Hyperventilation question

[TSandM]

"Hyperventilation" is different from "tachypnea". One implies that you are overVENTILATING the lung, which will result in a drop in CO2, a change in pH, and is symptomatically often manifested by perioral tingling and tingling or cramps in the hands and feet. The other is simply a rapid respiratory rate. What the effect of tachypnea is on O2 and CO2 levels, and pH, depends on the total minute ventilation (which may be very small, if the person is panting with small breaths), and the state of the lungs. On scuba, tachypnea is common, and usually results in elevated CO2 levels. True hyperventilation is quite rare, because of the increased work of breathing.

 

[Duke Dive Medicine]

Hi, I have a couple more questions. 1. Is there a difference, physiologically, between hyperventilating on land vs. when standing in, say, neck-deep water? 2. How about hyperventilating when standing vs. lying down?

We do a lot of head-out immersion studies, both at atmospheric pressure and at increased ambient pressures. It's equivalent to a diver in a diving helmet. Like TSandM pointed out, there will be a slightly higher work of breathing simply due to the pressure differential between the head and the diaphragm.

Re your original question, as a couple of members have already pointed out, it would be all but physically impossible for a person to consciously hyperventilate himself/herself to an arterial pCO2 of zero.

Best regards,
DDM