The Effect of Infraclavicular Block on Tourniquet-Induced Ischaemia Reperfusion Injury

The study group comprised 60 number of males and females, aged between 18 and 65 y with ASA physical status I–III undergoing routine upper extremity surgery with a pneumatic tourniquet. The exclusion criteria were as follows: cardiac, metabolic, renal, or hepatic diseases; systemic rheumatological diseases; inflammatory, autoimmune, or peripheral vascular diseases; symptomatic diabetic microangiopathy (diabetic foot, diabetic retinopathy, etc.); known limb ischemia; deep vein thrombosis; or hemodynamic instability. Additional exclusion criteria were a history of cancer, a history of coronary artery disease within the previous year or extremity surgery within the previous 3 months, drug use that could impair the acid-base balance, steroid drug use, alcohol consumption and smoking. The infraclavicular block (ICB) was applied using a USG multi-frequency linear probe (10–18 MHz) by a anesthesiologist. Lateral-sagittal technique was used when the block.. Then, 10 ml of 2% prilocaine and 10 ml of 0.5% bupivacaine (total dose = 20 ml) was given as intermittent negative aspiration as a local anesthetic mixture. U-shaped spread of local anesthesia around the three branches of the brachial plexus was confirmed by ultrasound. The tourniquet was continuously inflated to 250 mmHg on the operative arm and maintained to arrest blood flow until at the end of surgery. Blood samples were drawn before the ICB and induction of GA, and these values were accepted as T1 values before tourniquet application. A pneumatic tourniquet routinely used in upper extremity procedures was inflated just before surgery to maintain the patient’s mean systolic blood pressure above 100 mmHg. Blood samples were drawn again 2 h after tourniquet opening, and these values were accepted as T2 values too. The blood samples were collected in tubes and stored at -20°C. Serum ischemia-modified albumin (IMA) levels were measured spectrophotometrically using a spectrophotometer and the albumin-cobalt binding method. The results were recorded in absorbance units (ABSUs). Colorimetric method kits were used for the measurement of serum total antioxidant status (TAS) and total oxidant status (TOS) levels. TAS and TOS levels were calculated (µmol H2O2 equivalent/L) using commercially available diagnostic kits. The TAS, TOS and IMA levels in the groups were also measured at different tourniquet times: 0–60 min and 61–120 min. All of the intervention is managed by anesthesiology.