Validation of Commercially Available Infrared Thermometers for Measuring Skin Surface Temperature Associated with Deep and Surrounding Wound Infection

Use of Infrared Thermometry to Observe Temperature Variation Associated with the Healing Process in Wounds and Ulcers: TIHUAP Cohort Study Protocol

We are interested in observing how temperature differences between the wound bed and perilesional skin are related to the healing process in primary care patients with wounds. Multisite prospective cohort study with one-year follow-up in the Metropolitan North area of Barcelona. Recruitment of patients over 18 years with an open wound will take place from January 2023 to September 2023. Temperature checks will be conducted on a weekly basis at control visits and wound care. The following variables will be measured: Percentage reduction of wound area over time, thermal index, the Kundin Wound Gauge, and the Resvech 2.0 Scale. The temperature will be measured weekly using a handheld thermometer and mesh grid to frame the temperature points. The healing trajectory will also be monitored on a monthly basis via photographic imaging, the Resvech Scale, calculation of wound size, percentage reduction of wound area over time, and thermal index for one year of follow-up or until the wound is cured. This study may represent a turning point for its introduction into primary care. Early diagnosis of wound complications would facilitate treatment decision-making for healthcare professionals, thus improving the management of resources related to chronic wounds.

Clinical management of finger joint capsulitis/synovitis in a rock climber

This case study presents a 23-year-old male recreational rock climber, who climbed an average of 3-4 times per week and presented with finger joint capsulitis/synovitis after increasing his climbing intensity and training from moderate to high over 6 months, which led up to injury. During the exam, the diagnosis was ruled in with clinical orthopedic testing. Additional movement analyses revealed improper gripping mechanics contributing to asymmetric finger loading. A comprehensive rehabilitation program was developed based on the concept of a progressive framework that included unloading of the affected tissues, increasing mobility, improving muscle performance, and correcting suboptimal climbing movements. After 6 weeks, the climber's pain 24 h after climbing, which was rated on a visual analog pain scale (VAS), decreased from 5.5/10 to 1.5/10 and 0/10 at the 12-month follow-up. His patient-specific functional scale improved from 0% at the initial evaluation to 43% after 6 weeks and to 98% after 12 months. His sports-specific disabilities of the arm, shoulder, and hand improved from 69% to 34% to 6% during the initial evaluation, 6-week follow-up, and 12-month discharge. He made a full recovery to his previous grade of V8 bouldering. This is the first case study of its kind to provide a rehabilitation framework for the management of finger joint capsulitis/synovitis in a rock climber.

Effectiveness of a foot self-management intervention that utilized commercially available infrared thermometers: Mixed methods research incorporating a pilot RCT

OBJECTIVE

To evaluate the effectiveness of a foot self-management strategy that utilized a commercially-available infrared thermometer (CAIT) for prevention of diabetic foot ulcers.

RESEARCH DESIGN AND METHODS

In this six-month pilot randomized controlled trial, Phase 2 of a three-phase mixed methods research study, 62 participants were randomized to a thermometer and education group (n = 34) and an education-only group (n = 26). Both groups received foot care education and were assessed by a certified orthotist. All participants recorded their number of steps and recorded a foot assessment in a logbook daily. The thermometer and education group also recorded their daily temperature assessment. A temperature difference of >4° Fahrenheit (F) between the two feet prompted participants to rest their feet. Participants were directed to see their healthcare provider if the temperature difference did not decrease to below 4° F in two days. Phase 3 of the study explored the Phase 2 results to understand the findings further.

RESULTS

The strategy improved foot assessment and action: the thermometer and education group had significantly more days with any assessment completed than the education-only group (150.98/180 vs. 119.84/180, p = 0.02). Phase 3 findings showed that the thermometer engaged participants, prompted action, and offered reassurance regarding foot health.

CONCLUSIONS

A CAIT is a tool that could support foot self-management and may offer several benefits, such as promoting and providing structure for a foot assessment and direction for action.

