Tricks of the Trade: Alternatives to I&D Procedure and Fingernail Avulsion Repair
By Michelle Lin, MD
The traditional approach for administering local anesthesia for the incision and drainage (I&D) of abscesses is a circumferential field block. This involves infiltrating a subcutaneous ring of anesthesia around the abscess. For large abscesses, this may require a large volume of an anesthetic. This becomes important because of the risk of anesthetic toxicity.
Trick of the Trade: Calculate local anesthesia dosages. To calculate the number of milligrams you are administering, multiply the volume of the anesthetic (in cc) by the percent solution. Then simply add a zero at the end.
As an example, how many milligrams of lidocaine are you instilling by using 15 cc of 2% lidocaine? To find out, first multiply 15 by 2, which equals 30. Adding a zero results in 300 mg. This is near the toxic dose of lidocaine, which is 5 mg/kg, or 350 mg for a 70-kg person.
This trick is courtesy of Dr. Grant Seifred, an emergency physician at St. Joseph's Hospital in Hamilton, Ont.
Trick of the Trade: Anesthesia for an I&D procedure. To reduce the risk of anesthetic toxicity and to minimize the number of needlesticks needed to create a ring block around an abscess, an alternative is to infiltrate anesthetic directly over the maximal point of pain: the incision site.
Because the skin overlying the abscess is already under significant tension, minimize the volume of local anesthesia used. Often only 1 cc of a local anesthetic is necessary initially (see photo A). When it is infiltrated with a 29- or 30-gauge needle, many patients tolerate this initial step extremely well. Using a scalpel, make a stab-incision of the abscess through the wheal of anesthesia to release the purulent material. Squeeze as much pus out as possible.
Next, extend the area of anesthesia linearly along the diameter of the abscess now that the skin is under less tension (see photo B). Make an incision over this anesthetized area to release more pockets of pus. Pack the abscess in the usual fashion.
This two-part approach is a less painful technique in the treatment of abscesses.
Trick of the Trade: Fingernail avulsion repair. An avulsed fingernail traditionally is repaired by suturing it in place to keep the eponychial fold open. Premature fusion of the eponychial fold prevents outgrowth of a new nail.
Securing the nail to both paronychial skin edges often requires drilling two holes in the nail to pass the suture through more easily. Trying to use the suture needle without drilling may lead to needle bending or breakage.
A fast, safe, and effective alternative is to use a tissue adhesive to secure the reinserted nail in place (see photo C).
This trick is courtesy of Dr. David Carr, an emergency physician and assistant director of education at the University Health Network in Toronto.
Dr. Lin practices emergency medicine at San Francisco General Hospital (SFGH) and is the associate program director at the UCSF-SFGH Emergency Medicine Residency Program. Contact Dr. Lin at email@example.com for comments or suggestions for other "tricks of the trade."