Effect of Caffeine on Pulmonary Function Tests

Clinical Guidelines for PFT Preparation

The European Respiratory Society guidelines recommend that patients should avoid consuming caffeine within 2 hours of pulmonary function testing 1, 2, 3
Patients should also avoid smoking within 1 hour, alcohol within 4 hours, vigorous exercise within 30 minutes, and large meals within 2 hours of testing, as per the European Respiratory Society guidelines 2, 3
The European Respiratory Society guidelines suggest that when scheduling PFT appointments, patients should be instructed to adhere to these preparation requirements 2
Any deviations from these preparation guidelines should be recorded at the time of testing, according to the European Respiratory Society guidelines 3

For serial PFT monitoring, consistency in pre-test preparation, including caffeine avoidance, is essential for valid comparisons, as recommended by the European Respiratory Society 2