Hyperspectral Imaging to Study Dynamic Skin Perfusion after Injection of Articaine-4% with and without Epinephrine—Clinical Implications on Local Vasoconstriction

Abstract

This study aimed to investigate the dynamic skin perfusion via hyperspectral imaging (HSI) after application of Articaine-4% ± epinephrine as well as epinephrine only. After the subcutaneous injection of (A100) Articaine-4% with epinephrine 1:100,000, (A200) Articaine-4% with epinephrine 1:200,000, (Aw/o) Articaine-4% without epinephrine, and (EPI200) epinephrine 1:200,000, into the flexor side of the forearm in a split-arm design, dynamic skin perfusion measurement was performed over 120 min by determining tissue oxygen saturation (StO2) using HSI. After injection, all groups experienced a reactive hyperaemia. With A200, it took about three min for StO2 to drop below baseline. For Aw/o and EPI200, perfusion reduction when compared to baseline was seen at 30 min with vasoconstriction >120 min. A100 caused vasodilation with hyperaemia >60 min. After three minutes, the perfusion pattern differed significantly (p < 0.001) between all groups except Aw/o and EPI200. The vasoactive effect of epinephrine-containing local anaesthetics can be visualised and dynamically quantified via StO2 using HSI. Aw/o + epinephrine 1:100,000 and 1:200,000 leads to perfusion reduction and tissue ischaemia after 30 min, which lasts over 120 min with no significant difference between both formulations. When using Aw/o containing epinephrine in terms of haemostasis for surgical procedures, a prolonged waiting time before incision of 30 or more min can be recommended.

How long to wait after local infiltration anaesthesia: systematic review

“…Only two perfusion-imaging studies’ results closely reflect direct observations 35 , 83 . The first study used NIRS 35 .…”

“…This artefact may be related to tissue vascularity and the probe’s wavelength range 38–40 . It may be less pronounced peripheral to the injection site 83 . Thirdly, only three studies’ instruments had adequate depth and resolution to gauge the deep dermal plexus 35 , 38 , 39 .…”

“…The control (plain lidocaine) produced hyperperfusion for about 90 min. The second study used hyperspectral imaging (HSI) 83 . It used articaine, not lidocaine, but remains relevant to this review.…”

“…Multimodal analysis and hybrid imaging techniques that target the deep dermal plexus can better describe skin perfusion dynamics in response to epinephrine injection. Perfusion studies such as NIRS and HSI are promising as they have been shown to correlate clinically with blood loss 35 , 83 .…”