In film often when characters get stabbed/assaulted they can often continue to fight or don’t pass out immediately. How does adrenaline or shock factor into the physical reaction, especially when the character isn’t a cop or military and isn’t accustomed to being in these violent situations. How long would they be able to function before they crash? Is it possible to run away or even fight?
Taking these questions in reverse order: Yeah, kinda, sometimes, and it varies wildly, based on the injuries sustained. Also, it’s not the adrenaline crash that kills you.
Adrenaline rushes mean that you’re often unaware of injuries sustained in the moment. I’ve never been fully certain if adrenaline actually dulls the pain response, or if it simply causes your brain to ignore it. Either way, while you’re under an adrenaline rush you can suffer injuries and be unaware of them. It’s why you’ll sometimes see characters (and, for that matter, real people, with prior experience) checking themselves for injuries after combat (or any other traumatic event). It is entirely possible to be wounded and have no idea it’s happened until you’re trying to figure out where all that blood is coming from.
Depending on what you’ve just been through, coming down off an adrenaline rush can be deeply unpleasant. Your brain is sure something’s fucked up, but it can’t pin down exactly what or where, so it’s going to take that out on you, and everything aches. Adrenaline crashes won’t kill you. (There may be some weird outliers here for people with heart conditions, but, in general.) A crash may make you wish you were dead, or make you want to throw up on people, but it’s not lethal.
In the moment an adrenaline means that you can suffer (fairly severe) injuries and keep on fighting. If the injury doesn’t outright disable a limb, you can keep using it, even if that’s a very bad idea. Getting stabbed or shot is no guarantee that someone will sit down and peacefully bleed to death. Actually, shooting someone is a pretty good way to ensure they won’t sit down and bleed to death without protest.
When you’re trying to figure out how long it will take someone to die, you’re actually asking about how fast someone bleeds out. This relates directly to the injuries sustained. Someone who’s had a knife driven into their neck isn’t going to keep fighting. Someone who had it run through their bicep or buried in their shoulder blade, probably can.
We’ve covered blood loss before (and I strongly recommend you take a look at that tag, if you haven’t), but that’s the real factor here that controls if someone can fight. If they still have enough blood in their body to function. Lose too much, your ability to fight is impaired, and you’ll eventually fall unconscious and die.
Blood loss is why concepts like, “first blood,” are important in duels. Once that happens, the clock is ticking for that character; the longer the fight goes, the more their ability will decay, and unless they find a way to turn it around, they will die. (Even if they manage to prevail, they may still die without medical attention.)
Fighting through a stab wound is a fantastically bad idea. Engaging in any physically strenuous activity that raises your heart rate, (for example: fighting someone, or running away), will speed up blood loss, meaning impairment kicks in sooner. Still, the point of adrenaline is to keep you functional after sustaining an injury, so that you can survive.
If someone suffers an injury which disables them in some way, such as breaking an arm, there’s no powering through that. Adrenaline won’t let you override shattered bones. The biomechanical pulley system of muscles and tendons simply doesn’t work with broken bones.
So, the short answer is, “yeah, kinda.” You can keep fighting after being attacked. So far as it goes, there’s plenty of cases where someone took a stray bullet and kept on fighting, only to bleed to death later.