Crossing Business with Bridges by pdragon76 Dean underestimates a job in a fairly major way. https://www.fanfiction.net/s/3605166/1/Crossing_Business_With_Bridges
Bridging Two Solitudes by Scullspeare *whoops!* this one is NOT Sam giving CPR, but an OC A vengeful spirit's attack leaves Dean hypothermic and fighting for life, while a concussed Sam, lost and alone, battles to get back to his brother. https://www.fanfiction.net/s/4010528/1/Bridging_Two_Solitudes
No CPR on this one, but it's a water logged Dean...
On The Surface by gaelicspirit On the run from the FBI, the brothers are sidelined by a snowstorm and find themselves at the mercy of a sheltered town filled with secrets. Staying alive means staying together as they fight to stay on the surface. http://gaelicspirit.livejournal.com/111703.html
Hmm. I wrote Sam giving Dean CPR in one of my fics, called "Like a Woman Scorned." It's a case-fic, and is about 20,000 words, and the hurt!Dean is near the end and tied to the resolution of the case. I don't know if that's too long for you or not, but if you're interested, it can be found here (https://www.fanfiction.net/s/9995029/1/Like-a-Woman-Scorned) (And if you do like it, I'd love it if you could leave a review.) :D
Hey, so I got this short thing that meets the trifecta.. drowning, CPR and Gencest: https://archiveofourown.org/works/1111995 for your reading pleasure *g*
No near-drowning in this, but there is a scene where Sam gives Dean CPR, due to an anaphylactic reaction. (I hope I did the link thing right, it's my first time posting on here.)