This chapter discusses the diagnosis, evaluation and management of abdominal compartment syndrome (ACS). The neurological presentation for the ACS includes increased intra-abdominal pressure (IAP) that is shown to decrease cerebral perfusion pressure by decreased cardiac output (CO) and hypotension, as well as via increased thoracic pressure with functional obstruction of cerebral venous outflow. The most efficient way to recognize and treat ACS is by recognizing and correcting predisposing factors before ACS occurs. In the closed abdomen, the gold standard approach to measure IAP uses a urinary bladder catheter (bladder pressures) with the patient in full supine position. Early recognition of risk factors and delaying definitive abdominal wall closure remains the best therapy for ACS. In cases in which the abdominal wall is already closed or the decompression is inadequate, timely intervention can be life-saving. ACS can occur even in the already decompressed abdomen.

Urodynamic equipment varies in complexity and a range of urodynamics machines. External pressure transducers are mounted on the urodynamic equipment and connected to the fluid-filled lines. A fluid-filled pressure catheter is placed in the bladder to measure intravesical pressure, and a second catheter is inserted into the rectum or the vagina to measure intra-abdominal pressure. Solid-state catheters with a single-tip transducer inserted into the rectum and covered with a condom, sheath or gloved finger, can be used to measure intra-abdominal pressure. Setting up can be considered as connecting the transducers and filling line and setting zero pressure. The calibration of solid-state catheter-tip transducers should be checked regularly. This requires that the transducers are immersed to a set depth in water, rather than raised in air, or by means of a special calibration chamber which is capable of generating pressures in centimetres of water.

Pneumoperitoneum with CO2 gas begins the process of systemic acidification by altering the ultrastructural, metabolic, and immune functions of the peritoneum. Both direct and indirect effects of CO2 can be seen in numerous aspects of the cardiovascular system. Both obese and non-obese patients undergo laparoscopy at 15 mm Hg of CO2 gas in order to provide adequate visualization while minimizing the detrimental effects of increased intra-abdominal pressure (IAP). An overall decrease in renal perfusion and a resultant increase in hormonal activity occur with pneumoperitoneum. Patients with chronic obstructive pulmonary disease (COPD) often require lower IAP during laparoscopy. Effective preventions or control of detrimental effects of CO2 pneumoperitoneum are key to maintaining the safety profile of laparoscopy. Nevertheless, with the numerous benefits that stem from sequential compression devices (SCDs), their routine use has become widely recommended for all laparoscopic surgery.