Postoperative Infections Traced to Contamination of an Intravenous Anesthetic, Propofol

BACKGROUND: Between June 1990 and February 1993, the Centers for Disease Control and Prevention conducted investigations at seven hospitals because of unusual outbreaks of bloodstream infections, surgical-site infections, and acute febrile episodes after surgical procedures. METHODS: We conducted case-control or cohort studies, or both, to identify risk factors. A case patient was defined as any patient who had an organism-specific infection or acute febrile episode after a surgical procedure during the study period in that hospital. The investigations also included reviews of procedures, cultures, and microbiologic studies of infecting, contaminating, and colonizing strains. RESULTS: Sixty-two case patients were identified, 49 (79 percent) of whom underwent surgery during an epidemic period. Postoperative complications were more frequent during the epidemic period than before it. Only exposure to propofol, a lipid-based anesthetic agent, was significantly associated with the postoperative complications at all seven hospitals. In six of the outbreaks, an etiologic agent (Staphylococcus aureus, Candida albicans, Moraxella osloensis, Enterobacter agglomerans, or Serratia marcescens) was identified, and the same strains were isolated from the case patients. Although cultures of unopened containers of propofol were negative, at two hospitals cultures of propofol from syringes currently in use were positive. At one hospital, the recovered organism was identical to the organism isolated from the case patients. Interviews with and observation of anesthesiology personnel documented a wide variety of lapses in aseptic techniques. CONCLUSIONS: With the increasing use of lipid-based medications, which support rapid bacterial growth at room temperature, strict aseptic techniques are essential during the handling of these agents to prevent extrinsic contamination and dangerous infectious complications.