1. A patient that comes in with tachycardia, hypotension, and diminished breath sounds in one lung has a tension pneumothorax until proven otherwise. Stick a needle in them (mid clavicular line, 2nd intercostal space) immediately, ask questions later; use a large-bore needle (14+, push until you hear a hiss). You do not need any other clinical signs (tracheal deviation, JVD, etc), you don't need confirmation via CXR. If you see tension pneumo on a CXR, you waited too long.
2. Places your patients can hide blood/hemorrhage:
-thighs
-pelvis
-abdomen
-chest
-the floor... check the floor.
3. When you do your FAST ultrasound to detect intra-abdominal bleeding, look in the following four places where blood tends to pool: {source}
-Rectovesical pouch/Pouch of douglas in the pelvis
-Hepatorenal recess (pouch of morison): look at pleural space, sub-diphragmatic space, morison's pouch, R paracolic gutter/inferior kidney pole
-Splenorenal recess: same 4 places as above; fluid in LUQ tends to accrue in subphrenic before splenorenal. additionally, fluid on LUQ is blocked from going down L paracolic gutter by the phrenicocolic ligament (sustenaculum lienis-- slings under and supports spleen) so it tends to move across the midline to the R
-Pericardial space to r/o tamponade. Don't panic if you see a small amount of fluid-- its only bad if its circumferential.
4. Things to remember about FAST exam: {source}
-While some people say you can detect as little as 100cc of fluid, you normally need around 500-600, so recheck if the first one was negative
-Fat can sometimes be mistaken for free abdominal fluid, as can fluid contained within GI lumen. Free abdominal fluid will tend to have "pointy" edges,.
5. ABCDEs again, because anyone can't get enough of this: 
-Airway. Assess by trying to speak to someone, attempting to rouse them with pain.  Check patency by figuring out if you can ventilate them-- can you bag-mask them? meaning when you mask, do their sats improve, can you hear breath sounds? Try to DL them, can you see anything?
-Breathing: are they breathing? Does their chest move, can you feel air moving out of their mouth, can you hear lung sounds?
-Circulation: what are their vital signs? Make sure to use big IVs above the diaphragm, because you don't want to worse any potential abdominal hemorrhage. Initial bolus 20-30 mL/kg or just give them 2L. You also want to continually assess perfusion-- pulses, mental status, urine output.
-Disability: check long bones for fractures, check mental status/GCS
-Environment: remove all clothing, check everywhere for injury.
6. If you think you put an air embolus in someone, have them lie trendelenburg so that the air bubble becomes stuck in their heart and doesn't go to their lungs.
7. If you take someone to the OR for abdominal hemorrhage, open them up with a big incision and see if there is blood there; attempt to suction; if you are unable to keep up, then proceed to pack the crap out of it, like this: put your hand on the liver, press down, and shove lots of sponges behind the liver (like 4, 5 entire packs), then put your hand on the spleen, shove a lot behind that, then put your hand on the bladder and pack around that, and then pull up the mesentery and pack behind that. Then proceed to remove the least blood-soaked laps first and find and stop the bleeding, proceeding to bloodier areas.
8. In trauma, blood may be a better primary resuscitation fluid than crystalloids, avoiding dilutional coagulopathy; and it may be best to administer blood, ffp, and platelets in a 1:1:1 ratio. {review article}
9. If you go to the CT scan for someone who's been in a MVC with a star-sign (i.e. shattered windshield), do a non-contrast head CT first to r/o brain bleed, then do with-contrast chest abdomen pelvis to find an internal bleed.
10. LR may be a better resuscitation crystalloid than NS, possibly because of less acidosis and more coagulation-- i.e. less bleeding, as the calcium in LR soaks up the citrate chelator in pRBCs.