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06-25-2024, 06:52 AM
Off the top of my head (I am a medically retired intensive care charge nurse).
Carbon monoxide has a greater affinity for haemoglobin than oxygen. This is why it displaces oxygen and causes hypoxia and anoxia in carbon monoxide poisoning. Even so a small amount of oxygen remains dissolved in plasma (partial pressure* approximately 0.3 mmHg). We need an oxygen partial pressure of at least 85 mmHg in arterial blood to prevent brain and heart dysfunction. We measure this from a blood gas sample taken from an artery which is known as PO2. We can achieve this oxygen partial pressure from plasma alone by giving 100% oxygen and placing the victim in a hyperbaric chamber set at 3 atmospheres for approximately one hour. This also helps to displace the carbon monoxide quicker. The problem is not all hospitals have hyperbaric chambers.
*Standard atmospheric pressure at sea level is 760mmHg. As oxygen is 21% of the atmosphere its partial pressure would be 21% of 760mmHg which is 159.6 mmHg. Water vapour exerts its own pressure so this can reduce the partial pressure of the other gases in the atmosphere.
If you prefer kPa divide mmHg by 7.5
Carbon monoxide has a greater affinity for haemoglobin than oxygen. This is why it displaces oxygen and causes hypoxia and anoxia in carbon monoxide poisoning. Even so a small amount of oxygen remains dissolved in plasma (partial pressure* approximately 0.3 mmHg). We need an oxygen partial pressure of at least 85 mmHg in arterial blood to prevent brain and heart dysfunction. We measure this from a blood gas sample taken from an artery which is known as PO2. We can achieve this oxygen partial pressure from plasma alone by giving 100% oxygen and placing the victim in a hyperbaric chamber set at 3 atmospheres for approximately one hour. This also helps to displace the carbon monoxide quicker. The problem is not all hospitals have hyperbaric chambers.
*Standard atmospheric pressure at sea level is 760mmHg. As oxygen is 21% of the atmosphere its partial pressure would be 21% of 760mmHg which is 159.6 mmHg. Water vapour exerts its own pressure so this can reduce the partial pressure of the other gases in the atmosphere.
If you prefer kPa divide mmHg by 7.5
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