The digital tourniquet: how safe is it?

To measure the pressure generated beneath a digital tourniquet, this study was based on the mathematical relationship between pressure and resistance in latex rubber. The digital tourniquets were either a 1/4-inch Penrose drain or a rolled glove finger. Pressures generated beneath the rolled glove finger were noted to range between 200 and 1200 mm Hg. Pressure beneath the Penrose drain ranged between 100 and 650 mm Hg in one study group and between 120 and 500 mm Hg in a second study group consisting of fingertip injuries. A method was developed based on the same mathematical relationship to control pressure. Marks spaced 26 mm apart on a Penrose drain are wrapped around a finger until the marks touch and the Penrose drain is clamped. With this technique, the pressure beneath the Penrose drain will remain between 250 and 375 mm Hg. Less strain will be required for smaller fingers and more strain will be required for larger fingers; however, the pressure will remain within a predictable range.