Clinical predictors of subtherapeutic aminoglycoside levels in trauma patients undergoing once-daily dosing

Background After publication of the Hartford nomogram in 1995, conflicting data have emerged regarding the use of once-daily aminoglycoside (ODA) regimens in critically ill patients. The purpose of this study was to characterize a trauma patient population with low 10-hour aminoglycoside levels (THL) within the Hartford ODA protocol.Methods Patients admitted to a Level I trauma center who received aminoglycosides were eligible for study. Clinical and demographic data were prospectively collected. Patients were dosed according to the Hartford protocol and a THL was obtained. Patients with THL < 2.0 μg/mL (OFF cohort) were compared with those falling within the nomogram (ON cohort).Results Of 79 patients receiving ODA therapy, 46 (58.2%) patients fell off the nomogram. The OFF cohort was associated with younger age and higher creatinine clearance, and related inversely to net resuscitative volume. Conclusion Trauma patients undergoing ODA therapy with low THL are younger and exhibit less net preaminoglycoside resuscitative volume and higher creatinine clearance. These findings may have important clinical implications regarding antibiotic efficacy in these select patients.