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 DifferencesFirst 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

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

PSV with Differences

Paw

V•

insp

expPatient or vent ilator initiated

inspiration PSV cycledexpiration

Peak flow

Drop to 15% of peak flow

Pressure Support Ventilation (PSV)

Set Pinsp

Flow terminationautomatically compensates

for leak

Onset of inspiration

Onset ofexpiration

Leak flow

Pressure Support Ventilation with leak compensation

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 The average Inspiratory Time of the four patients on PSV above was ~ .25seconds – expect to see shorter I times, and was ~ .25seconds – expect to see shorter I times, and

consequently a drop in the MAPconsequently a drop in the MAP

Why let the infant end inspiration (set Tinsp ) ?

CBF variability increases IVH riskPerlman , 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 ConsumptionRoze, Liet, Gournay, Debillon, Gaultier; Eur Resp J, Nov 1997

• Reduced Stress Hormone LevelsQuinn, de Boer, Ansari, Baumer; Arch Dis Child, May 1998

• Decreased Effort and Respiratory RateBendel- Stenzel, Bing, Meyers, Connett, Mammel; Ped Res, May 1998

• Less Variation in Vt After SurfactantMrozek, 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.

•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.

Volume Guarantee: How does it work?

•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!

Problems with Volume Guarantee

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 injuryRosen WC, et al. Ped Pulm 1993 Sinha SK, et al. Arch Dis Child Fetal Neo Ed

1997

Consistent Vt Stable PaCO2 Stable CBF Less IVH

Postulated mechanism of action:

Why volume - oriented ventilation ( VOV ) in infants?

Pressure ventilation may cause hypoventilation or overdistention when CL changesDavis, 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 injuryHerandez, et al. J Appl Physiol 1989

Bjorkland, et al. Ped Res 1997

Variable PaCO2 in pressure ventilation increases IVHStewart, et al. Pediatrics 1981

Pressure Support Mode with Volume Guarantee :

Concept of “Autoweaning”

PIP

C lung

Vt

Extubate!Time

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.

PSV+VGA Happy Child

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