Remember Me: Use of Amnesia in Fiction

Heidi asks:

My question is, if I have a character that drowns but is revived, could they have temporary amnesia, especially if they hit their head? If so, how long might it last?  A few days? I know Goldie Hawn’s character in Overboard gets amnesia after falling off a boat into the water, but I’m not sure how accurate that really is.

Dianna says:
The definition of drowning: A submersion event where a patient is pronounced dead within 24 hours of the event.
 If a patient dies 24 hours post the event, it’s called a drowning-related death.
That said, your character did not drown and was then resuscitated. Instead, your character suffered a near-drowning event. In order for it to be referred to as a near-drowning event, the patient must be treated for at least one submersion-related complication. You say your character was resuscitated, so I’m assuming the patient was in cardiac arrest, which would definitely be considered a submersion-related complication.
Detail to consider: How long was the patient in cardiac arrest? In cold water, the mammalian diving reflex can prevent death, even after prolonged submersion (a patient in cardiac arrest can be resuscitated after 30 minutes or even longer).
I’d definitely write in that the character hit their head somehow and then suffered a prolonged cardiac arrest due to the submersion post hitting their head. (Basic background information: If the human body loses its oxygen supply, the heart stops. Since we can’t breathe under water, we’re unable to in-take oxygen.) If cold water isn’t fitting for your story, then lower the cardiac arrest time to 5-10 minutes, which is still long. The amnesia could occur simply from the trauma to the head only. The near-drowning event and long cardiac arrest time could worsen the amnesia.         
Anterograde amnesia: Memory disorder only affecting the retention of new information and events. Example: Patient Jim can only identify his friends, recall their names, retell stories about them ONLY if he knew them BEFORE the amnesia. So, when Patient Jim meets anyone after suffering with amnesia, it doesn’t matter how much time he spends with them, next time he sees that person he won’t remember them at all.   
Retrograde amnesia — Memory loss of the past or segments of the past.
Some patients can suffer with both anterograde and retrograde.
Some patients fully recover from amnesia, some don’t.
Every patient is truly unique with every medical situation — how one patient’s body responds medically, another patient responds completely different. So, you could write whatever you want (within reason) with amnesia and it would be realistic. Again, every patient is very different.
In Overboard, that character’s memory returned in a very realistic manner. What happened was she had a strong visual (her husband) of her past, which triggered her brain to remember her past, and pop her memory returned. Sometimes memory return is gradual, other times it comes all at once. However, the situation with her simply falling into the water and losing consciousness then coming to in the hospital with amnesia is over the top Hollywood. If I remember correctly, the storyline was that the cold water and the experience itself (floating in the ocean for hours), was the cause of amnesia.
Sure, it’s possible (again, everyone is different) but not a solid storyline. To me, what that storyline says is the amnesia is an emotional issue (the floating experience, plus not being happy in her life), not a medical issue, which is definitely possible, but they should’ve highlighted that point. Or, adding in head trauma would’ve made it an even better story.   
The tricky thing about amnesia (but it’s good for writers) is it deals with the brain, an organ us humans will never be able to truly understand like we do all other organs and systems, so we have little knowledge on how or why some things occur or don’t occur with: memory, personality, personality disorders, mental illness, etc.     

Medical Question: Submerged Vehicle Part 1/2

Mart asks a fairly detailed medical question so I’m going to split this post up over two days. Today, our resident EMS expert, Dianna Benson, will offer the EMS response. Next post, I’ll cover the emergency department treatment.

Mart asks:
This is the scenario:
Ruby, Gio and their parents are in a car that submerges in the river.
 Some of the things I need to know:
1.      What happens when paramedics get to them?
2.      Do they do CPR and if so for how long (with no pulse of a drowning victim and one that has a pulse but ends up being in a coma)
3.      Who declares them dead?
I’ve read that it depends on the state. Sometimes the doctor does. This takes place in NY. Ruby is the only one conscious. Do they treat her in any way? What happens to her sister if she is in a coma? Is that possible? What happens to her dead parents?
Dianna(EMS Response):
Clinical Definitions:
Drowning: An incident in which a victim has been submerged in water and dies within 24 hours of submersion.
 

