You need something more durable than a straw, something that won't compress easily. In the episode of MASH they used the stem off a plastic eye dropper (I wonder if they were using plastic commonly back then in medicine bottles?)...
The tracheal cartilage reinforce the trachea and keep it open. If you stick your finger in the notch at the top of your breast bone and feel there up to your Adam's Apple (either the cricoid or thyroid cartilage, it's been a long time since anatomy class), you'll feel several distinct rings. That's the tracheal cartilage. They're spaced fairly close together, and if the tube you use isn't durable enough, it will crush.