Table 3: Methods used in clinical trials and
animal studies.
Method |
Advantages |
Limitations |
Clinical
use/ future possibilities |
Carotid
pressure measurement |
-
better prediction of cardiovascular events than peripheral
BP values; |
-
highly observer dependent; -
peripheral interferences; -
imprecise; |
-
noninvasive central BP measurement; |
Brachial
waveform |
-
better prediction of cardiovascular events than peripheral
BP values; |
-
generalized transfer function is needed; -
identification of the late systolic shoulder of the
peripheral pressure waveform; -
proprietary algorithm to obtain central BP due to factors moulding pulse wave shape remote to aorta; |
-
noninvasive central BP measurement; |
Radial
waveform |
-
easier to obtain than brachial waveform; -
better prediction of cardiovascular events than peripheral
BP values; |
-
brachial to radial amplification; -
should not be calibrated to brachial BP; |
-
noninvasive central BP measurement; |
Photoplethysmography |
-
allows to measure BP on ear lope, finger or toe; -
additional information regarding oxygen saturation and
cardiac output; |
-
may be imprecise; -
outcomes may be influenced by temperature and sympathetic
activity; |
-
noninvasive, continuous BP measurements; -
especially in neonates and children; |
Volume
clamping |
-
noninvasive method; -
good reproducibility; -
information regarding beat-to-beat BP changes; |
-
differences in SBP may reach statistical significance; -
arterial pressure is calculated indirectly; |
-
noninvasive, continuous BP measurement; |
Pulse
Transit Time |
-
short-term changes in BP may be detected; -
continuous measurement is possible; |
-
affected by arterial stiffness, autoregulation and wave
reflection in peripheral arteries; |
-
continuous noninvasive BP measurements; |
Doppler
assessment of SBP (including
laser Doppler) |
-
very sensitive method; -
useful in low BP values; -
good reproducibility; |
-
high costs; -
a lot of equipment is needed; |
-
critical ischemia, when BP is not detectable by other
methods; |
Electrical
Impedance Tomography |
-
analyzes pulse in the aorta; -
free of peripheral interferences; |
-
complicated reconstruction algorithms; -
lack of sufficient data regarding usage; |
-
new method; -
introduced to animal studies; |
High
Definition Oscillometry |
-
allows measurements of AP in heart frequencies up to 500
bpm; -
allows to accomplish direct SBP and DBP; -
linearity during deflation; -
real time control; |
-
long term recordings are unavailable; - we
found no human studies; |
-
studies regarding pharmacology in animals; |
Radiofrequency
Ultrasound Wall Tracking of the carotid artery |
-
well correlated with directly measured SBP; -
gives information about central BP; -
noninvasive; -
more adequate in children; |
-
needs to be calibrated to mean and DBP measured i.e. with
sphygmomanometer on brachial artery; -
amplification between brachial and carotid artery; |
-
noninvasive control of central BP, i.e. in ICU stations; -
noninvasive control of central BP in children; |
Telemonitoring system |
-
improves treatment goals achievement; -
allows better patient monitoring; |
-
low availability; -
high costs; |
-
monitoring of patients, especially older, with multiple
comorbidities; |
AP: Arterial pressure; BP: Blood
pressure; DBP: Diastolic blood pressure;
ICU: Intensive care unit; SBP: Systolic blood pressure