Performing incision and drainage on an abscess is painful for the patient. I realize that is as obvious a statement as I could possibly make. I wanted to briefly touch on some of the many interventions that you can use to decrease pain during I&D.
Before the procedure
Consider factors that will impact tolerance of the procedure
- Developmental level – can the child comprehend what you are doing and agree to hold still
- Prior procedures/experiences – Has this patient had an I&D before? How was it done? Was adequate local anesthesia used – or were they just “held down” while some doctor squeezed the abscess.
- Patient and parent anxiety level – Generally the antidote to this is good preparation and education about what the procedure entails. You know, the risks and benefits stuff that should not be glossed over when obtaining consent.
- Expected duration of procedure – Is this a big abscess? Will it take longer than 30-40 minutes? Is it a pilonidal or hidraadenitis suppartiva? Some abscesses are better managed in the OR.
- Developmental delay, autism and sensory disorders – It goes without saying that a toddler and a teenager can tolerate an I&D in very different ways. Relying on the parent to help you understand how a child’s developmental delay will impact tolerance of the procedure is critical obviously.
- Location, size and number of abscesses – Children with abscesses in areas with a high density of nerve endings will experience more pain. Examples include the face, genitals and perirectal area.
- Can the patient be safely held? – You definitely want ot make sure the child can protect their airway. If a child cannot be safely held without compromising the ABCs then the abscess may need to be drained in the OR.
- Do you have support personnel like a Child Life Specialist available?
Utilize local anesthetics properly
- Apply Lidocaine 4% cream before the procedure – I recorded a podcast on this one. Note that LMX works a bit faster than EMLA, but that both are appropriate. LET is only used on lacerated skin. You can expect that LMX or EMLA will provide topical anesthesia for a depth of 2-3mm max. This is NOT sufficient for the full I&D, but it will reduce the pain of local injection to a degree.
- Use buffered Lidocaine (9:1 ratio with 8.4% Bicarbonate – e.g. 1 mL bicarb to 9 mL lidocaine) – Lidocaine is acidic. Acids hurt when they are injected into your skin. Buffering with bicarbonate solution can reduce the pain of subcutaneous injection.
- Use a smaller needle and inject slowly – I prefer a 1 inch to 1.5 inch 27 gauge needle. The smaller gauge limits the speed at which lidocaine enters the skin and reduces discomfort.
- Warm the lidocaine – colder lidocaine hurts more. Room temperature is fine.
- Stimulate the skin adjacent to the injection site – Do you find yourself instinctively rubbing your elbow when you smack your “funny bone?” What you are effectively doing is stimulating adjacent nerves to “cross the signals” and confuse the pain sensing fibers. You can do this by hand, or with a device like the Buzzy.
- Use good ring block/field block technique – Remember that an abscess is roughly a circular shaped lesion. Therefore, pain innervation comes from all angles. You should not simply inject at the incision site. Calculate your max dose of lidocaine (4-5 mg/kg for 1% lidocaine without epi, 7 mg/kg with epi) and aim just deep enough to create a subtle wheal and to hit the junction point of the local nerve fibers. Insert a 27 to 30 gauge needle at an oblique angle just under the epidermis a small distance away from the edge of the abscess (avoid injecting into the abscess which can be painful and ineffective). Inject in a ring around the abscess, going through already-numb skin when possible (this is where the topical 4% lidocaine helps). A recent survey based study indicated that only 60% of Emergency Medicine physicians used this technique.
- Wait at least 3 minutes for full effect – Lidocaine takes time to work on those sodium channels. Wait at least 3 minutes, but ideally 5 to 7 for the patient to be comfortably numb.
Consider adjuvant medications
It’s generally a good idea to give pain medicines before the procedure, especially if you aren’t going to use sedation. Remember that older children may need sedation as well, especially those who are anxious, have large abscesses (requiring packing), have had prior I&D’s, or have abscesses in painful locations (face, genitalia, axilla).
If you need to control pain only
- Fentanyl – 2 mcg/kg IN or 1 mcg/kg IV Max 100 mcg/dose. Useful in children with small abscesses when local anesthesia is adequate. May not be adequate if anxiety is a significant component.
If you only need a little anxiolysis
- Midazolam – 0.5-1 mg/kg PO (higher doses under age 6). Max 20 mg. Useful in children with small abscesses when local anesthesia is adequate. But NOT helpful if local anesthesia is not adequate to reduce anxiety (i.e. you can’t reason with them).
If you need to control pain and anxiety
- Moderate/procedural sedation – Institutional procedures may vary, but generally this involves drugs like ketamine, propofol or combinations thereof. I use ketamine most often and find that an initial dose of 1.5 to 2 mg/kg in children under 6-8 years of age is more effective.
- Nitrous – If you have it gas is a great option for the calm, mature child (> 4 years of age for nasal mask, > 2 years of age for face mask).