Recently Relearning Blood Gas Analysis, the tutorial mentioned the effects of respiratory acid-base imbalance on blood vessels but did not explain why. I thought about it and added the following:
Respiratory acidosis causes pulmonary vasoconstriction and peripheral vasodilation (this way, blood flows faster through peripheral tissues, quickly carrying away acidic products, and flows slower through the lungs, allowing more thorough gas exchange).
Respiratory alkalosis causes pulmonary vasodilation and peripheral vasoconstriction (peripheral blood flows slower, accumulating more acidic metabolites, while pulmonary blood flows faster, making it difficult to expel carbon dioxide, also leading to accumulation of more acidic metabolites).