Instructions: Meditech
microVENT
Page 13 of 28
Part number 011-0045-00
DOC300M
17/03/2021
Issue L
4 CHAPTER FOUR: OPERATING PROCEDURE
4.1 MANUAL VENTILATION AND CARDIAC MASSAGE (CPR)
4.1.1 The application of oxygen is recommended as soon as it is available in both basic life support
and advanced life support.
1,2
4.1.2 The Resuscitation Guidelines 2000 and 2005 highlighted the advantages of resuscitating with
lower volumes and flow rates. These help to limit airway pressures reducing the chances of
gastric insufflation, vomiting and subsequent aspiration and pneumonia.
1,2,3
4.1.3 With 100% oxygen resuscitation we help ensure oxygenation at these smaller tidal volumes.
4.1.4 The
microVENT
is fitted with a Manual Trigger to help the user to resuscitate the patient
following the appropriate basic life support resuscitation guidelines.
4.1.5 By using the Manual Trigger the operation of the device can be easily timed with the chest
compressions following the latest recommendations to ventilate during CPR at a ratio of two
ventilations to 30 compressions
4
. Squeezing the trigger initiates flow of 100% oxygen from the
device. Releasing the trigger allows the patient to exhale. The
microVENT
is designed to enable
the user to hold the resuscitation mask and control the airway with a two-handed grip,
operating the trigger with one finger (Fig:4). The use of the two-handed grip enables the user
to control the airway and give a good seal to the face mask. This grip is considered easier to
perform than the one-handed grip needed when operating a bag-valve-mask.
4.1.6 All
microVENTs
feature a pressure relief valve that prevents dangerous airway pressures being
achieved. An audible warning sounds when the relief valve is operating. Users should use the
test method described 5.3.18 (within warning section). The principle of the alarm detection is
that the pressure relief valve will relieve pressure within the device and therefore the patient
mask / airway device / patient airway and also simultaneously sound the alarm when the
delivered pressure by the means described above exceeds 45cm H2O / 4.5kPA. the pressure
relief valve and alarm function will continue to operate and the alarm will be audible until the
pressure drops below 45cm H2O / 4.5kPa.
4.1.7 Advanced models of the Microvent are fitted with a Patient Assist Valve. The Valve is
connected via a port to the patient connection (patient valve) and will trigger an inspiratory
phase of one breath (at the same BPM and Vti at which the device is currently set) if the
patient assist valve detects a negative pressure at the patient connection of -2.5cm H2O/ (-
0.25kPa) during the exhalation phase of automatic mode of cycling. The inspiration phase will
follow i.e. as per normal automatic cycling. The patient assist valve only operates during
automatic resuscitation and is disabled in the manual mode. If the patient assist valve
continues to detect the required negative pressure to trigger its operation after one cycle has
been delivered it will continue to deliver breaths. This ventilation mode is sometimes known
as SIPPV (Synchronised Intermittent Positive Pressure Ventilation).
WARNING
At all times during resuscitation the rise and fall of the patient's chest should be
monitored to ensure adequate ventilation.
CAUTION
Users are recommended to consult the ILCOR / AHA / ERC / UK or their national
resuscitation guidelines regarding the latest recommendations for CPR.
References:
