
Emergency War Surgery NATO Handbook: Part II: Response of the Body to Wounding: Chapter XI: Infection
United States Department of Defense
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The classic signs and symptoms of infection are redness, swelling, heat, and pain. Redness of the skin is due to intense hyperemia and is seen in infections which involve the skin or subcutaneous tissue and, in some patients, in the. skin overlying foci of suppurative thrombophlebitis hyperemia is responsible for the local increase in temperature. Fever and tachycardia are additional but nonspecific signs of infection. Rigors and chills are suggestive of septicemia.
Leukocytosis commonly accompanies acute bacterial infection. Generally, the more severe the infection, the greater the leukocytosis. The leukocytosis is characteristically accompanied by an increase in the proportion of immature granulocytes, the so-called "left shift."
Exudate from the area of infection should be examined for color, odor, and consistency. A Gram stain of the exudate should be performed immediately to facilitate prompt institution of appropriate antimicrobial therapy. For each bacterial cell observed under microscopic oil immersion lens examination, there are approximately 10^5 similar organisms in each milliliter of exudate from which the smear was prepared.
A wound biopsy is a useful method of confirming the presence of infection in a wound, particularly in a burn wound or wounds of the subcutaneous and soft tissues. Areas of the wound that appear purulent or reveal new focal areas of discoloration should be biopsied. If the technical capability exists, a portion of the specimen should be sent to the microbiology laboratory for quantitative culture. The recovery of 105 or more organisms per gram of tissue from a quantitative culture is suggestive but not necessarily diagnostic of infection. This finding is highly sensitive but not specific for infection, since proliferation of colonizing organisms may account for such bacterial densities. The remaining portion ofthe specimen is forwarded to the pathologist for histologic examination. The histologic finding of microorganisms in viable tissue is highly specific and is diagnostic of infection. Consequently, the examination of histologic sections prepared from a biopsy specimen is the most reliable means of differentiating contamination or colonization of nonviable tissue from infection of viable tissue.
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