Unexpected high risk of contamination with staphylococci species attributable to standard preparation of syringes for continuous intravenous drug administration in a simulation model in intensive care units.

ABSTRACT

OBJECTIVE: To determine the risk of bacterial contamination of the infusate in a simulation model of syringes prepared for continuous intravenous drug administration by intensive care unit nurses. Widely accepted standard procedures in the intensive care unit were compared with syringes prepared by pharmaceutical technicians working under standard aseptic conditions according to national guidelines. DESIGN: Prospective study. SETTING: Intensive care units of four general teaching hospitals and two university hospitals. SUBJECTS: We examined 650 syringes prepared from 10-mL ampules and 100 syringes prepared from rubber-compound-capped 50-mL vials by intensive care unit nurses of six hospitals. Also, 100 syringes from 10-mL ampules and 100 syringes from rubber-compound-capped 50-mL vials were prepared by pharmaceutical technicians. INTERVENTIONS: Turbidity of syringes after culturing for 7 days at 37 degrees C was used as the criterion for possible bacterial contamination, which was proved with subsequent Gram staining. MEASUREMENTS AND MAIN RESULTS: A median contamination rate of 22% (range, 7% to 44%) was observed for the syringes prepared from 10-mL ampules by intensive care unit nurses, compared with only 1% for the syringes prepared from ampules by technicians (p <.001). In >75% of all contaminated syringes, Gram-positive cocci were identified. At least 12% of all prepared syringes proved to be contaminated with staphylococci species. The contamination rate of syringes prepared from vials was much lower 2% in the intensive care unit and 0% at the department of clinical pharmacy. CONCLUSIONS: In the intensive care unit, standard procedures for preparing syringes for intravenous administration of drugs lack vigorous aseptic precautions, leading to a high contamination rate of the infusate. This risk is increased when ampules instead of 50 mL-vials are used to prepare the syringes.