Effect of patient positioning on intra-abdominal pressure monitoring

Am J Surg. 2007 May;193(5):644-7; discussion 647. doi: 10.1016/j.amjsurg.2007.01.013.


Background: Intra-abdominal hypertension affects multiple organ systems. Current measurement standard requires supine positioning, which jeopardizes patient safety by increasing the risk for ventilator-associated pneumonia. This study evaluated the relationship between intra-abdominal pressure (IAP) and head-of-bed (HOB) positioning in critically ill intubated patients.

Methods: IAP measurements were performed using intravesical catheters with manometry. IAP was measured in a range of patient HOB increases from 0 degrees to 45 degrees. Multivariable generalized estimating equation modeling was performed to describe the relationship between IAP and HOB positioning.

Results: Three hundred (300) observations were performed on 37 patients. In multivariable modeling, HOB increase was significantly associated with IAP. Body mass index, positive end-expiratory pressure, temperature, and diagnostic category were significant in this model, whereas age and Riker sedation score were not.

Conclusions: There is a significant, positive association between IAP and HOB positioning in critically ill patients. Clinically relevant changes in IAP occur at HOB increases >20 degrees.

MeSH terms

  • Abdomen*
  • Adult
  • Aged
  • Aged, 80 and over
  • Critical Illness*
  • Humans
  • Intubation
  • Middle Aged
  • Monitoring, Physiologic / methods
  • Posture*
  • Pressure