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Laser Doppler velocimetry in critically ill patients
Critical Care Medicine
|August 1, 1987
Summary
Laser Doppler velocimetry (LDV) can track directional changes in cardiac index (CI) in critically ill patients. However, absolute LDV values do not predict absolute CI due to gradual, independent changes over time.
Area of Science:
- Cardiovascular Physiology
- Medical Technology Assessment
- Critical Care Medicine
Background:
- Cutaneous blood flow, measured by laser Doppler velocimetry (LDV), is a potential indirect indicator of circulatory function.
- Previous research suggested LDV might effectively monitor changes in cardiac output.
Purpose of the Study:
- To evaluate the utility of LDV in critically ill patients.
- To determine if LDV can accurately reflect cardiac index (CI) changes.
Main Methods:
- Noninvasive LDV was used in 67 critically ill adults.
- Simultaneous measurements of cardiac index (CI) and other physiological variables were recorded.
- Both heated and unheated laser probes were employed.
Main Results:
- LDV successfully reflected acute directional changes in CI.
- The heated laser probe allowed LDV to mirror the magnitude of acute CI changes.
- Gradual, independent fluctuations in LDV were observed over time, unrelated to CI.
Conclusions:
- LDV is useful for detecting acute directional shifts in cardiac index.
- Absolute LDV values are not reliable predictors of absolute cardiac index.
- The heated probe enhances LDV's ability to reflect the magnitude of CI changes.