Western Journal of Emergency Medicine: Integrating Emergency Care with Population Health

Objectives: To determine whether there is a relationship between body mass index (BMI) and success or accuracy rate of BUS for the diagnosis of appendicitis. Methods: Patients 4 years of age and older presenting to the emergency department with suspected appendicitis were eligible.Enrollment was by convenience sampling. After informed consent, BUS wasperformed by trained emergency physicians who had undergone a minimum of 1-hour didactic training on the use of BUS to diagnose appendicitis. Subject outcomes were ascertained by a combination of medical recordreview and telephone follow-up.  Calculated BMI for adults and children were divided into 4 categories(underweight, normal, overweight, obese) according to Centers for Disease Control and Prevention classifications.Results: A total of 125 subjects consented for the study, and 116 of them had adequate image data for final analysis.  Seventy (60%) of the subjects werechildren.  Prevalence of appendicitis was 39%.  Fifty-two (45%) of the BUS studies were diagnostic (successful). Overall accuracy rate was 75%.  Analysis by Chi-square test or Mann Whitney U did not find any significant correlation between BMI category and BUS success. Similarly, there was no significant correlation between BMI category and BUS accuracy.  Same conclusion was reached when children and adults were analyzed separately, or when subjects were dichotomized into underweight/ normal and overweight/ obesecategories.  Conclusion: BMI category alone is a poor predictor of appendix BUS success or accuracy.