My buddy Brad Garmon (@1stArrivingClin) and I sat down and discussed the different options for a patient in refractory hypoxia. Brad has a mental flow chart that he uses when trying to improve oxygenation in the vented and spontaneous breathing patient. I had him externalize this flow chart and talk about it on the FOAMfrat Podcast!
The Show Notes!
Somewhere between a nasal cannula and VV ECMO lie most patients. How to we manage them? Outside of pain, hypoxia is one of the most common symptoms treated by EMS. but most are taught: NC ->NRB -> NIPPV.. intubate? then what? What do we know about the patho of hypoxia/hypoxemia and how does it affect WHY our patients are sating low and how we fix them? Additionally, we have to understand the idea of oxygen consumption vs delivery. Hypoxia causes -Hypoxic Hypoxia -Histotoxic Hypoxia -Stagnant Hypoxia -Anemic Hypoxia Ventilation and oxygenation are separate but cannot be discussed in isolation, ventilation affects oxygenation both in the ability to move gases and also the shift of the oxyhemoglobin curve effects the ability for O2 to get on or get off. Must be a consideration for fixing hypoxia. Perfusion is required for sats to be picked up, and perfusion = flow.. not pressure, not volume, but flow. Cardiac output has the greatest influence on oxygen delivery. An increase in cardiac output can even offset hypoxemia.
Pulse-Ox Lag yada yada Oxygen Extraction Ratio Stuff (NERDDDD) Lactate Production Absorptive Atelectasis ok... so the algorithm:
References:
https://www.ncbi.nlm.nih.gov/pubmed/27075163
https://www.uptodate.com/contents/prone-ventilation-for-adult-patients-with-acute-respiratory-distress-syndrome
https://www.hindawi.com/journals/cricc/2013/415851/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4759994/k