title: A comparison of infusion volumes in the measurement of intra-abdominal pressure.
abstract: Bladder pressure measurement through a foley catheter is the current standard in monitoring for intraabdominal hypertension (IAH) and abdominal compartment syndrome (ACS). Accurate pressure transduction requires a continuous fluid column with a small volume of transducing medium at the tip of the catheter. Infusing excessive fluid volume can falsely elevate the measured intra-abdominal pressure (IAP) due to bladder overdistention and can lead to intrinsic muscular contraction. This effect can be seen with volumes as low as 60 mL. Recent expert consensus has recommended 25 mL as the maximal infusion volume; however, 50 mL is the most commonly cited volume of infusion in the literature. The purpose of this analysis was to determine the variance between IAP values using a range of volume infusions between 10 and 60 mL. Eighteen adult, surgical intensive care unit (SICU) patients who were undergoing IAP measurement for IAH or clinically indicated monitoring were enrolled in a prospective, nontreatment study. Intra-abdominal pressure measurements were obtained with stepwise increases of injectate volume from 10 to 60 mL (in 10 mL increments). Bland-Altman analyses and receiver operating characteristic (ROC) curves were used for analysis. After analysis accounting for data correlation within patients, means and standard deviations were generated for differences between 50 mL and 10, 20, 30, 40, and 60 mL bladder infusion volumes. Bland-Altman analyses showed good agreement between measurements and no significant difference in variance (mean < or =1.35 mm Hg) between volume comparisons. The ROC curve generated for each test volume using a diagnostic pressure value for IAH (!12 mm Hg) showed that a value between 11 and 12 mm Hg gave the best combination of sensitivity and specificity for all test volumes. In SICU patients, with a clinical indication for IAP monitoring, bladder infusion volumes between 10 mL and 60 mL provide consistent IAP measurements.
authors.affiliation: Department of Surgery, University of Utah Health Sciences Center, Salt Lake City, Utah 84132, USA. edward.kimball@hsc.utah.edu
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Kimball
authors.forename: Gabriele K
authors.initials: GK
authors.lastname: Baraghoshi
authors.forename: Mary C
authors.initials: MC
authors.lastname: Mone
authors.forename: Heidi J
authors.initials: HJ
authors.lastname: Hansen
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Adams
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Alder
authors.forename: Peter
authors.initials: P
authors.lastname: Jackson
authors.forename: Philip
authors.initials: P
authors.lastname: Cannon
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Horn
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Wolfe
mesh_terms: D000005:Abdomen / Q000502:physiology*; D000328:Adult; D006801:Humans; D007263:Infusions, Parenteral / Q000379:methods; D011312:Pressure; D011446:Prospective Studies