Abstract
This chapter presents questions and key points of the procedure of abscess incision and drainage.
Keywords
abscess, drainage, incision
2
What causes a skin abscess?
Abscesses are usually caused by gram-positive cocci, commonly Staphylococcus aureus and group A streptococci. There is now an increase of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). Gram-negative bacteria may cause skin abscesses in the buttock and axilla. Infections may occur when the skin barrier is disrupted and bacteria enter the open wound.
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What is the difference between an abscess and cellulitis?
Cellulitis is a skin infection that usually involves the epidermis, dermis, and superficial subcutaneous tissues and does not have an organized cavity; abscesses have an organized fluid-filled cavity and involve deeper subcutaneous tissues.
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Is there a role for ultrasound when evaluating an abscess?
Point-of-care ultrasounds have been found to be 90%–97% sensitive and 67%–83% specific in detecting for skin abscesses and have been shown to improve accuracy in abscess diagnosis. Ultrasounds can also be used to measure the size of an abscess, detect loculations, and evaluate surrounding structures such as lymph nodes or blood vessels ( Fig. 47.1 ).
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What type of pain relief is used for incision and drainage?
Topical anesthetics can be used to promote drainage through maceration, but local anesthesia is best achieved with lidocaine infiltrate. A “field block” is often injected around the wound of an abscess. Injecting into the wound may not provide adequate local anesthesia. Often, lidocaine is injected over the area of the abscess where the incision is expected.
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How is incision and drainage of an abscess performed?
After proper local anesthesia is achieved, the wound is cleaned with antiseptic solution. Incision of the abscess along the area of maximum fluctuance is performed by using an 11-blade scalpel through the dermis. The length of the incision depends on the size of the abscess. Once incision is performed, pressure is applied to the surrounding tissue to express the abscess fluid from the incision site.
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How do I know if there are septations or loculations within the abscess?
Ultrasounds can potentially detect septations or loculations, but they may not be clinically detectable on physical exam. A hemostat is inserted into the incised wound to explore and break apart any septations and loculations.
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Are blood cultures necessary in a patient with an abscess?
Blood cultures are generally not obtained in immunocompetent patients with skin infections, unless patients have serious or complicated soft tissue infections from surgical or traumatic wounds or require further surgical intervention. The emergence of CA-MRSA increases patients’ risks of developing other types of infections such as pneumonia, but generally the incidences of bacteria are low for both immunocompetent patients and patients with CA-MRSA.