Demystifying APRV-TCAV yesterday at #TCAV course. Thank you for the invite @ThinkingCC #FOAMed #ventilation #COVID19 #ARDS 
Initial settings - important to distinguish between rescue and post op atalectasis.
Set :
P high to 2mmHg less than patient's peak pressure on current settings.
P low to 0mmHg.
Set :
P high to 2mmHg less than patient's peak pressure on current settings.
P low to 0mmHg.
To set your resp rate:
60/current resp rate is your Time at high pressure (T high) + Time at low pressure (T low)
Eg: Resp rate of 25
60/25 = Thigh + Tlo = 2.4 secs
60/current resp rate is your Time at high pressure (T high) + Time at low pressure (T low)
Eg: Resp rate of 25
60/25 = Thigh + Tlo = 2.4 secs
Some vents allow you to set the resp rate for APRV/Bi Level. Some go on just Thigh and Tlow. You will have to know your machine to set this properly.
Set Tlo first - Adjust T low so (Eft) to terminate at 75% of Expiratory flow peak (Efp).
75% X Efp = Eft as shown below
Set Tlo first - Adjust T low so (Eft) to terminate at 75% of Expiratory flow peak (Efp).
75% X Efp = Eft as shown below
I usually set it to 0.3 secs for most of my patients. But make sure you are not more than 75% of Efp. Higher values of T Lo (> 75% Efp) cause alveolar instability and can cause recruited alveoli to collapse again.
T high is then 2.4 - 0.3 = 2.1secs.
T high is then 2.4 - 0.3 = 2.1secs.
After this is set :
Check your driving pressure (Plateau pressure - PEEP).
Note this PEEP is not your P Low 0.
Pplat - perform an inspiratory hold
PEEP - perform an expiratory hold
This tells you your baseline driving pressure
Check your driving pressure (Plateau pressure - PEEP).
Note this PEEP is not your P Low 0.
Pplat - perform an inspiratory hold
PEEP - perform an expiratory hold
This tells you your baseline driving pressure
Patient on an improving trajectory:
Driving pressure will go down.
Tidal volumes will increase as lung compliance improves
PEEP/Trapping pressure will start to increase as more alveoli are kept open.
Allow some time of stability - time varies. Do not at this time reduce Phigh
Driving pressure will go down.
Tidal volumes will increase as lung compliance improves
PEEP/Trapping pressure will start to increase as more alveoli are kept open.
Allow some time of stability - time varies. Do not at this time reduce Phigh
Assessing suitability for weaning:
T high to 10 secs to allow spontaneous breaths. PCO2 will rise.
Patient may need more time on the vent if during spont breaths
- flow/time graphs are peaky, higher than they are wide (indicating gasping)
-pressure/time graphs show drops
T high to 10 secs to allow spontaneous breaths. PCO2 will rise.
Patient may need more time on the vent if during spont breaths
- flow/time graphs are peaky, higher than they are wide (indicating gasping)
-pressure/time graphs show drops
If not suitable, lower T high for a higher respiratory rate/increase P high if not felt to be recruiting. May need to sedate.
If suitable, progress to SBTs and extubate to High Flo or CPAP.
If suitable, progress to SBTs and extubate to High Flo or CPAP.
Why Bother?
1) an improvement in alveolar recruitment and homogeneity
2) reduction in alveolar and alveolar duct micro-strain and stress-risers
3) reduction in alveolar tidal volumes
4) recruitment of the chest wall by combating increased intra-abdominal pressure.
1) an improvement in alveolar recruitment and homogeneity
2) reduction in alveolar and alveolar duct micro-strain and stress-risers
3) reduction in alveolar tidal volumes
4) recruitment of the chest wall by combating increased intra-abdominal pressure.
5) patient can spontaneously breathe on this mode
6) Reduce the use of sedatives and opioids
and all the reasons below - courtesy of @PulmCrit
6) Reduce the use of sedatives and opioids
and all the reasons below - courtesy of @PulmCrit
• • •
Missing some Tweet in this thread? You can try to
force a refresh
