Serum gentamicin concentrations during intratracheal administration.

In artificially ventilated patients, intratracheal aminoglycoside administration is used as a form of prophylaxis of broncho-pulmonary infections. In artificially ventilated patients with multiple organ failure, serum gentamicin concentrations were measured dependent on renal function after endotracheal administration. A standard commercial ampule of 40 mg gentamicin in a 1 ml solution was injected in undiluted form, intratracheally through the tubus , every 6 h. In the patients without renal failure, values over 1 microgram/ml were only found in certain individual cases and reached a maximum of 1.5 micrograms/ml. In patients with renal failure even after prolonged application, the average serum concentrations were between 2 and 3.5 micrograms/ml. In a very few cases, however, levels of up to 10.5 micrograms/ml were measured. The daily serum pattern revealed a distinct dependence on the administration; 1 h after administration there was an increase in the serum concentrations which decreased to the initial levels after 6 h. When patients with renal impairment are given an aminoglycoside intratracheally, serum levels of up to 10.5 micrograms/ml may be reached and thus additional systemic aminoglycoside therapy should be avoided.