The effect of remote ischaemic preconditioning on endothelial function after hip fracture surgery

Endothelial dysfunction seems to play a role in the pathophysiology of myocardial injury after surgery. The aim of this randomised clinical trial was to examine whether remote ischaemic preconditioning in relation to hip fracture surgery ameliorates post-operative systemic endothelial dysfunction.This was a planned single-centre pilot sub-study of a multicentre, randomised clinical trial. Patients ≥45 years with a cardiovascular risk factor were randomised to remote ischaemic preconditioning (RIPC) or control (standard treatment) performed in relation with their hip fracture operation. RIPC consisted of four cycles of 5 minutes forearm ischaemia and reperfusion. The procedure was performed non-invasively with a tourniquet. The endothelial function was assessed with non-invasive digital pulse amplitude tonometry on post-operative day 1 and expressed as the reactive hyperaemia index (RHI). Endothelial dysfunction was defined as RHI < 1.22.Between February 2015 and December 2016, 18 patients were allocated to the RIPC group and 20 patients to the control group. The endothelial function was impaired in both groups on post-operative day 1. RHI did not differ between the groups, 1.47 (95% CI 1.20-1.75) in the RIPC group vs. 1.54 (95% CI 1.17-1.91) in the control group, P = .76. Endothelial dysfunction was present in 3/18 patients (16.7%) in the RIPC group and 8/20 patients (40%) in the control group, P = .11.No beneficial effect of remote ischaemic preconditioning on the systemic endothelial dysfunction, assessed at a single time point on post-operative day one, was detected after hip fracture surgery.