Background: Drugs administered endotracheally are effectively absorbed during normal spontaneous cardiac activity. However, animal cardiac arrest studies and limited clinical investigations do not support either the use of endotracheal (ET) drugs in doses currently recommended for adults or the method of direct endotracheal instillation. The purpose of this study was to compare the effect of intravenous (IV) and ET drug therapy on outcome from out-of-hospital cardiac arrest secondary to all cardiac arrest rhythms.
Design: Five and one-half year retrospective cohort study.
Setting: Municipal, university affiliated hospital.
Patients: Consecutive patients >18 years of age in nontraumatic out-of-hospital cardiac arrest who received advanced cardiac life support (ACLS) medications by only the ET or IV route were included.
Results: Five hundred and ninety-six patients met inclusion criteria (IV drugs=495, ET drugs=101). There was no difference between groups in the rate of witnessed arrest and the frequency of bystander cardiopulmonary resuscitation (CPR). In the ET drug group, a significantly greater number of patients had an initial documented arrest rhythm of asystole compared to the IV drug group (56 vs 37%, P=0.01). The rate of return of spontaneous circulation (27 vs 15%, P=0.01) and survival to hospital admission rate (20 vs 9%, P=0.01) were significantly greater in the IV drug group. No patient who received ET drugs survived to hospital discharge compared to 5% of those receiving IV drugs (P=0.01).
Conclusion: For our out-of-hospital advanced rescuer system, ET drugs at recommended doses (twice the IV dose) injected into an ET tube during cardiac arrest and CPR were of no benefit.