Accuracy of Ultrasonography for the Diagnosis of Pneumoperitoneum in the Emergency Department

Study Overview
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Brief Summary
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Pneumoperitoneum could be due to life threatening conditions and its quickly diagnosis is important in the emergency department (ED). Signs and symptoms are non-specific and radiography has low accuracy in the acute setting. Computed tomography (CT) is considered the gold standard, however it is not a cost-effective option in the vast population of patients with abdominal pain. Ultrasonography is able to detect as little as 2 ml of free air, however diagnostic accuracy of ultrasonography remains unclear. This study evaluates the accuracy of ultrasonography for the diagnosis of pneumoperitoneum, the most accurate abdominal scan and the most accurate echographic sign for the detection of free air. Methods Consecutive patients presenting to ED for acute abdominal pain and with a diagnosis of pneumoperitoneum at CT or at surgery (study group) and a similar number of patients without a diagnosis of pneumoperitoneum (control group) undergo abdominal ultrasonography in a standardized protocol that include 10 scans for each patient registered on a video of 5 seconds. The videos are randomly reviewed by 4 sonographers and by 2 physicians with no experience in ultrasonography blind to final diagnosis and to all clinical data with the aim of detecting for each scan pneumoperitoneum. Accuracy of ultrasonography for the diagnosis of pneumoperitoneum will be calculated considering CT or surgery as gold standard. Furthermore intra and interobserver agreement and the accuracy of each ultrasonographic sign and scan will be calculated.

Official Title
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Accuracy of Ultrasonography for the Diagnosis of Pneumoperitoneum in the Emergency Department

Conditions
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Pneumoperitoneum

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All patients more than 18 years with acute abdominal pain Exclusion Criteria: Refused consent Less than 18 years old Not possible to perform ultrasonography

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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Pneumoperitoneum<br>Patients with a diagnosis of pneumoperitoneum by CT or surgery | |
| no pneumoperitoneum<br>patients with acute abdominal pain with a diagnosis other than pneumoperitoneum in whom pneumoperitoneum was excluded by CT or surgery | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Accuracy of ultrasonography for the diagnosis of pneumoperitoneum | CT or surgery are considered the gold standard for the diagnosis of pneumoperitoneum | No follow-up for the included patients. Outcome is measured one month after the end of recruitment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Accuracy of each scan and of each sonographic sign for the diagnosis of pneumoperitoneum |  | No follow-up for the included patients. Outcome is measured one month after the end of recruitment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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pneumoperitoneum, free peritoneal air, ultrasonography