Respiratory alkalosis is a primary acid-base disorder which occurs when alveolar ventilation is increased to a level which exceeds the amount necessary to eliminate the daily load of carbon dioxide produced by the metabolic activity. This situation causes hypocapnia and is called hyperventilation. This should not be confused with tachypnea, i.e. an increased respiratory rate, which may or may not be associated with hyperventilation. When hyperventilation is present, carbon dioxide pressure is reduced in all body fluids. Alkalemia, i.e. a decrease in the proton concentration [H +] or an elevation of pH, will occur as a necessary consequence af alkalosis in all body fluid compartments unless some mechanism(s) of correction and/or compensation ensues.
Respiratory alkalosis can be explained using the alveolar gas equation
F&CQ2 = constant x VtOilr\
where VC02 is the carbon dioxide production, expressed in liters per minute, Vk is the alveolar ventilation at body temperature and ambient pressure, expressed in liters per minute, and the constant, which is given by is introduced to normalize the units of Vk to VC02. The alveolar ventilation is given by
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