A. Rajpura, B. V. Somanchi, L. T. S. W. Muir
J Bone Joint Surg Br, Apr 2007; 89-B: 532 – 534
The tourniquet still remains one of the most commonly used appliances in orthopaedic practice. The essence of using this contraption lies in the essentially bloodless field, which a proper application affords. Frequently though, it is observed that improper application causes contamination of the field with blood, obscuring vision and generally increasing operating times with increasing risk of complications.
Rajpura et al have reported the effect of padding on the efficiency of the pneumatic tourniquet for the upper limb. Varying thicknesses of two commercially available types of orthopaedic padding (Cellona and Velband) were applied to the arms of 20 volunteers, with three pressure transducers placed directly beneath the padding. A tourniquet was positioned over the padding and inflated to 220 mmHg.
Significant reductions in the transmitted pressure were recorded from the transducers with both padding materials. With eight layers of padding, reductions in pressure of 13% (1% to 26%) and 18% (7% to 35%) were seen with Cellona and Velband, respectively. With four layers in place, mean reductions in effective transmitted pressures were 5% (1% to 20 %) and 11% (2% to 27%). Pressure measurements were also co-related to the circumference of the arm. The reduction in pressure with Velband padding also correlated with increasing arm circumference.
There have been no past studies on the influence of tourniquet padding on transmitted pressures. The study is significant as it may help us to standardize the numbers of layers used under the tourniquet which would render the pressure it is inflated to, to be the most effective. It is likely that Velband with its three-layer structuring is less compressible and thus less effective in transmitting pressure than Cellona, which has a monolayer structure.