Aminoglycoside levels in critically ill surgical patients: The implications of physiologic criteria of sepsis

We retrospectively reviewed medical records and computerized critical care data for 40 consecutive critically ill surgical patients receiving 'standard' doses (1.5 to 2.0 mg/kg loading dose and 3 to 5 mg/kg/day) of gentamicin or tobramycin for gram-negative infections. End points measured were serum drug levels and clearance of infection. Therapeutic serum aminoglycoside levels were achieved within 48 hours of therapy by only 7 patients (17.5%). Among the remaining 38 patients, significantly fewer septic than nonseptic patients had clearance of their infection (11% vs 92%). Specific physiologic criteria of sepsis may be used to identify critically ill patients who will most likely benefit from aggressive initial aminoglycoside dosing when these drugs are used to treat gram-negative infections.