Intra-abdominal pressure (IAP) affects cardio-respiratory hemodynamics and can be assessed either directly, or by measuring gastric or urinary bladder pressure. However, in patients with morbid obesity, the correlations between gastric and urinary bladder pressures with IAP have not been addressed. The investigator's aim was to assess the correlations between IAP and gastric and urinary bladder pressure in patients with morbid obesity, at normal and elevated levels of IAP, and to examine the effects of increasing IAP and patient position on hemodynamic and respiratory parameters.
