Table 2 Adverse effects of intra abdominal hypertension (IAH) and abdominal compartment syndrome (ACS)

Cerebral

• An Increase in IAP forces the diaphragm up decreasing intra-thoracic space, increasing the intra-thoracic pressure.

• Jugular venous pressure elevates.

• Venous return decreases.

• Intra cerebral pressure will increase.

• Cerebral blood flow decreases.

Cardiac function

• An increase in IAP causes increased pressure on the inferior vena cava, intra abdominal circulation and perfusion.

• Venous return is impaired and peripheral oedema occurs.

• Increase in central venous pressure.

• Increased pulmonary artery wedge pressures as the myocardium is placed under an increasing workload.

Respiratory function

• An increased in IAP forces the diaphragm up decreasing intra-thoracic space and restricts respiration.

• Result in an increase in intra thoracic pressure particularly with mechanically ventilated patients.

• Left uncorrected will result in a decrease in lung compliance, functional residual capacity a VQ mismatch and hypoxia.

Renal function

• Defined as oliguria and anuria despite aggressive fluid resuscitation.

• Increase in abdominal pressure decreases renal blood flow coupled with a reduction in cardiac output.

• The rennin angiotensin system is activated further adding to intra- abdominal pressure and cardiac workload.

Gastrointestinal function

• Increased intra- abdominal pressure results in an increase in vascular resistance and decreased cardiac output.

• Results in a decrease in tissue perfusion.

• Ultimately tissue ischemia.

Peripheral perfusion

• Increased intra- abdominal pressure is said to increase femoral venous pressure increase peripheral vascular resistance and reduce femoral artery blood flow by up to 60%.