1. 1 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.

2. Inspiration (I) Expiration (E) Pressure Time (sec) e i OD.CPAP - I / E ratio : conventional rate expressed in seconds. - i / e ratio : high frequency rate expressed in milliseconds. Plateau equilibrium Step inflation lung Typicale HFPV waveform

3. Inspiratory Time Pulsatile Flowrate (PIP) Osc./Demand CPAP Expiratory Time Pulse Frequency Pulse i:e Ratio Conv. Pressure Rise

4. HFPV VDR4 : SET-UP IT = 2.8 sec ET = 1.8 sec (for Low Frequency = 12 - 14 cycles/min) HF = 500’/min i/e = 1 / 1 to 1/2 PIP = 40 cm H 2 O Oscillatory CPAP = 10 -14 cm H 2 O FiO2 : 1 (and according to BGA) Demande CPAP/PEEP = O ! * IE i e PIP

5. DEMAND CPAP –2 cmH 2 O for spontaneously breathing patients –0 cmH 2 O for non-spontaneously breathing patients. *

6. CO 2 Washout i/e (1/3 - 1/5) HF ( 300 - 500 cycles/min) ET to Low frequency (12-18 cycles/min) but hold sufficient IT for gas exchange. Osc.CPAP Progressive PIP by level of 2-3 cmH 2 O Convective Pressure rise.

7. Oxygenation i/e (1/1) HF ( 500 - 700 cycles/min) IT, ET will be adjusted for I/E =1.5/1 FIO 2 Osc. CPAP Convective Pressure rise. Progressive PIP by level of 2-3 cmH 2 O Convective Pressure rise.

8. VDR SET UP FIO2: SPO2 ≥ 95 % I Time: 2.8 seconds E Time: 1.8 seconds Low rate: ≈ 13 cycles/min Pulse Frequency: ≈ 500 (with i/e: 1/2) Pulsatile Flowrate: 35 - 45 cm H2O Oscillatory cpap: 10 cm H2O ARDS PIP/PEEP/FIO2 To keep: Ph ≥ 7.30, SpO2 ≥ 95%, PaCO2 ≈ 25-45 mm Hg Obtain: Chest XRay, ABG, Within 4 hours of VDR set Up If: SPO2 < 95 or PaO2 < 60 mmHg 1. Pulsatile Flowrate 2 cm H2O increment. 2. Add Convective Pressure Rise. 3. Oscillatory Cpap. 4.,, Inspiratory Time. 5.,, FIO2. If: ETCO2 > 40 mm Hg PaCO2 ≥ 45 mm Hg 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. If: ETCO2 ≤ 25mm Hg PaCO2 ≤ 25 mmHg 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 ≥ 98 % then: Reduce FIO2 10 % increment (30% lower limit). Reduce PEEP by 2 cm H2O increment. Don’t Reduce PEEP ≤ 8 cm H2O. Reduce Pulsatile flowrate by 2 cm H2O increment. Don’t reduce to < 10 cm H2O difference PIP/PEEP. Concider Extubation when: FIO2 ≤ 30 %. Pulsatile Flowrate 250. Chest X-Ray with minimal infiltrates. Patient stable for 24-48 hours. Transition To N.I.V To reduce W.O.B. Concider Periodic IPV Yes