Rapid administration of sodium bicarbonate causes an abrupt increase in pH equal to decreased ionized calcium due to alterations in the CHON binding. Hypocalcemia impairs cardiac contractility and limits the pressor effect of catecholamines. Calcium solution should be administered in 10-15 minutes to prevent bradycardia. You must check the BUN and creatinine to evaluate renal function. In hypovolemia, the BUN generally rises out of proportion to the creatinine, but significant elevations in creatinine may occur with isolated hypovolemia without underlying renal disease.
Inotropic agents have a distinct mechanism of action.
Dopamine is an intermediate product in the catecholamine pathway. The final product of this pathway is epinephrine and norepinephrine. Dopamine is used in early septic shock and in distributive shock. Dobutamine is principally used in cardiogenic shock or late septic shock. Additionally, there is vasodilatation, with a greater effect in the pulmonary vasculature.