Effects of ischemic preconditioning on the early recovery in patients after total knee arthroplasty

Objective To investigate the effects of ischemic preconditioning (IPC) on the early recovery of patients after total knee arthroplasty (TKA). Methods A total of 40 patients [American Society of Anesthesiologists(ASA) Stage Ⅰ, Ⅱ] initially undergoing unilateral TKA after general anesthesia were randomly divided into two groups (n=20): an IPC group (group I) and a control group (group C). Group I underwent three cycles of 5 min ischemia/5 min reperfusion after induction of anesthesia, while group C received no treatment. After surgery, patient-controlled intravenous analgesia (PCIA) was performed, with 4 μg/kg sufentanil and 12 mg tropisetron in normal saline to 200 ml, at a background infusion rate of 2 ml/h. The PCA pump was set up with a bolus dose of 0.5 ml within a lockout interval of 15 min for 72 h. Sufentanil was used for rescue analgesia to maintain the Visual Analogue Scale (VAS) score≤3. The VAS scores of both groups were recorded 12, 24, 48 h and 72 h after surgery. The numbers of attempts and successful press times within 72 h were recorded. The use of sufentanil within 72 h was recorded, while the per capita dose of sufentanil and rescue analgesia rate was calculated. The scores of patient satisfaction 72 h after operation was recorded, while the number of straight leg raise and the range of spontaneous activity 1, 3, 7, 14 d after surgery were also recorded. Results No significant differences were detected in VAS between the two groups 12, 24, 48 h and 72 h after surgery (P>0.05). Compared with group C, group I presented remarkable decreases in the numbers of attempts and successful delivered doses, the average sufentanil dose and rescue analgesia rate (P 0.05). Conclusions IPC can effectively relieve postoperative pain and promote knee functional recovery, so as to improve early recovery quality. Key words: Ischemic preconditioning; Reperfusion injury; Knee joint; Artificial joint replacement