It really depends on the specific injuries that the person has sustained. A good starting place, if you haven’t already checked it out, might be the medical terms section of my vocab list here. There’s a bunch of equipment and medicine listed there other than bacta, although bacta is normally a staple of medical treatment and is used in many other products.
If your character is bleeding to death, bacta will probably not be a first step in their treatment/stabilization. Although I don’t know what piece of equipment you’re referring to in the comics (you’re welcome to submit/message me a picture, if you like) I would guess that it may be some sort of tourniquet. Some tourniquets (such as the SGB-543) could apply micro-repulsor fields in specific places to stop internal bleeding, as opposed to various other bandages, coagulants and cauterizers, which stopped external bleeding. Depending on the exact type of wound, different methods would be used to do this; there are circumstances where cauterization is not appropriate, for example, and tourniquets are not necessarily always a good idea, especially if they must be improvised. I’m not a real-life medical expert, though, so you may want to take a look through @scriptmedic‘s blog, since they have answered questions on the topic.
If there is no significant bleeding (e.g., in the case of a lightsaber wound) but the character is still in critical condition, they would usually be kept in a bacta tank. Bacta is used as sort of a cure-all because it helps regenerate damaged cells, but it takes time to work and the character may need additional life support while they heal. Transporting someone in this sort of condition would be very risky, but could be made possible for short periods of time (for instance, until they got to a ship with a medbay) if there’s a medpac or medkit on hand. Since many ships, even small ones, could be fitted with decent medbays including a medical droid and/or diagnostic computer, that may be a good first stop for your characters. You can find a bit more detail on that in this post.
As for real-life medicine, there’s no reason you can’t revert to more simple, low-tech treatments in a pinch. However, many of these simpler treatments have different names or alternative versions in-universe, so taking a look through the vocab list and Wookieepedia may help.
Though they did have their own investigators with jurisdiction spanning most of the galaxy, when trying to track someone down the Empire was often known to employ bounty hunters. All of these sorts of investigations were carried out by the Imperial Office of Criminal Investigations. There’s a lot of information there, so I would suggest reading through that. Take special note of the Imperial Enforcement DataCore and the Imperial Peace-Keeping Certificates; this should all give you an idea of how the Empire does business with registered and unregistered bounty hunters.
I hope that helps! If you’ve got any follow-up questions, feel free to ask!
~ Jacen