Ultrasound Diagnosis of Intussusception

Alison Kearns, MS4

Article: Trigylidas TEHegenbarth MAPatel LKennedy CO'Rourke KKelly JC. Pediatric emergency medicine point-of-care ultrasound for the diagnosis of intussusception. Journal of Emergency Medicine. August 9, 2019.

Goal: Early recognition of ileocolic intussusception in children is important for early intervention with air enema to prevent further complications such as ischemia, necrosis and perforation. Therefore, the goal of this study was to evaluate the utility and accuracy of PEM POCUS in identifying ileocolic intussusception. Secondary objective was to determine factors associated with enema failure which may lead to further complications and need for surgery.

Experimental Design: Retrospective study of children who underwent POCUS for suspected intussusception in a pediatric emergency department between January 2001 and December 2015.  The facility was an urban, tertiary cared PED with an annual census of 70,000. The physicians of the study were trained on the use of POCUS for diagnosis of intussusception. Patients were included if the POCUS was confirmed by a radiologist, a radiologic ultrasound, or an air enema. Those that did not receive a confirmatory ultrasound either had resolution of symptoms or an alternative diagnosis established.

Results: 508 patients in the ED during this study period were found to have intussusception and 112 patients underwent POCUS. 11 patients were excluded: 7- small bowel intussusception, 2-negative POCUS and 2-indeterminant results. Of 75 patients with intussusception 72 were detected with POCUS. The mean age of patients was 22 months. 19% were <6mos of age, 67% were 6-36mos of age and 15% were >36mos of age. PEM POCUS had a sensitivity of 96.0% and a specificity of 92.6%. 20% of patients had lesions distal to the splenic flexure. 72 patients had air enema performed. 5 patients with confirmed POCUS for intussusception had resolution of the symptoms before initiation of air enema. 27% of patients failed air enema and required surgery. Air enema failure was found to be associated with location distal to the splenic flexure and age <6mos.  The finding of age <6mos was in contrast to other studies which have found age >36mos to be associated with air enema failure.

Room for improvement: This was a retrospective not prospective study making it vulnerable to omissions and selection bias.  Of 508 patients with intussusception only 112 underwent POCUS. Is it possible it was not done on older patients for suspected lead point or longer symptom durations. Physicians were not blinded to studies from outside hospitals. Small bowel intussusception was excluded, however some indeterminate studies were excluded possibly artificially improving their specificity.

Conclusion: PEM POCUS identifies intussusception with high sensitivity and specificity. These results emphasize the importance of specifying anatomic location of intussusception for predicting success or failure of air enema.