Abdominal Compartment Syndrome Definition and Diagnosis
Core Diagnostic Criteria
- The World Society of the Abdominal Compartment Syndrome established that abdominal compartment syndrome (ACS) is defined as a sustained intra-abdominal pressure (IAP) ≥ 20 mmHg that is associated with new organ dysfunction or failure 1, 2, 3, 4, 5
- The pressure threshold for ACS is a sustained IAP ≥ 20 mmHg, with new organ dysfunction/failure present and attributable to the elevated IAP 1, 2, 3
- Abdominal perfusion pressure (APP) < 60 mmHg may be present but is not required for diagnosis of ACS 1, 2, 3
Measurement Standards
- IAP measurement must follow specific technical requirements, including intravesical (bladder) measurement using a maximal instillation volume of 25 mL sterile saline, to ensure diagnostic accuracy 1, 2, 4
- IAP should be expressed in mmHg, measured at end-expiration in the supine position with abdominal muscle contractions absent, and the transducer should be zeroed at the level of the midaxillary line 1, 2, 4
Clinical Context and Relationship to Intra-Abdominal Hypertension
- Normal IAP in critically ill adults is approximately 5-7 mmHg, making the ACS threshold of ≥20 mmHg a substantial pathologic elevation 1, 2, 4, 5
- Intra-abdominal hypertension (IAH) is defined as sustained or repeated pathological elevation in IAP ≥ 12 mmHg, and is graded as follows:
Classification by Etiology
- ACS is categorized based on the anatomic origin of the pathology, including primary ACS, secondary ACS, and recurrent ACS 1, 2, 3, 6, 7, 8