Correlation Between Doppler Derived Carotid Artery Corrected Flow Time and Pressure Transducer Derived Radial Artery Corrected Flow Time: A Prospective Observational Study

  • Souvik Maitra
  • Sulagna BhattacharjeeEmail author
  • Dalim K. Baidya
Original Article



Carotid artery corrected flow time (cFT) derived from Doppler USG is a known predictor of volume responsiveness. However, it can’t be obtained continuously, and is operator dependent. In this prospective study, correlation between Doppler derived carotid artery cFT and pressure transducer derived radial artery cFT was evaluated in adult patients undergoing surgery under general anaesthesia.


Doppler derived carotid artery cFT were obtained from n = 51 adult patients at n = 125 time points. Simultaneously, pressure transducer waveforms were saved at the time of measurement of carotid artery cFT. Later, images were analyzed by an image processing computer software; both pulse pressure variation and cFT were estimated from pressure transducer waveform.


Radial artery flow times measured by two independent observers, were significantly correlated (r2 = 0.99, p < 0.00001). Bland–Altman analysis found limits of agreement − 8.3 to 6.3 ms [mean difference (95% CI) − 0.98 (− 1.63, − 0.32)]. Doppler derived carotid artery cFT & pressure transducer derived radial artery cFT were also significantly correlated [r2 = 0.78, p < 0.0001]. However, radial artery cFT was significantly higher than carotid artery cFT [p < 0.0001, paired sample t test]. Radial artery cFT > 404.4 ms had an sensitivity and specificity of 87.34% and 85% respectively with a grey zone was between 393.7 and 417 ms to predict PPV ≥ 12%.


Pressure transducer derived radial artery cFT correlated with Doppler derived carotid artery cFT and may be a reasonable predictor of volume responsiveness. Further studies are required to confirm its role in various clinical scenario for prediction of volume responsiveness.


corrected flow time fluid responsiveness radial artery cardiovascular monitoring hemodynamic monitoring 



  1. 1.
    Blehar, D. J., S. Glazier, and R. J. Gaspari. Correlation of corrected flow time in the carotid artery with changes in intravascular volume status. J. Crit. Care 29:486–488, 2014.CrossRefGoogle Scholar
  2. 2.
    Coste, J., and J. Pouchot. A grey zone for quantitative diagnostic and screening tests. Int. J. Epidemiol. 32:304–313, 2003.CrossRefGoogle Scholar
  3. 3.
    Esper, S. A., and M. R. Pinsky. Arterial waveform analysis. Best Pract. Res. Clin. Anaesthesiol. 28:363–380, 2014.CrossRefGoogle Scholar
  4. 4.
    Hossein-Nejad, H., P. Mohammadinejad, M. Lessan-Pezeshki, S. S. Davarani, and M. Banaie. Carotid artery corrected flow time measurement via bedside ultrasonography in monitoring volume status. J. Crit. Care. 30:1199–1203, 2015.CrossRefGoogle Scholar
  5. 5.
    Kim, D. H., S. Shin, N. Kim, T. Choi, S. H. Choi, and Y. S. Choi. Carotid ultrasound measurements for assessing fluid responsiveness in spontaneously breathing patients: corrected flow time and respirophasic variation in blood flow peak velocity. Br. J. Anaesth. 121:541–549, 2018.CrossRefGoogle Scholar
  6. 6.
    Lance, V. Q., and D. H. Spodick. Heart rate–left ventricular ejection time relations. Variations during postural change and cardiovascular challenges. Br. Heart J. 38:1332–1338, 1976.CrossRefGoogle Scholar
  7. 7.
    Schneider, C. A., W. S. Rasband, and K. W. Eliceiri. NIH Image to ImageJ: 25 years of image analysis. Nat. Methods. 9:671–675, 2012.CrossRefGoogle Scholar
  8. 8.
    Singh, O., and R. K. Sunkaria. Detection of onset, systolic peak and dicrotic notch in arterial blood pressure pulses. Meas. Control 50:170–176, 2017.CrossRefGoogle Scholar
  9. 9.
    Song, Y., Y. L. Kwak, J. W. Song, Y. J. Kim, and J. K. Shim. Respirophasic carotid artery peak velocity variation as a predictor of fluid responsiveness in mechanically ventilated patients with coronary artery disease. Br. J. Anaesth. 113:61–66, 2014.CrossRefGoogle Scholar
  10. 10.
    Youden, W. J. Index for rating diagnostic tests. Cancer 3:32–35, 1950.CrossRefGoogle Scholar

Copyright information

© Biomedical Engineering Society 2020

Authors and Affiliations

  1. 1.Department of Anaesthesiology, Pain Medicine & Critical CareAll India Institute of Medical SciencesNew DelhiIndia

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