I could have sworn I'd done this before, but I couldn't find it, so here goes:
It's really accurate. The protocols are a little different in the US than in Northern Ireland, but everything really checks out. Hospitals do have teams dedicated to traumas (they might be specifically dedicated to trauma that day or just assigned to trauma that day along with their other rooms depending on how much trauma an emergency department typically gets).
They're doing a bunch of different things to determine what is wrong with him. For one, they know that he was shot twice because the paramedics (and likely someone at the scene) said so. Note that they check that is accurate by turning him over and seeing if there are any other holes in him.
There's a lot of blood involved so they can assume blood loss, even if there's no way to really quantify it.
They know his heart is working correctly because they are both hearing sounds 1 and 2 (the "lub" and "dub" sounds normally heard in a healthy heart) and he is on a heart monitor (which is recording the electrical activity in his heart). They also know his blood pressure is too low to measure (and then later they can only get the top number).
They do an ultrasound of his lungs to make sure there are no pneumothoracies. They notice he isn't breathing well likely by listening to and counting his breaths. They know the intubation went in the right place (the lungs instead of the esophagus) because they listen to both lungs and are getting CO2 out of the tube.
We don't see a whole lot else directly done in the trauma bay, but they do notice in surgery that he's bleeding from his spleen just by looking and feeling.
As for the drugs: They picked the drugs before he got there because they're all standard drugs to use a trauma or code situation. So they just have them all ready to go.
Saline: a mix of water and salt that helps increase blood volume due to dehydration or blood loss
Tranexemic Acid: A drug that helps blood clot
Ketamine: a dissociative anesthetic (used because unlike other anesthetics it typically doesn't cause problems with breathing)
Sux (suxamethonium): a paralytic drug used in intubations and general anesthesia
Phenylephrine and ephedrine: drugs that makes blood vessels smaller which increases blood pressure
Atropine: drug that increases heart rate during a code
Epi (epinephrine): a drug used both to make blood vessels smaller to increase blood pressure and to change a bad heart rhythm into a better one during a code
Glycopyrrolate: a drug used to dry up secretions before intubation
FFP (fresh frozen plasma): a blood product full of clotting factors which helps blood clot
Platelets: another blood product that contains another thing that helps blood clot
