Correction for apparent prolongation of mean transit time resulting from response time in a thermodilution system

A method of correcting an apparent prolongation in the measured transit time (MTT) resulting from the response time of the thermodilution system was investigated. The mean response times (MRTs) were measured for five commercially available thermistor-tipped catheters by recording their step function response curves. Using a flow loop model filled with saline through a mixing chamber, pairs of thermodilution curves were recorded simultaneously with pairs of catheters, and the influence of MRT on MTT was studied for the constant flow rates of 1-6 L/min. The difference in MRTs between a pair of thermodilution systems correlated with the difference in MTTs between a corresponding pair of thermodilution curves, yielding an equation. It was concluded that the apparent prolongation of MTT due to response time can be eliminated by subtracting the MRT from the measured MTT.<<ETX>>

[1]  L. Lilienfield,et al.  Simplified Method for Calculating Flow, Mean Circulation Time and Downslope from Indicator-Dilution Curves , 1956, Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine.

[2]  E. Newman,et al.  Effect of the Sampling System on the Shape of Indicator Dilution Curves , 1957, Circulation research.

[3]  R. Schlant,et al.  A Figure of Merit For Catheter Sampling Systems , 1959, Circulation research.

[4]  C. Sheppard,et al.  Effect of Catheter Sampling on the Shape of Indicator‐Dilution Curves: Mean Concentration versus Mean Flux of Outflowing Dye , 1959, Circulation research.

[5]  W. Milnor,et al.  Distortion of indicator-dilution curves by sampling systems. , 1960, Journal of applied physiology.

[6]  J. W. Bell,et al.  A method for reducing the distortion produced by catheter sampling systems. , 1962, Journal of applied physiology.

[7]  K. Zierler.  Theoretical Basis of Indicator‐Dilution Methods For Measuring Flow and Volume , 1962 .

[8]  T. G. Arnold,et al.  Removal of Distortion from Indicator Dilution Curves with Analog Computer , 1963, Circulation research.

[9]  C. Goresky,et al.  EFFECT OF CORRECTION OF CATHETER DISTORTION ON CALCULATED LIVER SINUSOIDAL VOLUMES. , 1964, The American journal of physiology.

[10]  H. Milhorn,et al.  Correction of catheter distortion effects on mean transit time--dye-dilution method. , 1966, Journal of applied physiology.

[11]  R. Arcilla,et al.  Estimation of catheter delay for appearance time of dye-dilution curves. , 1967, The American journal of physiology.

[12]  M. Paul,et al.  Limitations of thermal dilution curves for cardiac output determinations. , 1971, Journal of applied physiology.

[13]  N. O'connor,et al.  Rapid estimation of pulmonary extravascular water with an instream catheter. , 1975, Journal of applied physiology.

[14]  K. Maret,et al.  Reappraisal of extravascular lung thermal volume as a measure of pulmonary edema. , 1980, Journal of applied physiology: respiratory, environmental and exercise physiology.

[15]  F. Lewis,et al.  THE MEASUREMENT OF EXTRAVASCULAR LUNG WATER BY THERMAL‐GREEN DYE INDICATOR DILUTION * , 1982, Annals of the New York Academy of Sciences.

[16]  F. Lewis,et al.  Measurement of extravascular lung water in dogs using the thermal-green dye indicator dilution method. , 1982, Anesthesiology.

[17]  A. Taylor,et al.  Effect of air embolism on the measurement of extravascular lung thermal volume. , 1983, Journal of applied physiology: respiratory, environmental and exercise physiology.

[18]  R. C. Beckett,et al.  Effect of edema and hemodynamic changes on extravascular thermal volume of the lung. , 1984, Journal of applied physiology: respiratory, environmental and exercise physiology.

[19]  Edwin D. Trautman,et al.  The Development of Indicator-Dilution Techniques , 1984, IEEE Transactions on Biomedical Engineering.

[20]  M. Arakawa,et al.  A problem in the measurements of pulmonary extravascular water volume by double indicator dilution method, using heat and dye--thermal diffusion into the left ventricular wall. , 1984, Japanese circulation journal.

[21]  P. Carlile,et al.  Thermodilution measurement of lung water. , 1985, Clinics in chest medicine.

[22]  J. Schauble,et al.  Limitations of thermodilution ejection fraction: degradation of frequency response by catheter mounting of fast-response thermistors. , 1985, Critical care medicine.

[23]  R. Effros.  Lung water measurements with the mean transit time approach. , 1985, Journal of applied physiology.

[24]  M. Arakawa,et al.  A problem intrinsic to the measurements of the pulmonary extravascular water volume by the thermal-dye technic with the sampling site in the bifurcation of the aorta. Thermal equilibrium with the aortic wall. , 1985, Japanese circulation journal.

[25]  R. C. Beckett,et al.  Relationship between CO and transit times for dye and thermal indicators in central circulation. , 1986, Journal of applied physiology.