Abstract 1: Loop drainage vs. incision and drainage in the ED

Loop drainage is noninferior to traditional incision and drainage of cutaneous abscesses in the emergency department Schechter-Perkins EM, Dwyer KH, Amin A, et al. Acad Emerg Med. Published online May 14, 2020. doi:10.1111/acem.13981

SUMMARY:

• This was a prospective, single-blinded, two-arm noninferiority trial of the loop drainage technique (LD) vs traditional incision and drainage (I&D) for management of cutaneous abscesses in the ED.
• Patients were eligible if they were ≥18 years old, had at least 1 abscess, could provide consent, had a contact phone number, and agreed to return for a study close-out visit in 2 weeks. The study excluded patients being hospitalized, patients previously treated for the abscess, and patients who had a surgical specialist perform the drainage.
• The decision to use ultrasound, the pain medication, the local anesthetic choice, and the discharge antibiotics were decided by the treating physicians.
• Participants in the I&D arm received long incision, loculations were broken up, and irrigation and packing were performed.
• Participants in the LD arm received two stab incisions, loculations were broken up, irrigation was performed, and a vessel loop (Coviden Devon surgical vessel loop) was threaded through and loosely tied; patients in this arm were told to manipulate the loop 2 or 3 times per day and, if they felt comfortable doing so, to cut and remove it themselves a few days after the abscess was better.
• The primary outcome was clinical resolution at 14 days (no erythema, warmth, induration, fluctuance, tenderness, or drainage), and secondary outcomes were the number of hospital visits and complications (repeat drainage, new or different antibiotics, or admission).
• Although the study enrolled and randomized 238 participants, after randomization, 5 patients from each group dropped out because of hospitalization, and approximately 100 more were lost because of failure to attend the 14-day follow-up for assessment of the primary outcome.
• The patients were approximately 40 years old, most patients were male, and approximately half had an abscess diameter <3 cm.
• The abscess resolved in 81.5% of participants in the I&D arm vs 88% in the LD arm (the difference was within the predetermined noninferiority margin of 10%).
• Because of the high rate of loss to follow-up, the authors performed several sensitivity analyses with different assumptions about missing data, and noninferiority was maintained in each.
• The mean number of ED visits was 1.3 in the LD group vs 1.8 in the I&D group, and complications were seen in 9.3% of the LD patients vs 24.6% of the I&D patients (mostly new antibiotics).
• Although not presented as such, the specific complications in Table 3 indicated that 5.3% of the patients in the LD group required another procedure vs 1.5% of the patients in I&D group.
• Study limitations (beyond the loss to follow-up) include that a convenience sample of patients was studied; there was a potential for loss of blinding in the assessment; information on repeat visits came from the electronic medical records, and therefore any visits to other EDs were missed; the abscesses appeared to be fairly small; and all patients in the I&D group were packed—a controversial practice.
• The study could have been improved by reporting patient-focused data, such as pain during the procedure, patient satisfaction with treatment, and how many patients actually removed their own loops.

PMID: 32406569

EDITOR’S COMMENTARY: In this randomized trial, the authors found the LD technique to be noninferior to traditional I&D for ED management of cutaneous abscesses, at a 14-day follow-up. Although the authors conducted various sensitivity analyses, almost half the patients were lost to follow-up. The overall complication rate was lower with LD; however, the proportion of patients needing a second procedure was higher. I think this technique is worth learning, and other studies have suggested that it is superior in terms of patient comfort and for specific populations (eg, pediatric), but I would have liked to see some patient-focused data in this trial.

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