BACKGROUNDIntraosseous (IO) access is a recommended method when venous access cannot be rapidly established in an emergency. Experimental data suggest that major hemorrhage and catecholamine administration both reduce bone marrow blood flow. We studied the uptake of gentamicin as a tracer substance administered IO following adrenaline administration in hemorrhagic shock and in cardiac arrest.METHODSTwenty anesthetized pigs underwent hemorrhage corresponding to 50% of the blood volume. They then received injections of either; adrenaline IO (n = 5), saline IO n = 5), adrenaline IO during cardiac arrest and cardiopulmonary resuscitation (CPR, n = 5), or intravenous adrenaline. The injections were followed by an injection of gentamicin by the same route. Doses and volumes were equivalent among the groups. In all animals, mixed venous antibiotic concentrations were analyzed at 5, 15 and 30 min after administration.RESULTSMean (SD) plasma gentamicin concentrations (mg x L- 1) at 5 min were 26.4 (2.3) in the group with previous IO adrenaline administration, 26.6 (4.5) in the IO saline group, 31. 2 (12) in the IO adrenaline + CPR group and 23 (4.5) in the IV group. Concentrations in the CPR group were significantly higher than the others.CONCLUSIONSNo impairment of drug uptake with IO administration after recent IO adrenaline exposure was demonstrable in this shock model.