You arrive at the bedside of a 42-year-old woman to perform a postoperative check four hours after she underwent a gastric bypass operation. Before you enter the room you note that she currently has a temperature of 102.3°F. She tells you her abdominal incision is excruciatingly painful, and on exam you are surprised by the unusual degree of tenderness in the region under and around her dressing.
Necrotizing Soft Tissue Infection
You should remove the dressing and examine the wound for any signs of necrotizing fasciitis.
The term necrotizing fasciitis was coined in 1951 to describe all gas-forming and non–gas-forming necrotizing infections, both of which shared the common feature of fascial necrosis. Recently, the term necrotizing soft tissue infection (NSTI) has replaced the older terminology, as this encompasses all infections regardless of the depth of tissue involved.
Patients who are most at risk for NSTIs include individuals with diabetes mellitus, obesity, peripheral vascular disease, chronic kidney disease, and alcohol abuse. NSTIs present with pain out of proportion to the physical exam, anxiety, and diaphoresis within 48 hours of bacterial inoculation in a wound. Other classic findings include erythema, pain or tenderness beyond the margins of erythema, woody edema, crepitus, bronzing of the skin, grayish, or “dishwater” discharge from the wound, skin necrosis, bullae formation, induration, fluctuance, fever, and hypotension. For examples of these skin findings, see Figure 40-1. Unfortunately, many of these distinctive features are late findings that are indicative of severe, life-threatening infection. You should therefore have a high index of suspicion for this type of infection, especially in a patient who has an otherwise unexplained fever in the acute postoperative period. In those cases it is incumbent on you to take down the dressing and, using sterile technique, examine the wound and surrounding skin.
Images of several examples of characteristic physical exam findings of NSTI. Variations in the appearance of bullae overlying NSTIs. (Reproduced with permission from Knoop K, Stack L, Storrow A, et al. Atlas of Emergency Medicine. 3rd ed. New York: McGraw-Hill Education; 2010. Figure 12.8. Photo contributed by Lawrence B. Stack, MD.)
One of the hallmarks of NSTIs is a rapid progression of symptoms that can lead to death within hours. Delays in diagnosis and debridement are associated with a nine times greater mortality rate. It should be clear that any consult for a potential NSTI must be seen quickly, taken seriously, and be escalated to more senior residents or attendings should any suspicion of NSTI exist.
When evaluating a patient for an NSTI, it is essential to remember that the more dramatic physical exam findings associated with NSTIs are often not seen at the time ...