Comparison of Intraabdominal Pressure

Comparison of Intraabdominal Pressure and Respiratory Parameter Changes According to Positional Apparatus in the Prone Position

Increased intra-abdominal pressure(IAP) might influence on perioperative morbidity related to increased CVP, PVWP, SVR, PAP and decreased venous return and cardiac output. Prone position has been known to increase IAP. In clinical field, various apparatuses has developed to minimize IAP elevation during prone position operation.

In this study, we would compare the changes of IAP and respiratory system compliance according to positional apparatus in prone position.

In clinical field, Wison frame, chest rolls and Jackson table have been widely used for prone position surgery. Among those apparatus, Jackson table has padded supports under the chest and pelvis, so that the abdomen can hang freely and prevent the abdominal compression. By reducing abdominal and thoracic pressure, Jackson table would reduce blood loss, and less effects on pulmonary mechanics. But few studies has known to compare IAP with other positioning apparatus such as Wilson frame or chest roll.

Inclusion Criteria:

• Patients who are scheduled for prone positioned spinal surgery
• ASA Physical Status Classification System class I or II

Exclusion Criteria:

• Patients who did not agree
• BMI > 30kg/m2
• Patients who did not insert urinary foley catheter
• Patients who have COPD or emphysema
• Patients who have severe spine deformities such as scoliosis