I need some medical advice!

[Miz Erie]

I'm writing a scene, and I need to know if it's plausible.

So here's the setup... I have a victim that has a depressed fracture of the occipital bone (just noticeable to the touch) from falling into the corner of a piece of furniture after being shoved forcefully. As he tried to defend himself with vertigo, he was startled and manged to fall on a large chef's knife, penetrating his right/left lumbar region but more medial than lateral. (I'm not very specific on the location.)

His attacker (Long story short, it's a stalker fan in love with a rock star, the victim from above, that has kidnapped and is holding said rock star captive.) tries to save him. He gives the victim an overdose of morphine combined with a heavy dose of unidentified sedatives so he can sew him up. (The sedatives have been shown in the story to be able to render the victim practically unconscious at the drug's peak with a half-life of about six to seven hours. I don't even know if there is such a drug.) On top of a head injury and blood loss from the stab wound (which I, again, have been less than specific but said enough to know he's lost two, maybe three, pints), stalker fan is pretty much killing his rock star, but hey, stalker fan isn't a doctor he's a recovering druggie. (Oh, and rock star's a little guy, about 5'4" and 140lbs.) Where I left the story off at is rock star is unconscious with slow, shallow breathing, and stalker fan has sewn his wounds closed with fishing line.

Now that I have lost everyone's attention, I get to my question. I want to know if this is plausible scenario. Rock star is never going to wake up. About seven hours after the injuries (six since the drugs were on board), rock star is going to seize. About three hours, give or take, later, rock star is going to go into respiratory distress. Stalker fan will be asleep, so no one is going to resuscitate him. Stalker fan wakes up next to a dead, cooling rock star.

I'm really stretching that timeline, I know. And forgive me if my jargon is off a little; I studied nursing for a while long ago but gave it up for engineering graphics which I gave up for writing.

So, anyone? Is this a plausible scenario?