Adrenaline infusion is the continuous intravenous administration of adrenaline, a potent catecholamine that stimulates alpha and beta-adrenergic receptors to increase heart rate, contractility, and vasoconstriction. It is critical in managing severe anaphylaxis, cardiac arrest, and refractory hypotension. Excessive infusion can cause arrhythmias and tissue ischemia, requiring careful dose titration.