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 Near-drowning: An incident in which a victim has suffered a submersion but has not died or dies more than 24 hours after the incident. A near-drowning patient must be treated for at least one submersion-related complication or it’s not considered a near-drowning.

Submersion: An incident where a victim is submerged in water and requires some type of emergency care due to the submersion.
When we (EMS) are dispatched to a water-related emergency, we often suspect a possible spinal injury. In the case of a car landing in water somehow, we’d definitely take spinal precautions, and thus apply a neck collar and strap the patient onto a backboard while the patient is still in the water.
Cold water and warm water emergencies are different. If a victim goes into cardiac arrest in cold water (68 degrees or colder), the mammalian diving reflex may prevent death even after prolonged submersion (even 30 minutes)  – a body could be frozen in cold water temperatures to the point all the systems go into a hibernation-like state.
 Firefighters do not extricate victims from submerged vehicles unless they are trained in water extrication. I’m a scuba diver and trained in water extrication, so when I arrive on scene of a water-related incident, I’d be one of the emergency crew members extricating. Emergency crews include: firefighters, EMS, law enforcement, forest ranger, etc. However, if no one on the scene is trained in water extrication, then whoever is there improvises until someone with training arrives, but risking your own life in ways you’re not trained for causes more chaos to the situation.

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A dry team works on shore and a wet team is in the water extricating (removing from vehicle) and immobilizing (collar and backboarding) the patient. The wet team doesn’t just jump in the water (unless it’s safe for us to do so) – we throw the victim a floating device and pull them to the boat we’re in, or dock, or shore (or whatever).

For EMS – we first focus on a patient’s airway, breathing, circulation, and any hemorrhaging issues (bleeding). If Ruby is breathing efficiently, if she has a solid pulse, if she’s A&O X 4 (alert and oriented times four), and if she’s not hemorrhaging anywhere, then she’s a stable patient. Submersion patients can develop complications that lead to death even after 72 hours post incident, so EMS transports ALL submersion patients, so Ruby would be transported as a stable patient.      
On-scene the sister would be considered unconscious (not in a comma). As a writer, you can make the situation be whatever you want, so if you want the sister to be in serious condition, have her respiratory system either be failing or have her be in respiratory arrest with a rapid pulse when EMS arrives. I’ve seen a MVC – motor vehicle collision – where in the same car four people died and one person didn’t. I’ve seen an airline crash where two dozen people survived the crash, hundreds of people died on impact, and of the two dozen who survived the impact most died within an hour or so of the crash. So, whatever you write is believable if you make the details of the “after the incident” believable.  
EMS can “call it” – meaning, we can determine if a patient is dead and we can either stop resuscitation attempts or not initiate them. Every county within each state has different protocols (and criteria to follow) on calling death, but they’re all similar. So, you can certainly have EMS “call it”, and that would increase your tension, especially for Ruby, instead of waiting for the ME to arrive on scene. For fiction, there’s no reason to wait for the ME; just have EMS do it. 
For Ruby: We’d insert an IV line and place her on oxygen at 2 liters per minute via a nasal cannula and we’d monitor her. If she’s stable, we’d retake vital signs every 15 minutes en route to the hospital. If she’s not stable, we’d retake vital signs every 5 minutes en route. We’d place a 12-lead on her (cardiac monitor/defibrillator) to obtain her heart rhythm and to monitor her cardiac functions. We’d inject meds depending on her situation and needs.
 For the sister: We’d insert an IV line and inject meds as needed. We’d place her on O2 via a NRB at 15 lmp. We’d place 12-leads on her as well to do the same as I stated above. We’d retake vital signs every 5 minutes and transport her to a trauma center, possibly via a flight for life helicopter.

Any other thoughts for Mart?

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