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Hypoperfusion following the injection of epinephrine in human forearm skin can be measured by RGB analysis but not with laser speckle contrast imaging

Sheikh, Rafi LU ; Bunke, Josefine LU ; Thorisdottir, Linda LU ; Hult, Jenny LU ; Tenland, Kajsa LU ; Gesslein, Bodil LU ; Reistad, Nina LU and Malmsjö, Malin LU (2019) In Microvascular Research 121. p.7-13
Abstract (Swedish)
Background

The time taken for epinephrine to achieve its optimal effect during local anesthesia has recently become the subject of debate. The time from injection to commencement of surgery is traditionally quoted to be 7 to 10 min, while recent reports claim that it may take 30 min to achieve maximum hypoperfusion, which would prolong the time required for surgical procedures. The discrepancy may be related to difficulties associated with the techniques used to measure blood perfusion. The aim of this study was to test two methods of determining the time to maximum hypoperfusion.
Methods

Laser speckle contrast imaging (LSCI) and red, green, blue (RGB) analysis of images obtained with a commercial digital camera, were... (More)
Background

The time taken for epinephrine to achieve its optimal effect during local anesthesia has recently become the subject of debate. The time from injection to commencement of surgery is traditionally quoted to be 7 to 10 min, while recent reports claim that it may take 30 min to achieve maximum hypoperfusion, which would prolong the time required for surgical procedures. The discrepancy may be related to difficulties associated with the techniques used to measure blood perfusion. The aim of this study was to test two methods of determining the time to maximum hypoperfusion.
Methods

Laser speckle contrast imaging (LSCI) and red, green, blue (RGB) analysis of images obtained with a commercial digital camera, were used to monitor the effect of infiltration with commonly used local anesthetic preparations: lidocaine (20 mg/ml) + epinephrine (12.5 μg/ml), lidocaine (10 mg/ml) + epinephrine (5 μg/ml), and lidocaine (20 mg/ml) alone, in healthy subjects.
Results

LSCI showed a paradoxical increase in signal after the injection of local anesthetics containing epinephrine, probably due to a change in the laser penetration depth resulting from blanching of the skin. However, RGB analysis of digital photographs gave more reliable results, showing skin blanching that corresponded to the expected effect of epinephrine in local anesthetics. The time to maximum effect was found to be 7 (range 5–10) minutes for 12.5 μg/ml epinephrine, and 9 (range 7–13) minutes for 5 μg/ml epinephrine in lidocaine.
Conclusions

RGB analysis of digital images proved to be a valid technique for monitoring the effect of local anesthetics with epinephrine in human skin. The technique requires only a commercial digital camera and constitutes a cheap, simple method. The optimal delay between epinephrine injection and incision, to minimize bleeding, was found to be 7 to 9 min, which is in good agreement with common surgical practice. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Microvascular Research
volume
121
pages
7 - 13
publisher
Academic Press
external identifiers
  • pmid:30153456
  • scopus:85052625488
ISSN
0026-2862
DOI
10.1016/j.mvr.2018.08.005
language
English
LU publication?
yes
id
f495e666-4bbb-4bb8-8d90-dfdf12b3672b
date added to LUP
2018-08-27 15:57:49
date last changed
2019-02-20 11:24:55
@article{f495e666-4bbb-4bb8-8d90-dfdf12b3672b,
  abstract     = {Background<br/><br/>The time taken for epinephrine to achieve its optimal effect during local anesthesia has recently become the subject of debate. The time from injection to commencement of surgery is traditionally quoted to be 7 to 10 min, while recent reports claim that it may take 30 min to achieve maximum hypoperfusion, which would prolong the time required for surgical procedures. The discrepancy may be related to difficulties associated with the techniques used to measure blood perfusion. The aim of this study was to test two methods of determining the time to maximum hypoperfusion.<br/>Methods<br/><br/>Laser speckle contrast imaging (LSCI) and red, green, blue (RGB) analysis of images obtained with a commercial digital camera, were used to monitor the effect of infiltration with commonly used local anesthetic preparations: lidocaine (20 mg/ml) + epinephrine (12.5 μg/ml), lidocaine (10 mg/ml) + epinephrine (5 μg/ml), and lidocaine (20 mg/ml) alone, in healthy subjects.<br/>Results<br/><br/>LSCI showed a paradoxical increase in signal after the injection of local anesthetics containing epinephrine, probably due to a change in the laser penetration depth resulting from blanching of the skin. However, RGB analysis of digital photographs gave more reliable results, showing skin blanching that corresponded to the expected effect of epinephrine in local anesthetics. The time to maximum effect was found to be 7 (range 5–10) minutes for 12.5 μg/ml epinephrine, and 9 (range 7–13) minutes for 5 μg/ml epinephrine in lidocaine.<br/>Conclusions<br/><br/>RGB analysis of digital images proved to be a valid technique for monitoring the effect of local anesthetics with epinephrine in human skin. The technique requires only a commercial digital camera and constitutes a cheap, simple method. The optimal delay between epinephrine injection and incision, to minimize bleeding, was found to be 7 to 9 min, which is in good agreement with common surgical practice.},
  author       = {Sheikh, Rafi and Bunke, Josefine and Thorisdottir, Linda and Hult, Jenny and Tenland, Kajsa and Gesslein, Bodil and Reistad, Nina and Malmsjö, Malin},
  issn         = {0026-2862},
  language     = {eng},
  pages        = {7--13},
  publisher    = {Academic Press},
  series       = {Microvascular Research},
  title        = {Hypoperfusion following the injection of epinephrine in human forearm skin can be measured by RGB analysis but not with laser speckle contrast imaging},
  url          = {http://dx.doi.org/10.1016/j.mvr.2018.08.005},
  volume       = {121},
  year         = {2019},
}