What is normal intra-abdominal pressure (IAP)? What is Intra-abdominal hypertension (IAH) and how is it graded? What is abdominal compartment syndrome?

  • IAP is approximately 5–7 mmHg in critically ill adults
  • It is not static and varies with respiration

IAH is defined by the World Society of Abdominal Compartment Syndrome as:

A sustained or repeated pathological elevation in IAP >12 mmHg

It is graded according according to pressure:

Grade I
12-15 mmHg
Grade II
16-20 mmHg
Grade III
21-25 mmHg
Grade IV
>25 mmHg

ACS is defined by the World Society of Abdominal Compartment Syndrome as:

A sustained IAP >20 mmHg that is associated with new organ dysfunction/failure

WSACS Guidelines

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