[Serum and bronchial concentrations of netilmicin during its continuous intratracheal administration]

Respiratory tract infections in intensive care units have a high fatality rate, perhaps as a result of the poor diffusion into bronchial secretions of aminoglucosides given by a systemic route. Endotracheal administration of aminoglycosides has been advocated but the optimal dosage remains to be determined. To investigate this problem we studied 13 patients free of renal failure and 6 patients with renal failure. Netilmicin was given by continuous endotracheal infusion in a daily dosage of 3 to 30 mg/kg. A good correlation was found between infused doses and serum concentrations; very high bronchial secretion concentrations were consistently found. There is a significant risk of accumulation in patients with renal failure. The characteristics of the respiratory tract secretions had no influence on the passage of netilmicin into the bloodstream. The dosages we advocate on the basis of our results are 8 mg/kg/day in patients free of renal failure and 4 mg/kg/day in patients with renal failure; serum netilmicin concentrations should not exceed 1 microgram/ml.