BloodSweatxED
PRN Education · No. 016 · Procedures Series

Abscess
I&D.

The incision is the cure. Antibiotics are the adjunct, not the treatment — an abscess with an intact roof gets worse on antibiotics alone, and an abscess opened adequately usually gets better without them.

The two failure modes are the same failure: an opening too small to drain the cavity, and loculations left intact behind it.

When to cut

And when to put the blade down

Drain it

  • Fluctuant collection on exam — or a pocket on POCUS when the exam is equivocal
  • Cellulitis that failed antibiotics: look again for the abscess you missed the first time
  • Recurrent abscess at a prior site — drain and consider what's underneath (pilonidal, hidradenitis, retained foreign body)

Stop and think

  • Face inside the "danger triangle," palms, soles, and anything overlying vessels — small incisions, cautious depth, low consult threshold
  • Perirectal beyond a simple perianal abscess, and any concern for deep space infection of the hand or neck — these drain in the OR
  • Pulsatile mass or bruit: aspirate nothing, incise nothing — image first. Mycotic aneurysms have been "drained" before.
  • Large, deep, or multiloculated collections may exceed bedside anesthesia — plan sedation or the OR rather than a painful partial job

Setup

Protect yourself first

Kit

#11 blade

Scalpel, hemostat or curette, irrigation syringe, gauze stacks, packing strip or vessel loop, absorbent dressing. Culture swab if it will change management.

Position

Splash zone

Abscesses are under pressure. Face shield, gown, absorbent pads, and the incision aimed away from you. Patient lying down.

Prep

POCUS + field block

Ultrasound confirms pus, maps depth and loculations, and finds the vessel you don't want to hit. Anesthetize per institutional reference — a field block around the cavity beats infiltrating inflamed tissue.

The technique

5 steps
RIGHT · INCISION SPANS THE CAVITY open ~2/3 of the diameter hemostat sweeps break every wall cavity drains and stays open WRONG · STAB INCISION too small loculations intact · roof reseals "failed I&D" returns in 48 hours
Fig. 1 — Adequate drainage versus the stab that reseals. The incision should span roughly two-thirds of the cavity, and the hemostat should feel every wall.

Confirm pus and map the cavity

POCUS over the point of maximal fluctuance · note depth and neighbors

Induration without a pocket is cellulitis — cutting it yields blood, pain, and a callback. Ultrasound shows the pocket, its depth, loculations, and any vessel in the path. Mark the point of maximal fluctuance.

Incise along the tension lines

#11 blade · over maximal fluctuance · parallel to skin creases

One deliberate incision through the roof, oriented along the skin tension lines for a better scar, spanning roughly two-thirds of the cavity's diameter (Fig. 1). Expect pressurized pus — that's what the shield is for.

Depth discipline: the blade only needs to breach the roof. Everything deeper is done bluntly — especially in the neck, groin, and antecubital fossa.

Break every loculation

Hemostat sweep · every quadrant · until the walls feel smooth

Insert a closed hemostat, open it, and sweep the cavity in all directions until no septations remain and the walls feel uniform. This is the most therapeutic and most skipped step. Express residual pus with gentle circumferential pressure.

Irrigate and decide on drainage

Irrigate the cavity · pack loosely if at all · or place a loop

Irrigate until the return runs clear. Small, well-drained cavities generally need nothing in them. For larger cavities, either a loosely placed wick of packing strip to hold the incision open, or a loop drain (vessel loop through two incisions, tied loosely) — loop drainage is better tolerated, especially in children, and avoids repeat packing visits.

Packing is a wick, not a plug: tightly packed gauze blocks drainage, hurts, and can extend the cavity. If it doesn't slide in easily, it's too much.

Dress and arrange follow-up

Absorbent dressing · recheck 48 hours if packed or high-risk

Absorbent dressing over the site. Packed wounds and high-risk patients (diabetes, immunocompromise, large cavities) get a 48-hour recheck. Antibiotics are an adjunct decided by your local guidance — typically for surrounding cellulitis, systemic signs, or host risk factors, not for a simple drained abscess. Warm soaks after 24–48 hours help it keep draining.

Disposition

Who goes home and who doesn't
ScenarioCallWhy
Simple, drained, wellhomeWound care, return precautions, recheck if packed. Antibiotics per local guidance.
Surrounding cellulitishome + abxDrainage plus antibiotics; mark the margins so progression is visible at recheck
Systemic signsworkupFever, tachycardia, or ill appearance after drainage means the abscess wasn't the whole story
Hand deep space, neck, perirectalconsultBedside I&D is inadequate; these need the OR before they need you
Pain out of proportionstopCrepitus, bullae, rapidly advancing margins — think necrotizing infection, not a bigger incision

Pearls & pitfalls

Where this goes wrong
Pearl

Ultrasound before the blade

POCUS changes management in a meaningful fraction of "obvious" skin infections — finding the pocket cellulitis was hiding, or proving there's nothing to drain. It also shows you the artery next door.

Pearl

Anesthesia is the rate limiter

Local anesthetic works poorly in the acidic environment of an abscess. A field block around the cavity, adequate time of onset, and honest consideration of sedation for large collections make the difference between a complete job and a partial one.

Pitfall

The timid stab

A 5 mm nick in a 4 cm abscess reseals within a day and comes back angrier. The incision must be long enough to drain the cavity and stay open while it heals from the bottom up.

Pitfall

Skipping the sweep

Pus out under pressure feels like success, but loculated pockets left behind are the classic cause of the 48-hour bounce-back. The hemostat sweep is the difference between drainage and decompression.

Pitfall

Packing as a reflex

Routine packing of small abscesses adds pain and follow-up visits without reducing recurrence. Pack loosely, pack selectively, or use a loop drain — and never pack so tight it plugs.

Pitfall

Missing the mimic

Not every red lump is an abscess: inguinal hernias, lymph nodes, pseudoaneurysms in people who inject drugs, and necrotizing infections have all met a scalpel that should have met an ultrasound first.

Sample Epic documentation

Copy · edit · attest

A starting template for the procedure note. Text in brackets [ ] and pick-lists in { } are fields to complete. Save it as a SmartPhrase, then edit every field to match the actual procedure.

.procIandD
PROCEDURE: INCISION AND DRAINAGE OF ABSCESS

Site: [***]   Size: *** x *** cm
Consent: {verbal : written} consent obtained; risks including
pain, bleeding, scarring, recurrence, and need for further
drainage discussed. Timeout performed. Operator: @ME@

Bedside ultrasound: {fluid collection confirmed, *** cm deep :
not performed}. Anesthesia: [agent/technique per institutional
protocol ***].

Procedure: site prepped. Incision made with #11 blade over
point of maximal fluctuance, *** cm, along skin tension lines.
{Purulent : serosanguinous} drainage expressed, ~*** mL.
Loculations broken with hemostat; cavity irrigated until clear.
{Packing placed loosely : loop drain placed : no packing}.
Culture: {sent : not sent}.

Complications: {none : ***}
EBL: minimal

Aftercare: wound care and return precautions given.
Recheck in {48 hours : *** days}. Antibiotics: {none :
prescribed per local guidance ***}.

Electronically signed: @ME@  @TD@ @NOW@

Sample template only — not a validated institutional SmartPhrase. Verify wording, consent, and attestation requirements against your department's documentation, coding, and compliance policies before clinical use.

PRN Education · Procedures Series

Keep your hands busy