Objectives: Remote ischemic preconditioning (rIPC) is a novel technique in which brief episodes of ischemia and reperfusion in one organ confer protection against prolonged ischemia in a distant organ. In contrast, anesthetic-induced preconditioning (APC) utilizes volatile anesthetics to protect multiple organs from ischemia-reperfusion injury. Both methods are easily integrated into various clinical scenarios for cardioprotection. However, it remains unclear whether simultaneous application of these techniques could result in complementary, additive, synergistic, or adverse effects.

Methods: An adult rabbit heart Langendorff model of global ischemia/reperfusion injury was used to compare the cardioprotective effect of rIPC and APC alone and in combination relative to untreated (control) hearts. The rIPC group underwent four cycles of 5-minute ischemia on the hind limb, each followed by 5 minutes of reperfusion. The APC group received 2.5 vol% sevoflurane for 20 minutes via a face mask, followed by a 20-minute washout period.

Results: Both in vivo rIPC, induced by four 5-minute cycles of ischemia/reperfusion on the hind limb, and APC, administered as 2.5 vol% sevoflurane via a mask, significantly reduced the size of myocardial infarction following 30 minutes of global ischemia by >50% compared to the untreated control group (rIPC, 12.1±1.7%; APC, 13.5±2.1%; P<0.01 compared to control, 31.3±3.0%). However, no additional protective effect was observed when rIPC and APC were combined (rIPC+APC, 14.4±3.3%).

Conclusion: Although combining rIPC and APC did not provide additional protection, there was no inhibitory effect of one intervention on the other.

Animal models of peripheral nerve ischemia have yielded variable results.

The question of whether postischemia re-estableshment of blood flow to the nerves auguments injury has not been examined.

To study this question, the ipsilateral common iliac and femoral arteries were occluded with arterial snares for 3 hours in rats. C14-butanol tissue distribution was then used to measure blood flow in both sciatic and posterior tivial nerve trunks during occlusion and reperfusion.

Clinical limb function was graded serially, with the undisturbed contralateral limb serving as the study control. Nerve blood flow was reduced throughout the ischemic period and was only 20% of the control value in the posterior tibial nerve. All rats had functional impairment with an average limb function score of 7.5(normal score<2). During reperfusion period, blood flow in the distal sciatic and posterior tibial nerves was approximately double that of control nerbes at 2 hours.

At 21 hours, tibial nerve blood flow was still twice that of the control nerve, but flows in the distal sciatic nerve were unchanged from control levels. Clinically, limb function improved progressively after reperfusion.

It was concluded that nerve ischemia is attended by a relatively prolonged hyperemic flow response during reperfusion.

No abstract available in English.