Cfrgtkky

I remember only one scene, which involved an unexpected sudden depressurization (maybe a blown airlock) in a space station. The main character rushed to an emergency air chamber and survived, barely. The detail that stuck in my mind is an apparent blood spatter on the wall, which makes the audience think the protagonist was injured, but soon after the broken bottle of ketchup is revealed.

I honestly don't know whether this was a book or a movie. I clearly described it visually above, but I also seem to remember bits of the protagonist's internal monologue, such as how many seconds he had to get to the emergency chamber (I believe it was 90-120 seconds, but at the upper end that would require a second person to revive him with CPR or something, and there was nobody else around/alive/awake), so maybe it was a book with vivid descriptions.

I recently rewatched 2001: A Space Odyssey, and was confused when I didn't see this scene, which is from a book or movie that I somehow confused with 2001. So I likely watched or read this in the early aughts.

This is from the book version of 2001: A Space Odyssey.

There are differences between the movie and the book, and the scene in question is immediately before Dave disconnects HAL.

In the movie, Dave goes outside to retrieve Frank's body, then is stuck outside (because HAL won't let him back in) and must enter through an emergency airlock without his helmet.

In the book, HAL depressurises the Discovery while Dave is still onboard, and Dave seeks shelter in an emergency cubicle.

Like any properly trained man in good health, he could survive in vacuum for at
least a minute - if he had time to prepare for it. But there had been no time; he could only count on the normal fifteen seconds of consciousness before his brain was starved and anoxia overcame him.

Even then, he could still recover completely after one or two minutes in vacuum - if he was properly recompressed; it took a long time for the body fluids to start boiling, in their various well-protected systems. The record time for exposure to vacuum was almost five minutes. That bad not been an experiment but an emergency rescue, and though the subject had been partly paralyzed by an air embolism, he had survived.

But all this was of no use to Bowman. There was no one aboard Discovery who could recompress him. He had to reach safety in the next few seconds, by his own unaided efforts.

The specific scene occurs in the book after Dave leaves the cubicle and is on his way to disconnect HAL:

Once, Bowman's light fell upon a hideous smear of sticky red fluid, left where it had splashed against a panel. He had a few moments of nausea before he saw fragments of a plastic container, and realized that it was only some foodstuff - probably jam - from one of the dispensers. It bubbled obscenely in the vacuum as he floated past.

This scene does not, of course, occur in the movie.

As Andrew has stated in a comment, this is strongly reminiscent of a scene from the 1990 World War II film Memphis Belle, about a United States Army Air Forces B-17 bomber crew on their last mission in 1943. Their plane is hit by anti-aircraft fire, spraying red liquid across the cockpit. However, nobody seems to be injured, and they eventually realize that the flak hit a thermos bottle of tomato soup.

Andrew declined to make this an answer, since Memphis Belle is not a science fiction film. However, since you already have said that you had confused the scene you were thinking of with 2001, I think the most likely explanation is that you have conflated the tomato soup scene from Memphis Belle with the depressurization scene from an actual science fiction book or movie.