Can air plethysmography accurately identify upper extremity deep venous thrombosis?

Air plethysmography (APG) is an established, noninvasive means of evaluating lower extremity venous outflow.

To determine whether APG could identify deep venous thrombosis (DVT) of the upper extremity, we measured the percentage of venous outflow in the first second (maximum venous outflow [MVO]) of four groups of arms: (1) normal volunteers (no previous central vein catheters), (2) the affected, (3) the unaffected arms of the patients with DVT (proven by venography or duplex scanning), and (4) hospital patients (no previous central vein catheters).

The results of an analysis of variance were as follows: the mean MVO (%) of the affected arms of patients with DVT, 29.4 +/- 2.6, was significantly less than their unaffected arms, 55.3 +/- 3.9, hospital controls, 64.3 +/- 2.2, and normal volunteers, 64.2 +/- 0.9 (p < 0.05). In addition, the unaffected arms differed significantly from all groups (p < 0.05). An MVO of 45% was 2 SD below the mean MVO of the normal volunteer group. Two unaffected arms of the patients with DVT were below 45%, whereas only one affected arm of the patients with DVT was above 45% (45.6%). Therefore a comparison of the distribution of the MVO values revealed virtually no overlap of the affected arms of the patients with DVT with the other three groups.

We conclude that APG clearly discriminated arms with documented DVT from controls and is a highly accurate means of identifying upper extremity DVT.