DIAgnostic iMaging or Observation in Early Equivocal appeNDicitis

Study Overview
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Brief Summary
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The aim of the study is to evaluate whether patients with early equivocal appendicitis can be observed instead of immediate diagnostic imaging. Half of the patients are randomly assigned to observation group, while the other half will undergo diagnostic imaging. The hypothesis is that resolving appendicitis is common in these patients. Thus, in observation group there will be fewer patients with appendicitis diagnosis and observation reduces the use of diagnostic imaging and surgery.

Detailed Description
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For the study equivocal appendicitis is defined as clinical suspicion of appendicitis with Adult Appendicitis Score between 11 and 15. The estimated prevalence of appendicitis in such patients is around 50%. Diagnostic imaging is done using conditional computed tomography i.e. abdominal ultrasound first and computed tomography only after negative or inconclusive appendicitis after ultrasound. In observation group repeated clinical examination is done after 6-8 hours interval with repeated blood test for calculation of Adult Appendicitis Score. Patients with decreasing score value continue observation without imaging, whereas patients with the same score value or higher (but below 16) undergo diagnostic imaging as in other group. Laparoscopy is done without imaging in patients with high score (16 or higher). Antibiotics are not allowed, but prophylactic antibiotics during induction of anesthesia are allowed.

Official Title
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DIAgnostic iMaging or Observation in Early Equivocal appeNDicitis - a Randomized Controlled Trial

Conditions
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Appendicitis

Intervention / Treatment
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* Other: Diagnostic imaging
* Other: Observation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Clinical suspicion of acute appendicitis Equivocal appendicitis defined by Adult Appendicitis Score: Score ≥11 and ≤15. Exclusion Criteria: C-reactive protein >99 mg/l Time from symptom onset over 24 hours Pregnancy Antibiotics given within last 24 hours Suspicion of other disease than appendicitis, that would require immediate interventions such as surgery, diagnostic imaging or gynecologic consultation Missing written informed consent Patient randomized earlier to the study

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Observation<br>Clinical follow-up for at least 6-8 hours, after follow-up repeated laboratory tests and repeated clinical examination is done. Adult Appendicitis Score is calculated after observation to determine further actions. Observation is continued in patients with decreasing score. Patients with the same or higher score undergo diagnostic imaging (score 11-15) or laparoscopy (score 16 or higher). Diagnostic imaging is abdominal ultrasound first and if the result is inconclusive or negative for appendicitis abdominal computed tomography is done. Laparoscopic appendectomy is done for those patients with appendicitis in diagnostic imaging. | Other: Observation<br>* Observation for 6 to 8 hours. After observation period repeated clinical examination and repeated blood test for calculation of Adult Appendicitis Score is done.<br>|
| Active Comparator: Diagnostic imaging<br>Patients undergo abdominal ultrasound and if the result is inconclusive or negative for appendicitis patients will have abdominal computed tomography. Laparoscopic appendectomy is done for patients with appendicitis in diagnostic imaging. | Other: Diagnostic imaging<br>* Abdominal ultrasound, followed by abdominal computed tomography when necessary<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Appendicitis requiring surgery or other intervention |  | 30 days from randomization | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Complicated appendicitis | Perforated appendicitis or appendiceal abscess | 30 days from randomization | 
| Delayed appendicitis diagnosis | Diagnosis is delayed if appendicitis is diagnosed later than 24 hours from randomization | 30 days from randomization | 
| Number of diagnostic imaging studies needed | Number of abdominal ultrasound and abdominal computed tomography per patient | 30 days from randomization and within 1 year after randomization | 
| Appendicitis requiring surgery or other intervention |  | within 1 year after randomization | 
| Negative appendectomy | Laparoscopy done for suspected appendicitis, but patient does not have appendicitis | 30 days from randomization | 
| Number of re-admissions to emergency unit | Any reason for re-admission are accounted | 1 year | 
| Number of other clinically relevant findings | Findings unrelated to appendicitis | 30 days from randomization | 
| Number of patients requiring of gynecological consultation | Applicable only in female patients | 30 days from randomization | 
| Time for decision | The time from randomization to either decision to operate in appendicitis patients or to discharge in non-appendicitis patients. | 30 days from randomization |