Conservative Versus Operative ManageMent of Acute Uncomplicated Appendicitis (COMMA)

This study aims to compare antibiotic treatment versus surgery for patients with uncomplicated appendicitis.

The study will include patients aged 16 and over, with a first admission with right iliac fossa pain and a raised white cell count or C-reactive protein. Patients will be randomised electronically in a 1:1 ratio either to undergo emergency appendectomy or to receive intravenous antibiotics as an inpatient, until clinical and biochemical improvement is observed, followed by outpatient oral antibiotics. Those who have surgery will have 3 post-operative doses of intravenous antibiotics, unless perforation was identified at the time of surgery, in which case, microbiology will be contacted to advise regarding antibiotic choice and duration. Follow-up by telephone interview will be at 1 week, 1, 3 and 12-month intervals.

Laparoscopic +/- open appendicectomy, with antibiotics at induction and 3 further doses of intravenous antibiotics. Co-amoxiclav, or cefuroxime and metronidazole if previous rash-allergy to penicillin.

Intravenous antibiotics until clinical improvement and then 5 further days of oral antibiotics. Co-amoxiclav, or if rash-allergy to penicillin, cefuroxime and metronidazole.

Laparoscopic +/- open appendicectomy , with antibiotics at induction (intravenous co-amoxiclav 1.2g, or if penicillin allergic, cefuroxime 1.5g + metronidazole 500mg ), followed by 3 further intravenous doses of the same antibiotic. If a perforation is identified at the time of surgery, microbiology will be contacted regarding choice and duration of of antibiotic.

Intravenous co-amoxiclav 1.2g three times daily, then 625mg, orally three times daily. If penicillin allergic, intravenous cefuroxime 1.5g three times daily + metronidazole 500mg three times daily, then oral cefuroxime 500mg twice daily + oral metronidazole 400mg three times daily. The patient will receive inpatient intravenous antibiotics until sufficient clinical improvement is noted by the surgical team, who will be assessing the patient twice daily. After discharge the patient will receive 5 further days of oral antibiotics.

Successful treatment is defined as the resolution of appendicitis resulting in discharge from the hospital and no recurrent appendicitis during the one-year follow-up. The number of patients requiring surgery for appendicitis in the non-operative group will be measured.

Confirmed appendicitis occurring after discharge and within one year of enrolment. The number of patients with appendicitis confirmed on either imaging or pathology will be measured.

Confirmed symptomatic clostridium difficile infection occurring within one year of enrolment. Any patient who presents with diarrhea during the follow-up period or reports diarrhea during assessment with the follow-up questionnaire will be asked to provide a stool sample which will be tested for clostridium difficile toxins.

Recurrence or non-resolution of abdominal pain requiring re-admission or re-imaging after discharge and within one year of enrolment. The number of patients who need to be re-admitted to hospital for abdominal pain or require ultrasound, MRI or CT for investigation of abdominal pain during the one year follow-up will be measured.

Quality of life will be measured in both treatment groups at 1 week, 1 month, 3 months and 1 year post enrolment. Quality of life will be measured using the EQ-5D-3L validated quality of life questionnaire.

Complications of treatment including surgical site infection, abscess formation and ongoing pain will be measured.

Inclusion Criteria: Right iliac fossa pain 1st episode in the past 1 year Raised WCC or CRP Fluent in English Exclusion Criteria: History of inflammatory bowel disease or appendectomy B-HCG positive Significant co-morbidities Complicated appendicitis as proven by ultrasound, CT or MRI Anaphylaxis to penicillin