Getting the Bugs Out of Bronchoscopes
Abstracts & Commentary
Synopsis: Bacterial contamination of bronchoscopes, resulting in both unnecessary antibiotic use and clinical infection, resulted from a change in design of the instruments.
Sources: Kirschke DL, et al. Pseudomonas aeruginosa and Serratia marcescens contamination associated with a manufacturing defect in bronchoscopes. N Engl J Med. 2003;348:214-220; Srinivasan A, et al. An outbreak of Pseudomonas aeruginosa infections associated with flexible bronchoscopes. N Engl J Med. 2003;348: 221-227.
In the first of these 2 reports, an infection control practitioner reported an increase in bronchoscopy specimens yielding Pseudomonas aeruginosa and Serratia marcescens, prompting an investigation by the state health department and the CDC. Investigators reviewed microbiology and clinical records of patients undergoing bronchoscopy during the outbreak period (July 1, 2001, to October 31, 2001).
Of 66 procedures performed in 60 patients, 43 specimens were submitted for bacterial cultures. Of these, 20 (47%) yielded P aeruginosa; six of these also yielded S marcescens. The first positive culture occurred 8 days after acquisition of several new model bronchoscopes. All the positive cultures occurred following procedures using the new model, and none occurred following procedures using the older model instrument (P < .001). Examination of the instruments showed that the biopsy port caps were loose; culture from the ports in 3 of the 4 new bronchoscopes was positive for P aeruginosa. The bronchoscope isolates were identical on PFGE testing to the 10 patient isolates that were available for testing. They were also identical from 2 isolates recovered from the sink in which the bronchoscopes were washed prior to being placed in the automated reprocessor. The automated reprocessor was functioning properly, and cultures from the device were negative. One patient developed P aeruginosa pneumonia after a bronchoscopy, and 5 others received antimicrobial therapy based on what, in retrospect, were most likely to have been false-positive cultures.
In the second report, microbiologic surveillance in a large university hospital revealed a 3-fold increase in the proportion of bronchoalveolar lavage (BAL) specimens yielding P aeruginosa. During the outbreak period, June 2001 to January 2002, 414 patients underwent 665 procedures; ninety-seven (23.4%) had a BAL culture positive for P aeruginosa. Three bronchoscopes yielded 3 strains of P aeruginosa distinguishable by PFGE. Thirty-two infections due to P aeruginosa occurred within 14 days of bronchoscopy, with 3 deaths. Twenty of 48 available BAL isolates were genetically related to one of the strains, as was one of 4 bloodstream isolates. The contaminated instruments were removed from service in February 2002, and the isolation rates of P aeruginosa returned to baseline. The investigators subsequently learned that the implicated bronchoscope model had been recalled by the manufacturer in November 2001 due to complaints of loose biopsy port caps and bacterial contamination.
Comment by Robert Muder, MD
These 2 reports illustrate several important points regarding patient safety. Minor modifications of FDA-approved devices do not usually require that the device undergo the complete approval process again. A major means of monitoring the safety of devices relies on reporting of device-associated injury. Such reporting is mandatory on the part of manufacturers and voluntary on the part of health care providers and consumers. In this instance, a loose biopsy port on a new model bronchoscope appeared to permit bacterial contamination of the port during washing. While disinfection procedures appeared appropriate in both of the hospitals, the instruments were not adequately sterilized. Although the problem was appropriately reported by the manufacturer and the affected models recalled, it is troubling that a major university hospital was not aware of the recall and that the affected devices were still in use 3 months after the recall. The reasons for this aren’t given, but it’s clear that the procedures for recalling defective devices need to be improved substantially.
It’s also important to note that in both facilities, the problem was first identified by a standard infection control procedure, laboratory-based surveillance. A marked increase in the frequency of isolation of a common pathogen, the occurrence of unusual resistance patterns, or the isolation of an uncommon pathogen may be the first indication of a major threat to patient safety. It remains an essential component of an effective infection control program—you won’t see what you’re not looking for.
Bacterial contamination of bronchoscopes, resulting in both unnecessary antibiotic use and clinical infection, resulted from a change in design of the instruments.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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