1) The splanchnic circulation supplies blood to the gastrointestinal tract and accounts for 30% of total cardiac output. It is regulated by intrinsic, humoral, and extrinsic factors. Disorders include ischemic reperfusion injury and sepsis. 2) Abdominal compartment syndrome occurs when intra-abdominal pressure exceeds 20 mmHg and leads to organ dysfunction. It can be caused by diminished abdominal wall compliance, increased abdominal contents, or fluid resuscitation. 3) Abdominal compartment syndrome causes cardiovascular, respiratory, renal, and central nervous system effects by increasing intra-abdominal and intrathoracic pressures. Management includes lowering intra-abdominal pressure non-surgically or with