Selection Of Appropriate Pressure Level - MIETHKE M.blue Instrucciones De Manejo

Consequently, the opening pressure of M.blue
in the horizontal position is characterised by
the fixed differential pressure unit pre selected
at implantation to be either 0, 5 or 10 cm
H O. It is not adjustable. The main opera-
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tion method used by the adjustable differential
pressure unit is shown in Fig. 2a and b.
Fig. 2: Operation of the differential pressure unit
a) closed b) open
In fig. 2a the valve is closed, hence drainage
is not possible.
If the patient's intraventricular pressure (IVP)
exceeds the spring force of the micro-coil
spring, the sealing ball moves out of the cone,
leaving a gap for CSF drainage (fig. 2b).
Vertical position
As the patients body moves from prone to
vertical, the gravitational unit closes the dis-
charge channel in the proximal part of the
valve (Fig. 3a). Thus, the opening pressure
of M.blue is increased in the upright posi-
tion, because now the weight of the tanta-
lum weight (opening pressure of the gravita-
tional unit) must be overcome in addition to
the opening pressure of the differential pres-
sure unit. Drainage is only possible once the
sum of IVP and hydrostatic suction is greater
than the opening pressure of both units (fig.
3b). For individual adaptation of the open-
ing pressure to the patient, a valve opening
pressure between 0 and 40 cm H
selected for the adjustable gravitational unit.
Fig. 3: Gravitational unit in vertical body position
a) closed b) open
During physical activity which is associated
with shock (e.g. jogging) the opening pressure
of M.blue may decrease temporarily accord-
ing to laboratory results. Generally however,
functionality is retained. At the end of physi-
cal activity, the opening pressure returns to its
original level and remains stable.
SELECTION OF APPROPRIATE
PRESSURE LEVEL
Horizontal position
In the lying position, the gravitational unit has
no influence on the valve opening pressure.
In this position, the valve opening pressure is
thus determined exclusively by the differential
pressure unit. In this case, the pressure level
should be set in accordance with the clinical
picture and indications. By default, a differen-
tial pressure unit with an opening pressure of
5 cmH
Vertical position
The M.blue opening pressure for the ver-
tical body position is calculated from the
sum of the opening pressure in the differ-
ential pressure unit and the adjustable grav-
itational unit. Patient height, activity level
and potentially increased abdominal pres-
sure (obesity) should be taken into account
in selecting the opening pressure for the
O can be
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gravitational unit (see pressure level recom-
mendations at https://www.miethke.com/en/
products/downloads). This is a non-binding
recommendation for the attending physician.
According to his diagnosis, the physician
decides each case independently, without
instructions and individually.
INSTRUCTIONS FOR USE | GB
O is recommended.
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