How long does it take to pass out from oxygen deprivation? The person is panicked and screaming so they accidentally breathe water into the lungs. So how long would it take for them to pass out? After they pass out they are administered Mouth-to-mouth resuscitation immediately and are only out of it for a couple of half a minute. Then they are taken to the hospital. Would there be any long term affects to the body?
A couple of half a minute? Anything under 5 minutes is a 90% chance of being safe if resuscitated. Drowning people don't make much noise because they are too distracted by the water. They only fill their lungs significantly after becoming unconscious.
complex description: https://en.wikipedia.org/wiki/Drowning#Pathophysiology
The damages that occur are: lung injury, cardiac arrest, brain injury from oxygen deprivation.
The breathing pattern and physiology vary depending on hyperventilation, panic, physical exertion, fullness of the lungs at the time of submersion, so there is no simple answer to your query.
When they breathe significant amounts of water, it is because they have just lost consciousness and their body relaxes.
While they are is still conscious, they hold their breath for as long as they can, voluntarily / because they have breathed a sip of water and their epiglottis shuts and seals closed, by reflex.
There is a spasm called laryngospasm which occurs when the person is at the end of their breath and their body is trying to breath but their epiglottis is closed, that occurs at very low oxygen levels and a high oxygen debt because of the panic, so unconsciousness is only a few seconds away when the throat is convulsing, and it continues to convulse when they are unconscious and 90% of the time they breathe water and their heart continues beating.
I can't find how long it takes to have cardiac arrest after asphyxia or wet drowning. Probably it is not very well studied becuase it is so dangerous.
There is also the mammalian dive reflex, which occurs mostly in children who are suddenly immersed in freezing water. It can cause their metabolism and heart rate to go into slow motion, and stops circulation to their extremities, causing them to survive for more than 15-30 minutes.
From avalanche asphyxia, the heart can continue 15-20 minutes: https://www.scancrit.com/2013/08/27/heart-rate-monitor-watches-avalanches/
There's a dutch man who lost his wife and then started diving in freezing water, and he can stay in freezing water for 30 minutes using conscious mammalian dive reflex.