I wrote an article for JEMS back when it first started from Paramedics International to the rag it is today about alternative intubation techniques. I had not found any material about nasal or digital intubation, from even emergency medicine and definitely not pre-hospital care at that time. What I did find was a 1965 article from anesthesia journal about "ring" triger ETT.
Wow! How come we have not used these? Well, short and simple ... no one was used to them and the costs..(you know $$ had to come in there somewhere!) We actually shared the costs with OR, ER, ICU, and so forth so we could carry some. Yes, they do facilitate nasal intubation(s) and patients with high grade scores such as those with anterior anatomy.
There are as well flex stylet guides that mimick the same type of manuever of the trigger tube.
There are several "tricks of the trade" to help facilitate intubation, such as ambient noisy area the end of a cheap stethescope dropped into the ET itself to hear respirations, use of Lidocaine topical to decrease pain and possibly use of Neo-Synephrine to reduce bleeding and swelling.
I personally clip or shortened the end of the ETT to reduce movement after proper placement (auscultation and EtCo2 wave form). Of course, most practitioners prefer to remove as soon as possible and have patient orally intubated for several reasons.
R/r 911