If the jet ventilator isn't working, and I have an airway emergency (can't intubate, can't ventilate), can I:
1. Put 14g angiocath through cricothyroid membrane.
2. Attach 3 cc syringe, with plunger removed, to angiocath
3. Attach the plastic connector from a 7.0 ETT to the 3cc syringe
4. Attach breathing circuit and use the oxygen flush to ventilate
Yes / no?
No. Never done it in a person, however my own ex vivo experiments were not confidence inspiring. You can get a lot of air through a 14 g IV under ideal circumstances, but these aren't going to be ideal circumstances.
The first problem is that a 1.88 inch angiocath that's thrust through someone's cricothyroid membrane and directed south is likely to be somewhat bent, and the tip is likely to be up against the side of the trachea. It takes
very little deformation of the catheter or occlusion to the tip to make it impossible to get
any air through it, regardless of the pressure. Any kink, or just lightly touching the tip seals the thing. Even a bend hurts you badly.
The second problem, and this is the dealbreaker, is that if you use the O2 flush button on the machine, you're still working through the breathing circuit which includes a high compliance bag and valves that will sabotage your efforts to create high pressures. You're better off scrapping the machine entirely at this point and attaching a regular ambubag connected to wall O2. You'll probably still flail around ineffectively though.
If you're at the point where you have an angiocath in place, and can't get air through it, and you don't want to just get stabby with an 11 blade followed by a real tube, it may worth replacing the angiocath with something larger over a wire. A Cordis would be cool, and it might even work.
🙂