CLINICAL TRIAL REG NO

NCT0306776 clinicaltrials.gov.

Infrared Thermography as a Diagnostic Tool for Peripheral Artery Disease

OBJECTIVE

The prevalence of peripheral arterial disease (PAD) is increasing worldwide. The ankle-brachial index (ABI) is considered the criterion standard of noninvasive screening, but it does have limitations. The present study aimed to clarify the clinical diagnostic potential of infrared thermography (IRT) compared with conventional noninvasive measurements for PAD.

METHODS

Patients were divided into two groups: the healthy control group (n = 93) and the PAD group (n = 164). Control participants had an ABI 0.9 to 1.4 and no former PAD diagnosis. The PAD group was divided into three subgroups based on ABI classifications and two subgroups based on toe pressure measurements. Investigators performed IRT using a standardized protocol with temperature measurements at five different foot sites.

MAIN RESULTS

Differences in skin temperatures between feet were greater (P < .001) in the PAD group than in healthy controls. In general, mean foot temperatures were lower in the PAD group than in controls but did not differ significantly among PAD subgroups based on ABI classifications or toe pressure measurements.

CONCLUSIONS

Infrared thermography effectively distinguished temperature differences between feet and thus might be diagnostically useful. However, because normal skin surface temperature varies among individuals, IRT alone cannot be recommended for evaluating PAD. However, it does have potential to provide additional information about circulation, subclinical infections, and the severity of vascular disease.

Postoperative wound assessment in cattle: How reliable is the back hand palpation?

Background

As part of clinical wound assessment in bovine surgery, discrepancies in skin temperature are evaluated by placing the back of the hand on the area to be examined. Generally, an increased skin temperature at the wound site for a prolonged period is considered as an indicator of impaired wound healing.

The aim of this study was to verify the reliability of palpation under bovine practice conditions using laparotomy as an example. Fourteen cows (German Holstein) with a left displacement of the abomasum (LDA) without other severe concurrent diseases were examined preoperatively and once daily for ten days after surgery. The skin temperature of the wound site in the right flank was assessed by palpation, followed by thermographic evaluation using an infrared camera after a 45-min acclimatisation period, under standardised conditions in a closed examination room daily for 10 days.

Results

All the incisions healed without clinical detectable perturbances. The ambient temperature range during the study period was 7.8 − 24.1 °C. Two groups were retrospectively defined according to the ambient temperature: high ambient temperature (HT group; median: 20.2 °C 25/75 quartile: 18.5 °C / 21.7 °C; n = 6) and low ambient temperature (LT group; 10.8 °C; 9.4 °C / 12.8 °C; n = 8). The temperature differences (Δϑ) between the mean skin temperature of the wound site and a defined reference area cranial to the wound were assessed. A significant negative correlation was found between the ambient temperature (ϑ_Amb) and Δϑ (r=-0.51; P < 0.001). The Δϑ was postoperatively higher in the cows in the LT group (median of the individual animals 0.8–2.5 °C) than in the HT group (0.1–0.5 °C; P < 0.05). In contrast to the thermographic findings, manual palpation rarely detected local hyperthermia (> 1 °C) at the wound site (sensitivity 0.20; specificity 0.96).

Conclusions

The infrared thermography provides a more reliable assessment of temperature changes at the wound site in comparison to manual palpation. The ambient temperature markedly affects the extent of local hyperthermia at the wound site.

Handheld infrared thermometer to evaluate cellulitis: the HI-TEC study

OBJECTIVES

Differentiating cellulitis from pseudocellulitis is challenging, and misdiagnosis leads to unnecessary antimicrobial use and increased healthcare expenditure. Clinical diagnosis remains the criterion standard and may involve expert consultation. Our objective was to evaluate the usefulness of a handheld infrared thermometer to improve diagnostic certainty in cases of suspected cellulitis.

