A 65 year old female complains of pain abdomen for ten hours, single episode of vomiting, tenesmus. There are no comorbidities. Heart rate 80 per minute, afebrile. On examination, there is epigastric tenderness.

Rest of the abdomen is soft. Ultrasound abdomen is suggestive of acute appendicitis. The patient responses to single injection of tramadol. What should be the next line of management?