A couple of days ago I was reviewing (triaging, actually) the spirometry portion of a full panel of PFTs performed with pretty terrible test quality and was trying to decide if the technician responsible for performing the tests had made the right selections from the patient’s test results. I noticed that the FEV1 that had been selected was actually the lowest FEV1 from the all the spirometry efforts the patient made, and was trying to decide whether this was really the correct choice. We use peak flow to help determine which FEV1 to select and that particular spirometry effort appeared to have the highest and sharpest peak flow by a large margin:
particularly when compared to the other spirometry efforts:
But this was hard to reconcile given how low the FEV1 was relative to the others:
Test #1 | Test #2 | Test #3 | ||||
Observed: | %Predicted: | Observed: | %Predicted: | Observed: | %Predicted: | |
FVC (L): | 1.71 | 41% | 2.46 | 59% | 2.39 | 58% |
FEV1 (L): | 1.24 | 39% | 1.81 | 57% | 1.77 | 55% |
FEV1/FVC: | 73 | 95% | 74 | 96% | 74 | 97% |