Effect of ischemic preconditioning combined with dexmedetomidine on distal organ function in elderly patients undergoing knee arthroplasty

Objective To evaluate the effect of ischemic preconditioning combined with dexmedetomidine on distal organ function and oxidative stress after lower extremity ischemia-reperfusion in elderly patients undergoing unilateral knee arthroplasty. Methods Elderly patients who underwent unilateral knee replacement in Nantong Hospital of Traditional Chinese Medicine from May 2018 to April 2021 were included. According to the random number table method, they were divided into four groups (n=25):an ischemic preconditioning combined dexmedetomidine group (group I+D), an ischemic preconditioning group (group I), a dexmedetomidine group (group D) and a control group (group C). Then, arterial blood samples were collected before the use of tourniquet (T0), 15 min after tourniquet removal (T1) and 6 h after discharge from the room (T2).The levels of oxidative stress response related indicators were measured, inlcuding malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1), and interleukin-6 (IL-6). Meanwhile, organ function related indexes at T0, T1 and T2 were determined, including creatine kinase isoenzyme (CKMB), lactate dehydrogenase (LDH), alanine transaminase (ALT), aspartate transferase (AST), serum creatinine (Scr), and blood urea nitrogen (BUN).Results Group I+D, group I, and group D produced significantly lower levels of MDA, TNF-α, IL-1, IL-6, ALT and AST than group C at T1 (P<0.05). The levels of MDA, ALT and AST were significantly reduced in groups I+D, I and D at T2, compared with those in group C (P<0.05).Conclusions In elderly patients undergoing unilateral knee arthroplasty, both ischemia-preconditioning and dexmedetomidine can function against oxidative stress and liver injury induced by lower extremity ischemia-reperfusion, but their combined protective effect is not enhanced.