Clinical outcomes unaffected by ultrasound-first paradigm

Transitioning to an ultrasound-first pathway for the imaging workup of acute appendicitis in children occurred without evidence of a corresponding increase in the proportion of patients or in the median hospital length of stay (LOS), according to a study published in the December 2013 issue of the American Journal of Roentgenology.

With the increasing frequency of appendicitis in pediatric patients in the US, ultrasound and CT are most often used to evaluate patients with symptoms of acute appendicitis. However, the use of CT in pediatric patients is under reevaluation due to risks associated with pediatric patient exposure to ionizing radiation.

“As a result, there has been increasing support for an ‘ultrasound-first’ paradigm in the imaging evaluation of appendicitis in which ultrasound is used as the initial imaging modality and CT is used if the ultrasound results are equivocal or raise additional questions, such as a possible abscess,” wrote Jenna Le, MD, Montefiore Medical Center and the Children’s Hospital at Montefiore, located in the Bronx, New York, and colleagues.

The authors designed a retrospective study to investigate whether there was an increase in the rate of complicated appendicitis and in the median LOS during the transition to an ultrasound-first pathway. All pediatric patients with surgically proven appendicitis from 2005-2011 at the authors’ institution were identified by using the hospital billing database. The annual trends of the proportions of patients who underwent ultrasound and CT were determined and plotted for the study period. The authors then assessed the correlation of complicated appendicitis and median hospital LOS with calendar year.

The study’s inclusion criteria was met by 804 patients. The percentage of patients who underwent CT only showed a moderate downward association with year, and the percentage of patients who underwent ultrasound first showed a moderate upward trend. The percentage of patients with ultrasound as the only study performed before appendectomy increased moderately over the seven year study period. The percentage of patients with complicated appendicitis and the median hospital LOS did not increase significantly over the study duration.

“A staged protocol of first performing ultrasound and then performing CT if necessary has been shown to be cost-effective and follows the principle of ALARA (as low as reasonably achievable) and the goal of the Image Gently campaign,” wrote the authors. “Our study now provides data to suggest that in a routine hospital setting (without either a special research study protocol or research study selection bias) the transition to the ultrasound-first paradigm was not associated with an increase in the proportion of patients with complicated appendicitis or a change in the median LOS.”