Intravenous adrenaline (epinephrine): its use in the critical care setting

Adrenaline (epinephrine) is an endogenous catecholamine with potent β₁-adrenergic, moderate β₂-, and α₁-adrenergic activity, widely used in resuscitation and critical care. At lower infusion rates, it increases cardiac output and decreases systemic vascular resistance. While at higher doses it will result in greater inotropy and peripheral vasoconstriction, with potential adverse effects such as arrhythmias, lactic acidosis, and ischemia. This review synthesises contemporary evidence surrounding adrenaline's physiological and pharmacological profile, highlighting its role in cardiac arrest, perioperative medicine, sepsis, toxidromes, and specific contraindicated states. Clinical trials, including PARAMEDIC-2 and various observational registries, support adrenaline's effectiveness in achieving return of spontaneous circulation but raise concerns regarding neurological outcomes. The timing and dosing of adrenaline administration, particularly in non-shockable rhythms and in-hospital cardiac arrests, appear critical to optimising survival. Specific scenarios, such as post-cardiac surgery, neurosurgery, tamponade, and paediatric sepsis, demand tailored approaches due to distinct haemodynamic and pharmacological considerations. Conversely, adrenaline use may be contraindicated or require modification in patients with hypertrophic cardiomyopathies, carcinoid syndrome, or catecholamine-sensitive conditions. Despite its ubiquitous role in acute care, ongoing research is needed to define optimal dosing strategies and identify patient subgroups most likely to benefit from its use. Thoughtful, context-specific administration of adrenaline is essential to balancing efficacy with risk across the spectrum of emergency and perioperative medicine.