Chapter 8: Infected Wounds

INTRODUCTION

Any wound can become infected, and some infections can compromise the integumentary tissue to the extent that they cause wounds. The purpose of this chapter is to give the clinician guidelines as to when and if a wound is infected, as well as to discuss diseases that can cause skin changes and/or open wounds.

Every wound has flora on its surface, and whether or not the wound becomes infected, as well as the resulting impairment of the wound healing process, depends upon both the type of microbe present and the host immune system. Table 8-1 defines the terms used to describe the presence of bacteria on the wound surface and Table 8-2 lists the microorganisms that are most commonly present in chronic wounds. Gram-positive organisms may be the first to invade the chronic wound, followed by gram-negative bacteria, and then anaerobes.¹ Bacterial testing via tissue biopsies or swabs using the Levine method are helpful to determine the number of colony forming units present, as well as antimicrobial sensitivity for antibiotic selection; however, the differential diagnosis of local, superficial critical colonization versus deep chronic wound infection invading the surrounding tissue can be made clinically based on the following signs and symptoms:

• Critical colonization will have three or more of these signs

  • Static size as measured by length × width over a 2–4 week period

  • Increased amount of exudate

  • Red friable granulation tissue on the wound surface

  • Debris or dead cells on the wound surface

  • Odor that indicates presence of gram-negative or anaerobic organisms

• Infected wounds ...