ABSTRACT
Emergencies happen frequently in anaesthesia. There are many categories of emergency drugs. These are metaraminol, ephedrine, atropine plus or minus glycopyrrolate and suxamethonium. Metaraminol is a very potent drug and must be diluted and used with care. Phenylephrine is a pure direct-acting a1 vasoconstrictor with similar properties to metaraminol. Ephedrine has direct α and β actions at adrenoceptors and an indirect action to increase noradrenaline release from nerve terminals. Noradrenaline is a far more potent drug and must be given centrally to avoid tissue necrosis. Indirect measurements of adequate flow such as capillary refill time, urine output, lactate level and, if appropriate, level of consciousness can be monitored during anaesthesia. Both atropine and glycopyrrolate are competitive antagonists at muscarinic receptors that act to block vagal parasympathetic stimulation. Atropine causes a profound vagal block and is more useful for profound bradycardias.
