11
EN
WARNING
Avoid disturbing the mask during use.
7.8. Usage with Spontaneous Ventilation
The Ambu AuraOnce is suitable for spontaneously breathing patients when used with volatile agents or intravenous
aesthesia on condition that anaesthesia is adequate to match the level of surgical stimulus and the cuff is not
overinfl ated.
Coughing, breath-holding, or movement may occur if the level of anaesthesia is inadequate for maintenance. This
may well occur following the introduction of an external stimulus such as surgery or turning the patient if the level
of anaesthesia has been misjudged. Gently assist ventilation until breathing returns.
7.9. Usage with Positive Pressure Ventilation
Before using the Ambu AuraOnce with positive pressure ventilation (PPV), the operator should fi rst acquire
experience in its usage in spontaneously breathing patients.
Choose a ventilatory pattern giving peak airway pressures less than 20 cmH
2
O and tidal volumes less than 8 ml/kg
while the capnography is closely monitored.
In the event of leakage occurring during PPV, check for the following:
• light anaesthesia causing a degree of glottis closure
• inadequate neuromuscular block
• a reduction in lung compliance related to the surgical or diagnostic procedure
• displacement of the Ambu AuraOnce by head turning or traction.
After identifying the cause of the leakage, take appropriate corrective measures.
If leakage should occur around the cuff,
do not simply add more air
. This will not necessarily improve the seal
pressure and may even increase the leak by adding tension to the normally soft cuff, pushing it away from the
larynx. Instead remove the mask and reinsert while providing that anaesthetic depth is adequate.
7.10. Critical observations during use
Inadequate level of anaesthesia:
The most likely problem following insertion is failure to maintain an adequate
level of anaesthesia. Administer an additional bolus of induction agent and/or increase the concentration of volatile
agent while gently assisting ventilation.
Incorrect positioning of the Ambu AuraOnce
can be assessed by capnography, the observation of equal
movements or by observation of changes in tidal volume, e.g. a reduction in expired tidal volume. If you suspect
that the Ambu AuraOnce has been positioned incorrectly, remove and reinsert – and provide that anaesthetic depth
is adequate.
Unexpected regurgitation:
Regurgitation may occur even in fasted patients. This may be caused by inadequate
level of anaesthesia. One early sign of regurgitation is the appearance of fl uid travelling up the Ambu AuraOnce
airway tube. The fi rst signs of regurgitation may be spontaneous breathing, coughing or breath-holding.
If regurgitation occurs, provided that oxygen saturation remains at acceptable levels, the Ambu AuraOnce should
not be removed. This should be managed by putting the patient in a “head-down” position. Briefl y disconnect
the anaesthetic circuit so that the gastric contents are not forced into the lungs. Check that anaesthetic depth is
adequate and deepen anaesthesia intravenously, if appropriate.
