Catheter-based impedance measurements in the right atrium for continuously monitoring hematocrit and estimating blood viscosity changes; an in vivo feasibility study in swine.

Hematocrit is the most important determinant of whole blood viscosity and it affects thrombosis. As hematocrit can be measured accurately in vitro by using an electrical impedance technique, aim of the present study is to investigate the diagnostic potential of using this technique in vivo to continuously monitor hematocrit. Characteristics of a special catheter for in vivo measurement of electrical resistivity in blood in the right atrium are described. In five anesthetized swine hematocrit is monitored continuously with this catheter while different levels of hemoconcentration are induced. In addition, blood viscosity is increased by inducing 'acute phase' reaction the day before surgery, resulting in variable degree of elevated fibrinogen levels in the five swine. Good reproducibility of the resistivity measurements (S.D < 0.01) and excellent correlation between resistivity data in vivo and hematocrit levels in each swine are found (r2 = 0.95-0.99). Furthermore, stepwise regression analysis of data from all swine shows a highly significant contribution also of other important parameters of blood viscosity, such as fibrinogen, total protein and temperature (cumulative r2 = 0.97). Determining hematocrit continuously in vivo by electrical resistivity measurements with a catheter in the right atrium is feasible and these measurements correlate significantly also with other important parameters of blood viscosity.

[1]  F. Thompson,et al.  The effect of haematocrit on the resistivity of human blood at 37°C and 100 kHz , 1975, Medical and biological engineering.

[2]  H. Meiselman,et al.  Dielectric approach to investigation of erythrocyte aggregation. II. Kinetics of erythrocyte aggregation-disaggregation in quiescent and flowing blood. , 2000, Biorheology.

[3]  S. Chien.  Clinical hemorheology : applications in cardiovascular and hematological disease, diabetes, surgery, and gynecology , 1987 .

[4]  J. Agmon,et al.  Plasma viscosity and haematocrit in the course of acute myocardial infarction. , 1987, European heart journal.

[5]  Y. Hirota,et al.  Circadian variations of onset of acute myocardial infarction and efficacy of thrombolytic therapy. , 1996, Journal of the American College of Cardiology.

[6]  S. Chien,et al.  Effects of hematocrit variations on regional hemodynamics and oxygen transport in the dog. , 1980, The American journal of physiology.

[7]  D. Lillicrap,et al.  The Factor VIII Acute Phase Response Requires the Participation of NFκB and C/EBP , 2000, Thrombosis and Haemostasis.

[8]  R. M. Heethaar,et al.  A wideband high common mode rejection ratio amplifier and phase-locked loop demodulator for multifrequency impedance measurement , 2006, Medical and Biological Engineering and Computing.

[9]  C. Forbes,et al.  Contribution of the haematocrit to the bleeding time. , 1983, Haemostasis.

[10]  B. Jacobson,et al.  Quantitative correlations among fibrinogen concentration, sedimentation rate and electrical impedance of blood , 1997, Medical and Biological Engineering and Computing.

[11]  S. Chien,et al.  Blood Viscosity: Influence of Erythrocyte Deformation , 1967, Science.

[12]  H. Goldsmith,et al.  Rheological Aspects of Thrombosis and Haemostasis: Basic Principles and Applications , 1986, Thrombosis and Haemostasis.

[13]  D. Durand,et al.  Low haematocrit and prolonged bleeding time in uraemic patients: effect of red cell transfusions , 1985, British journal of haematology.

[14]  P. Steendijk,et al.  The four-electrode resistivity technique in anisotropic media: theoretical analysis and application on myocardial tissue in vivo , 1993, IEEE Transactions on Biomedical Engineering.

[15]  R. W. Brower,et al.  Coronary patency after intravenous infusion of recombinant tissue-type plasminogen activator in acute myocardial infarction. , 1988, Journal of the American College of Cardiology.

[16]  G. Cloutier,et al.  Influence of acute-phase proteins on erythrocyte aggregation. , 1996, The American journal of physiology.

[17]  J. Grotta,et al.  Whole blood viscosity parameters and cerebral blood flow. , 1982, Stroke.

[18]  R. Swank,et al.  Circadian Periodicity in Some Physicochemical Parameters of Circulating Blood , 1965, Nature.

[19]  K. Asplund,et al.  A Randomized Controlled Trial of Hemodilution Therapy in Acute Ischemic Stroke , 1984, Stroke.

