I&D: How to perform an Incision & Drainage
An I&D or Incision and Drainage is a procedure that is done to treat infections that have turned into abscesses.
Knowing how to perform an I&D is important for a nurse practitioner in most settings, but especially in the ER or Urgent Care.
What is an I&D?
An I&D or Incision and Drainage is performed when there is an accumulation of fluid within the body that needs to be drained.
This is usually from a skin abscess.
An I&D is performed in urgent cares, emergency departments, or in outpatient clinics like general surgery.
Patients with an abscess will usually complain of pain, welling, and redness of the affected area.
Abscesses can occur anywhere on the body, but commonly occur:
- In the axillae (armpits)
- On the upper legs and buttock
- Pilonidal region (above the buttcrack)
- On fingertips next to nail (termed paronychia)
While anyone can get an abscess, these are more common in those with poor hygiene, as well as those who are immunocompromised.
Diabetics and patients who are obese are also at risk for abscess formation.
When To Do an I&D?
An I&D is performed to drain purulent fluid (pus) from the body.
These collections of pus are termed “abscesses”, and draining them is the best way to treat the infection, as well as preventing the abscess from getting bigger and causing a more serious infection.
If there is no fluctuance palpated (fluid felt underneath the skin), then a trial of PO antibiotics can likely be used without having to do an I&D.
Most cases of obvious abscesses will benefit from an I&D.
There are certain abscesses that require the expertise of a surgeon to drain. These include:
- Perirectal or perianal abscesses
- Anterior and lateral neck abscesses
- Hand abscesses (except paronychia)
- Abscesses adjacent to vital nerves or blood vessels
- Abscesses in the center of the face
- Breast abscesses near the areola and nipple
It is also best for abscesses >5cm to be drained and managed by a surgeon.
I&D and ANTBIOTICS
While antibiotics can help for skin infections like cellulitis, they often won’t be able to fully treat an infection if an abscess is there.
This is why an I&D is necessary.
Young, healthy patients who are not immunocompromised do not need antibiotics if an I&D is performed on a small abscess < 2cm.
Most others will require systemic antibiotics including:
- Deep abscesses like in the abdomen
- Multiple abscesses
- Significant surrounding cellulitis
- >2cm in size
However, these antibiotics likely won’t work without also performing an I&D!
Like skin infections, most abscesses are caused by staphylococcus aureus and other gram-positive bacteria.
However, MRSA is very common, especially with abscess formation. This means that standard antibiotics for cellulitis like Keflex may not work.
Antibiotic selection should cover MRSA
MRSA-covering PO agents include:
- Bactrim 1-2 tabs BID x 10 days
- Doxycycline 100mg BID x 10 days
- Minocycline 100mg BID x 10 days
- Clindamycin 300mg q6-8h x 10 days
- Linezolid 600mg BID x 10 days (expensive)
Perirectal abscesses that are drained will need additional coverage for gram-negative bacilli and anaerobes, so options include:
- Add Augmentin to the MRSA-covering agents above
- Add Levaquin AND Flagyl to the MRSA-covering agents above
- Add Cipro to Clindamycin
Severe infections and abscesses that require inpatient admission would be started on IV Vancomycin +/- Cipro/Flagyl or Zosyn.
Aerobic and anaerobic cultures should be obtained and sent to the lab to guide antibiotic use.
Patients at risk of bacterial endocarditis should be started on antibiotic prophylaxis. These should be given 1 hour prior to the I&D.
Bacterial Endocarditis Prophylaxis
Antibiotic prophylaxis is given to certain people at risk for developing bacterial endocarditis. These oral antibiotics should be given 1 hour prior to the I&D.
Antibiotic prophylaxis should be given for patients with:
- Prosthetic heart valves
- Rheumatic heart disease
- Unrepaired congenital heart disease
- H/o infective endocarditis
- Central lines
Antibiotic prophylaxis for bacterial endocarditis include:
- Doxycycline and amoxicillin
- Minocycline and amoxicillin
HOW TO PERFORM AN I&D
1. Collect your Equipment
An I&D is an invasive procedure and will require some equipment.
An I&D is also considered a clean procedure, so you do not need sterile gloves or a sterile field, although some do still utilize sterile technique.
Your facilities may have kits put together which contain much of what you need for the I&D.
|PACKING & DRESSING||Culture Swabs|
2. Prep the Patient
Once your equipment is ready, you need to prepare the patient.
Inform them of what the procedure will entail. A procedural consent form may or may not be required depending on your facility’s protocols.
Position the patient in a relaxed position where you can easily access the abscess.
Raise the stretcher or bed if able, and set up the bedside table or suture cart where you will set up your equipment.
Systemic analgesics may be required in larger abscesses, as they can be very painful.
IV or IM Morphine 4mg or Dilaudid 1mg is usually sufficient, if needed at all.
Before you make the incision, you should anesthetize the area you are going to cut.
Abscesses are already irritated and will be very painful.
