ACUTRONIC fabian HFO User Manual

Guide to volume guarantee 149
fabian HFO | SW 5.1.x
Ref: 113003.EN / Date 2020-02-10
16 Guide to volume guarantee
Mechanical Ventilation is required to manage neonates with severe respiratory failure. Pressure-
limited ventilation (PLV), delivering a fixed peak inspiratory pressure (PIP), has traditionally been
used to control the arterial carbon dioxide (PaCO
2
). During PLV the tidal volume (V
T
) fluctuates
widely due to the baby's breathing effort, changes in lung mechanics and variable endotracheal tube
(ETT) teak.
For some patients, a strategy of targeting a required exhaled tidal volume while maintaining pressure
within a prescribed range can improve gas exchange without the risk of lung injury associated with
volume control ventilation in preterm infants.
The fabian™ series of neonatal/pediatric microprocessor-controlled ventilators allow volume-targeted
ventilation (V
TV
) even in very preterm infants. Measurements are done with the Flow Sensor placed
at the Y-piece. The Flow Sensor measures inspired and expired V
T
, and ETT Leak is calculated and
displayed. The advantage of targeting inspired volume (V
Ti
) is that the ventilator controls the V
Ti
as it
is delivered. The major disadvantage is that variable ETT Leak alters volume entering the lungs. The
advantage of using the expired volume (V
Te
) is that this most accurately reflects the V
T
that entered
the infant's lung and is less influenced by ETT Leaks unless they are very large.
Volume Guarantee (VG) Ventilation is a VTV-mode controlling the V
Te
.
16.1 fabian volume guarantee (VG) operation
The operator sets a target expired volume V
Te
(set V
Te
). The ventilator measures the expired V
Te
for
each inflation and automatically adjusts the PIP(P
peak
) for the next inflation of the same type,
triggered or untriggered, aiming to deliver the VTe around the Set Level. The detailed guide how to
start VG function on the fabian™ Ventilators is described in detail on the following pages.
The maximum difference in Pressure from breath to breath is limited to one-third of the previous
breath to avoid any overdistension due to excessive pressure compensation.
The main issue is to choose an appropriate VTe at the start and to give enough pressure to get it in.
The following procedure describes the use of VG in (A / C) - SIPPVmode, however, the same
procedure can be followed in the other modes where VG function is available. IPPV, SIPPV,
SIMV+PSV and PSV.
Look at what V
Te
the baby is currently getting with the current ventilation settings. You can get this
value from the Measured Parameters displayed on the right side of the display.
The usual VTe to aim for is 4 to 6mL / kg per breath. Starting with 5mL/kg is usually a safe point but
could be slightly high for some babies.
Look at the pressure settings. The pressure settings are alarm settings. If the ventilator cannot
deliver the VTe at the maximum pressure prescribed, it will alarm "Tidal Volume not reached". You
may need to increase the P
max
) to stop it from alarming.
The Rate Setting is a "back-up" rate if the baby is not breathing. However, it should be set 10 to15
breaths below the baby's apparent rate so that the baby has an opportunity to Trigger.
If VG is added to the SIPPV, each breath is maintained at same Exhaled Tidal Volume. In case of an
improvement of lung compliance, the Pinsp is automatically reduced.
Every single Inspiratory effort of the patient is supported with a mechanical breath with fixed
Inspiratory time and pressure. If the breath was triggered by patient, it is colored Green on the
waveform graphics, if none triggered, Grey. The baby controls the rate of ventilation.

ACUTRONIC fabian HFO Specifications

General

Brand	ACUTRONIC
Model	fabian HFO
Category	Medical Equipment
Language	English