The abdominal compartment syndrome (ACS) is considered as the result of hypoperfusionand ischemia of intra-abdominal viscera with multiple organ failure due to raisedintra-abdominal pressure (IAP). This syndrome is very difficult to identify because itusually occurs in critically ill patients in Intensive Care Units. Normal IAP ranges between0 and 5 mmHg. When it is mildly increased (10-15 mmHg), cardiac index ismaintained or lightly increased due to the abdominal viscera squeezing and venousreturn increasing. In this phase intravascular gradient volume will probably be correctspontaneously. At 15-25 mmHg, intra-abdominal pressure is moderately increased andthe full syndrome may be observed, but can be still corrected with simple interventions.At higher pressures (>25mmHg) it must be realized surgical decompression,fluid resuscitation together with vasoconstrictive agents. Current diagnostic proceduresfor intra-abdominal measurement relies on bladder pressure’s evaluation.