What are the guidelines for incision and drainage procedures in the ER, including anesthesia options and indications for referral to surgery?

Incision and Drainage in the Emergency Department: Technique, Anesthesia, and Referral Guidelines

When to Perform I&D vs. Refer to Surgery

For most simple cutaneous abscesses, perform I&D in the ER under local anesthesia; refer to surgery for perianal abscesses requiring general anesthesia, complex horseshoe abscesses, abscesses with suspected fistulas, or patients with sepsis/septic shock requiring emergent operative drainage. 1, 2

Indications for ER Management with I&D:

• Simple cutaneous abscesses in immunocompetent patients 2
• Well-localized collections without systemic symptoms 2
• Superficial perirectal abscesses in stable patients (can be done under local anesthesia) 1
• Abscesses <5cm without multiple loculations 3

Mandatory Surgical Referral Criteria:

• Sepsis or septic shock - requires emergent operative drainage 2
• Perianal/perirectal abscesses with systemic symptoms - need examination under general anesthesia 1, 3
• Horseshoe abscesses - high recurrence risk, require operative management 3
• Suspected fistula - do not probe or lay open in ER; requires surgical evaluation 1
• Immunocompromised patients (diabetes, steroids, HIV) with deep or extensive abscesses 2, 3
• Multiple loculations or inadequate drainage anticipated 3
• Recurrent abscesses - may need definitive surgical excision 1

Anesthesia Selection Algorithm

Local Anesthesia (Preferred for ER):

Use local anesthesia with lidocaine 1% or bupivacaine 0.25-0.5% for simple, well-localized abscesses in cooperative patients without severe pain or anxiety. 4, 5

Technique for Local Anesthesia:

• Lidocaine 1%: Maximum dose 4.5 mg/kg without epinephrine, 7 mg/kg with epinephrine 6
• Bupivacaine 0.25-0.5%: Maximum 175 mg without epinephrine, 225 mg with epinephrine; can repeat every 3 hours 4
• Field block technique: Infiltrate around (not into) the abscess in a circumferential pattern 5
• Alternative aspiration-injection technique: Aspirate abscess contents, then inject local anesthetic into the cavity itself - this reduces pain from multiple infiltrations 7

Adjuncts to Local Anesthesia:

• Topical lidocaine/tetracaine patches provide similar analgesia to injectable lidocaine but are not superior 5
• Entonox (nitrous oxide) shows no significant pain reduction benefit, though it may reduce anxiety 8
• Consider oral or IV analgesics (opioids, NSAIDs) 30 minutes before procedure for anxious patients 1

Procedural Sedation Indications:

Use procedural sedation for large abscesses (>5cm), multiple abscesses, perianal location, highly anxious patients, or when adequate local anesthesia cannot be achieved. 2, 3

• Large or deep abscesses requiring extensive exploration 2
• Perianal/perirectal abscesses needing thorough examination 1
• Pediatric patients or extremely anxious adults 2
• Failed local anesthesia attempt 5

General Anesthesia (Operating Room):

Refer for general anesthesia when the abscess requires extensive surgical exploration, involves complex anatomy (horseshoe, deep perirectal), or the patient has sepsis requiring damage control surgery. 1, 3

I&D Technique

Procedure Steps:

1. Prepare the patient: Position appropriately (prone for sacrococcygeal, lithotomy for perianal) 7

2. Anesthetize: Use field block or aspiration-injection technique as described above 7, 5

3. Incision: Make an adequate incision (not just a stab) to prevent premature closure - use a #11 blade and extend the incision the full length of fluctuance 1

4. Drainage: Express purulent material completely 1

5. Break up loculations: Use hemostat or finger to gently break up septations within the cavity 1

6. Irrigate: Copiously irrigate the cavity with normal saline 9

7. Packing decision:

   • Packing is controversial - some practitioners pack for hemostasis and to prevent premature skin closure 2
   • No routine packing required for simple abscesses 1
   • If packing is placed, instruct patient on removal in 24-48 hours 9

Critical Pitfall - Avoid Simple "Incision and Drainage":

For hidradenitis suppurativa and recurrent abscesses, deroofing (removing the entire roof of the abscess cavity) is superior to simple I&D, which has nearly 100% recurrence rates. 1

• Simple I&D has 100% recurrence in HS 1
• Deroofing technique: probe the abscess, remove overlying skin stepwise, leave base intact - 17% recurrence rate 1
• For small lesions, use punch biopsy tool for deroofing 1

Antibiotic Indications

Antibiotics are NOT routinely needed after I&D of simple cutaneous abscesses; prescribe antibiotics only for surrounding cellulitis, systemic symptoms, immunocompromised state, or failed drainage. 2, 9

When to Prescribe Antibiotics:

• Surrounding cellulitis extending >2cm from abscess 2
• Fever or systemic inflammatory response 2
• Immunocompromised (diabetes, steroids, chemotherapy) 2, 3
• Multiple abscesses or recurrent MRSA infections 9

Antibiotic Coverage:

• Simple abscesses: Cover Staphylococcus aureus (including MRSA) - use TMP-SMX or doxycycline 2
• Perianal abscesses: Broad-spectrum coverage for mixed flora - use fluoroquinolone plus metronidazole or amoxicillin-clavulanate 1

Post-Procedure Care and Follow-Up

Discharge Instructions:

• Daily wound care: Clean with mild soap and water, apply clean dressing 9
• Sitz baths 2-3 times daily for perianal abscesses 9
• Remove packing in 24-48 hours if placed 9
• Pain control: NSAIDs preferred over opioids 9

Follow-Up Timing:

• Recheck in 48-72 hours to ensure clinical improvement 9
• Routine imaging follow-up is NOT indicated after successful drainage unless symptoms persist, abscess recurs, or fistula is suspected 10

Warning Signs Requiring Immediate Return:

• Increasing redness, warmth, or swelling 9
• Fever or chills 9
• Red streaks extending from the site 9
• Worsening pain after initial improvement 9

Special Populations and Considerations

High-Risk Patients for Poor Outcomes:

• Morbid obesity - 3x risk of reoperation 3
• Preoperative sepsis - increased hospitalization and reoperation risk 3
• Dependent functional status - higher reoperation and readmission rates 3
• Female sex - increased readmission risk for perirectal abscesses 3
• Immunosuppression/steroids - higher readmission rates 3

Perianal Abscess Specific Considerations:

For perianal abscesses in Crohn's disease, drain adequately but do NOT probe for fistulas or lay open any obvious fistula tracts - place a loose draining seton only if a fistula is obvious without probing. 1

• Assess rectum for proctitis during drainage 1
• 44% recurrence rate after drainage - close surveillance needed 10
• Risk factors for recurrence: inadequate drainage, multiple locules, horseshoe configuration, delayed presentation 10

COVID-19 Era Modifications:

• Treat all patients as potentially COVID-positive until proven otherwise 1
• Use appropriate PPE for all procedures 1
• Consider conservative management when feasible to preserve resources 1
• Perform procedures under local anesthesia in outpatient settings when possible to avoid OR utilization 1