Is my wound infected? A study on the use of hyperspectral imaging to assess wound infection.

Introduction: Clinical signs and symptoms (CSS) of infection are a standard part of wound care, yet they can have low specificity and sensitivity, which can further vary due to clinician knowledge, experience, and education. Wound photography is becoming more widely adopted to support wound care. Thermography has been studied in the medical literature to assess signs of perfusion and inflammation for decades. Bacterial fluorescence has recently emerged as a valuable tool to detect a high bacterial load within wounds. Combining these modalities offers a potential objective screening tool for wound infection. Methods: A multi-center prospective study of 66 outpatient wound care patients used hyperspectral imaging to collect visible light, thermography, and bacterial fluorescence images. Wounds were assessed and screened using the International Wound Infection Institute (IWII) checklist for CSS of infection. Principal component analysis was performed on the images to identify wounds presenting as infected, inflamed, or non-infected. Results: The model could accurately predict all three wound classes (infected, inflamed, and non-infected) with an accuracy of 74%. They performed best on infected wounds (100% sensitivity and 91% specificity) compared to non-inflamed (sensitivity 94%, specificity 70%) and inflamed wounds (85% sensitivity, 77% specificity). Discussion: Combining multiple imaging modalities enables the application of models to improve wound assessment. Infection detection by CSS is vulnerable to subjective interpretation and variability based on clinicians' education and skills. Enabling clinicians to use point-of-care hyperspectral imaging may allow earlier infection detection and intervention, possibly preventing delays in wound healing and minimizing adverse events.

Local Insulin Improves Wound Healing: A Systematic Review and Bayesian Network Meta-Analysis.

BACKGROUND: Wounds are a significant health issue, and reliable and safe strategies to promote repair are needed. Clinical trials have demonstrated that local insulin promotes healing in acute and chronic wounds (ie, reductions of 7% to 40% versus placebo). However, the trials' sample sizes have prevented drawing solid conclusions. Furthermore, no analysis has focused on safety concerns (ie, hypoglycemia). Under the hypothesis that local insulin promotes healing through proangiogenic effects and cellular recruitment, the aim of this systematic review and network meta-analysis (NMA) was to assess its safety and relative effectiveness using a Bayesian approach. METHODS: Medline, CENTRAL, Embase, Scopus, LILACS, and gray literature sources were searched for human studies assessing the local use of insulin versus any comparator since inception to October of 2020. Data on glucose changes and adverse events, wound and treatment characteristics, and healing outcomes were extracted, and an NMA was conducted. RESULTS: A total of 949 reports were found, of which 23 ( n = 1240 patients) were included in the NMA. The studies evaluated six different therapies, and most comparisons were against placebo. NMA showed -1.8 mg/dL blood glucose level change with insulin and a lack of reported adverse events. Statistically significant clinical outcomes identified include reduction in wound size (-27%), increased healing rate (23 mm/day), reduction in Pressure Ulcer Scale for Healing scores (-2.7), -10 days to attain complete closure, and an odds ratio of 20 for complete wound closure with insulin use. Likewise, significantly increased neoangiogenesis (+30 vessels/mm 2 ) and granulation tissue (+25%) were also found. CONCLUSION: Local insulin promotes wound healing without significant adverse events.

Limitaciones de los estudiantes en el curso de cirugía de pregrado durante la pandemia de COVID-19.

OBJECTIVE: To know the limitations that the students encountered during the undergraduate surgery course during COVID-19 pandemic. METHOD: Through an online questionnaire, students were asked about the evaluation of the undergraduate surgery course, the limitations encountered during the course, both those perceived by themselves, and the limitations they perceived in teachers. Questions were asked about the total evaluation of the surgery course and the clinical part of the course. RESULTS: 63 students of the subject of surgery were included. The most mentioned limitations of the students were the availability of schedule and teaching material. The most mentioned limitation in relation to the teachers was the lack of technical knowledge. A relationship was found between the evaluation of the course and the interaction between the teacher and the student. CONCLUSIONS: The medical education have undergone great changes, especially the clinical part. There are several limitations in this process that can be improved by teachers and students and the perception of the quality of the course is related to the degree of interaction that teachers had with the students.

OBJETIVO: Conocer las limitaciones que los estudiantes encontraron durante el curso de pregrado de cirugía durante la pandemia de COVID-19. MÉTODO: Mediante un cuestionario en línea, se interrogó a los estudiantes acerca de la evaluación del curso de cirugía de pregrado y las limitaciones encontradas durante el curso, tanto las percibidas por ellos mismos como las que percibieron en sus maestros. Se preguntó acerca de la evaluación total del curso de cirugía y de la parte clínica del curso. RESULTADOS: Se incluyeron 63 estudiantes de la materia de cirugía. Las limitaciones de los estudiantes más mencionadas fueron la disponibilidad de horario y de material didáctico. La limitación más mencionada en relación a los maestros fue la falta de conocimientos técnicos. Se encontró relación entre la evaluación del curso y la interacción que se tuvo entre el maestro y el estudiante. CONCLUSIONES: La educación en medicina ha sufrido grandes cambios, sobre todo la parte clínica. Existen diversas limitaciones en este proceso que pueden mejorarse por parte de maestros y estudiantes, y la percepción de la calidad del curso está relacionada con el grado de interacción que los maestros tuvieron con los estudiantes.

Use of Infrared Thermal Imaging for Assessing Acute Inflammatory Changes: A Case Series.

