FIGURE 1.

Physiologic response to β-adrenergic receptor agonism and antagonism in critical illness. The catecholamine response characterized by epinephrine, norepinephrine, and dopamine release result in stimulation of β1 (majorly) and β2 (minorly). In contrast, β3 agonism blunts the catecholamine response. The physiologic response to β1, β2, and β3 agonism culminates in numerous negative effects within critical illness that can ultimately lead to negative clinical outcomes including increased mortality. This introduces the beneficial physiologic response of βB antagonism as a way to mediate the detrimental effects of the hyperadrenergic state prominent in various types of critical illness. Illustration created with BioRender.com.