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0/ Buongiorno, #medtwitter! We bring to you a #tweetorial on ventilator management for all those folks who don’t normally manage ARDS who have stepped up to help in this pandemic.
All credit goes to @AvrahamCooperMD; the following tweetorial is his brainchild. Thanks, Avi!
All credit goes to @AvrahamCooperMD; the following tweetorial is his brainchild. Thanks, Avi!
1/ Many clinicians are being/will be called to manage ARDS on the ventilator.
Imagine that your patient has just been intubated. Let's walk through the steps of vent mgmt 101:
- Initial housekeeping
- Basic vent management decisions in ARDS
- Management of refractory hypoxemia
Imagine that your patient has just been intubated. Let's walk through the steps of vent mgmt 101:
- Initial housekeeping
- Basic vent management decisions in ARDS
- Management of refractory hypoxemia
2/ First, confirm endotracheal tube position:
- Did capnography confirm tracheal placement?
- Are breath sounds bilateral?
- Is the tube placed appropriately on CXR? (typically 2-5 cm from carina)
Pic from SAEM https://bit.ly/3bJrTpa
- Did capnography confirm tracheal placement?
- Are breath sounds bilateral?
- Is the tube placed appropriately on CXR? (typically 2-5 cm from carina)
Pic from SAEM https://bit.ly/3bJrTpa
3/ Next, set the ventilator. You'll need to choose an initial setting.
Typically this will be assist control/volume control (AC/VC) which allows you to:
Maintain low tidal volume ventilation
Guarantee a respiratory rate
Pic from https://bit.ly/3462mny
Typically this will be assist control/volume control (AC/VC) which allows you to:
Maintain low tidal volume ventilation Guarantee a respiratory ratePic from https://bit.ly/3462mny
4/ You'll need to set minute ventilation (MV = tidal volume x respiratory rate)
-Try to approximate pre-intubation MV (not always possible)
-Use low tidal volume ventilation (4-8 ml/kg ideal body weight)
-Goal plateau pressure < 30 mmHg
-Goal pH > 7.2
https://www.ncbi.nlm.nih.gov/pubmed/17855672
-Try to approximate pre-intubation MV (not always possible)
-Use low tidal volume ventilation (4-8 ml/kg ideal body weight)
-Goal plateau pressure < 30 mmHg
-Goal pH > 7.2
https://www.ncbi.nlm.nih.gov/pubmed/17855672
5/ Finally, set PEEP/FiO2:
- Avoid O2 sats of 100% (hyperoxia is bad), aim for 92%-95%
- Set adequate PEEP, typically >10 mmHg in ARDS
COVID19 patients are PEEP-sensitive. In general aim for higher PEEP and lower FiO2. https://www.ebmedicine.net/topics/infectious-disease/COVID-19
- Avoid O2 sats of 100% (hyperoxia is bad), aim for 92%-95%
- Set adequate PEEP, typically >10 mmHg in ARDS
COVID19 patients are PEEP-sensitive. In general aim for higher PEEP and lower FiO2. https://www.ebmedicine.net/topics/infectious-disease/COVID-19
6/ Now that the ventilator's set, choose a sedation strategy.
- Patients with moderate to severe ARDS usually need sedation to ensure vent synchrony
- Vent Dyssynchrony
oxygenation and 
lung injury
- Whatever sedation you choose, achieve synchrony
https://link.springer.com/chapter/10.1007/978-3-319-89981-7_7
- Patients with moderate to severe ARDS usually need sedation to ensure vent synchrony
- Vent Dyssynchrony
oxygenation and lung injury- Whatever sedation you choose, achieve synchrony
https://link.springer.com/chapter/10.1007/978-3-319-89981-7_7
7/ Some patients will oxygenate well with adequate PEEP and sedation.
Others will require additional therapies. Let's briefly review:
Paralysis
Proning
Inhaled pulmonary vasodilators
Others will require additional therapies. Let's briefly review:
ParalysisProningInhaled pulmonary vasodilators
8/Who may require paralysis?
Those patients that remain dyssynchronous/hypoxemic despite sedation.
Paralysis does not improve mortality in severe ARDS but individual patients may benefit. https://www.nejm.org/doi/full/10.1056/NEJMoa1901686
Those patients that remain dyssynchronous/hypoxemic despite sedation.
Paralysis does not improve mortality in severe ARDS but individual patients may benefit. https://www.nejm.org/doi/full/10.1056/NEJMoa1901686
9/ Benefits of proning?
Turning patients to the prone position optimizes V/Q matching and lung recruitment, and may dramatically improve hypoxemia.
It has been shown to reduce mortality in those with PaO2:FiO2 < 150.
https://www.ncbi.nlm.nih.gov/pubmed/24134414
Turning patients to the prone position optimizes V/Q matching and lung recruitment, and may dramatically improve hypoxemia.It has been shown to reduce mortality in those with PaO2:FiO2 < 150.https://www.ncbi.nlm.nih.gov/pubmed/24134414
10/ What are ex. of inhaled pulmonary vasodilators?
Epoprostenol or
nitric oxide
- Preferentially vasodilate aerated lung units, V/Q matching and SpO2
- No impact on mortality or lung mechanics so should only be added for refractory hypoxemia
https://www.ncbi.nlm.nih.gov/pubmed/27203510
Epoprostenol or nitric oxide- Preferentially vasodilate aerated lung units,
V/Q matching and SpO2- No impact on mortality or lung mechanics so should only be added for refractory hypoxemia
https://www.ncbi.nlm.nih.gov/pubmed/27203510
11/ Finally, when to call the veno-venous ECMO team.
There's no hard/fast rule but this is reserved for patients w/ refractory severe hypoxemia or respiratory acidosis despite conventional therapies.
A general rule is "it's better to call for ECMO too early than too late."
There's no hard/fast rule but this is reserved for patients w/ refractory severe hypoxemia or respiratory acidosis despite conventional therapies.
A general rule is "it's better to call for ECMO too early than too late."
12/ To summarize:
Confirm tube position
Low tidal volumes, adequate PEEP
Tolerate respiratory acidosis
Sedate for synchrony
If still hypoxemic, prone and probably paralyze, inhaled vasodilators if refractory
Better to call for ECMO too early than too late
Confirm tube positionLow tidal volumes, adequate PEEPTolerate respiratory acidosis Sedate for synchrony If still hypoxemic, prone and probably paralyze, inhaled vasodilators if refractory Better to call for ECMO too early than too late
