Table 1.

Consensus definitions by the World Society of Abdominal Compartment Syndrome (WSACS).

Normal IAP	0 to 5–7 mmHg
IAH	Persistent elevation of IAP > 12 mmHg: Grade I: 12–15 mmHg Grade II: 16–20 mmHg Grade III: 21–25 mmHg Grade IV: >25 mmHg
ACS	IAP > 20 mmHg + new organ failure (SOFA score ≥ 3)
APP	PAM-IAP
Measuring technique	Patient in complete supine position Introduce 25 mL of sterile saline into the empty bladder Transducer zeroed at the level of the midaxillary line After 60 s at end expiration, IAP is registered in a monitor IAP should be expressed in mmHg

IAP: intra-abdominal pressure IAH: intra-abdominal hypertension, ACS: abdominal compartment syndrome APP: abdominal perfusion pressure, PAM: mean arterial pressure SOFA: Sequential Organ Failure Assessment.