Choice of the hypnotic and the opioid for rapid-sequence induction

The choice of hypnotics and opioids for rapid-sequence induction, and the use of premedication, is influenced by the choice of the muscle relaxant. Anaesthetic agents have a major influence on the quality of intubation when rapid-sequence induction is achieved without a muscle relaxant. Premedication is important, along with a high dose of propofol (2.5 mg kg-1 or more) and a short-acting opioid such as alfentanil (30-40 micrograms kg-1) or remifentanil (up to 4 micrograms kg-1). It has also been demonstrated that i.v. lidocaine can improve intubating conditions. When a muscle relaxant is used, the choice of the anaesthetic agents depends on the onset of action of the relaxant. With a rapid-acting compound such as rocuronium at a dose of 0.6 mg kg-1, the hypnotic agents need to be supplemented with only a small dose of opioids, e.g. alfentanil 10-20 micrograms kg-1. When succinylcholine, rocuronium 1.0 mg kg-1 or rapacuronium 1.5 mg kg-1 are used, excellent intubating conditions may be obtained by relatively smaller doses of hypnotic agents even without opioids; however, haemodynamic and intraocular pressure changes are better controlled when small doses of opioids are administered.