Objective: To compare plasma concentrations and cardiovascular effects of epinephrine after application via a conventional endotracheal airway and via the esophageal lumen of a new emergency airway, the esophageal tracheal Combitube.
Design: Prospective, randomized study.
Setting: Center for Biomedical Research, University of Vienna.
Subjects: Fourteen juvenile swine received either an endotracheal tube (Group 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 Group 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 cardiac output in Part I, and end-tidal CO2 and coronary perfusion pressure in Part II were recorded.
Main results: In Part I, increased levels of plasma epinephrine and systolic arterial pressure were maintained significantly longer in Group B when compared with Group A. In Part II, no significant differences between the groups were found with regard to plasma epinephrine levels and hemodynamic variables.
Conclusion: Epinephrine applied via the esophageal lumen of the Combitube in a ten-fold higher dosage has similar effects on plasma epinephrine levels and hemodynamic variables compared to endotracheal administration.