12 Respiratory Failure
12.1 What this covers
- ##Ventilatory Failure
- Work of breathing
- Not synonymous with respiratory rate
12.2 Learning objectives
- ##Ventilatory Failure
- Work of breathing
- Not synonymous with respiratory rate
- Phasic contraction of sternocleinomastoid is most sensitive exam maneuver.
- Think about the effect of deadspace (Vd/Vt) - increase will lead to an increased minute ventilation required to maintain a given pCO2.
- Consider requirements (not necessarily hypercarbic, e.g. in DKA)
- Why do we get short of breath in pneumonia? TODO
12.3 Bottom line / summary
- ##Ventilatory Failure
- Not synonymous with respiratory rate
- Phasic contraction of sternocleinomastoid is most sensitive exam maneuver.
- Think about the effect of deadspace (Vd/Vt) - increase will lead to an increased minute ventilation required to maintain a given pCO2.
- Consider requirements (not necessarily hypercarbic, e.g.
12.4 Approach
- Respiratory Failure
12.5 Red flags / when to escalate
- TODO: List red flags that require urgent escalation.
12.6 Common pitfalls
- TODO: Capture common errors or missed steps.
12.7 References
- https://photos.collectednotes.com/photos/5187/5191101d-2ab3-4827-93bb-7a01313a6380
12.8 Source notes
12.8.1 Respiratory Failure
13 Respiratory Failure
13.1 Ventilatory Failure
Work of breathing
Not synonymous with respiratory rate
Phasic contraction of sternocleinomastoid is most sensitive exam maneuver.
Think about the effect of deadspace (Vd/Vt) - increase will lead to an increased minute ventilation required to maintain a given pCO2.
Consider requirements (not necessarily hypercarbic, e.g. in DKA)
Why do we get short of breath in pneumonia? TODO
13.2 Hypoxemic Respiratory failure
13.3 Devices
Low flow = nasal cannula (no reservoir), simple face mask (no reservoir), oxymask/partial rebreather (no 1 way valve for co2 exhalation control)/non-rebreather (reservoir-based)
Note on Non-reserveroir devices, including NC: fio2 decreases when your total inspiratory rate (usually 25-40 lpm, 60-100 lpm in respiratory distress) is much faster than the device inspiratory rate (because you suck in room air)
Reservoir = when you breath faster, you bring in O2 from the bag. Idea is to control fio2 better. 
Intermediate flow = venturi mask (controls entrainment of O2 by diameter of tube to give more control over FiO2)
High flow - Note: HFNC is O2 AND CO2 support. Also allows controlling fio2 because rate is fast enough that patient does entrain much air. The flow rate will help more with ventilation (never less than 30 min, 45-60 is most common).
NIPPV: titration similar to ventilator where RR+TV (controlled by IPAP - EPAP) = vent parameters, Fio2 and Mean airway pressure (primarily EPAP, as more of time is spent exhaling) control oxygenation.