An investigation into the effect of ischaemia and pressure on irritant inflammation.

Reports of chemical burns beneath tourniquets during orthopaedic procedures led us to explore the irritant effects produced by the skin antiseptics used during such procedures. A sphygmomanometer and tourniquet, at a pressure of 200 mmHg for 30 min, was used to created pressure and ischaemia which were then examined separately for their respective effects on irritant inflammation in normal subjects and those with atopic eczema. As no inflammation could be demonstrated with the antiseptics, we subsequently used the known irritant chemical anthralin to examine the effect of ischaemia with and without pressure. Site-related variation in anthralin-induced inflammation was observed but there was no demonstrable effect of either pressure or ischaemia on the inflammatory response. Therefore, as we are unable to show a relationship between ischaemia with or without pressure and irritant inflammation, we conclude that burns under tourniquets are likely to be idiosyncratic reactions and their further investigation requires examination of the individuals affected.