Unfortunately, lidocaine doesn’t work as well as usual because abscesses are an acidic environment.
Draw up your 1-2% lidocaine into your 3cc syringe with a blunt needle.
Switch out to the smaller gauge needle (25-30g) and prime the lidocaine. You are now ready to infiltrate.
You have a few options when it comes to HOW you are going to anesthetize the area.
For smaller abscesses <5cm, locally infiltrate the lidocaine in a line where the incision will be, across the entire length of the abscess. This will be painful for the patient.
Incisions should be made along the lines of the body that have decreased tension to reduce scarring.
Local infiltration involves sticking the needle just underneath the epidermis, and injecting a small amount of lidocaine while you gently pull the needle back out.
You are infiltrating the subcutaneous tissue, but not deep enough to actually inject into the abscess itself.
This is done multiple times until the projected line where you will cut is fully infiltrated.
After 3-5 minutes, you can begin the incision.
For larger abscesses >5cm, the linear approach above should be used, IN ADDITION to a ring or field block.
A field block is achieved by injecting a ring of subcutaneous 1% lidocaine around the abscess, approximately 1cm peripheral to the erythematous border.
Remember the max dose of lidocaine is 4.5mg/kg
This means for lidocaine 1% (10mg/mL) the max dose would be 30mL in most adults over 65kg – you hopefully should not be using anywhere near this amount.
Lidocaine should start working in 45-90 seconds, but you should give it 3-7 minutes to fully kick with an abscess.
Tips to Decrease pain with lidocaine
- Buffer the lidocaine with 9:1 ratio (lidocaine to 8.4% bicarb)
- Use a smaller needle
- Inject slowly
- Use room temperature lidocaine
- Stimulate adjacent skin
- Ring block/field block technique as above
4. Make the Incision
Once you have given enough time for the lidocaine to work (3-5 minutes), make a linear incision with the scalpel.
This needs to be deep enough to penetrate the abscess wall, but not too deep to cause injury.
It helps if you have 4×4 gauze in the other hand, as purulent fluid will usually immediately start gushing out.
Cut the entire length of the abscess, as not making a wide enough incision is one of the main causes of a recurrent abscess.
5. Obtain Cultures
Young healthy patients with small abscesses <2cm who won’t get antibiotics don’t need cultures obtained.
Patients started on antibiotics should have cultures obtained if:
- Significant cellulitis
- Systemic symptoms like fevers
- History of recurrent abscesses
- Failure of initial antibiotics
- Very young or old
Make sure to obtain swabs for both aerobic and anaerobic gram stain and culture.
6. Loculations & Irrigation
Abscesses have a tendency to become loculated. This means there can be individual pockets of pus within the abscess itself.
To “break these up”, insert a hemostat into the incision and open it up in all directions in order to break up any possible loculations. This is often painful.
Draw up sterile saline with the 20-60cc syringe, attach the splash guard or IV catheter, and irrigate the incision to effectively clean out the abscess.
This is best practice although not always performed, especially for smaller abscesses.
7. Pack wound (optional)
I&D incisions are almost never closed with sutures but are left open to heal by “secondary intention”, meaning naturally.
Sometimes packing should be used.
Packing is when you insert special gauze into the wound that promotes drainage.
Packing is generally recommended for:
- Abscesses >5cm
- Pilonidal abscesses
- Immunocompromised / diabetics
If you decide to pack the wound, do not over-pack the wound too tightly. This increased pressure can cause tissue damage.
Gently insert the iodoform ribbon into the wound with a blunt object such as a cutip swab. This does not have to “stuff” the wound. Leave a 1cm tail outside of the wound.
Cover the packing with an absorbable dressing.
Patients with packing will need to return for a wound check-in 2 days. If there is still significant drainage, more packing can be placed.
Before discharge, make sure their tetanus is uptodate.
I&D without packing should soak in warm soapy water 2-3 times per day, and f/u in 7-10 days or sooner if systemic signs of infection present.
I&D with packing should return in 24-48 hours. Once packing is removed and the drainage stops, warm soapy soaks can be started.
Approach to management of drainable abscess or skin infection with purulent drainage in adults. (2021). UpToDate. Retrieved September 7, 2021, from https://www.uptodate.com/contents/image?imageKey=ID%2F114919&topicKey=ID%2F110530
Graphic 114919 Version 10.0
Buttaravoli, P. M., & Leffler, S. M. (2012). Cutaneous Abscess or Pustule. In Minor emergencies (3rd ed., pp. 655-659). Saunders.
Downey, K. A., & Becker, T. (2021). Techniques for skin abscess drainage. In T. W. Post (Ed.), UpToDate. https://www.uptodate.com/contents/techniques-for-skin-abscess-drainage
Sexton, D. J., & Chu, V. H. (2021). Antimicrobial prophylaxis for the prevention of bacterial endocarditis. In T. W. Post (Ed.), UpToDate. https://www.uptodate.com/contents/antimicrobial-prophylaxis-for-the-prevention-of-bacterial-endocarditis