in this presentation, I have discussed the holistic management of ARDS patient through invasive ventilation.

1. Ventilation in ARDS
Dr. Tarun Betha
Internal medicine resident
Poona hospital and research centre

2. Outline
• Supportive care.
• Hypoxia management.
• Invasive mechanical ventilation.
• Different modes of ventilation.
• Recommended ventilator settings.
• Weaning from ventilator.
• Recruitment manoeuvres.
• Refractory hypoxemia.
• Extracorporeal assistive
devices- ECMO, ECCO2R.
• Recent advances.
2Dr.Tarun Betha

3. Supportive care
• Sedation and analgesia.
• Neuromuscular blockade.
• Nutritional support.
• Hemodynamic monitoring.
• Glucose control.
• Nosocomial pneumonia.
• DVT prophylaxis.
• GI prophylaxis.
• Venous access.
3Dr.Tarun Betha

4. Supportive care
Sedation and analgesia
• Intermittent injections are preferred over continuous infusions.
• Continuous infusions for patients requiring more injections.
• Some studies showed no sedation is superior to infusion.1
• Treat the underlying cause before sedating (pain/anxiety).
1. Strøm T, Martinussen T, Toft P. A protocol of no sedation for critically ill patients receiving mechanical ventilation: a randomised
trial. Lancet. 2010;375(9713):475-480. doi:10.1016/S0140-6736(09)62072-9 4Dr.Tarun Betha

5. 5Dr.Tarun Betha

6. 6Dr.Tarun Betha

7. Supportive care
Neuromuscular blockade (NMB)
• Improves oxygenation and reduces the oxygen requirements.
• Prolonged neuromuscular weakness is undesirable.
• Studies done on cisatracurium besylate, prefer continuous
infusion in initial 48hrs.
• Recommendation: early moderate to severe ARDS.2
2. Griffiths MJD, McAuley DF, Perkins GD, et al. Guidelines on the management of acute respiratory distress syndrome. BMJ Open Resp Res
2019;6:e000420. doi:10.1136/ bmjresp-2019-000420 7Dr.Tarun Betha

8. Supportive care
Highly catabolic.
Enteral feeding is preferred.
Patients fed in semi recumbent position with head
upright position
Nutritional support
8Dr.Tarun Betha

9. Supportive care
Hemodynamic monitoring
• CVP vs PAC were studied in trials.
• Both showed same results in terms of stay and mortality.
• PAC is associated with increased risk of arrythmias.
• Recommendation: use CVP for hemodynamic monitoring.
Griffiths MJD, McAuley DF, Perkins GD, et al. Guidelines on the management of acute respiratory distress syndrome. BMJ Open Resp Res
2019;6:e000420. doi:10.1136/ bmjresp-2019-000420 9Dr.Tarun Betha

10. Glucose monitoring:
Target 140-180mg/dL.
Avoid IIT.
GI prophylaxis with
Proton pump
inhibitors
DVT prophylaxis with
LMWH or heparin
Obtaining a secured
venous access.
ARDS
Supportive care
Source: UpToDate
10Dr.Tarun Betha

11. Hypoxia Management
• Using high fractions of O2.
• Decreased oxygen consumption.
• Improve oxygen delivery.
• Manipulate ventilatory support.
Invasive.
HFNC.
BPAP.
11Dr.Tarun Betha

12. Oxygenation considerations.
• Risk of oxygen toxicity.
• Starts at fio2 50% and increases as it approaches to fio2
100%.
• Atelectasis, hypercapnia, airway injury, parenchymal
or extra pulmonary injury.
• Reactive oxygen species.
Prevention:
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Titrate fio2 to minimum to achieve - PaO2 60-65mm of Hg (SO2 90%)
Dr.Tarun Betha

13. Oxygenation considerations.
Strategies for reducing FiO2 requirements
• PEEP to reduce alveolar derecruitment.
• Protective ventilation strategies.
• Alveolar recruitment maneuvers- (CPAP 40cm for 60sec).
• Prone positioning.
• Alternate modes of ventilation, Inverse ratio ventilation.
• ECMO or ECCO2R.
• Diuresis.
• Bronchopulmonary hygiene.
• Liquid ventilation.
15Dr.Tarun Betha

14. Fluid management
• ARDS patients have increased vascular
permeability.
• Hydrostatic pressures increases
pulmonary fluid.
• This in turn will worsens the hypoxia.
• Trials showed conservative fluid therapy
is better than liberal fluid therapy.
• CVP targeted to <4mm Hg/ 5.4 cm of
H2O.
16Dr.Tarun Betha

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Other measures to improve
oxygenation
Decrease oxygen consumption
Improved
oxygen delivery
Transfuse only if
Hb<7
Dr.Tarun Betha

16. Invasive mechanical ventilation
indication:
moderate to
severe ards,
peep >/=5cm.
low tidal
volumes
6ml/kg.
target plateau
pressure
<30cm h2o.
peep
according to
ardsnet
protocol.
initial rr
≤35bpm.
18Dr.Tarun Betha

17. Modes of ventilation
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VOLUME LIMITED PRESSURE LIMITED
Dr.Tarun Betha

18. Volume limited
modes.
• Delivers a stable tidal volume.
• Trigger- ventilator or patient.
• Cycle termination- set volume is attained.
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CMV AC IMV SIMV
Dr.Tarun Betha

19. Pressure limited
modes.
Pressure support
ventilation. (PSV)
• Set inspiratory pressure.
• RR, I:E ratio, PEEP and Fio2 are set.
• TV is variable.
• Cycle terminates once the set pressure is
delivered.
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• flow-limited mode of ventilation.
• Set pressure support level (inspiratory
pressure level), applied PEEP, and FiO2.
• work of breathing is inversely proportional
to the pressure support level
Uses: weaning from ventilator.
Along with SIMV.Dr.Tarun Betha

20. APRV • High continuous positive airway pressure (P high) is delivered
for a long duration (T high) and then falls to a lower pressure (P
low) for a shorter duration (T low).
• P high to p low deflates the lungs and eliminates carbon
dioxide.
• P low to p high inflates the lungs.
• It is well tolerated hemodynamically.
• Decreases the peak airway pressure, improve alveolar
recruitment, increase ventilation of the dependent lung zones
and improve oxygenation
27Dr.Tarun Betha

21. Patients who are not improving
Supportive measures.
Alternative ventilator settings.
Inverse ratio ventilation.
Treat dyssynchrony
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22. Refractory hypoxia
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Prone ventilation
High PEEP pressure, open lung strategy
NMB
ECMO
Dr.Tarun Betha

23. ECMO
• ECMO – venoarterial (VA) and venovenous (VV).
• Indication in ARDS- selected adults suffering severe ARDS (defined as
a Lung Injury Score of 3 or more or pH <7.20.3
• Contraindication: bleeding diathesis, severe neurologic impairment.
• Side effects: Bleeding, thromboembolism, HIT, Neurological injury.
• Technique:
• blood is drained from the vascular system, circulated outside the body by a
mechanical pump, and reinfused into the circulation.
• outside the body, the blood passes through an oxygenator and heat exchanger.
• In the oxygenator, haemoglobin becomes fully saturated with oxygen, while carbon
dioxide (CO2) is removed.
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24. NEWER ADVANCES
• NEURONAL ADJUSTED VENTILATOR ASSIST VENTILATION
(NAVA).
• ADAPTIVE SUPPORT VENTILATION.
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25. Thank you
32Dr.Tarun Betha