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Point-of-care infrared thermal imaging for differentiating venomous snakebites from non-venomous and dry bites

BACKGROUND: Local envenomation following snakebites is accompanied by thermal changes, which could be visualized using infrared imaging. We explored whether infrared thermal imaging could be used to differentiate venomous snakebites from non-venomous and dry bites. METHODS: We prospectively enrolled...

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Autores principales: Sabitha, Paramasivam, Bammigatti, Chanaveerappa, Deepanjali, Surendran, Suryanarayana, Bettadpura Shamanna, Kadhiravan, Tamilarasu
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7924804/
https://www.ncbi.nlm.nih.gov/pubmed/33600429
http://dx.doi.org/10.1371/journal.pntd.0008580
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author Sabitha, Paramasivam
Bammigatti, Chanaveerappa
Deepanjali, Surendran
Suryanarayana, Bettadpura Shamanna
Kadhiravan, Tamilarasu
author_facet Sabitha, Paramasivam
Bammigatti, Chanaveerappa
Deepanjali, Surendran
Suryanarayana, Bettadpura Shamanna
Kadhiravan, Tamilarasu
author_sort Sabitha, Paramasivam
collection PubMed
description BACKGROUND: Local envenomation following snakebites is accompanied by thermal changes, which could be visualized using infrared imaging. We explored whether infrared thermal imaging could be used to differentiate venomous snakebites from non-venomous and dry bites. METHODS: We prospectively enrolled adult patients with a history of snakebite in the past 24 hours presenting to the emergency of a teaching hospital in southern India. A standardized clinical evaluation for symptoms and signs of envenomation including 20-minute whole-blood clotting test and prothrombin time was performed to assess envenomation status. Infrared thermal imaging was done at enrolment, 6 hours, and 24 hours later using a smartphone-based device under ambient conditions. Processed infrared thermal images were independently interpreted twice by a reference rater and once by three novice raters. FINDINGS: We studied 89 patients; 60 (67%) of them were male. Median (IQR) time from bite to enrolment was 11 (6.5–15) hours; 21 (24%) patients were enrolled within 6 hours of snakebite. In all, 48 patients had local envenomation with/without systemic envenomation, and 35 patients were classified as non-venomous/dry bites. Envenomation status was unclear in six patients. At enrolment, area of increased temperature around the bite site (Hot spot) was evident on infrared thermal imaging in 45 of the 48 patients with envenomation, while hot spot was evident in only 6 of the 35 patients without envenomation. Presence of hot spot on baseline infrared thermal images had a sensitivity of 93.7% (95% CI 82.8% to 98.7%) and a specificity of 82.9% (66.3% to 93.4%) to differentiate envenomed patients from those without envenomation. Interrater agreement for identifying hot spots was more than substantial (Kappa statistic >0.85), and intrarater agreement was almost perfect (Kappa = 0.93). Paradoxical thermal changes were observed in 14 patients. CONCLUSIONS: Point-of-care infrared thermal imaging could be useful in the early identification of non-venomous and dry snakebites.
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spelling pubmed-79248042021-03-10 Point-of-care infrared thermal imaging for differentiating venomous snakebites from non-venomous and dry bites Sabitha, Paramasivam Bammigatti, Chanaveerappa Deepanjali, Surendran Suryanarayana, Bettadpura Shamanna Kadhiravan, Tamilarasu PLoS Negl Trop Dis Research Article BACKGROUND: Local envenomation following snakebites is accompanied by thermal changes, which could be visualized using infrared imaging. We explored whether infrared thermal imaging could be used to differentiate venomous snakebites from non-venomous and dry bites. METHODS: We prospectively enrolled adult patients with a history of snakebite in the past 24 hours presenting to the emergency of a teaching hospital in southern India. A standardized clinical evaluation for symptoms and signs of envenomation including 20-minute whole-blood clotting test and prothrombin time was performed to assess envenomation status. Infrared thermal imaging was done at enrolment, 6 hours, and 24 hours later using a smartphone-based device under ambient conditions. Processed infrared thermal images were independently interpreted twice by a reference rater and once by three novice raters. FINDINGS: We studied 89 patients; 60 (67%) of them were male. Median (IQR) time from bite to enrolment was 11 (6.5–15) hours; 21 (24%) patients were enrolled within 6 hours of snakebite. In all, 48 patients had local envenomation with/without systemic envenomation, and 35 patients were classified as non-venomous/dry bites. Envenomation status was unclear in six patients. At enrolment, area of increased temperature around the bite site (Hot spot) was evident on infrared thermal imaging in 45 of the 48 patients with envenomation, while hot spot was evident in only 6 of the 35 patients without envenomation. Presence of hot spot on baseline infrared thermal images had a sensitivity of 93.7% (95% CI 82.8% to 98.7%) and a specificity of 82.9% (66.3% to 93.4%) to differentiate envenomed patients from those without envenomation. Interrater agreement for identifying hot spots was more than substantial (Kappa statistic >0.85), and intrarater agreement was almost perfect (Kappa = 0.93). Paradoxical thermal changes were observed in 14 patients. CONCLUSIONS: Point-of-care infrared thermal imaging could be useful in the early identification of non-venomous and dry snakebites. Public Library of Science 2021-02-18 /pmc/articles/PMC7924804/ /pubmed/33600429 http://dx.doi.org/10.1371/journal.pntd.0008580 Text en © 2021 Sabitha et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Sabitha, Paramasivam
Bammigatti, Chanaveerappa
Deepanjali, Surendran
Suryanarayana, Bettadpura Shamanna
Kadhiravan, Tamilarasu
Point-of-care infrared thermal imaging for differentiating venomous snakebites from non-venomous and dry bites
title Point-of-care infrared thermal imaging for differentiating venomous snakebites from non-venomous and dry bites
title_full Point-of-care infrared thermal imaging for differentiating venomous snakebites from non-venomous and dry bites
title_fullStr Point-of-care infrared thermal imaging for differentiating venomous snakebites from non-venomous and dry bites
title_full_unstemmed Point-of-care infrared thermal imaging for differentiating venomous snakebites from non-venomous and dry bites
title_short Point-of-care infrared thermal imaging for differentiating venomous snakebites from non-venomous and dry bites
title_sort point-of-care infrared thermal imaging for differentiating venomous snakebites from non-venomous and dry bites
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7924804/
https://www.ncbi.nlm.nih.gov/pubmed/33600429
http://dx.doi.org/10.1371/journal.pntd.0008580
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