title: The impact of body position on intra-abdominal pressure measurement: a multicenter analysis.
abstract: OBJECTIVE
  Elevated intra-abdominal pressure (IAP) is a frequent cause of morbidity and mortality among the critically ill. IAP is most commonly measured using the intravesicular or "bladder" technique. The impact of changes in body position on the accuracy of IAP measurements, such as head of bed elevation to reduce the risk of ventilator-associated pneumonia, remains unclear.
  
  
  METHODS
  Prospective, cohort study.
  
  
  METHODS
  Twelve international intensive care units.
  
  
  METHODS
  One hundred thirty-two critically ill medical and surgical patients at risk for intra-abdominal hypertension and abdominal compartment syndrome.
  
  
  METHODS
  Triplicate intravesicular pressure measurements were performed at least 4 hours apart with the patient in the supine, 15 degrees , and 30 degrees head of bed elevated positions. The zero reference point was the mid-axillary line at the iliac crest.
  
  
  RESULTS
  Mean IAP values at each head of bed position were significantly different (p < 0.0001). The bias between IAPsupine and IAP15 degrees was 1.5 mm Hg (1.3-1.7). The bias between IAPsupine and IAP30 degrees was 3.7 mm Hg (3.4-4.0).
  
  
  CONCLUSIONS
  Head of bed elevation results in clinically significant increases in measured IAP. Consistent body positioning from one IAP measurement to the next is necessary to allow consistent trending of IAP for accurate clinical decision making. Studies that involve IAP measurements should describe the patient's body position so that these values may be properly interpreted.
authors.affiliation: Department of Surgical Education, Orlando Regional Medical Center, Orlando, FL, USA. michael.cheatham@orlandohealth.com
authors.forename: Michael L
authors.initials: ML
authors.lastname: Cheatham
authors.forename: Jan J
authors.initials: JJ
authors.lastname: De Waele
authors.forename: Inneke
authors.initials: I
authors.lastname: De Laet
authors.forename: Bart
authors.initials: B
authors.lastname: De Keulenaer
authors.forename: Sandy
authors.initials: S
authors.lastname: Widder
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Kirkpatrick
authors.forename: Adrian B
authors.initials: AB
authors.lastname: Cresswell
authors.forename: Manu
authors.initials: M
authors.lastname: Malbrain
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Bodnar
authors.forename: Jorge H
authors.initials: JH
authors.lastname: Mejia-Mantilla
authors.forename: Richard
authors.initials: R
authors.lastname: Reis
authors.forename: Michael
authors.initials: M
authors.lastname: Parr
authors.forename: Robert
authors.initials: R
authors.lastname: Schulze
authors.forename: Sonia
authors.initials: S
authors.lastname: Puig
mesh_terms: D000005:Abdomen; D000283:Administration, Intravesical; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003161:Compartment Syndromes / Q000175:diagnosis* / Q000453:epidemiology; D003422:Critical Care; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011187:Posture / Q000502:physiology*; D011237:Predictive Value of Tests; D011312:Pressure; D015203:Reproducibility of Results; D012307:Risk Factors; D014159:Transducers; D014546:Urinary Catheterization / Q000379:methods*