On Jan 30, 2008 1:34 PM, Johnson, Bill <[log in to unmask]
The issue of reflux time has been around for decades. I have seen 1 sec, 2 sec and 3 sec used as a cutoff time for normal, but little in the formal research arena.
This reference might help;
Labropoulos N, Tiongson J, Pryor L, et al. Definition of Venous Reflux in Lower Extremity Veins. J Vasc Surg. 2003; 38: 793-798. Their cutoff values for "normal" subjects were <500 ms in superficial veins and calf veins, <350 ms for perforators, and <1000 ms for femoropopliteal veins. Longer duration of reflux was observed in supine subjects than standing subjects.
If you are going to use this reference, I would strongly suggest reading the entire article.
And of course, if the Valsalva maneuver or manual compression is not adequate, reflux measurements are pretty useless.
Bill Johnson, RVT, FSVU