Acute microcirculatory effects of remote ischaemic conditioning in hard-to-heal wounds

Objective: Remote ischaemic conditioning (RIC) is known to have a positive impact on heart muscle cells, kidney and liver cells. RIC improves microcirculation in healthy skin. Microcirculation is a crucial factor in wound healing. This study examined the microcirculatory effects of RIC in hard-to-heal (chronic) wounds based on the hypothesis that RIC improves cutaneous microcirculation in hard-to-heal wounds. Method: Patients with hard-to-heal wounds (>3 weeks) participated in the study. RIC comprised three ischaemia cycles (five-minute inflation of blood pressure cuff to 200mmHg), each followed by a 10-minute reperfusion phase on a healthy upper limb. After the third and final ischaemia cycle, a reperfusion of 20 minutes ensued. Microcirculation was continuously recorded through a combined laser Doppler and white light spectrometry. Results: The cohort comprised 20 patients. In hard-to-heal wounds, oxygen saturation in a 6–8mm tissue depth was increased by a maximum of 11.2% (percentage change from baseline; p<0.02) and capillary blood flow was increased by a maximum of 47.7% (p<0.0001). There was no significant change of the postcapillary venous filling pressure. Conclusion: The results of this study showed that RIC enhanced microcirculation in hard-to-heal wounds by elevating capillary blood flow and oxygen saturation.