Respiratory Variations For Assessing Blood Withdrawal

OBJECTIVES: To investigate whether respiratory variations of the inferior vena cava (ΔIVC) and internal jugular vein (ΔIJV) diameters during standardized breathing (ΔIVCST and ΔIJVST) increase after a therapeutic bleeding in spontaneously breathing and non-obese patients with genetic hemochromatosis. DESIGN: Prospective, monocentric study in the EFS Nord-de-France blood center. PATIENTS: Non-obese patients with genetic hemochromatosis undergoing a therapeutic bleeding. INTERVENTIONS: Ultrasound measures and collected clinical parameters before and after a therapeutic bleeding, during a standardized respiratory maneuver. MAIN OUTCOME AND MEASURES: The primary endpoint was the ΔIVCST change induced by a 300 to 500ml therapeutic bleeding. It measured the minimal and maximal IVC and IJV diameters during a standardized respiratory maneuver. ΔIVCST and ΔIJVST were calculated as follows: \[(maximal diameter - minimal diameter)/maximal diameter\].100.