Naveed S. Hamid

Neurosurgically related nosocomial Acinetobacter baumannii meningitis: report of two cases and literature review.

Nosocomial meningitis is an uncommon complication of neurosurgical procedures, although nosocomial Gram-negative bacillary meningitis does occur occasionally in neurosurgical intensive care units (NSICUs). Acinetobacter baumannii is a rare cause of nosocomial meningitis, and is an even rarer cause of meningitis outbreaks in NSICUs. We report two cases of A. baumannii meningitis in an NSICU due to suboptimal aseptic technique in obtaining cerebrospinal fluid (CSF) specimens. After institution of infection control measures, i.e. aseptically collecting CSF specimens from distal external ventricular drain ports, there were no further cases. This report also reviews nosocomial Acinetobacter meningitis in adult neurosurgical patients.

Cost-ineffectiveness of serum vancomycin levels

Initial vancomycin preparations contained a variety of impurities, and early reports of “vancomycin nephrotoxicity” were apparently related to impurities in the solution and not to vancomycin per se. With improved production techniques, purified vancomycin preparations have not been associated with nephrotoxicity [1–3]. Several clinical studies have studied the nephrotoxic potential of vancomycin. Early reports of vancomycin nephrotoxicity were attributed to impurities in the solution. In these studies, the majority of patients on vancomycin were also receiving nephrotoxic drugs or had some degree of pre-existing renal impairment [4–7]. Vancomycin is primarily excreted renally by glomerular filtration without tubular reabsorption. In patients with normal renal function, the elimination half-life (t1/2) of vancomycin is ∼6 h. Using a vancomycin dose of 1 g (IV) predictably achieves peak serum concentrations of 30– 40 μg/ml and trough concentrations of 5–10 μg/ml, which reliably results in therapeutic serum concentrations for staphylococci [8]. In patients with renal insufficiency, the daily dose of vancomycin should be decreased in proportion to the degree of renal function, as determined by creatinine clearance [9]. Vancomycin may be correctly dosed based on creatinine clearance, and this rationale for trough vancomycin serum levels has been questioned [10– 14]. To determine the real-life cost/usefulness of obtaining serum vancomycin trough levels, we retrospectively reviewed the data on 351 hospitalized patients receiving parenteral vancomycin. Vancomycin was given using a 1-g (IV) q12-h dosing regimen over a four-month period, in order to determine if vancomycin trough levels are costeffective or clinically relevant.