HFPV VDR4 ®
Definition:
“The VDR® is classified as a pneumatically
powered, pressure regulated, time cycled,
high frequency flow interrupter.”
- Delivers high frequency in a range of 200-900 cycles/min.
- Passive exhalation
Adel Bougatef
MD, PhD.
1
Conv.
Pressure
Rise
Pulse Frequency
Pulse i:e Ratio
Inspiratory Time
Pulsatile
Flowrate
(PIP)
Expiratory Time
Osc./Demand CPAP
Typicale HFPV waveform
i
Pressure
e
Plateau equilibrium
Step inflation
lung
OD.CPAP
Inspiration (I)
- I / E ratio : conventional rate expressed in seconds.
- i / e ratio : high frequency rate expressed in milliseconds.
Expiration (E)
Time (sec)
HFPV VDR4 : Pediatric SET-UP
IT = 1.1 to 1.6 sec
ET = 0.8 to 0.9sec
( I/E ≈ 1/1 for Low Frequency = 32 a 38 cycles/min)
HF = 500 to 700 cycles/min
i/e = 1 / 1 to 1/1.5
PIP = 25 to 35 cm H2O
i
Oscillatory CPAP = 6 – 8-10 cm H2O
e
PIP
FiO2 : 1 (and according to BGA)
Demande CPAP/PEEP = O
!
I
E
CO2 Washout
• i/e (1/2.5 - 1/3.5)
• HF ( ≈ 400 - 450 cycles/min)
• ET to
Low frequency
• Progressive
PIP by level of 2 cmH2O
• Convective Pressure rise.
Oxygenation
• i/e (1/1)
• HF ( 750 - 800 cycles/min)
• IT ,
ET will be adjusted for I/E =1.6/1
•
FIO2
•
Osc. CPAP
• Convective Pressure rise.
• Progressive
PIP by level of 2 cmH2O
VDR4
VDR SET UP
PIP/PEEP/FIO2
To
keep:
Ph ≥ 7.30,
SpO2 ≈ 92-95%, PaCO2 ≈ 35-45
mm Hg
FIO2: SPO2 ≈ 95 to 100 %
I Time: 1.4 seconds
E Time: 0.8 seconds
Low rate: ≈ 34
Pulse Frequency: ≈ 500 (with i/e: 1/2)
Pulsatile Flowrate: 30 - 40 cm H2O
Obtain:
Chest
XRay, ABG, Within 2 hours of
VDR set Up
If:
SPO2 <
90 or PaO2 < 60 mmHg
If:
Oscillatory cpap: 6 cm H2O
Yes
PaCO2
Yes
PaCO2
Yes
> 45 mmHg
If:
< 30 mmHg
1. Pulsatile Flowrate 2 cm H2O increment.
2.
Add Convective Pressure Rise.
3. Oscillatory Cpap.
4.
,, Inspiratory Time 0.1 second increment.
5. ,,
FIO2.
1. Pulsatile Flowrate 2 cm H2O increment.
2.
Inspiratory Time 0.1 second increment.
3. Reduce Pulse Frequency ( i/e: 1/2 to 1/3).
4.
,, ,, ,, Oscillatory Cpap.
5. Add
Convective Pressure Rise.
6. Assess
for airway obstruction.
1. Pulsatile Flowrate 2 cm H2O increment.
2.
Expiratory Time.
3. Pulse
Frequency ( i/e: 1/1).
4. Oscillatory
Cpap if SPO2 ≥ 95 %.
If SPO2 ≥ 95 % then:
Reduce FIO2 10 % increment.
Reduce
Pulsatile Flowrate 2 cm H2O increment. Reduce Oscillatory
Cpap by 1cm H2O increment. Don’t reduce Osc.Cpap < 4
cm H2O.
Concider Extubation when:
FIO2 ≤ 30 %.
Pulsatile
Flowrate < 20 cm H2O.
Low rate ≤ 15
cycles /min. With I time ≈ 1.2 second.
Chest X-Ray with
minimal infiltrates.
Eventually Transition To N.I.V. To reduce W.O.B.