The quality of evidence is downgraded by study limitations (lack of/unclear allocation concealment) and by imprecise results (few patients).
A Cochrane review included 3 studies with a total of 176 subjects. Use of a tourniquet appeared to reduce blood loss during surgery; the reported blood loss when using a tourniquet was between 0 and 16 ml compared to between 107 to 133 ml when not using a tourniquet (P < 0.01). There were no reported differences between the use or non-use of a tourniquet in terms of complications and morbidity. However, the available trials were not of sufficient size to detect rarer complications such as nerve damage.