A cleaning and calibration method for the spiropro portable spirometer's pneumotachometer tube in a remote field study

BACKGROUND: We developed a systematic method of cleaning and calibration-checking for the pneumotachometer tube of the SpiroPro portable spirometer; this method maximized spirometry accuracy in a population-based study in a remote area of Nepal.& METHODS: We tested 10 factory-calibrated pneumotachometer tubes. Each use consisted of a full set of spirometry maneuvers, per the American Thoracic Society (ATS) spirometry criteria.& RESULTS: The pneumotachometers remained accurate, per the ATS criteria, for 5-9 disinfections, but began to drift toward inaccuracy after the first disinfection. All the pneumotachometers had become inaccurate, per the ATS criteria, after 10 disinfections.& CONCLUSIONS: In a remote field setting the SpiroPro pneumotachometer tube can be cleaned and reused 5-9 times before it becomes inaccurate per the ATS criteria. Rigorous rinsing in distilled water and repeated calibration checks, at various flows up to 12 L/s, are essential for precise and accurate spirometry with the SpiroPro. Reusing the SpiroPro pneu-motachometer in a remote setting may impose measurement bias. Single use of SpiroPro pneumo-tachometers, albeit more costly, will provide better data.