title: Accuracy of central venous pressure monitoring in the intraabdominal inferior vena cava: a canine study.
abstract: OBJECTIVE
  To test the hypotheses that in multiple pathophysiologic settings (1) end-expiratory central venous pressure measurements in the intraabdominal inferior vena cava accurately reflect those in the superior vena cava and (2) mean central venous pressure monitoring is as reliable in the inferior vena cava as it is in the superior vena cava.
  
  
  METHODS
  Simultaneous inferior vena caval and superior vena caval pressures were measured during five ventilatory phases: apnea, end-expiratory mechanical ventilation, maximal inspiratory mechanical ventilation, end-expiratory spontaneous ventilation, and maximal inspiratory spontaneous ventilation. Measurements were repeated after progressive intravascular volume depletion.
  
  
  METHODS
  Eight puppies.
  
  
  RESULTS
  Simultaneous inferior vena caval and superior vena caval end-expiratory pressures did not differ significantly (mean differences 0 to 0.1 mm Hg) and the limits of agreement of these measurements were within 2 mm Hg. Differences between mean maximal inspiratory pressures in the inferior vena cava and superior vena cava during mechanical and spontaneous ventilation were -0.7 and 3.6 mm Hg, respectively (p less than 0.01), and the limits of agreement extended beyond 2 mm Hg. Furthermore, mean maximal inspiratory pressures in the superior vena cava differed from end-expiratory pressures in the superior vena cava (1.1 and -3.6 mm Hg, p less than 0.01), whereas those in the inferior vena cava did not differ from end-expiratory superior vena caval pressures.
  
  
  CONCLUSIONS
  Under the experimental conditions studied (1) end-expiratory intraabdominal inferior vena caval pressures accurately reflected end-expiratory superior vena caval pressures and (2) mean central venous pressure monitoring was as reliable in the inferior vena cava as in the superior vena cava.
authors.affiliation: Department of Pediatrics, University of Arizona College of Medicine, Tucson.
authors.forename: R A
authors.initials: RA
authors.lastname: Berg
authors.forename: T R
authors.initials: TR
authors.lastname: Lloyd
authors.forename: R L
authors.initials: RL
authors.lastname: Donnerstein
mesh_terms: D000005:Abdomen / Q000098:blood supply; D000402:Airway Obstruction / Q000503:physiopathology; D000818:Animals; D001049:Apnea / Q000503:physiopathology; D015924:Blood Pressure Monitors; D001810:Blood Volume / Q000502:physiology; D002496:Central Venous Pressure / Q000502:physiology*; D004285:Dogs; D011175:Positive-Pressure Respiration; D012119:Respiration / Q000502:physiology; D012121:Respiration, Artificial; D012769:Shock / Q000503:physiopathology; D013909:Thorax / Q000098:blood supply; D014682:Vena Cava, Inferior / Q000502:physiology*; D014683:Vena Cava, Superior / Q000502:physiology