Effectiveness of cephalosporins in the sputum of patients with nosocomial bronchopneumonia

Nosocomial bronchopneumonia is a frequent complication in patients with chronic intratracheal intubation. Despite targeted antibiotic treatment, production of abundant bronchial secretion containing pathogen bacteria often tends to be chronic, and so mortality drastically increases. This problem led to an investigation of the penetration of five cephalosporin antibiotics into the sputum. Serum and sputum were collected from 24 chronically intubated patients having purulent nosocomial bronchopneumonia treated in an intensive care unit (ICU). Patients received the following doses intravenously every 24 h: five received 70 mg/kg of body weight cefuroxime, four received 110 mg/kg cefamandole, six received 80 mg/kg ceftriaxone, four received 80 mg/kg ceftazidime, and five received 80 mg/kg cefepime. Antibiotic concentrations in the serum and sputum were evaluated by capillary electrophoresis. MICs were determined for bacteria isolated from the purulent bronchial secretions. The mean levels of the cephalosporins in the sputum did not reach the MICs for the bacteria isolated from the same samples. Ceftriaxone was the only one of the investigated five cephalosporins that had a measurable concentration in the sputum (1.4 +/- 1.2 mg/liter). The low concentration of antibiotics in the purulent tracheobronchial secretion can be one of the many reasons for ineffective therapy of nosocomial bronchopneumonia in intubated patients in the ICUs. In the case of intubated or mechanically ventilated patients having chronic bronchopneumonia, determination of drug concentration in the bronchial secretion might be considered when selecting an antibiotic for treatment.