Technique for performing spirometry

Unlike most other medical tests in which the patient remains passive, accurate spirometry requires a coordinated maximum effort. The technician should instruct and encourage the patient to perform the breathing maneuvers in three phases: Phase 1: coach the patient to take as deep a breath as possible; Phase 2: loudly prompt the patient to BLAST out the air into the spirometer; Phase 3: encourage the patient to continue exhaling for several more seconds.