Fig. 1.

Experimental designSequence of experimental procedures for RIC undertaken in presence and absence of brachial plexus block. 10 ​min recording sessions are indicated by clear bars. Three cycles of ischaemia (applied for 3 ​min) followed by 5 ​min of reperfusion were applied. Blood samples were obtained at the times indicated by the collection bottles. A. For the first visit, brachial plexus block with ultrasound guided injection of local anaesthetic was undertaken. B. For the return visit, a time-matched protocol was followed without brachial plexus block before three cycles of RIC were undertaken.