Which of the following statement(s) is/are true concerning respiratory alkalosis?

a. Exposure to high altitudes can result in respiratory alkalosis

c. Symptoms of respiratory alkalosis may mimic those of hypocalcemia

d. The treatment of acute respiratory alkalosis may involve a brown paper bag

A primary decrease in PCO2 resulting in an increase extracellular pH is referred to as respiratory alkalosis. Hyperventilation and the ensuing fall in PCO2 may be secondary to hypoxia, reflux simulation from decreased pulmonary compliance, drugs, mechanical ventilation, and other causes. The two most common causes of hypoxia resulting in respiratory alkalosis are pulmonary disease and exposure to high altitudes. Renal compensation for respiratory alkalosis is not achieved by increasing excretion of bicarbonate but by decreasing net acid excretion, primarily through the reduction in ammonia excretion and increases in organic anion excretion. Chronic respiratory alkalosis is generally asymptomatic. Acute respiratory alkalosis may cause sensations of breathlessness, dizziness, and nervousness and can result in circumoral and extremity parathesias, altered levels of consciousness, and tetany. These signs are related to decreased cerebral blood flow secondary to decreased PCO2 and decreased ionized calcium concentration secondary to increased blood pH. In acute symptomatic respiratory alkalosis rebreathing, by breathing in and out of a paper bag, can temporarily relieve the symptoms.