PHYSIOLOGICAL EFFECTS OF ALKALOSIS
Alkalosis increases the affinity of hemoglobin for oxygen and shifts the
oxygen dissociation curve to the left, making it more difficult for hemoglobin
to give up oxygen to tissues. Movement of H+ out of cells in exchange for the movement of extracellular K+ into cells can produce hypokalemia.
Alkalosis increases the number of anionic binding sites for Ca2+ on plasma proteins and can therefore
decrease ionized plasma [Ca2+], leading to circulatory depres-sion and neuromuscular irritability.
Respiratory alkalosis reduces cerebral blood flow, increases sys-temic vascular
resistance, and may precipitate coro-nary vasospasm. In the lungs, respiratory
alkalosis increases bronchial smooth muscle tone (broncho-constriction), but
decreases pulmonary vascular resistance.