Abscess Drainage

An abscess is a collection of pus within the tissues of the body.

They can be drained surgically, carried out under general or local anaesthetic, depending on location of abscess and patient tolerance.

For example, a perianal abscess almost exclusively general anaesthetic (GA) or spinal. Simple abscess, such as infected sebaceous cyst on the back, can be drained under local anaesthetic (LA) with supplement oral analgesia.

Procedure

The aim of the procedure is to drain the abscess, remove unhealthy tissues and ensure the cavity does not close to prevent abscess reformation. The wound is left open to heal (known as healing by secondary intention).

• Make a stab incision, then open the abscess cavity fully either extending the incision or making a cruciate incision and taking off the edges (known as de-roofing)

• Take a sample of pus with the syringe for microscopy, culture and sensitivity (MC+S)
  • This can also be done with a microbiology swab

• Explore the cavity and break down the loculations with a finger gently. If under local anaesthetic, do this quickly as it can be uncomfortable

• Wash out cavity with the sterile saline in the syringe. If there is bleeding, press for a minute with a dry swab and reassess

• Pack cavity loosely with the alginate ribbon dressing

Points to Remember

If the patient is diabetic, then the abscess should ideally be drained on the same day of admission, even out of hours.

Be aware of any developing necrotising fasciitis (more common in patients with a background of immunosuppression), which can present with sepsis, a rapidly spreading infection, and / or palpable surgical emphysema.

As with any surgical procedure, it is vital to avoid important structures when draining an abscess, most notably anal sphincters* or large superficial vessels in the axilla.

*Any abscess in the perianal region, a circum-anal incision is required (do not cut towards the sphincter) to ensure the anal sphincter is maintained, whilst any pilonidal abscess requires a longitudinal off-midline incision.