I will not dispute that the organ harvesting industry has some shady shit going on, but I have to disagree with Dr. Byrne's statement that "brain death" does not exist. Firat, the semantics: "brain death" isn't always an accurate description of what is occuring. If you want to argue about terminology and definitions, we can do that separately. I would like to focus on two procedures (Dr. Byrne is correct that these are not "tests"), the apnea challenge, and the brain perfusion scan.
First, the apnea challenge. A patient on a ventilator, who shows no electrical activity on the EEG (electroencephalogam) and who also is unresponsive to other brain activity tests (like the nystagmus test, which Dr. Byrne referred to as the eye and ear test) is a candidate for the apnea challenge. During the apnea challenge, the goal is to stimulate the patient's central chemoreceptors. The human body has two internal breathing triggers: the central chemoteceptors in the brain stem, activated by the presence of too much CO2 in the blood ("I need to get rid of this metabolic waste product by expelling it out of my lungs"), and peripheral chemoreceptors in the carotid artery and aorta, activated by the absence of O2 in the blood ("I need to get more oxygen into my body by breathing in").
The patient's sedation is lowered to prevent interference with breathing, and oxygen is delivered through the endotracheal tube while the ventilator rate is set to 0 breaths per minute for 10 minutes. The body's metaboloc processes continue, using the high-flow oxygen that is coming into the tube (enough O2 reaches the distal airways by way of Fick's law of gas diffusion) and these processes produce CO2 as waste. As CO2 builds up in the blood, the central chemoreceptors should be triggered, meaning that the body recognizes that it needs to breath. In a scenario where the brain does not trigger a breath, perhaps the term "brain inactivity" would be a more appropriate term, but the person would not survive on their won without mechanical ventilation, and is als umresponsive with no voluntary muscular activity. I'd also like to comment that while Dr. Byrne's comment about the apnea challenge causing a toxicity in the brain is true in theory (rising CO2 levels decrease pH making the blood more acidic, which is bad for the brain), the normal metabolic processes involved during the time limit of the test (max 10 minutes) cannot cause a damaging change in pH.
Second procedure, is one that I don't think Dr. Byrne mentioned (yes, I watched the 16 minute version of the video), called the brain perfusion scan. This is a computed tomography scan of the blood flow through the brain. If this test shows no blood flow, the brain is in fact dead. Just like any other organ or body part, the brain requires blood flow to bring oxygen and remove metabolic waste (including CO2). Without that blood flow, the brain tissues will become necrotic and eventually die.
Again, I do not dispute then FACT that there is shady shit going on in hospitals, with medical personnel pushing for organ harvesting in cases where the patient could have or would have survived. And to anyone in this thread who has gone through an experience like that I am truly sorry. This post is simply disagreeing with (and providing rationale against) Dr Byrne's assertion that "brain death" does not exist.
I will not dispute that the organ harvesting industry has some shady shit going on, but I have to disagree with Dr. Byrne's statement that "brain death" does not exist. Firat, the semantics: "brain death" isn't always an accurate description of what is occuring. If you want to argue about terminology and definitions, we can do that separately. I would like to focus on two procedures (Dr. Byrne is correct that these are not "tests"), the apnea challenge, and the brain perfusion scan.
First, the apnea challenge. A patient on a ventilator, who shows no electrical activity on the EEG (electroencephalogam) and who also is unresponsive to other brain activity tests (like the nystagmus test, which Dr. Byrne referred to as the eye and ear test) is a candidate for the apnea challenge. During the apnea challenge, the goal is to stimulate the patient's central chemoreceptors. The human body has two internal breathing triggers: the central chemoteceptors in the brain stem, activated by the presence of too much CO2 in the blood ("I need to get rid of this metabolic waste product by expelling it out of my lungs"), and peripheral chemoreceptors in the carotid artery and aorta, activated by the absence of O2 in the blood ("I need to get more oxygen into my body by breathing in").
The patient's sedation is lowered to prevent interference with breathing, and oxygen is delivered through the endotracheal tube while the ventilator rate is set to 0 breaths per minute for 10 minutes. The body's metaboloc processes continue, using the high-flow oxygen that is coming into the tube (enough O2 reaches the distal airways by way of Fick's law of gas diffusion) and these processes produce CO2 as waste. As CO2 builds up in the blood, the central chemoreceptors should be triggered, meaning that the body recognizes that it needs to breath. In a scenario where the brain does not trigger a breath, perhaps the term "brain inactivity" would be a more appropriate term, but the person would not survive on their won without mechanical ventilation, and is als umresponsive with no voluntary muscular activity. I'd also like to comment that while Dr. Byrne's comment about the apnea challenge causing a toxicity in the brain is true in theory (rising CO2 levels decrease pH making the blood more acidic, which is bad for the brain), the normal metabolic processes involved during the time limit of the test (max 10 minutes) cannot cause a damaging change in pH.
Second procedure, is one that I don't think Dr. Byrne mentioned (yes, I watched the 16 minute version of the video), called the brain perfusion scan. This is a computed tomography scan of the blood flow through the brain. If this test shows no blood flow, the brain is in fact dead. Just like any other organ or body part, the brain requires blood flow to bring oxygen and remove metabolic waste (including CO2). Without that blood flow, the brain tissues will become necrotic and eventually die.
Again, I do not dispute then FACT that there is shady shit going on in hospitals, with medical personnel pushing for organ harvesting in cases where the patient could have or would have survived. And to anyone in this thread who has gone through an experience like that I am truly sorry. This post is simply disagreeing with (and providing rationale against) Dr Byrne's assertion that "brain death" does not exist.
Thank you for this explanation!