I have an elderly character who is about 90-years-old. As things stand, he is very sharp mentally and physically and fairly strong for his age. The story needs are for him to be in a coma, whether natural or medically induced, for several weeks.
My question is, is there a cause or condition that would make this plausible at his age, that he could still awake from when it’s time for him to re-enter the story? I did some preliminary poking around and it seems like medically-induced comas are less common in the elderly. What might happen to him to put him in such a state (naturally or medically), that he could still awake from?
It could be anything at all for the story. I just don’t know what’s feasible and what’s not. And how long can he be in the unconscious state before it becomes too unrealistic?
Lots of things can cause someone to be in a coma caused by direct injury to the brain or something that would cause lack of oxygen to the brain.
One thing that is quite common in the elderly is a subdural hemotoma. Sometimes, if the clot is big enough, it will cause pressure and swelling on the brain enough to induce a coma. Usually, surgery would be used to drain a blood collection like this. One of the most common causes of a subdural hematoma in the elderly is a fall where they strike their head. As we age, our blood vessels become more fragile. If your character was also on a blood thinner for any reason— this would increase his risk for bleeding and potentially the size of the blood clot.
Any significant, direct injury to the brain can cause coma. A serious car accident. Falling off a ladder onto your head. Etc.
More medical causes, particularly in his age group, could be a stroke or a heart attack. A stroke causing a coma might be hard to write. In real life, it has a high mortality rate. Not to say it’s impossible but any direct injury in the brain (either through blood bleeding where it shouldn’t or the brain dying because of lack of oxygen causing death of brain tissue) is going to be hard to overcome with a mentally intact patient on the other end.
A heart attack, where he was deprived of oxygen for a period of time, could cause coma. Generally, over four minutes of down time without resusitative efforts is getting into the brain death arena. Even patients who are revived after four minutes will typically have brain death or proceed there. Of course, there are always outliers.
However, even a patient who gets immediate resuscitation (CPR at the least) can still proceed to coma once a pulse and good blood pressure are reestablished.
If I were you, I would pick either a subdural hematoma or a heart attack. I think this will be more likely to preserve the mental state of your character. If the heart attack, I would have it be a very short down time before he is treated and gets his pulse back.
Comas are very hard to write into stories. The length of time is up to you— that happens in real life. A coma of 1-2 weeks for these situations might be a little on the outside but possible.
The problem with a character in a coma for a lengthy period is that normal bodily functions must be tended to. We have to maintain the body functioning as close to how it does when we’re awake. So, the patient must be fed (either through a nasal, oral, or surgically implanted feeding tube). The character will still need to pee and poop— so a catheter can be placed to drain urine. We generally don’t like catheters to stay in long term because it increases the risk of infection for the patient and the elderly are more at risk for this.
Also, a patient in a coma is likely going to need ventilatory assistance and if they are on a vent over 7-10 days then generally there will be talk of putting in a trach.
The longer the coma, the more rehab a person will need. Even if in a coma for 1-2 weeks, the amount of generalized muscle atrophy will be significant. A character who is a 90 y/o who awakens from a coma after being bedridden for 1-2 weeks would probably go to inpatient rehab for several weeks/months and then outpatient rehab for a couple of months– and that might be underestimating. It’s just hard to recover from these types of injures as we age.
Hope this helps and best of luck with your story!