Here - EWMA 2013

POSTER PRESENTATIONS
P 238
Poster: Devices & Intervention
DISTAL BLOOD PRESSURE: COMPARISON OF STRAIN GAUGE AND
PHOTO-PLETHYSMOGRAPHY; IMPORTANCE OF STANDARDIZATION
Eva G. Hansen 1 , Anne K. Arveschoug 2 , Karsten Fogh 1
1 Dept. of Dermatology, Aarhus University Hospital (Aarhus, Denmark);
2 Dept. of Nuclear Medicine, aarhus University Hospital (Aarhus, Denmark).
Aim: Investigation the potential use of a hand-held photoplethysmograph in clinical
practice, and to validate the photoplethysmograph against the strain-gauge
plethysmograph. This includes comparison of the results with strain gauge both before
and after the standardization.
Material and Methods: A photoplethysmograph (vascular assist) and strain gauge
plethysmograph were used to measure distal blood pressure at toe level. The
reproducibility of the photoplethysmograph was determinated by making two separate
measurements of the same toe. To evaluate the precision of the photoplethysmograph,
the patients’ distal blood pressure was measured with both methods. Standardization of
measuring conditions: Resting supine patient with toes at hearth level. Body, toes and
probe should be temperate, no conversation, no movement of toes and lead, correctly
positioned probe to obtain the best signals. The agreement between the two methods
was assessed by using Bland-Altman statistics.
Results: Initial comparative measurements resulted in a significant difference between
results obtained with the two Methods: mean difference of 19.4 mmHg (34 toes of 19
patients). After standardization, the difference was reduced to a mean difference of 6.3
mmHg (40 toes of 24 patients). Reproducibility of the photoplethysmograph: an average
standard deviation between two sets of measurement of the same patient was 4.0
mmHg (21 toes of 12 patients).
Conclusion: The results show that a portable fully automated photoplethysmograph can
be used in clinical practice and is helpful in screening patients to detect arterial disease
with critically low peripheral perfusion. It is of great importance to obtain measurements
under standardized conditions.
POSTER: DEVICES & INTERVENTION
P 239
Poster: Devices & Intervention
NORMAL COMPRESSION DOES NOT AFFECT DISTAL BLOOD PRESSURE:
EFFECT OF INCREASING EXTERNAL PRESSURE
Eva G. Hansen 1 , Anne K. Arveschoug 2 , Karsten Fogh 1
1 Dept. of Dermatology, Aarhus University Hospital (Aarhus, Denmark);
2 Dept. of Nuclear Medicine, Aarhus University Hospital (Aarhus, Denmark).
Aim: To investigate the correctness of avoiding compression therapy in patients with
arterial- or mixed arterial and venous leg ulcers with reduced ABPI. Furthermore, to
investigate the potential influence of compression therapy on peripheral perfusion, (i.e.
by measuring systolic toe pressure), and to obtain more important information about
safety of compression. Finally, the aim was to measure distal systolic blood pressure at
baseline and with increasing external compression using an experimental compression
device.
Material and Methods: In this experimental study patients acted as their own control as
measurements from the same leg were compared. Patients with arterial insufficiency
were included (ABPI < 0.8). Toe pressure was measured without compression to obtain
baseline value before a possible external influence. A compression boot with known
external pressure was applied and systolic toe pressure was measured with increasing
external pressure (20 mmHg, 40 mmHg, 60 mmHg and 80 mmHg). For comparison,
similar measurements were carried out among persons with ABPI > 0.8.
Results: The toe pressure can be reduced by applying external compression, if the
compression pressure is high enough, often around 60-80 mmHg. Compression
pressure in the range of these pressure values does not seem to reduce the distal blood
pressure at toe level.
Conclusion: Clarification of the patients’ capability to wear compression therapy without
reducing the distal blood pressure is very helpful in the treatment of patients with arterialor
mixed arterial and venous leg ulcers. The results seem to indicate that these patients
can be treated with compression therapy.
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