title: Comparison of superior vena cava and femoroiliac vein pressure according to intra-abdominal pressure.
abstract: BACKGROUND
  Previous studies have shown a good agreement between central venous pressure (CVP) measurements from catheters placed in superior vena cava and catheters placed in the abdominal cava/common iliac vein. However, the influence of intra-abdominal pressure on such measurements remains unknown.
  
  
  METHODS
  We conducted a prospective, observational study in a tertiary teaching hospital. We enrolled patients who had indwelling catheters in both superior vena cava (double lumen catheter) and femoroiliac veins (dialysis catheter) and into the bladder. Pressures were measured from all the sites, CVP, femoroiliac venous pressure (FIVP), and intra-abdominal pressure.
  
  
  RESULTS
  A total of 30 patients were enrolled (age 62 ± 14 years; SAPS II 62 (52-76)). Fifty complete sets of measurements were performed. All of the studied patients were mechanically ventilated (PEP 3 cmH20 (2-5)). We observed that the concordance between CVP and FIVP decreased when intra-abdominal pressure increased. We identified 14 mmHg as the best intra-abdominal pressure cutoff, and we found that CVP and FIVP were significantly more in agreement below this threshold than above (94% versus 50%, P = 0.002).
  
  
  CONCLUSIONS
  We reported that intra-abdominal pressure affected agreement between CVP measurements from catheter placed in superior vena cava and catheters placed in the femoroiliac vein. Agreement was excellent when intra-abdominal pressure was below 14 mmHg.
authors: AP-HP, Hôpital Saint-Antoine, Service de réanimation médicale, Paris, 75571 Cedex 12, France. hafid.aitoufella@sat.aphp.fr.
authors: Hafid
authors: H
authors: Ait-Oufella
authors: Pierre-Yves
authors: PY
authors: Boelle
authors: Arnaud
authors: A
authors: Galbois
authors: Jean-Luc
authors: JL
authors: Baudel
authors: Dimitri
authors: D
authors: Margetis
authors: Mikael
authors: M
authors: Alves
authors: Georges
authors: G
authors: Offenstadt
authors: Eric
authors: E
authors: Maury
authors: Bertrand
authors: B
authors: Guidet