Optimizing the Diagnosis of Acute Appendicitis (OPTIMA)

Optimizing the Diagnosis of Acute Appendicitis - Open, Randomized, Parallel Groups, Prospective Clinical Trial

Aim of the study: to identify the signs of acute appendicitis delta signs - clinical, laboratory or ultrasound signs, whose change (delta) would allow to identify or deny the diagnosis of acute appendicitis without a computed tomography examination and thus to lower computed tomography rates.

This study consists of two parts: In the first part investigators enroll all patients (except pregnant) that are refered to Vilnius University Hospital Santaros clinics with suspected acute appendicitis in order to get cohort data. All patient get primary clinical evaluation, laboratory tests (WBC, CRP) an ultrasound examination. After primary evaluation if final diagnosis could not be made, and investigator still suspect acute appendicitis, participant is included in to randomised study part. Randomised sudy part has two arms: control and observation groups. Control group get the traditional diagnostic path - is refered to CT scan examination. Observation group get repeated evaluation after 8-12 hours and only than is diagnosis stays unclear, patient gets a CT scan. All patient are contacted after 30 days after visit to our hospital, to get information about their health status and possible additional visits to other hospitals or operations.

Patient after inconclusive primary evaluation is observed in emergency room for 8-12 hours and after the clinical evaluation, laboratory results and ultrasound examination is repeated.

Patient after primary investigation is observed for 8-12 hours, (instead of being send directly to CT scan), after observation repeated clinical evaluation, laboratory tests and ultrasound examination are done , if final diagnosis stays unclear the patient is refered to CT scan.

when performing alternative diagnostic protocol, that includes patient observation for short period we expect to reduce a number of CT scans performed, for the patients with suspected acute appendicitis.

We expect the negative appendectomy rate will will not increase while using alternative diagnostic protocol that includes patient observation.

The changes in white blood cell count over the time that might show higher or lower probability of possible acute appendicitis.

The changes CRP level over the time that might show higher or lower probability of possible acute appendicitis.

Delta marker Alvarado acute appendicitis risk evaluation score Tha changes in score over the time that might show higher or lower probability of possible acute appendicitis. Scale ranges decribe a prediction of having acute appendicitis: 1-4 33 % of having appendicitis, 5-6 66 % of hanving, 7-10 93 % of having appendicitis.

The changes in ultrasound findings over the time may progress and influence investigator to change opinion about the concusion. Repeated ultrasound diagnosis might change from unequivocal to acute apendicitis (and CT scan can be avoided then). We do use structured conclusions of the ultrasound exam, that might be: accute appendicitis; apendix visualised but changes are equivocal; apendix visualised uninflamed; apendix not visualised, but there are secondary findings; apendix not visualised and there is no secondary findings. We are going to measure the change in final ultrasound diagnosis over the time.

'Appendicitis Inflammatory Response (AIR) Score') evaluates the risk for acute appendicitis. scale ranges are: 0-4 low probability outpatient follow up, 5-8 inermediate probability in hospital observation, 9-12 high probability, surgical treatment..

Inclusion Criteria: Patient with the symptoms of acute appendicitis: pain in the right lower quadrant, pain migration from epigastrium to right lower quadrant, nausea, rebound pain, elevated temperature. Exclusion Criteria for randomized part: Pregnant patient. Inclusion Criteria for randomized part: After primary clinical, laboratory and ultrasound examination diagnosis of acute appendicitis could not be confirmed or excluded. No other gynecological, urological ir gastroenterological pathology is confirmed. Exclusion Criteria for randomized part: Clinical symptoms lasts for longer than 48 hours Signs of peritonitis

Faculty of medicine, Institue of clinical medicine, Clinic of gastroenterology, nephrourology and surgery