I&D: How to Perform an Incision & Drainage
An I&D (Incision & Drainage) treats infections that have turned into abscesses. Knowing how to perform one is important for a nurse practitioner in most settings — especially the ER or urgent care.
This guide covers when an I&D is (and isn't) indicated, the role of antibiotics including MRSA coverage and endocarditis prophylaxis, and the full step-by-step procedure for draining an abscess.
What Is an I&D?
An Incision & Drainage is performed when fluid accumulates in the body and needs to be drained — usually from a skin abscess. It's done in urgent cares, emergency departments, or outpatient clinics like general surgery. Patients typically complain of pain, swelling, and redness of the affected area.
When to Do an I&D
An I&D drains purulent fluid (pus) from an abscess — the best way to treat the infection and prevent it from enlarging into something more serious. If no fluctuance is palpated (no fluid felt under the skin), a trial of PO antibiotics can likely be used instead. Most obvious abscesses, though, benefit from an I&D.
Refer These to a Surgeon
Some abscesses need surgical expertise: perirectal/perianal, anterior and lateral neck, hand abscesses (except paronychia), those adjacent to vital nerves or vessels, central facial abscesses, and breast abscesses near the areola/nipple. Abscesses >5 cm are also best drained and managed by a surgeon.
I&D & Antibiotics
While antibiotics help skin infections like cellulitis, they often can't fully treat an infection once an abscess has formed — which is why the I&D is necessary. Young, healthy, non-immunocompromised patients don't need antibiotics after an I&D of a small abscess <2 cm.
- Bactrim 1–2 tabs BID × 10 days
- Doxycycline 100 mg BID × 10 days
- Minocycline 100 mg BID × 10 days
- Clindamycin 300 mg q6–8h × 10 days
- Linezolid 600 mg BID × 10 days (expensive)
Bacterial Endocarditis Prophylaxis
Certain at-risk patients should get oral antibiotic prophylaxis 1 hour before the I&D.
Equipment
An I&D is invasive but is considered a clean procedure — you don't strictly need sterile gloves or a sterile field, though some still use sterile technique. Many facilities have pre-assembled kits.
Prep & Anesthetize
Explain the procedure (a consent form may be required by facility protocol), position the patient comfortably with easy access to the abscess, raise the bed, and set up your equipment. Larger abscesses can be very painful — IV or IM morphine 4 mg or Dilaudid 1 mg may help if needed.
Tips to Decrease Lidocaine Pain
Buffer the lidocaine 9:1 with 8.4% bicarb, use a smaller needle, inject slowly, use room-temperature lidocaine, stimulate adjacent skin, and use the ring/field block technique.
Make the Incision
Once the lidocaine has worked (3–5 minutes), make a linear incision with the scalpel — deep enough to penetrate the abscess wall but not so deep as to cause injury. Keep 4×4 gauze in your other hand, since purulent fluid usually gushes out immediately.
Cut the Full Length
Incise the entire length of the abscess — too small an incision is one of the main causes of a recurrent abscess.
Obtain Cultures, Break Loculations & Irrigate
Young, healthy patients with abscesses <2 cm who won't get antibiotics don't need cultures.
Abscesses often become loculated — separate pockets of pus. Insert a hemostat into the incision and open it in all directions to break up loculations (this is often painful).
Draw sterile saline into a 20–60 cc syringe, attach a splash guard or IV catheter, and irrigate to clean out the abscess. Best practice, though not always done for smaller abscesses.
Pack the Wound (Optional)
I&D incisions are almost never sutured closed — they're left open to heal by secondary intention (naturally). Packing inserts special gauze that promotes drainage.
Don't Over-Pack
Packing too tightly increases pressure and can cause tissue damage. Gently insert iodoform ribbon with a blunt object (like a cotton swab) — don't "stuff" it — and leave a 1 cm tail outside the wound. Cover with an absorbable dressing. Packed patients return for a wound check in 2 days; more packing can be placed if drainage continues.
Discharge Instructions
Before discharge, confirm the patient's tetanus is up to date.
Clinical Pearls
Related Guides
References
- Downey KA, Becker T. Techniques for skin abscess drainage. UpToDate.
- Approach to management of drainable abscess or skin infection with purulent drainage in adults. UpToDate.
- Sexton DJ, Chu VH. Antimicrobial prophylaxis for the prevention of bacterial endocarditis. UpToDate.
- Buttaravoli P, Leffler S. Cutaneous Abscess or Pustule. In Minor Emergencies. 3rd ed, pp. 655–659. Saunders, 2012.
Rather than lance it with a scalpel, using a 4mm skin biopsy tool works rather well and doesn’t require it to be packed afterwards.
That’s a good idea, Thanks for sharing!
What do you do if the infection keeps coming back?
This would be best treated by an infectious disease specialist! 🙂