Konstantin Yastrebov1,2, Anders Aneman2,3,4, Michel Slama5,6, Vladimir Kokhno7, Vsevolod Luchansky8, Sam Orde6, Andrew Hilton9, Dmitriy Lukiyanov8, Irina Volobueva8, Svetlana Sidelnikova8, Evgeniy Polovnikov10. 1. St George Hospital, Sydney, New South Wales, Australia. 2. Faculty of Medicine, The University of New South Wales, Sydney, New South Wales, Australia. 3. Liverpool Hospital, Liverpool, New South Wales, Australia. 4. Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia. 5. University Hospital of Amiens and INSERM 1088, University of Picardie Jules Verne, Amiens, France. 6. Nepean Hospital, Penrith, Sydney, New South Wales, Australia. 7. Novosibirsk Government Medical University, Novosibirsk, Russia. 8. Federal Center for Neurosurgery, Novosibirsk, Russia. 9. Austin Hospital, Heidelberg, Melbourne, Victoria, Australia. 10. Novosibirsk Regional University Hospital, Novosibirsk, Russia.
Abstract
BACKGROUND: The distending intravascular pressure at no flow conditions reflects the stressed volume. While this haemodynamic variable is recognised as clinically important, there is a paucity of reports of its range and responsiveness to volume expansion in patients without cardiovascular disease and no reports of correlations to echocardiographic assessments of left ventricular filling. METHODS: Twenty-seven awake (13 male), spontaneously breathing patients without any history of cardiopulmonary, vascular or renal disease were studied prior to induction of anaesthesia. The no-flow equilibrium pressure in the arm following rapid circulatory occlusion (Parm ) was measured via a radial arterial catheter. Transthoracic echocardiography was used to measure left ventricular end diastolic area and volume as well as the diameter of the inferior vena cava. The Parm and echocardiographic variables were measured before and after administration of 500 mL 0.9% NaCl over 10 minutes. Changes were analysed by paired t test, Pearson's correlation and multiple linear regression. RESULTS: Parm increased overall from 22 ± 5 mm Hg to 25 ± 6 mm Hg (mean difference 3.0 ± 4.5 mm Hg, P = 0.002) following the fluid bolus with corresponding increases in arterial pressure and echocardiographic variables. Variability in the direction of the Parm response reflected concomitant changes in vascular compliance. Only weak correlations were observed between changes in Parm and inferior vena cava diameter indexed to body surface area (R2 = 0.29, P = 0.01). CONCLUSION: Preoperative measurements of Parm increased following acute expansion of the intravascular volume. Echocardiography demonstrated poor correlation with Parm .
BACKGROUND: The distending intravascular pressure at no flow conditions reflects the stressed volume. While this haemodynamic variable is recognised as clinically important, there is a paucity of reports of its range and responsiveness to volume expansion in patients without cardiovascular disease and no reports of correlations to echocardiographic assessments of left ventricular filling. METHODS: Twenty-seven awake (13 male), spontaneously breathing patients without any history of cardiopulmonary, vascular or renal disease were studied prior to induction of anaesthesia. The no-flow equilibrium pressure in the arm following rapid circulatory occlusion (Parm ) was measured via a radial arterial catheter. Transthoracic echocardiography was used to measure left ventricular end diastolic area and volume as well as the diameter of the inferior vena cava. The Parm and echocardiographic variables were measured before and after administration of 500 mL 0.9% NaCl over 10 minutes. Changes were analysed by paired t test, Pearson's correlation and multiple linear regression. RESULTS: Parm increased overall from 22 ± 5 mm Hg to 25 ± 6 mm Hg (mean difference 3.0 ± 4.5 mm Hg, P = 0.002) following the fluid bolus with corresponding increases in arterial pressure and echocardiographic variables. Variability in the direction of the Parm response reflected concomitant changes in vascular compliance. Only weak correlations were observed between changes in Parm and inferior vena cava diameter indexed to body surface area (R2 = 0.29, P = 0.01). CONCLUSION: Preoperative measurements of Parm increased following acute expansion of the intravascular volume. Echocardiography demonstrated poor correlation with Parm .