Lung Protective Jet Ventilation Basic Lung Protective Strategy for Treating RDS and Air Leaks with HFJV
Jan 18, 2016
Lung Protective Jet Ventilation
Basic Lung Protective Strategyfor
Treating RDS and Air Leakswith HFJV
Lung Protective Positive Pressure Ventilation
1. Recruit collapsed alveoli.
2. Stabilize alveoli with adequate PEEP and MAP (mean airway pressure).
3. Maintain adequate ventilation as gently as possible.
Lung Protective Ventilation with HFJV
Recruitment
Gentle Ventilation
IMV from Conventional Vent
Positive End-Expiratory (PEEP) & Mean Airway Pressure (MAP)
Stabilization
HFJV(Higher Rates Enable Smaller Tidal Volumes)
Recruitment with IMV
IMV (“Sigh” breaths) are most useful
for alveolar recruitment, but
contraindicated when airleaks are
present.
The following experiment illustrates
why...
Move your cursor over picture and click it to start video.
Double click here to continue on to next slide.
HFJV: 420 bpmPIP = 30CV:15 bpmPIP = 20
Note: CV breaths find the leak as path of least resistance while HFJV breaths continue to ventilate the other “alveoli”
Stabilization with
PEEP / MAP
Alveoli must be kept open,
whether air leaks are present or not.
HFJV = Most Gentle Ventilation
No other form of
ventilation uses smaller
tidal volumes.
HFJV uses the least overall
flow and airway pressure.
5 Keys to Optimal Patient Management
1. Start HFJV while maintaining MAP.
2. Use CV to recruit collapsed alveoli and find optimal PEEP.
3. Monitor Servo Pressure to stay on track.
5 Keys to Optimal Patient Management
4. Use HFJV rate to match lung time constants, encourage spontaneous breathing, & hasten extubation.
5. Wean to nasal CPAP.
HFJV Patient Management # 1
Don’t let MAP fall when
initiating HFJV.
Conventional HFJVP
ress
ure
Time
HFJV = Gentle Ventilation
PEEP and MAP enable Stabilization / Oxygenation
IMV enables Alveolar Recruitment
You must raise PEEP to maintain MAP for Stabilization / Oxygenation when starting HFJV.
Don’t Lose Mean Airway Pressure!
HFJV Patient Management # 2
Use Conventional Ventilator
to Recruit Alveoli and
Find Optimal PEEP
Alveolar Recruitment
Open collapsed alveoli with CV “Sigh” breaths.
V
P
Critical Opening Pressure
5
Big breaths open collapsed alveoli easier than little breaths.
CV + Low PEEP = Atelectrauma
V
P5 8
PEEP
Critical Closing Pressure
Stabilize with PEEP
Keep open alveoli from collapsing
PEEP = 5 does not work when Critical Closing Pressure = 8.
Find & Set Optimal PEEP
V
P5 9 25
Start HFJV and lower CV rate to 5 while keeping alveoli from collapsing by maintaining MAP with increased PEEP :
7
Maintain CV = 5 bpm& adjust FiO2 to stabilize SaO2 at 90%.
PEEP
Then switch CV to CPAP mode to test PEEP. Maintain HFJV at this PEEP level, weaning FiO2 to maintain target SaO2 until FiO2 ~ 30%.
Wean HFJV PIP to maintain target PCO2 .
If SaO2 falls, increase PEEP as necessary to keep SaO2 stable with HFJV + CPAP.
Does SaO2 fall when 5 IMV breaths CPAP?
Assume you started with CV and PEEP = 5, MAP = 10:
MAP
10
HFJV Patient Management # 3
Monitor Servo Pressure• If S.P. you may need to wean PIP
to keep PaCO2 and pH in target range.
• If S.P. you may need to suction, re-position ETT, or treat bronchospasms or pneumothoraces…
Reacting appropriately to Servo Pressure changes will enable continuous
Lung Protective HFJV.
V
P
Critical Closing Pressure
Gentle, open-lung, lung-protective ventilation …
HFJV Patient Management # 4
Wean to nasal CPAP.
As ventilation improves:
1. Reduce HFJV PIP first.
2. Reduce HFJV Rate to encourage spontaneous breathing.
HFJV Rate I : E
600 bpm 1 : 4
420 1 : 6
360 1 : 7
300 1 : 9
240 1 : 12
More time for spontaneous
breathing!
Warning
Reducing PIP for PCO2
also reduces MAP.
0
20
15
10
5
25
PEEP
P
Time
Reducing PIP Reduces VT (PaCO2 )
and MAP (PaO2 )PIP
MAP
HFJV Waveform
0
20
15
10
5
25
Paw
PIP
P
Time
PEEP
Reducing PIP and Raising PEEP ( VT , PaCO2 )
keeps MAP ( and hopefully PaO2 ) constant.
How can one keep MAP constant?
What if patient is hyperventilated &
hypoxemic?
0
20
15
10
5
25
PMAP
PEEP
Time
PIP
Increasing PEEP while keeping PIP constant
raises MAP ( PaO2 ) & decreases VT ( PaCO2 ).
As oxygenation improves:
1. Wean big breaths first.(Get CV into CPAP mode.)
2. Wean FiO2 before PEEP/MAP.
Wean to Nasal CPAP
You may want to offer a short trial of low rate CV or endotracheal CPAP with Jet in Standby before extubation to gauge patient’s readiness…
5
10
15
20
0.0 0.5 1.0
Time, seconds
cm H2O
P
2.01.5
It’s time to extubate when…
Patient is breathing spontaneously.HFJV PIP < 15, PEEP < 8, FiO2 < 0.3
Set Nasal CPAP = HFJV MAP
Questions?
- www.bunl.com- 800-800-HFJV
(Available 24/7)
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