Background: Patients undergoing surgical operations in prone position do not have a measure of intra abdominal pressure as a standard procedure. Many of them could have elevated values of this parameter and could be exposed to possible renal damage due to a stiffening of the abdominal muscles while being positioned prone.

Purpose of study: Intraoperative intrabdominal pressure measurement and evaluation of correlation with possible postsurgical complications.

Methodology: Electronic device able to measure intra abdominal pressure is connected between a Foley catheter and a urinary collecting bag. During the procedure, values of the intra abdominal pressure are displayed on a monitor next to anaesthetic machine in real time. The numbers representing the pressure in mmHG are assessed and recorded.

Discussion: Possible correlation between intra abdominal hypertension and postsurgical complications in patients operated in prone position could be a foundation to further clinical trials and presurgical assessment of intraabdominal pressure.

Inclusion Criteria:

• Consent to participate in the study
• Patients qualified for surgical stabilization of the spine in prone position

Exclusion Criteria:

• No consent to participate in the study or inability to obtain consent
• The inability to insert a urinary catheter
• No indication for urinary catheter
• Patients undergoing palliative treatment
• Patients with advanced liver and kidney disease

Patients qualified for spinal surgery in prone position, who consent to praticipate in the study.