In this study, it was aimed to compare the effects of three different PEEP levels (0-4, 5-8, 9-12 cmH2O) on intraabdominal pressure and hemodynamic parameters of patients in intensive care unit.

Patients between 18-80 years old whom were mechanically ventilated without any spontaneous respiratory efforts on supine position were included into the study. Bladder pressure measurement as a practical and frequently preferred method was used in order to measure intra-abdominal pressure. 100 ml isotonic fluid was given during the measurement. Level of symphysis pubis was chosen for zeroing the pressure transducer to measure the intra-abdominal pressure.

Three patient groups, each containing 22 cases, totally 66 patients were planned in this study. All patients were mechanically ventilated with various PEEP levels. The patients with 0-4 cmH2O PEEP levels were named Group 4; the patients with 5-8 cmH2O PEEP levels were named Group 8; the patients with 9-12 cmH2O PEEP levels were named Group 12. The levels of patients' PEEP levels were arranged by the responsible intensive care physician regarding to the patients' clinic.

Intraabdominal, central venous, arterial blood pressures, pulse rates, peripheric oxygen saturation, body temperature, instant fluid balances and amounts of urine (in ml/kg/hour unit) of the patients were measured on the 0. 6. 12. 18. and 24. hours and recorded.

Inclusion Criteria:

• age between 18-80,
• connected to mechanical ventilator in intensive care,
• had not undergone surgery of the abdomen,
• patients followed at the same PEEP levels for at least 24 hours

Exclusion Criteria:

• The consent for the study,
• initial intrabdominal pressure level is over 12 cmH2O,
• undergoing abdominal surgery or bladder surgery,
• neurogenic bladder,
• morbid obesity,
• Chronic Obstructive Pulmonary Disease Patients were excluded from the study.