Catecholamines in critical care

Catecholamines (norepinephrine, epinephrine, and dopamine) are released into circulation in response to stress and injury and as part of the body's attempt at vasoregulation in response to circulatory failure. Norepinephrine is released from sympathetic nerve terminal, and epinephrine and dopamine are released from the adrenal medulla. Plasma levels of these catecholamines have been reported to be elevated in various clinical settings: congestive heart failure, myocardial infarction, cardiopulmonary bypass, diabetic ketoacidosis, hypoxia, hemorrhage, and septic shock. These amines have both beneficial and detrimental effects on survival. Both norepinephrine and dopamine are often employed in the critically ill to selectively increase cardiocerebral and renal blood flow, respectively.