RT Journal Article SR Electronic T1 Bacterial Contamination of Circuit Inner Surfaces After High-Flow Oxygen Therapy JF Respiratory Care FD American Association for Respiratory Care SP respcare.06299 DO 10.4187/respcare.06299 A1 Mutsuo Onodera A1 Emiko Nakataki A1 Nobuto Nakanishi A1 Taiga Itagaki A1 Masami Sato A1 Jun Oto A1 Masaji Nishimura YR 2019 UL http://rc.rcjournal.com/content/early/2019/02/05/respcare.06299.abstract AB BACKGROUND: During high-flow oxygen therapy, heated humidified gas is delivered at high flow. Although the warmth and humidity of this gas facilitates mucociliary function in the lower airway, warm and humid conditions also promote bacterial growth. Bacterial contamination of high-flow oxygen therapy circuits has not been well investigated. We examined the incidence of bacterial contamination in high-flow oxygen therapy circuits.METHODS: This was a prospective observational study in a university hospital 10-bed general ICU. After final high-flow oxygen therapy discontinuation, samples were obtained from the interface and the chamber ends of the circuit. Initially, a half circumference of each inner surface was swabbed, after which the whole tube was left in the ICU at room temperature for 6 h. The samples were then, in the same way, taken from the previously unswabbed arcs of the end inner surfaces. All the samples were sent to a biology laboratory and cultured.RESULTS: In all, 118 samples were collected from 31 tubes. The median duration of high-flow oxygen therapy was 48 h (interquartile range, 26–96 h). Of 31 tubes, contamination occurred in 5 tubes (16.1% [95% CI 5.5–33.7%]).CONCLUSIONS: Bacterial contamination of inner surfaces of the circuit after high-flow oxygen therapy was relatively high.