Abstract
To estimate the appropriate tourniquet pressure for venipuncuture, tourniquets made of gum-tube or elastic belt were fastened around the upper arm of 12 healthy subjects with the length adjusted to 95% to 75% of the upper arm circumference. Tourniquet pressure, vein overswelling score and pain score were recorded. Tourniquet pressure was linearly increased according to the fastening strength in both tourniquets. Average pressures after fastening the gum-tube at 95% and at 75% of upper arm circumference were 38.6 mmHg and 166.4 mmHg respectively, whereas the average pressures after fastening an elastic belt at 95% and at 75% of upper arm circumference were 20.1 mmHg and 121.2 mmHg respectively. Using the gum-tube fastening, 9 subjects showed detectable overswelling at 90% (68.2mmHg) and overswelling increased at 85% (92.6mmHg) tightening. Thereafter, overswelling did not further increase at 80% and 75% tightening. Using the elastic belt fastening, eight subjects showed detectable overswelling at 90% (45.6mmHg) and overswelling increased at 80% (94.9mmHg) tightening. Thereafter, overswelling did not increase at 75% tightening. These data suggested that the appropriate tourniquet pressure for venipuncture ranges from 70-95 mmHg in gum-tube tourniquet and from 45-95 mmHg for elastic belt tourniquet. If the tourniquet pressure is greater than the range described here, overswelling of the vein did not increase but subjective pain perception increased in the subjects.
