Blue Water Hunting and Freediving - Digital Version 1 - Page 69

freediver physiology
RESCUE AND RESUSCITATION : Some freedive trainers teach that the human brain blackout is somehow “ protective ” yet the disconnection of the body ’ s computer from functional leg and arm muscles that might still propel it to the surface only hinder self-rescue . With the complete shutdown of the conscious part of the brain , your body is defenseless , even while your heart still beats and cramped muscles are still capable of movement toward the surface .
My suggestion is to follow the advice of medical professionals and begin rescue breathing immediately -- do not waste precious seconds with the blow-and-tap . Providing oxygen a few seconds earlier might mean the difference in preserving millions of brain cells and preventing death . Retrain yourself to respond to blackout victims by tipping their chins up and giving mouth-to-mouth breathing immediately . You may have to be quite forceful in order to break possible laryngospasm and drive oxygen past the vocal cords . Also be aware that your unconscious buddy may be so deprived of oxygen that his face turns deep blue or black .
“ Dry drowning ” is the term used to describe the condition when the laryngospasm reflex keeps water from entering the lungs . “ Wet drowning ” results from the early relaxation of the vocal cords and the subsequent entry of water into the lungs .
In the un-rescued diver , as oxygen starvation continues , death is so near that even the protective laryngospasm reflex relaxes . Within seconds , water enters the lungs . It is still possible to revive a diver at this stage ; however , he will require hospitalization and intensive treatment . Water entering the lungs is very irritating to the delicate lining — fresh water more so than salt water . The irritation causes the lung tissue to swell and fill with fluid . Left untreated , this condition can become severe enough to prevent respiration and cause death by socalled “ secondary drowning .” This is why it is so important that divers resuscitated from blackout
This graph from a divers watch illustrates surface blackout . Almost immediately upon reaching the surface , this diver became unconscious . Luckily his buddy was alert and close enough to intercept his rapid descent and he made a full recovery .