Investigation of the Effects of Different Intra-abdominal Pressures on Optic Nerve Size Measured by Orbital USG in Patients Undergoing Major Abdominal Surgery

In intensive care patients, high intraabdominal pressure is frequently encountered. Intra-abdominal pressure is often measured as high, especially after major abdominal surgery procedures. This situation creates ischemia in the abdominal organs in the patient, decreases venous return as a result of inferior vena cava compression and leads to a decrease in cardiac output. In addition, intracranial pressure frequently increases as a result of the venous circulation being affected. In recent years, various studies have reported that the increase in optic nerve diameter measured by ultrasound correlates with the level of intracranial pressure. Optic nerve diameter measurement with ultrasound is a non-invasive procedure. Intra-abdominal pressure measurements are also routinely performed in intensive care patients. In the measurement of abdominal pressure, the bladder catheter, which is already available in every patient who comes to intensive care, is used. In this study, the intra-abdominal pressure values present in the file of each patient undergoing major abdominal surgery who were taken to intensive care unit will be taken. Orbital USG will be performed on the 6th, 12th and 24th hours on admission to the intensive care unit to measure the diameter of the optic nerve, and the relationship between the intra-abdominal pressure value and optic nerve diameters will be investigated.