Question

Robert Hines celebrated his graduation from college by going to Alaska for some climbing. Robert is in excellent physical condition: he runs 5 miles daily, played intramural spikeball, and was a volunteer firefighter. Because his parents are obligated to pay his private student loans after his death, they had Robert undergo a complete medical examination before climbing Mount Vancouver.
Mount Vancouver has its southern side in Glacier Bay National Park and Preserve in Alaska and its northern side in Kluane National Park and Reserve in Canada. You plan to climb the mountain to take advantage of the local duty-free shop on the Canadian side. The summit is approximately 15,787 feet above sea level, and the barometric pressure is around 420 mm Hg (sea level is 760 mm Hg).

1.   If Robert’s arterial Pco2 (PaCO2) had been measured on Mount Vancouver, would it have been increased, decreased, or unchanged compared with normal? Why? If you predicted a change in PaCO2, what effect would this change have had on arterial pH? What acid–base disorder would it have caused?

Answer 1

PaCO2 will be decreased after climbing because for the same CO2 production,the alveolar PCO2 is inversely related to alveolar ventilation. The pH will be increased causing alkaline environment and resulting in respiratory alkalosis.