[20]  R. Sothern,et al.  Relation between circadian patterns in levels of circulating lipoprotein(a), fibrinogen, platelets, and related lipid variables in men. , 2000, American heart journal.

[21]  P Coriat,et al.  Role of the hematocrit in a rabbit model of arterial thrombosis and bleeding. , 1999, Anesthesiology.

[22]  H. Schmid-schönbein,et al.  Custom‐Tailored Hemodilution With Albumin and Crystalloids in Acute Ischemic Stroke , 1992, Stroke.

[23]  R. Heros,et al.  Optimum degree of hemodilution for brain protection in a canine model of focal cerebral ischemia. , 1994, Journal of neurosurgery.

[24]  Shu Chien,et al.  Shear Dependence of Effective Cell Volume as a Determinant of Blood Viscosity , 1970, Science.

[25]  R. Heros,et al.  Mechanism of Cerebral Blood Flow Augmentation by Hemodilution in Rabbits , 1992, Stroke.

[26]  I. Kushner,et al.  Acute-phase proteins and other systemic responses to inflammation. , 1999, The New England journal of medicine.

[27]  C. Avezaat,et al.  Impact of medical treatment on the outcome of patients after aneurysmal subarachnoid hemorrhage. , 1998, Stroke.

[28]  H. Altunbas,et al.  Circadian Variations in Natural Coagulation Inhibitors Protein C, Protein S and Antithrombin in Healthy Men: A Possible Association with Interleukin-6 , 1999, Thrombosis and Haemostasis.

[29]  H. Goldsmith,et al.  Effect of hematocrit on adenosine diphosphate-induced aggregation of human platelets in tube flow. , 1995, Biorheology.

[30]  C. Slager,et al.  Blood Electrical Impedance Closely Matches Whole Blood Viscosity as Parameter of Hemorheology and Inflammation , 2003 .

[31]  D. N. Walder,et al.  The effect of increased fibrinogen content on the viscosity of blood. , 1969, Clinical science.

[32]  B. Coull,et al.  Chronic blood hyperviscosity in subjects with acute stroke, transient ischemic attack, and risk factors for stroke. , 1991, Stroke.

[33]  L. Cohn,et al.  The effect of hemodilution on experimental myocardial infarct size. , 1980, European surgical research. Europaische chirurgische Forschung. Recherches chirurgicales europeennes.

[34]  J. Crowell,et al.  Determinant of the optimal hematocrit. , 1967, Journal of applied physiology.

[35]  R. Krams,et al.  Cardiovascular profile of the calcium sensitizer EMD 57033 in open‐chest anaesthetized pigs with regionally stunned myocardium , 2000, British journal of pharmacology.

[36]  W. H. Austin,et al.  VISCOSITY OF NORMAL HUMAN BLOOD UNDER NORMOTHERMIC AND HYPOTHERMIC CONDITIONS. , 1964, Journal of applied physiology.

[37]  A. Ehrly,et al.  Circadian rhythm of human blood viscosity. , 1973, Biorheology.

[38]  H. Fricke,et al.  Relation of the Permittivity of Biological Cell Suspensions to Fractional Cell Volume , 1953, Nature.

[39]  P. Kurnik.  Circadian variation in the efficacy of tissue-type plasminogen activator. , 1995, Circulation.

[40]  L. Geddes,et al.  The specific resistance of biological material—A compendium of data for the biomedical engineer and physiologist , 1967, Medical and biological engineering.

[41]  J. Dormandy,et al.  Prognostic Significance of Rheological and Biochemical Findings in Patients with Intermittent Claudication , 1973, British medical journal.

[42]  E. Merrill,et al.  Influence of flow properties of blood upon viscosity-hematocrit relationships. , 1962, The Journal of clinical investigation.

[43]  S. Mohapatra,et al.  The changes in blood resistivity with haematocrit and temperature , 1975, European journal of intensive care medicine.

[44]  S Chien,et al.  Blood Viscosity: Influence of Erythrocyte Aggregation , 1967, Science.

[45]  H. Fuller.  The electrical impedance of plasma: A laboratory simulation of the effect of changes in chemistry , 2006, Annals of Biomedical Engineering.

[46]  A. Seiyama,et al.  Erythrocyte aggregation: bridging by macromolecules and electrostatic repulsion by sialic acid. , 1991, Biochimica et biophysica acta.