Prospective audit of aminoglycoside usage in a general hospital with assessments of clinical processes and adverse clinical outcomes
Li, S.C.; Ioannides-Demos, L.L.; Spicer, W.J.; Berbatis, C.; Spelman, D.W.; Tong, N.; McLean, A.J.
Medical Journal of Australia 151(4): 224-232
1989
ISSN/ISBN: 0025-729X PMID: 2761465 Document Number: 340486
A comprehensive, multiphasic review of gentamicin and tobramycin utilization was undertaken with audits of the microbiological sensitivity of Gram-negative pathogens; indications for the prescription of aminoglycoside agents; the utilization of assay services; the adequacy of clinical drug delivery by measures of serum antibiotic levels; and the assessment of adverse outcomes by markers of nephrotoxicity. The great majority of clinical isolates of target organisms (n = 4208) was more sensitive to gentamicin (96%) and to tobramycin (99%) than to all alternative agents, including first- and third-generation cephalosporin agents. A review of the A review of the indications for the prescription of aminoglycoside agents by clinical criteria showed that in 85.6% of 278 documented cases, the choice of agent was appropriate by clinical and microbiological criteria. In a substantial (77.6%) proportion of the 511 patients who were receiving therapeutic courses of an aminoglycoside agent, serum drug assays had been performed. Assay data could not be interpreted adequately in 52.6% of 3079 assayed cases as a result of inadequate data on administration regimens (39.7%) or sampling regimens (12.9%). Where sampling was documented adequately, there was extreme variation (zero to five hours) in post-dose sampling. In only 33.2% of cases could it be concluded unambiguously that the patients were receiving safer, adequate therapy for clinically significant infections, 5.6% of patients were receiving potentially toxic doses, and 8.6% of patients showed suboptimal concentration profiles. The majority of potentially toxic levels were associated with adverse effects. Serum creatinine concentrations rose to levels of equal to or greater than 0.05 mmol/L in 67.3% (33/49) and 71% (66/93) of potentially toxic cases during the utilization-audit and therapeutic-audit phases, respectively, even though aminoglycoside agents could be implicated as the single causative factor in only 30.6% (15/49) and 37.6% (35/93) of cases, respectively. We conclude that most strains of common Gram-negative pathogens remain sensitive to aminoglycoside agents, and that these drugs are prescribed according to appropriate indications in the majority of instances. Delivery of drug is suboptimal in many instances, indicating the need for clinical intervention that is aimed at the optimization of drug dosage and drug delivery.