SAER 181: Oxygen Therapy Flashcards
How do you calculate CaO2?
CaO2 = (1.34 x Hb x SaO2) + (0.003 x PaO2)
What FiO2 do you achieve with flow-by oxygen?
25-40%
What FiO2 do you achieve with a mask for oxygen support?
35-60%
What is the typical oxygen flow rate for face masks?
200 mL/kg/min
What are the risks of a face-mask?
- rebreathing of CO2
- hyperthermia
- patient not tolerating mask
- worsening of facial trauma
What is the highest FiO2 achievable with nasal cannulas?
an FiO2 of up to 70%
What are the recommended flow rates for nasal cannulas?
100 mL/kg/min per nostril, i.e., if 2 cannulas placed, can turn up to 200 mL/kg/min
What is the starting Oxygen flow rate for transtracheal catheters?
start with 50 mL/kg/min
What FiO2 can be achieved with a transtracheal catheter?
up to 60-80%
How does HFNO allow the administration of higher flow rates with less patient discomfort?
oxygen is humidified to 99% relative humidity and warmed
What is the achievable FiO2 with HFNO?
21-100%
How does HFNO presumably improve oxygenation?
high flow rates will lead to a deadspace washout ⇒ desired FiO2 is delivered to the lungs without any mixing of end-expiratory gas
potentially also has a certain degree of pressure support (depends on flow rate and whether mouth is open)
What is a relative contraindication for HFNO?
Pneumothorax
only shown to inhibit resolution of pneumothorax in one case report, nevertheless likely reasonable to avoid in these cases
What are indications to intubate an animal?
despite noninvasive strategies ⇒ hypoxemia (PaO2 < 80 or SpO2 < 90) or hypercapnia (PCO2 > 60)
or imminent respiratory exhaustion
List complications of HBO treatments
- Oxygen toxicity
- Barotrauma
- Decompression sickness
- Oxygen-induced seizures
