AJR:191,0ctober2008
Robert O. Nathan, C. Craig Blackmore, Jeffrey G. Jarvik
OBJECTIVE. The purpose of this study was to prospectively evaluate the therapeutic impact of CT of the appendix in a community hospital.
SUBJECTS AND METHODS. For each of 100 consecutive adult patients who presented to a community hospital emergency department from August 2006 to November 2006 and underwent CT of the appendix, the proposed treatment plan and the likelihood of appendicitis were recorded before CT and were compared with the actual treatment after CT. The primary outcome assessed was change in patient management after CT. The percentage likelihood of appendicitis, whether patient disposition changed after CT, and the presence or absence of appendicitis were examined. The accuracy of CT was also calculated.
RESULTS. The treatment plans of the emergency clinicians changed in 29 patients (29%). Appendicitis was ruled out on the basis of CT findings in 50% (9/18) of patients when appendicitis was considered probable and in 60% (3/5) when appendicitis was considered very likely. When appendicitis was considered unlikely, appendicitis was ruled out by CT in 100% (20/20) of patients. CT of the appendix was shown to have high sensitivity (94%), specificity (100%), positive predictive value (100%), negative predictive value (99%), and accuracy (99%).
CONCLUSION. CT of the appendix had an important therapeutic impact on patients presenting to a community hospital emergency department. The data suggest that CT can be withheld in patients in whom emergency clinicians rate the likelihood of appendicitis as unlikely but that CT findings are often of benefit even when appendicitis is judged to be very likely.