Ischemic preconditioning attenuates the lipid peroxidation and remote lung injury in the rat model of unilateral lower limb ischemia reperfusion.

BACKGROUND: Ischemia and reperfusion of the skeletal muscle tissue may cause remote lung injury. We aimed to evaluate the protective effect of ischemic preconditioning (IP) on the lung during unilateral lower limb ischemia reperfusion (IR). METHODS: Four groups of rats were used in this study: (i) the sham group (sham, n = 6) served as time controls, they remained anesthetized for the whole duration of the study; (ii) the ischemia and reperfusion group (IR, n = 10) underwent 4 h of left lower limb ischemia followed by 2 h of reperfusion; (iii) the ischemic preconditioning group (IP, n = 10), the left lower limbs of rats were exposed to three cycles of IP (10 min of ischemia followed by 10 min of reperfusion); and (iv) the ischemic preconditioning plus ischemia reperfusion group (IP/IR, n = 10) underwent IP followed by IR as in the IP and IR groups. Plasma and tissue samples were taken at the end of the study period for determination of lung tissue myeloperoxidase activity (MPO) and polymorphonuclear leukocyte count (PMNL), histological lung injury score and plasma thiobarbituric acid reactive substances (TBARS) level. RESULTS: PMNL count and MPO activity in the lung tissue, and plasma TBARS level were higher in the IR group compared with other groups while there were no differences between the sham and the IP and between the sham and the IP/IR groups. Histological lung injury score was higher in the IR group than in the IP/IR and sham groups. The plasma TBARS level in the IP group was significantly lower than in the IP/IR group. CONCLUSION: IP pretreatment reduces lipid peroxidation and lung injury caused by lower limb IR.

Comparison of the haemodynamic effects of interscalene block combined with general anaesthesia and interscalene block alone for shoulder surgery.

Interscalene brachial plexus block (ISB) anaesthesia is widely used with or without general anaesthesia in patients undergoing shoulder surgery, which is generally done with the patient in a sitting position. This position affects haemodynamics, and supplementing ISB with general anaesthesia can exaggerate these haemodynamic changes. This study compared ISB combined with general anaesthesia, with ISB alone, in 29 patients undergoing elective shoulder surgery. Heart rate and oxygen saturation remained stable throughout the study in both groups. Mean arterial pressure was significantly decreased when the patient moved into the sitting position in those given combined anaesthesia, whereas in those given ISB alone mean arterial pressure did not change significantly. Neither pain scores nor patient satisfaction scores differed significantly between the two groups. All of the patients were either satisfied or entirely satisfied with their anaesthesia/analgesia. There were no significant differences in side-effects and no severe complications in either group. We advocate using ISB alone for patients undergoing shoulder surgery, but further larger studies are needed to confirm the present results.