Epinephrine absorption after intratracheal administration.

Tracheal intubation during cardiopulmonary resuscitation often precedes establishment of an intravenous route for the administration of drugs. To determine the efficacy of intratracheal administration of drugs during cardiopulmonary resuscitation we measured plasma catecholamine levels and hemodynamic responses to intratracheal epinephrine (EPI) administration using a double-blind, randomized crossover design in 7 male baboons (Papio anubis), each studied twice, who received 5 ml of 1:10000 EPI on one day and 5 ml of 0.9% NaCl on another day. Arterial blood samples for measurement of plasma EPI and norepinephrine (NE) concentrations were collected, and heart rate (HR) and mean arterial blood pressure (MAP) were measured before and 1, 2, 4, 8, 16, and 30 min after intratracheal drug administration. Intratracheal EPI significantly (P less than 0.05) elevated HR to 120 +/- 6 from 105 +/- 6 beats/min, MAP to 120 +/- 4 from 112 +/- 5 mm Hg, and plasma EPI to 8882 +/- 2143 from 928 +/- 209 pg/ml within 1 min of administration, and these effects persisted for 30 min. Plasma NE levels did not change after intratracheal EPI administration. None of the four variables changed after intratracheal saline was given. We conclude that in subhuman primates, intratracheal EPI is rapidly absorbed and is an effective pressor agent when given by this route; and that these data lend support to the clinical practice of intratracheal EPI administration during cardiac arrest or in the treatment of shock.