To the Editor:—
Continuous peripheral nerve blocks have been associated with sustained effective postoperative analgesia, 1–3opioid sparing, 4,5improved rehabilitation, 6and improved patient well being. However, the catheters used to deliver local anesthetic are frequently difficult to secure and maintain in the correct position. Several methods to fasten catheters have been advocated, such as suturing, retrograde subcutaneous tunneling, 7cutaneous sutures, 8and different methods of taping. Nevertheless, accidental dislodgement is still a frequent problem particularly with freely mobile sites, such as the neck and the axilla or lumbar region where perspiration is prominent. Having a simple, noninvasive, reliable method for catheter fixation would be beneficial. We report cases of three patients undergoing outpatient continuous nerve catheters secured with 2-octyl cyanoacrylate glue (Dermabond® Topical Skin Adhesive, Ethicon, Somerville, NJ).
The first patient was scheduled for left knee manipulation followed by use of a continuous passive range of motion machine. As part of the anesthetic plan a lumbar plexus block 9was performed. The patient's back was prepped using Betadine® (Purdue Fredrick, Stamford, CT) and isopropyl alcohol. The block was placed using an 18-gauge 150-mm insulated Tuohy needle (B. Braun Medical, Bethlehem, PA) and a 20-gauge standard polyamide epidural catheter. After placement, the catheter was pulled taught against the skin. Using a sterile applicator the 2-octyl cyanoacrylate adhesive (Dermabond® Topical Skin Adhesive) was applied from the puncture site along 5 cm of the catheter's length. After approximately 4 min, the adhesive formed a clear coating that was not tacky to touch. The puncture site was then covered with a sterile transparent dressing. The patient was discharged home the next day with a disposable infusion pump delivering local anesthetic. On return to the ambulatory center 56 h later, the lumbar plexus transparent dressing was firmly adherent but easily peeled off. With moderate force, the catheter was then pulled away from the skin, from its distal attachment toward the puncture site. The catheter was then easily removed. No abrasion or irritation of the skin was noted along the previous location of the catheter.
The second patient was scheduled for a rotator cuff repair and placement of an interscalene catheter. Using a 3.8-cm insulated Tuohy needle and the same technique, a continuous interscalene block was performed. 10After the catheter was placed, it was also secured using the 2-octyl cyanoacrylate adhesive as described with the first patient. This patient spent the first postoperative night in the recovery care center and was discharged home with a continuous interscalene infusion. On return to the ambulatory center 59 h after the initial block, there was no leaking at the insertion site. This catheter was also firmly adherent but easily removed. A transparent strip of adhesive approximately 1 cm wide was still firmly attached to the catheter. No abrasion or irritation of the skin was noted along the previous location of the catheter.
A third patient was scheduled for left knee arthroscopy. The surgeon anticipated an extensive repair with expected intense postoperative pain. A continuous lumbar plexus block was performed without difficulty. After placing the catheter, it was secured using the 2-octyl cyanoacrylate adhesive. The arthroscopy revealed less damage than the initial physical examination and imaging studies and no formal operative procedure was done. The patient was expected to have minimal postoperative pain and be discharged the same day. In the post anesthesia care unit, despite its recent placement, the catheter was easily removed. A 5-cm abrasion was noted along the previous location of the catheter. The patient reported no pain with removal.
The bonding agent used in these three cases was 2-octyl cyanoacrylate (Dermabond® Topical Skin Adhesive). The adhesive comes as a sterile liquid in a monomeric formulation along with the colorant D & C violet #2. It is supplied in a single-use sterile blister pouch. The applicator is composed of a crushable glass ampoule contained within a plastic vial with attached applicator tip. Once applied to the skin, the liquid adhesive is slightly more viscous than water and polymerizes within 1–3 min. This forms a flexible coating that is permanently bound to the keratin in the epidermis and cannot be removed with water-based products. During the bonding process, a mild exothermic reaction takes place that may be perceived as heat by the patient. The bond may be weakened with acetone or petroleum jelly. Prior to administration, it is necessary to remove iodine-based antiseptic solutions because these may inhibit polymerization. After a typical application, the coating lasts approximately 5–10 days and sloughs off naturally with the epithelium. The product is approved by the Food and Drug Administration in place of topical sutures or staples and is marketed for its improved cosmetic results.
In these three cases, the glue formed a transparent shiny layer over the insertion site and appeared to completely seal the needle puncture site as well as the catheter. No break in the layer could be detected. However, as a precaution against contamination, a transparent dressing was also placed over the entry site. Because of the cyanoacrylate, the dressing adheres tighter than it normally does to skin. We hypothesize that placing the dressing over the glued layer may be superfluous but clinical data are necessary to support this.
An obvious disadvantage of an adhesive that binds so permanently to the skin is seen when a catheter needs to be removed soon after administration. During this time, the epidermis may not have had time to slough off, making removal difficult. In the third patient presented here, this situation occurred. Despite the tight bond, we were able to peel the catheter from the skin. This maneuver created a thin (diameter of the 20-gauge catheter) 4-cm-long abrasion that was barely visualized, where the keratin of the epidermis was removed with the catheter. We suspect that if the catheter had been glued with a greater surface area (coiled on the skin) or below a flat piece of plastic it would have been harder or more traumatic to remove.
In summary, this technique offers a simple, alternative method to secure a catheter for a prolonged period of time. Because of the permanent bond, this method may be advantageous in highly mobile locations as well as areas subject to perspiration. The technique may have applicability for other uses, such as epidural catheters, invasive lines, and surgical drains. Given the results in these patients, further study comparing this technique with more traditional methods seems warranted.