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4.2
Handling leakages
-
In general,
leakages are not compensated
by Dräger anesthesia devices. This has to be
considered by the user, especially during all volume controlled ventilation modes. Otherwise,
insufficient ventilation situations may occur. If leakages can’t be avoided, the Pressure Control
mode has an advantage in that it delivers the set inspiratory pressure independently of any
leakage as long as the capacity of the breathing bag is sufficient. Depending on the device type,
the PEEP level might not be maintained. In fresh gas deficit situations (leakage plus patient
uptake are higher than fresh gas flow), ventilation will be affected
. Appropriate alarms like “Fresh
gas low
or leakage” will appear. The immediate reaction of the operator is required (reduce
leakage, increase FG flow; add up 70 L/min O2 by pressing the O2-flush to refill the system with
pure oxygen immediately). As an alternative, disconnect the manual breathing bag to entrain
ambient air. This prevents a low fresh gas situation and increases the availability of ventilation.
In this case, the resulting inspiratory oxygen concentration will be between the set fresh gas
oxygen concentration and the 21% of the ambient air. If the fresh gas flow is high, less ambient
air is entrained and the inspiratory oxygen concentration increases.
4.3
Modes of operation
-
Modes, measurement values, settings, maneuvers etc. that are possibly used with ICU
ventilators might not be available in the anesthesia devices.
4.3.1 Ventilation mode - Man / Spon
-
The user has to understand
the Man/Spon mode (Manual or Spontaneous Ventilation),
which
is a unique ventilation mode that is not available in most intensive care ventilators. This
mode can be live-saving in case of a failure of automatic ventilation and in absence of a
resuscitator. The influence of the
APL valve has to be understood as well.
Users with no
anesthesia background may expect that it also limits airway pressure during mechanical
ventilation.
The APL valve has no influence on mechanical ventilation
. It is only active in
Man/Spon mode. In the event of a ventilator failure, Man/Spon becomes active automatically
and the fresh gas flow will make the airway pressure rise up to the APL setting. Therefore,
in
Summary of Contents for Perseus A500
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