The Babylog 8000 plus
with Pressure Support and Volume Guarantee
The Key to Breathing Harmony
Babylog 8000 plus
•
A ventilator designed specifically for
critically ill newborn infants
• Comprehensive modes: CPAP, IMV,
SIMV, A/C, PSV
• Volutrauma protection strategy: Volume
Guarantee option in SIMV, A/C, and PSV
modes
• Leak- adapted flow synchronization
PSV with Differences
First the Similarities:
• Pressure targeted breath (both
spontaneous and set)
• Flow terminated at 15% of peak
inspiratory flow
• Inspiratory time will vary and is
patient dependent
• Preset Insp. Time still functions as
a back-up, breath will not exceed
clinician setting
PSV with Differences
Now the big differences:
•A “back-up” rate is set - so yes, in
theory a paralyzed patient can be
placed on PSV, Babylog style
•All breaths, whether patient assisted
or not will be pressure targeted and
flow terminated
•PSV may be combined with the volume
guarantee (VG) option – allowing
clinicians to set tidal volume
Pressure Support Ventilation (PSV)
Set Pinsp
Paw
Peak flow
insp
•
Drop to 15%
of peak flow
V
exp
Patient or
vent ilator
initiated
inspiration
PSV cycled
expiration
Pressure Support Ventilation
with leak compensation
Flow termination
automatically compensates
for leak
Leak
flow
Onset of
inspiration
Onset of
expiration
Patient- Set Inspiratory Time in Neonatal
Pressure Support Ventilation (PSV)
Examples courtesy of Prof. JC Rozé, Nantes, France
The average Inspiratory Time of the four patients on PSV above was ~
.25seconds – expect to see shorter I times, and consequently a drop in
the MAP
Why let the infant end inspiration (set Tinsp ) ?
CBF variability increases IVH risk
Perlman , et al. N Engl J Med 1983
CBF variability and IVH increases with
infant- ventilator asynchrony
Perlman , et al. N Engl J Med 1985
Rennie, et al. Arch Dis Child, 1987
So, harmonizing ventilator- infant
interaction should reduce IVH.
Why give mechanical support for all breaths?
• Decreases Work of Breathing
Jarreau, Moriette, Mussat, et al; Am J Resp CCM, Mar 1996
• Decreases Oxygen Consumption
Roze, Liet, Gournay, Debillon, Gaultier; Eur Resp J, Nov 1997
• Reduced Stress Hormone Levels
Quinn, de Boer, Ansari, Baumer; Arch Dis Child, May 1998
• Decreased Effort and Respiratory Rate
Bendel- Stenzel, Bing, Meyers, Connett, Mammel; Ped Res, May 1998
• Less Variation in Vt After Surfactant
Mrozek, Bendel- Stenzel, Meyers, Bing,, Mammel; Ped Res, May 1998
Problems with a Preset Ti: Patient Asynchrony
The infant attempts to breathe during a set ventilator
inspiratory cycle, resulting in lower lung pressure and
excessive volume.
Volume Guarantee: How does it work?
•The VG option allows for delivery of a set
volume during mandatory pressure breaths in
A/C, SIMV, and PSV
•Similar to Autoflow on the Dura, the PIP will
adjust automatically up to a set maximum,
compensating for changes in resistance and/or
compliance, to ensure the set tidal volume is
delivered
•The inspiratory Pressure knob now functions
as the maximum pressure allowed, NOT the set
PIP. PIP is not set, and will vary.
Problems with Volume Guarantee
•Similar to autoflow, high respiratory demand
from the patient will result in a lower PIP
delivered to the airway, i.e. less support for the
patient.
•PATIENTS MUST BE CLOSELY MONITORED
FOR SIGNS OF INCREASED WOB WHEN
UTILIZING THE VOLUME GUARENTEE
MODE!
Why volume - oriented ventilation ( VOV ) in infants?
VOV vs SIMV: Equivalent ventilation
at lower MAP
Herrera, at al. Ped Res 1999
VOV reduces IVH, acute lung injury
Rosen WC, et al. Ped Pulm 1993
Sinha SK, et al. Arch Dis Child Fetal Neo Ed 1997
Postulated mechanism of action:
Consistent Vt
Stable PaCO2
Stable CBF
Less IVH
Why volume - oriented ventilation ( VOV ) in infants?
Pressure ventilation may cause hypoventilation or
overdistention when CL changes
Davis, et al. N Engl J Med 1988
Gibson, et al. Eur J Pediatr 1994
Bjorklund, et al. Am J Respir Crit Care Med 1996
Dimitriou, et al. J Perinat Med 1997
Lung overdistention creates acute / chronic lung injury
Herandez, et al. J Appl Physiol 1989
Bjorkland, et al. Ped Res 1997
Variable PaCO2 in pressure ventilation increases IVH
Stewart, et al. Pediatrics 1981
Pressure Support Mode with Volume Guarantee
:
Concept of “Autoweaning”
PIP
Vt
C lung
Time
Extubate!
Tidal volume delivery in mechanically
ventilated preterm infants
Appropriate tidal volume for mechanical
ventilation of preterm infants with
surfactant deficiency is
4 - 6 mL/ kg body weight.
A Happy Child
PSV+VG
Two Extra Pictures - The Neonatal flow sensor
• Hot wire anemometer
• Sensitive to 0.17 mL
• 0 - 30 lpm range
• Weighs 10 grams
• 0.5 mL added
deadspace
• Inexpensive
• 6 month use
Flow Sensor Measurement Principle
Hot wire anemometer:
•
•
•
•
Two tiny platinum wires are heated to 400°C
One wire is shaded to determine direction of gas flow
Wire cooling is proportional to gas flow
Flow is integrated with time for volume measurement