Introduction- Acute abdomen is a sudden onset abdominal disease condition which often requires an immediate surgical intervention. Appendicitis is an inflammation of the vermiform appendix and is one of the most common causes of an acute abdomen in young adults. Appendicitis can cause severe periumbilical pain that radiates to the right lower quadrant, nausea, vomiting and anorexia. If left untreated, it can also cause appendiceal abscess, perforation and peritonitis.

Objective- To assess treatment outcomes of Acute Appendicitis and associated factors among admitted patients with a diagnosis of acute abdomen in Debre Markos referral hospital from September 11/2018 to March 9/2019.

Methods and materials- Institutional based cross sectional study was employed among 169 patients using a census sampling method. Data were collected from patient medical records, registration books and anesthesia charts available in the hospital by using checklist. Data was entered using Epi-data version 4.2 and analyzed by SPSS version 25 software. Logistic regression analysis was employed to describe the relationship between outcome and predictor variables.

Results - Among 303 patients with a diagnosis acute abdomen, 169(55.7%) were developed acute appendicitis, of whom, 107(63.7%) were males and 62 (36.7%) were females.  Among 169 patients who underwent appendectomy for treatment of acute appendicitis, 45(26.6%) of them were developed unfavorable treatment outcomes. The odds of unfavorable treatment outcomes for acute appendicitis was higher among patients who had elevated WBC count at the time of presentation [AOR=4.7; 95% CI (1.95, 11.35)] as compared with their counterparts. Similarly, those patients who had an intraoperative appendiceal abscess were more likely to have unfavorable treatment outcome for acute appendicitis [AOR= 3.8; 95% CI (1.61, 9.07)] as compared to those who didn’t have appendiceal abscess.

Conclusion and recommendation- Nearly one-fourth of patients who underwent appendectomy for appendicitis treatment were developed unfavorable treatment outcomes.  Elevated WBC count at the time of presentation and presence of intraoperative appendiceal abscess were the factors associated with unfavorable treatment outcome of acute appendicitis. Therefore, immediately evaluate patients having similar features with laboratory investigations is crucial