Discrepancies Between Estimated and Expressed Abscess Volume in Pediatric Incision and Drainage

Abstract

Background: Incision and drainage (I&D) is the standard treatment for pediatric abscesses. However, discrepancies between estimated abscess volume, determined clinically or by point-of-care ultrasound (POCUS), and the actual volume expressed may result from poor ultrasound or I&D technique. These discrepancies may lead to inappropriate management decisions and unnecessary procedures.

Objective: To determine the prevalence of discrepancies between estimated and expressed abscess volumes during pediatric I&D.

Methods: We conducted a cross-sectional chart review at a tertiary care pediatric emergency department (ED) between 2017 and 2023. Patients younger than or qual to 21 years with an attempted I&D were identified using a natural language processing tool. We focused on 2 groups based off of documented abscess diameter: predicted volumes of ≤1 mL and ≥10 mL. Per author discretion, these values correspond with decision-making of 'not worth pursuing I&D' and 'definitely worth pursuing I&D', respectively. We considered a positive discrepancy if for an expected abscess volume of ≤1 mL, the documented volume expressed was ≥10 mL (underestimated), and if for an expected volume of ≥10 mL, the documented volume was ≤3 mL (overestimated). Prevalence and confidence intervals were calculated using descriptive statistics.

Results: Among 653 patients, 13.2% of sonographic and 7.6% of clinical estimates underestimated abscess volume, whereas 2.3% of sonographic and 19.6% of clinical estimates overestimated abscess volume. Combined assessment reduced discrepancies to 5.2% underestimated and 1.2% overestimated.

Conclusions: Combining clinical with POCUS assessment of pediatric abscesses provides better prediction of volume than reliance on a single method potentially reducing unnecessary procedures and missed I&D opportunities.

Keywords: abscess; incision & drainage; pediatric; point-of-care ultrasound.