Two Cases with Unusual Vancomycin Measurements

摘要

Patient A was a 68-year-old woman with a history of lymphoplasmacytic lymphoma who presented after several weeks of mucosal bleeding. On admission, her cancer involved 95% of bone marrow cells. She was pancytopenic and febrile (38.3 degC). Leukocyte countwas 0.39 X 10~/muL (neutrophils, 0.03 X 10muL), hematocrit 25%, platelet count21 X 10~3/muL, relative serum viscosity 2.3 (reference interval, 1.4-1.8), blood urea nitrogen 6.4 mmol/L (18 mg/dL), creatinine 62 (mu)mol/L (0.7 mg/dL), and estimated glomerular filtration rate >60 mL/min/1.73 m~2. She had an IgMk monoclonal component of 42.8 g/L. This patient was started on vancomycin 1 g intravenously (IV) every 12 h, ceftazidime 2 g IV every 8 h, and a course of chemotherapy. On day 3 after the beginning of antibiotic treatment, a trough specimen was collected for measurement of vancomycin. The concentration, measured with a Beckman Coulter Synchron competitive tur-bidimetric immunoassay, was <0.1 mg/L.