Infrared thermal imaging is a non-contact imaging modality that captures the heat emitted by the human body. Thermal regulation or heat load to the different body parts is mainly regulated via blood supply, which is increased during inflammation. The assessment of the body's level of inflammation with pain, erythema and heat is subjective clinical measurement. Infrared imaging can be an objective tool for identifying and following inflammatory and perfusion changes, thereby helping clinicians locate and document the extent of the inflammation as well as monitor the response to treatment. As an example of this, here, we present three clinical cases where the use of thermography aided the assessment of acute inflammatory changes due to trauma, vasodilation, and allergy.

A Randomized Controlled Trial on the Effect of Local Insulin Glargine on Venous Ulcer Healing.

INTRODUCTION: To determine whether the local administration of insulin glargine compared with placebo in nondiabetic patients with venous ulcers (VUs) leads to increased wound healing. METHODS: A randomized controlled trial using a split-plot design was performed in 36 adults with leg VUs >25 cm2 and more than 3 mo of evolution. Each hemi-wound received either 10 UI insulin glargine or saline solution once a day for 7 d. Size of the wounds, thermal asymmetry, the number of blood vessels, and the percentage area of collagen content in wound biopsies were assessed at baseline and after 7 d of treatment. Blood capillary glucose was monitored once a day after the insulin injection. RESULTS: After 7 d of treatment, the hemi-wounds treated with insulin glargine were significantly smaller, had less thermal asymmetry, more blood vessels, and more collagen content than the saline-treated side. Correlation between thermal asymmetry and the number of blood vessels was also found (r2 = 66.2, P < 0.001). No patient presented capillary glucose levels ≤3.3 mmol/L nor any adverse effects. CONCLUSIONS: In nondiabetic patients with chronic VUs, the topical administration of insulin glargine seems to be safe and promotes wound healing and tissue repair after 7 d of treatment.

Postoperative inguinal pain and disability after Lichtenstein versus ONSTEP hernia repair: analysis of responses to the inguinal pain questionnaire in Spanish.

PURPOSE: To validate the Inguinal Pain Questionnaire (IPQ) in the Spanish Language and test its use in a randomized controlled trial (RCT) of hernia repair using the Lichtenstein technique vs. the ONSTEP technique. We simplified the IPQ using a principal component analysis (PCA) approach as a secondary objective. METHODS: The IPQ was translated into Spanish and validated in a cohort of 21 patients. Thereafter, 40 patients were randomized to undergo hernia repair by the Lichtenstein technique or the ONSTEP technique. IPQ and pain visual analogue (VAS) score trends over time were compared using a repeated-measures mixed-effects model. RESULTS: The Spanish version of the IPQ showed an internal consistency similar to that of the original score. No significant differences were found in the IPQ responses, pain VAS, or the rate of self-reported pain between patients who underwent the Lichtenstein technique and those who underwent the ONSTEP technique. Following PCA analysis, the number of items on the IPQ was reduced from 18 to 10. CONCLUSIONS: The Spanish version of the IPQ measures postoperative inguinal pain adequately. Based on our findings, the ONSTEP technique was not superior to the Lichtenstein technique. The simplified version of the IPQ is not significantly different from the full version and it is easier to complete. CLINICAL TRIAL REGISTRATION: NCT04138329, registered on October 24, 2019.

Diagnostic accuracy of infrared thermal imaging for detecting COVID-19 infection in minimally symptomatic patients.

INTRODUCTION: Despite being widely used as a screening tool, a rigorous scientific evaluation of infrared thermography for the diagnosis of minimally symptomatic patients suspected of having COVID-19 infection has not been performed. METHODS: A consecutive sample of 60 adult individuals with a history of close contact with COVID-19 infected individuals and mild respiratory symptoms for less than 7 days and 20 confirmed COVID-19 negative healthy volunteers were enrolled in the study. Infrared thermograms of the face were obtained with a mobile camera, and RT-PCR was used as the reference standard test to diagnose COVID-19 infection. Temperature values and distribution of the face of healthy volunteers and patients with and without COVID-19 infection were then compared. RESULTS: Thirty-four patients had an RT-PCR confirmed diagnosis of COVID-19 and 26 had negative test results. The temperature asymmetry between the lacrimal caruncles and the forehead was significantly higher in COVID-19 positive individuals. Through a random forest analysis, a cut-off value of 0.55°C was found to discriminate with an 82% accuracy between patients with and without COVID-19 confirmed infection. CONCLUSIONS: Among adults with a history of COVID-19 exposure and mild respiratory symptoms, a temperature asymmetry of ≥ 0.55°C between the lacrimal caruncle and the forehead is highly suggestive of COVID-19 infection. This finding questions the widespread use of the measurement of absolute temperature values of the forehead as a COVID-19 screening tool.

Pain Measurement through Temperature Changes in Children Undergoing Dental Extractions.

Background and Objective. Pain evaluation in children can be a difficult task, since it possesses sensory and affective components that are often hard to discriminate. Infrared thermography has previously been used as a diagnostic tool for pain detection in animals; therefore, the aim of this study was to assess the presence of temperature changes during dental extractions and to evaluate its correlation with heart rate changes as markers of pain and discomfort. Methods. Thermographic changes in the lacrimal caruncle and heart rate measurements were recorded in healthy children scheduled for dental extraction before and during the procedure and compared. Afterwards, correlation between temperature and heart rate was assessed. Results. We found significant differences in temperature and heart rate before the procedure and during the dental extraction (mean difference 4.07°C, p < 0.001, and 18.11 beats per minute, p < 0.001) and no evidence of correlation between both measurements. Conclusion. Thermographic changes in the lacrimal caruncle can be detected in patients who undergo dental extractions. These changes appear to be stable throughout time and to possess very little intersubject variation, thus making them a candidate for a surrogate marker of pain and discomfort. Future studies should be performed to confirm this claim.