LAUSR

Background: Currently, there are no regulatory guidelines indicating spacer devices/valved holding chamber (VHC) should be used routinely during pulmonary function tests, and few studies evaluated if spacer devices reduce beta-agonist bronchodilators' side effects. Methods: A prospective study compared salbutamol's cardiovascular effects and bronchodilation response during spirometry tests with and without a spacer device/VHC. Heart rate (HR), the corrected QT interval (QTc), and systolic and diastolic blood pressure were measured 10 minutes after the first spirometry test, before the drug administration, and 20 minutes after inhalation in both groups. Spirometric parameters (forced expiratory volume in the first second [FEV1], forced vital capacity [FVC], and FEV1/FVC) were also measured for both groups. Results: HR and QTc increase were significantly higher in the pressurized meter dose inhalers alone group versus the VHC group [mean SD] [73.1 ± 10 bpm to 74.3 + 10 bpm, p = 0.021] and [median (25%-75% interquartile range)] [389 ms (381-404) to 398 ms (387-407), p = 0.045] vs. [mean SD] [75.4 ± 9 to 73.8 + 8 bpm, p = 0.4] and [median (25%-75% interquartile range)] [388 ms (347-408) to 385 ms (366-408), p = 0.35], respectively. FEV1 variation before and after salbutamol were similar between both groups. Discussion: Although VHC significantly reduces HR and QTc variation when using beta-agonist bronchodilators in healthy patients, no clinical repercussions of this variation were found in this study, since no event of tachycardia or pathological QTc was recorded. Conclusion: VHC has a diminished clinical impact for healthy patients when considering cardiovascular effects and spirometric parameters. Beta-agonist bronchodilators may be administrated despite the use of spacer devices in patients without known cardiovascular diseases. Its significance for other populations still needs to be determined.