[Pharmacokinetics and dynamics of endogenously released and therapeutically administered adrenaline in resuscitation. A comparative animal experimental study].

In this study, catecholamine plasma levels and hemodynamic response were measured to compare the effects of endogenously released (group A; n = 8), intravenously injected (group B; 10 micrograms/kg; n = 8), and endobronchially instilled (e.b.) epinephrine (group C; 100 micrograms/kg; n = 8) on resuscitation. Although the endogenous release of epinephrine produced peak plasma concentrations of 214 +/- 86 ng/ml (mean +/- SEM) during cardiac massage, only 5 animals were successfully resuscitated in group A. Mean arterial pressure and cardiac output were significantly lower in the first hour of restored spontaneous circulation compared to groups B and C. Endobronchial and intravenous epinephrine administration proved equally effective with regard to resuscitability and hemodynamic response during cardiac massage. All animals in groups B and C were successfully resuscitated and peak plasma concentrations of epinephrine were achieved with comparable onset times (317 +/- 53 ng/ml after 2.5 min in group B, 634 +/- 202 ng/ml after 3 min in group C). The tenfold epinephrine dose administered endobronchially was able to generate only a twofold increase in peak plasma epinephrine concentrations. The mean bioavailability with this route of administration, however, was 40% (5-71%). The ongoing absorption and therefore significantly longer half life of e.b. epinephrine compared to i.v. administration improved the hemodynamic situation of group C animals during the early postresuscitation period. More extensive use of e.b. epinephrine administration can be recommended, especially in out-of-hospital resuscitation, when intubation is achieved before an intravenous line can be established.(ABSTRACT TRUNCATED AT 250 WORDS)