There are usually only two situations where a patient’s exercise Ve is greater than their predicted max Ve. Since both Wasserman and the ATS/ACCP statement on cardiopulmonary exercise testing recommend the use of FEV1 x 35 or FEV1 x 40 as the predicted maximum minute ventilation we no longer use the MVV. Patients often have difficulty performing the MVV test correctly and realistically even if it is performed well the breathing maneuver used during an MVV test is not the same as what occurs during exercise. We have tried performing pre-exercise MVV tests in the past and using the maximum observed MVV as the predicted maximum Ve but our experience with this has been poor. We derive our predicted max Ve from baseline spirometry and calculate it using FEV1 x 40. It is unusual to see a Ve that is greater than 100% of predicted. How is this possible and does it indicate a pulmonary mechanical limitation or not? Recently a CPET report came across my desk with a maximum minute ventilation that was 142% of predicted.
When I review the results from a CPET I am used to considering a maximum minute ventilation (Ve) greater than 85% of predicted as an indication of a pulmonary mechanical limitation.
