4 Key signs of wound infection—and what to do next

A wound that’s not healing as expected may be infected. Foul odor, tissue breakdown, and increasing drainage are common clues. Recognizing the signs of wound infection is critical.

In this lesson from our wound management course, you’ll learn how to:

• Spot underappreciated early indicators of infection
• Take a wound culture correctly and avoid the pitfalls of surface swabbing
• Choose the right sampling method: swab, aspiration, or biopsy
• Begin empiric treatment with confidence, before lab results are back
• Use antibiotics and antimicrobial dressings wisely
• Order lab tests to detect systemic infection

Whether you’re in primary care, outpatient clinics, or the emergency department, this course will sharpen your instincts and help you act decisively when an infection presents.
 

[00:03]
Of course, no matter the etiology, all wounds are at risk of developing an infection. In fact, patients may even present with an infection upon their first visit. Therefore, we must be sure we can quickly identify that an infection is present and how to treat it. Wound infections can lead to severe complications like amputations, and even death. Initiating a management plan and identifying the organisms responsible will reduce morbidity and mortality.

Key signs of wound infection 

[00:34]
Let's go over key indications of infection. These could include a strong odor, a decrease in the quality of tissue to slough or eschar, granulation tissue that bleeds very easily, or an increase in the size of the wound. Changes to the periwound such as redness or hyperpigmentation may occur. The drainage may also increase in amount, become thicker or change color to dark yellow or green. The patient may complain of increased pain and warmth in the area. 

Wound cultures 

Swab cultures

[01:08]
A wound culture should be taken to identify organisms and select the appropriate antimicrobial. A wound swab is the most commonly used method. Here, the wound is cleansed with a solution that will not kill the bacteria before taking the culture to reduce the number of surface organisms in the sample. The swab should then be placed in the deepest portion of the wound and placed in a sterile container for transport to the lab. Not taking these steps will decrease the accuracy of the sample due to colonization of the wound.

Needle aspiration and tissue culture 

[01:39]
Additionally, infected fluid from the wound can be sent to the lab using a technique called needle aspiration. Tissue cultures obtained by sharp debridement or biopsy are usually more accurate as they are from deeper areas of the wound. This gives better identification of the organisms causing the infection versus surface organisms alone. However, there are some caveats to this method. To start, it requires special training and can, therefore, only be done by a qualified clinician. Additionally, it can be quite painful or may not be possible depending on the patient's location and equipment availability. 

Treating wound infections 

[02:19]
Since it usually takes several days for a result, no matter which method is used to get the culture, treatment should be started empirically. Patients may be given either topical antibiotics applied to the wound bed or oral antibiotics if there are signs that the patient is being affected systemically. Dressings with antimicrobial properties can also be used on the wound to improve the infection. There should be a high index of suspicion for infection before starting antibiotics to prevent the development of multidrug-resistant organisms.

Assessing wound infection severity 

[02:54]
Bloodwork to identify the presence of systemic infection should also be taken. You should order a complete blood count with differential, as well as inflammatory markers such as C-reactive protein, erythrocyte sedimentation rate and procalcitonin. New technology is also available that shows the infected areas of the wound when a photo is taken with the device. This device uses specialized light imaging technology to identify the presence of microorganisms. Patients with severe infections may need to be hospitalized for intravenous antibiotics and the surgical removal of infected tissue from the wound bed.