title: Comparison of different techniques of central venous pressure measurement in mechanically ventilated critically ill patients.
abstract: BACKGROUND
  Several techniques exist for measuring central venous pressure (CVP) but little information is available about the accuracy of each method. The aim of this study was to compare different methods of CVP measurements in mechanically ventilated patients.
  
  
  METHODS
  CVP was measured in mechanically ventilated patients without spontaneous breathing using four different techniques: 1) end expiratory CVP measurement at the base of the" c" wave (CVPMEASURED), chosen as the reference method; 2) CVP measurement from the monitor averaging CVP over the cardiac and respiratory cycles (CVPMONITOR); 3) CVP measurement after a transient withdrawing of mechanical ventilation (CVPNADIR); 4) CVP measurement corrected for the transmitted respiratory pressure induced by intrinsic PEEP (calculated CVP: CVPCALCULATED). Bias, precision, limits of agreement, and proportions of outliers (difference > 2 mm Hg) were determined.
  
  
  RESULTS
  Among 61 included patients, 103 CVP assessments were performed. CVPMONITORbias [-0.87  (1.06) mm Hg] was significantly different from those of CVPCALCULATED[1.42  (1.07), P < 0.001 and CVPNADIR(1.04  (1.29), P < 0.001]. The limits of agreement of CVPMONITOR[-2.96 to 1.21 mm Hg] were not significantly different to those of CVPNADIR(-1.49 to 3.57 mm Hg, P = 0.39) and CVPCALCULATED(-0.68 to 3.53 mm Hg, P = 0.31). The proportion of outliers was not significantly different between CVPMONITOR(n = 5, 5%) and CVPNADIR(n = 9, 9%, P = 0.27) but was greater with CVPCALCULATED(n = 16, 15%, P = 0.01).
  
  
  CONCLUSIONS
  In mechanically ventilated patients, CVPMONITORis a reliable method for assessing CVPMEASUREDTaking into account transmitted respiratory pressures, CVPCALCULATEDhad a higher proportion of outliers and precision than CVPNADIR.
authors.affiliation: Division of Anesthesia Intensive Care Pain and Emergency, Nîmes University Hospital, Place de Professeur Robert Debré, Nîmes, 30029, France.|Faculty of Medicine, Montpellier-Nimes University I, Chemin du Carreau de Lane, Nîmes, 30000, France EA 2992, Chemin du Carreau de Lane, 30000 Nimes, France.|Burns, Trauma, and Critical Care Research Centre, The University of Queensland, Brisbane, Queensland, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Roger
authors.affiliation: Division of Anesthesia Intensive Care Pain and Emergency, Nîmes University Hospital, Place de Professeur Robert Debré, Nîmes, 30029, France.|Faculty of Medicine, Montpellier-Nimes University I, Chemin du Carreau de Lane, Nîmes, 30000, France EA 2992, Chemin du Carreau de Lane, 30000 Nimes, France.
authors.forename: L
authors.initials: L
authors.lastname: Muller
authors.affiliation: Institute of Cardiometabolism and Nutrition and Department of Emergency medicine and Surgery, Assistance Publique-Hôpitaux de Paris (APHP), Sorbonne Universités, UPMC Univ Paris 06, UMRS INSERM 1156, Paris, France.
authors.forename: B
authors.initials: B
authors.lastname: Riou
authors.affiliation: PhyMedExp, University of Montpellier, INSERM U1046, CNRS UMR 9214, Montpellier hospital, Montpellier cedex 5, 34295.
authors.forename: N
authors.initials: N
authors.lastname: Molinari
authors.affiliation: Division of Anesthesia Intensive Care Pain and Emergency, Nîmes University Hospital, Place de Professeur Robert Debré, Nîmes, 30029, France.|Faculty of Medicine, Montpellier-Nimes University I, Chemin du Carreau de Lane, Nîmes, 30000, France EA 2992, Chemin du Carreau de Lane, 30000 Nimes, France.
authors.forename: B
authors.initials: B
authors.lastname: Louart
authors.affiliation: Division of Anesthesia Intensive Care Pain and Emergency, Nîmes University Hospital, Place de Professeur Robert Debré, Nîmes, 30029, France.
authors.forename: H
authors.initials: H
authors.lastname: Kerbrat
authors.affiliation: Service de Réanimation médicale, Kremlin, Hôpital de Bicêtre, APHP, Le Bicêtre, France.
authors.forename: J-L
authors.initials: JL
authors.lastname: Teboul
authors.affiliation: Division of Anesthesia Intensive Care Pain and Emergency, Nîmes University Hospital, Place de Professeur Robert Debré, Nîmes, 30029, France jean-yves.lefrant@wanadoo.fr.|Faculty of Medicine, Montpellier-Nimes University I, Chemin du Carreau de Lane, Nîmes, 30000, France EA 2992, Chemin du Carreau de Lane, 30000 Nimes, France.
authors.forename: J-Y
authors.initials: JY
authors.lastname: Lefrant
mesh_terms: D000328:Adult; D000368:Aged; D001795:Blood Pressure Determination; D002496:Central Venous Pressure; D016638:Critical Illness; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012121:Respiration, Artificial
keywords: central venous pressure; measurement