The effect of patient positioning on ultrasound landmarking for cricothyrotomy.

The location of the ultrasound-identified surface landmark of the CTM moves in a cephalad direction by changing the position of the HOB from supine 0° to elevation at 30° and 90°. This may be clinically important when attempting cricothyrotomy using a percutaneous (blind) technique, particularly when CTM identification and cricothyrotomy are performed at different head elevations.