[Validation of continuous blood pressure measurements by pulse transit time: a comparison with invasive measurements in a cardiac intensive care unit].
OBJECTIVE
Arterial blood pressure measured by pulse transit time (PTT) can be used as an alternative to the gold standard of invasive measurement. It was the aim of this study to compare these two methods in order to validate PTT in patients with cardiac diseases.


METHODS
In 40 patients (29 males; mean age 68.7 ± 15 years) in a cardiac intensive care unit, blood pressures were continuously measured by PTT and the standardized invasive method for one hour. Values were analysed and compared in 30-second intervals (9,600 values for each method).


RESULTS
Blood pressures obtained with either method were not statistically different, neither in the whole group nor in subgroups. However, the number of analysable data was significantly higher using the invasive method, by which appropriate signals were obtained in 99.2 % of systolic and in 99.1 % of diastolic blood pressure measurements. In contrast, using the PTT-method, appropriate signals were seen in 85.8 % of systolic and 85.9 % of diastolic pressure measurements.


CONCLUSIONS
Blood pressures measured by PTT in patients in cardiac intensive care units provide reliable values over a period of at least one hour. However, the PTT method seems to be more susceptible to errors as evidenced by the number of failed measurements.
Kardiologische Klinik, Herz- und Diabeteszentrum NRW, Universitätsklinikum der Ruhr-Universität Bochum, Bad Oeynhausen.
S
S
Bartsch
D
D
Ostojic
H
H
Schmalgemeier
T
T
Bitter
N
N
Westerheide
S
S
Eckert
D
D
Horstkotte
O
O
Oldenburg
D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000502:physiology*; D003325:Coronary Care Units / Q000706:statistics & numerical data*; D003971:Diastole / Q000502:physiology; D004867:Equipment Design; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation / Q000379:methods*; D011674:Pulse; D015203:Reproducibility of Results; D013599:Systole / Q000502:physiology