-sided heart valves (see Chapter 50, Bacterial Endocarditis).2 They are also at risk of septic emboli to the lungs, group A β-hemolytic streptococcal septicemia, septic arthritis, and candidal and other fungal infections.


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