Comparison of i.v. and intra-tracheal administration of adrenaline

Adrenaline is the single most important therapeutic agent used in advanced cardiac life support (ACLS). Ideally it should be given into a large central vein but the European Resuscitation Council, the American Heart Association and the Resuscitation Council (U.K.) advise that adrenaline may be given into the trachea if i.v. access is not available. We have studied the effects of intra-tracheal and i.v. adrenaline in 16 patients undergoing mechanical ventilation. Log dose-response curves were constructed for systolic arterial pressure and heart rate responses. Intra-tracheal doses of adrenaline up to 10 micrograms kg-1, approximately one-third of that recommended for resuscitation, had no effect on arterial pressure or heart rate, whereas adrenaline 0.1 microgram kg-1 i.v. produced a mean increase in systolic pressure of 24 mm Hg. The intra-tracheal doses recommended for resuscitation (2-3 mg) are likely to be ineffective and consideration should be given to abandoning the tracheal route for adrenaline in ACLS.