Epinephrine application via an endotracheal airway and via the Combitube in esophageal position

Objective: To compare plasma concentrations and cardiovascular effects of e pinephrine after application via a conventional endotracheal airway and via the esophageal lumen of a new emergency airway, the esophageal tracheal Co mbitube, Design: Prospective, randomized study. Setting: Center for Biomedical Research, University of Vienna, Subjects: Fourteen juvenile swine received either an endotracheal tube (Gro up A) or a Combitube in esophageal position (Group B). Interventions: In Part I of the study, epinephrine was administered during spontaneous beating of the heart; in Part II, epinephrine was administered during cardiopulmonary resuscitation, using a ten-fold higher dosage in Gro up B, respectively. Measurements: Plasma epinephrine levels were measured 1, 2, 3, 5, 7, 10, 15 , and 30 mins after application, systolic arterial blood pressure and cardi ac output in Part I, and end-tidal co, and coronary perfusion pressure in P art II were recorded. Main Results: In Part I, increased levels of plasma epinephrine and systoli c arterial pressure were maintained significantly longer in Group B when co mpared with Group A. In Part II, no significant differences between the gro ups were found with regard to plasma epinephrine levels and hemodynamic var iables. Conclusion: Epinephrine applied via the esophageal lumen of the Combitube i n a ten-fold higher dosage has similar effects on plasma epinephrine levels and hemodynamic variables compared to endotracheal administration.