Chapter 188 - Mechanical Ventilation in the Emergency Room

Question 1

When do we consider intermittent positive pressure ventilation (IPPV)?

Answer 1

1. respiratory distress/failure or rapidly developing failure
   - recent studies : CHF, pulmonary contusion
2. toxicity (e.g. baclofen or ivermectin in dogs), envenomation
3. severe hypoventilation
   - tetraparesis, In animals with hypoxemia/hypoventilation from lower motor neuron disease, the prognosis is much more grave
4. support following successful CPR

Question 2

Ventilation is a humane option. WHY?

Answer 2

It removes anxiety and fear associated with hypoxemia.

Question 3

How to practically rule out hypoventilation?

Answer 3

Pulse oximetry values of>95% while breathing room air practically exclude hypoventilation but with lower values, an arterial blood gas should be obtained.

Question 4

Care should be taken to not provide supplemental oxygen to a patient with hypoxemia, without excluding hypoventilation. WHY?

Answer 4

Because while the PaO2 will improve, the PaCO2 may be rapidly worsened

Question 5

End-tidal CO2 analysis is not helpful when assessing hypoventilation. WHY?

Answer 5

End-tidal CO2 analysis is not helpful when assessing hypoventilation as ETCO2 may only assess expired air from the anatomical deadspace.