A report came across my desk today and at first glance it looked fairly straightforward. There was a mildly reduced TLC and FVC, and although the SVC was slightly lower than the FVC it looked like this patient had mild restriction.
| Observed: | %Predicted: | Predicted: | |
| FVC: | 1.73 | 68% | 2.56 |
| FEV1: | 1.23 | 65% | 1.89 |
| FEV1/FVC: | 71 | 97% | 73 |
| TLC: | 3.58 | 73% | 4.89 |
| FRC: | 2.07 | 75% | 2.78 |
| RV: | 1.94 | 83% | 2.33 |
| RV/TLC: | 54 | 114% | 48 |
| SVC: | 1.69 | 66% | 2.56 |
| IC: | 1.51 | 72% | 2.11 |
| ERV: | 0.13 | 30% | 0.45 |
In addition, the flow-volume loop looked fairly typical for restriction, with a normal peak flow and a reduced volume.
When I looked at the DLCO results however, I suddenly got a different picture. Specifically, the VA from the DLCO was larger than the TLC and the inspired volume (Vinsp) was significantly larger than both the FVC and the SVC.
| Observed: | %Predicted: | Predicted: | |
| DLCO: | 13.51 | 83% | 16.23 |
| VA: | 3.87 | 82% | 4.73 |
| Vinsp: | 2.26 |