Mike and Matt of the awesome ULTRASOUNDPODCAST have released Volume 2 of their brilliant Introduction to Ultrasound iBook.
Whats in it? There is prehospital section by none other than Cliff Reid
There is section by Casey Parker of BROOMEDOCS and James Rippey of the ULTRASOUNDVILLAGE
on using ultrasound in the secondary trauma survey
Okay its not free but hey not everything in life is free. I highly recommend both volumes. I have used Volume 1 as a teaching aid whilst flying out to a prehospital patient with a colleague to help supervise him doing a nerve block and reducing a dislocation.
Prehospital and Retrieval Medicine - THE PHARM dedicated to the memory of Dr John Hinds 