Abstract: Objective To reduce the incidence of complications caused by excessive tourniquet pressure by modifying the setting of pneumatic tourniquet pressure in lower limb surgery.Methods Seventy patients whose expected operation time was less than 90 min under general anesthesia were randomly divided into two groups.In the control group, the pressure of pneumatic tourniquet was set at twice the systolic blood pressure measured with a non-invasive cuff on the upper arm of the patient and locked.In the improved group, the pressure of pneumatic tourniquet was set at 130% of the systolic blood pressure measured with a non-invasive cuff on the lower limb of the healthy side and with a tourniquet applied to a specific location on the limb of the affected side and locked.The blood pressure measurements of right upper limb and unaffected lower limb were observed and recorded after anesthesia.Comparisons were made on indicators such as intraoperative hemorrhage, tourniquet shock, skin conditions where tourniquet was applied at the end of the operation, pains where tourniquet was applied on the first day after the operation, and paresthesia of the affected limb.Results There was no significant difference between the two groups in the proportion of patients requiring pressure release (P=0.051) and intraoperative hemorrhage (P>0.05).The skin conditions of the improved group was better than that of the control group (P<0.05).The postoperative pain degree of the improved group was lower than that of the control group (P<0.001).There were no complications such as tourniquet shock and associated paresthesia in both groups.Conclusion Setting pneumatic tourniquet pressure according to the systolic blood pressure of the unaffected lower limb could achieve a good hemostasis during a fast lower limb surgery.

Key words: Lower limb surgery, Tourniquet, Inflation pressure