Which adverse effect is NOT attributable to respiratory or metabolic acidosis?

Which adverse effect is NOT attributable to respiratory or metabolic acidosis?

• A. Increased incidence of cardiac dysrhythmias
• B. Vasoconstriction
• C. Increased pulmonary vascular resistance
• D. Increased serum potassium concentration

Answer: (B)

In acidosis, hydrogen ions entering cells cause potassium to shift out of cells, elevating serum potassium and increasing the risk of cardiac dysrhythmias. Acidemia also tends to depress myocardial contractility and reduce the heart’s responsiveness to catecholamines. In the pulmonary circulation, acidosis can provoke pulmonary vasoconstriction, increasing pulmonary vascular resistance. However, systemic vasomotor tone generally decreases with acidosis because the vascular smooth muscle becomes less responsive to catecholamines, leading to vasodilation rather than vasoconstriction. Therefore, vasoconstriction is not a typical adverse effect of respiratory or metabolic acidosis, making it the correct choice.

In acidosis, hydrogen ions entering cells cause potassium to shift out of cells, elevating serum potassium and increasing the risk of cardiac dysrhythmias. Acidemia also tends to depress myocardial contractility and reduce the heart’s responsiveness to catecholamines. In the pulmonary circulation, acidosis can provoke pulmonary vasoconstriction, increasing pulmonary vascular resistance. However, systemic vasomotor tone generally decreases with acidosis because the vascular smooth muscle becomes less responsive to catecholamines, leading to vasodilation rather than vasoconstriction. Therefore, vasoconstriction is not a typical adverse effect of respiratory or metabolic acidosis, making it the correct choice.