title: Validation of a novel method for measuring intra-abdominal pressure and gastric residual volume in critically ill patients.
abstract: BACKGROUND
  Gastric residual volume (GRV) can be measured in a variety of ways in critically ill patients, most often, the nasogastric tube is disconnected and the GRV is aspirated via a 60 mL syringe. Bladder pressure (IBP) measurement is the gold standard for intra-abdominal pressure (IAP) estimation. This study will look at the validation of a novel method combining measurement of GRV and estimation of IAP via intra-gastric pressure (IGP).
  
  
  METHODS
  In total 135 paired IAP and 146 paired GRV measurements were performed in 37 mechanically ventilated ICU patients. The IAP was estimated via the bladder (i.e. IBP) using the FoleyManometer and via the stomach (i.e. IGP) with the new device. The GRV was measured with the new device (GRVprototype) and via the classic method (GRVclassic). The devices were provided by Holtech Medical (Charlottenlund, Denmark) and data were retrospectively analysed.
  
  
  RESULTS
  The number of paired measurements in each patient was 4 ± 1. The mean IBP was 10.7 ± 4.1 and mean IGP was 11.6 ± 4.1 mm Hg. Correlation between the IBP and IGP was significant, however moderate (R2 = 0.51). Analysis according to Bland and Altman showed a bias and precision of 0.8 and 2.7 mm Hg respectively, however the limits of agreement (LA) were large and ranged from -4.5 to 6.1 mm Hg. Changes in IGP correlated well with changes in IBP. The median GRVprototype was 80 mL (0-1050) and equal to the median GRVclassic of 80 mL (0-1250). Correlation between the 2 methods was excellent (R2 = 0.89). Analysis according to Bland and Altman showed a bias and precision of -0.8 and 52.3 mL respectively and the LA ranged from -103 to 102 mL. Changes in GRVclassic correlated well with changes in GRVprototype.
  
  
  CONCLUSIONS
  The results of this multicentre pilot study show that GRV can be measured with the new device. Furthermore this allows simultaneous screening for intra-abdominal hypertension with IAP estimation via IGP.
authors.forename: Johan
authors.initials: J
authors.lastname: Van Stappen
authors.forename: Chiara
authors.initials: C
authors.lastname: Pigozzi
authors.forename: Robert
authors.initials: R
authors.lastname: Tepaske
authors.forename: Niels
authors.initials: N
authors.lastname: Van Regenmortel
authors.forename: Inneke
authors.initials: I
authors.lastname: De Laet
authors.forename: Karen
authors.initials: K
authors.lastname: Schoonheydt
authors.forename: Hilde
authors.initials: H
authors.lastname: Dits
authors.forename: Paolo
authors.initials: P
authors.lastname: Severgnini
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Roberts
authors.affiliation: Department of Intensive Care, ICU and High Care Burn Unit, Ziekenhuis Netwerk Antwerpen, ZNA Stuivenberg, Antwerpen, Belgium. manu.malbrain@skynet.be.
authors.forename: Manu L N G
authors.initials: ML
authors.lastname: Malbrain
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003422:Critical Care / Q000379:methods*; D016638:Critical Illness; D004867:Equipment Design; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism*; D006801:Humans; D059325:Intra-Abdominal Hypertension / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011312:Pressure; D012115:Residual Volume; D012121:Respiration, Artificial; D012189:Retrospective Studies; D055815:Young Adult