Clinical Characteristics, Outcomes, and Interobserver Agreement of Point-of-Care Ultrasound Detected Mesenteric Adenitis in Nonsurgical Pediatric Abdominal Pain: A Retrospective Cohort Study.

Objectives: Point-of-care ultrasound (POCUS) in the emergency department (ED) may facilitate the diagnosis of nonsurgical sources of abdominal pain after surgical causes are excluded. Identifying mesenteric adenitis is a feasible POCUS application due to its ease of use and speed. However, there are scant data regarding the diagnosis of mesenteric adenitis by POCUS. The objective of this study was to describe the clinical characteristics, outcomes, and interobserver agreement of mesenteric adenitis identified on POCUS in pediatric patients with nonsurgical abdominal pain.

Methods: This was a retrospective review at a tertiary-care, urban pediatric ED. All cases of mesenteric adenitis diagnosed on POCUS from January 2018 to August 2022 were reviewed. Demographics and clinical data, including relevant outcomes, were recorded. All POCUS videos were reviewed by a senior sonologist-physician for determination of mesenteric adenitis in children 21 years and younger with nonsurgical abdominal pain. Interobserver agreement by Cohen κ was calculated between experienced and novice physician sonologists blinded to diagnosis, who reviewed 77 six-second video clips for presence or absence of mesenteric adenitis.

Results: Thirty - three subjects were identified by POCUS to have mesenteric adenitis in the setting of nonsurgical abdominal pain presenting to our ED. Most common indications for POCUS were for suspected appendicitis, suspected intussusception, or undifferentiated abdominal pain. Forty-six percent of patients were male; median age was 9 years (interquartile range, 4-14 years). On 4-week clinical follow-up, 1 patient returned to our ED with a surgical abdomen. Cohen κ values were 0.83 (95% confidence interval, 0.70-0.97) between experienced sonologist-physicians and 0.76 (95% confidence interval, 0.61-.90) between novice and experienced sonologist-physicians.

Conclusions: POCUS can identify mesenteric adenitis, typically a diagnosis of exclusion, in pediatric patients with nonsurgical abdominal pain, both by novice and experienced physician-sonologists. Use of POCUS may help ED clinicians identify a common cause of nonsurgical abdominal pain in children.