Twelve healthy medical students participated in a study where they hyperventilated for a period of 20 minutes, with a breathing volume of 36 litres per minute (six times higher than normal). They did this twice, once with normal air, and the second time with air that had a 5% level of carbon dioxide – i.e. a level 100 times higher than normal air.
The study was set up to exclude the extra muscle work needed while hyperventilating from affecting the results. The carbon dioxide levels only sank by ten present when the participants hyperventilated with the air containing high CO2 levels, compared to a decrease of more than 50% when using the normal air, which implies a significant lack of CO2 for the latter. The blood platelet levels increased by eight per cent when the participants hyperventilated with regular air, but was unchanged when they used the air with a 5% CO2 content. This indicates that the low carbon dioxide levels resulting from hyperventilating with normal air themselves resulted in the increased forming of blood platelets.
In addition, the stress hormone, adrenaline, increased by 360%. When the participants hyperventilated with the high CO2 content air, the levels of adrenaline remained unchanged. In other words, low carbon dioxide levels lead to a strong stress response
– Stäubli M et. al, Hyperventilation-induced changes of blood cell counts depend on hypocapnia, Eur J Appl Physiol Occup Physiol 1994;69:402-7
Comments: The increase in adrenaline levels is striking and is well corroborated by other studies. Blood platelets (thrombocytes) are tasked with ensuring that blood clots at injury sites. If the number of blood plates increase at the wrong time, or too many are formed, an embolism may result.