Introduction: Locally and neurally mediated vasodilation of the cutaneous vasculature has been shown to occur in response to locally and systemically applied heat stresses. The resultant shunting of blood to the periphery can be upwards of 7 L/min to 8 L/min when profound heat stresses are applied. The increased cutaneous circulation from local heat stress may benefit extremities afflicted with a wound or area of compromised arterial supply. Insulating the extremity also may increase local cutaneous perfusion.
Objective: This study aims to determine if increased local warmth from an insulated offloading boot or mitt (designed to protect an extremity from trauma, offload the extremity to prevent pressure ulcers, and insulate the extremity to minimize heat loss) also results in increased local cutaneous perfusion using indocyanine green fluorescence angiography (ICGFA).
Materials and methods: Nine patients from an outpatient wound care clinic with a wound or area of compromised arterial supply on the upper or lower extremity were studied prior to and following a minimum of a single 60-minute session of insulated offloading boot or mitt use utilizing ICGFA. Measurements taken were time to first onset of fluorescence (seconds) and ingress and egress rates for the area of concern and the remainder of the area imaged.
Results: All 9 patients exhibited signs of increased local warmth by a mean of 3.1ºF while body temperature decreased by a mean of 1.2ºF. Local cutaneous perfusion increased with a mean change of 1 for the ingress rate to the area of concern and a mean change of 0.1 to the remainder of the area imaged. Also, ICGFA was able to demonstrate preferential shunting of the increased cutaneous perfusion to the site of most need.
Conclusions: These findings suggest enhanced skin perfusion may be an additional advantage of insulated offloading boot or mitt use.