In essence, I think the evidence shows that CPAP is one of the most useful tools in the pre-hospital armament in the treatment of respiratory illness. The pitfalls as I see them are using them in the wrong patient (one who needs another form of therapy first) and not selling CPAP well to the patient. Five minutes of really good coaching is worth the next 45 minutes of fighting a hypoxic patient on a call, and even worse, intubating them when a few kind words and CPAP would have done the work. Ventilator Acquired Pneumonia in intubated patients is very costly to the health care system and results in increased patient mortality and morbidity.
The following is the position statement of the National Association of EMS physicians http://www.naemsp.org/Documents/Position%20Papers/POSITION%20NIPPV-Resource%20Doc-2011.pdf
The Canadian Pre-hosital Evidence Based Practices group (paramedicresearch.com) has extensively reviewed evidence around the use of CPAP and it has one of the strongest evidence for pre-hospital intervention. See this page for their levels of evidence https://emspep.cdha.nshealth.ca/MethodLOEChart.aspx. and check out the Methods tab on the left side of the main page.
PEBP reviewed 19 studies which showed positive benefit with the use of CPAP in CHF with Pulmonary Edema and 9 neutral studies. See the section entitled NIPPV
In the case of COPD, there were 5 positive studies and 1 neutral https://emspep.cdha.nshealth.ca/LOE.aspx?VProtStr=COPD&VProtID=201
In the case of Asthma there were 3 studies they were positive and 1 neutral
Finally, in the case of SOB NYD, there were two positive studies https://emspep.cdha.nshealth.ca/LOE.aspx?VProtStr=Respiratory%20Distress%20NYD&VProtID=204
As to the variability in FiO2 in BVM as mentioned in the presentation, see http://monashanaesthesia.org/bvm/
You can find the article by Levitan and Weingart on the NODESAT technique at http://www.annemergmed.com/article/S0196-0644%2811%2901667-2/pdf
Also see on the notion of poor man’s CPAP and BiPAP on this great video at https://www.youtube.com/watch?v=6AXyW7zrde4
As usual, if you have question, feel free to comment below.