METHODS

We conducted a cross-sectional study from August 2018 to January 2020 at a tertiary-care hospital in Montreal, Canada. We enrolled adult patients with suspected limb cellulitis. Using the infrared thermometer, we compared the average temperature of the affected area with that of the contralateral limb, and we used Youden's method to determine the optimal temperature difference which best differentiated cellulitis from pseudocellulitis as determined by an independent and blinded infectious diseases specialist. We used bootstrapping to estimate 95% confidence intervals for the sensitivity, specificity, and area under the receiver operating curve.

RESULTS

Of 65 patients screened for enrolment, 52 patients were recruited (median age: 64 years, IQR 52-76); 39 of these were diagnosed with cellulitis and 13 were not. The mean temperature difference between affected and unaffected limbs was 2.6°C (95%CI 2.1-3.1°C) for patients with cellulitis and 0.4°C (95%CI -1.2°C to 2.1°C) for patients without (p < 0.001). An average temperature difference between limbs of 0.8°C or more was 95% sensitive (95%CI 74-100%) and 69% specific (95%CI 44-95%) for the diagnosis of cellulitis (c-statistic 0.82).

CONCLUSIONS

In this proof-of-concept single-centre study, a handheld infrared thermometer was a useful aid to differentiate cellulitis from pseudocellulitis.

25-Hydroxyvitamin D Deficiency: Impacting Deep-Wound Infection and Poor Healing Outcomes in Patients With Diabetes

BACKGROUND

The Kingdom of Bahrain has a high incidence of diabetes and associated foot complications. Simultaneously, low 25-hydroxyvitamin D (25[OH]D) levels are common in this population and may be associated with the traditional clothing used in desert climates.

METHODS

This investigation compared 25(OH)D levels and glycemic control with quantifiable wound healing parameters in a prospective, analytic, nonexperimental, cross-sectional pilot study. Consecutive consenting adult patients (N = 80) who presented to the regional wound care unit in January 2016 with either an existing or new wound were included. Collected data included three-dimensional wound photography, NERDS and STONEES criteria, and an X-ray with a positive probe-to-bone test. Blood values for 25(OH)D and hemoglobin A1c (HbA1c) were collected simultaneously.

RESULTS

Diabetes mellitus (types 1 and 2) was present in 90% of the sample patients. No patient had sufficient 25(OH)D levels; 15% had insufficient levels (30-50 ng/mL), and deficiency (levels <#20 ng/mL) was found in 85% of the sample. Males were slightly less affected by 25(OH)D deficiency compared with females (82.4% vs 91.3%). Poor glycemic control (HbA1c levels >#6.8%) was found in 69.4% (n = 50) of the persons with diabetes included in the sample. Those with both diabetes mellitus and a 25(OH)D deficiency (76.3%; n = 61) were more likely to demonstrate healing difficulty (40.9%; n = 25) or present with a stalled or deteriorating wound (44.2%, n = 27). A 3° F or higher periwound surface temperature elevation over a mirror image site was present in 82.5% of all wounds. Exposed bone in the ulcer base was found in 50% of the cases. For persons with diabetes, general linear modeling statistical analysis (adjusted R value = 47.9%) linked poor wound healing with three studied variables: 25(OH)D deficiency, poor glycemic control, and an exposed bone in the wound bed.

CONCLUSIONS

Vitamin D may be an overlooked factor in the pathophysiology of diabetic foot ulcer development and subsequent delay in wound healing outcomes. The authors recommend adding 25(OH)D deficiency to the list of multifactorial aggravating factors providers should consider correcting in this subgroup of patients.

Evaluation of Systemic and Local Inflammatory Parameters and Manifestations of Pain in an Equine Experimental Wound Model

In the last decades, a well-established equine wound model has been used to study fibroproliferative wound healing disorders. The aim of this study was to characterize the degree of discomfort of wounding and sampling in an equine excisional wound model by evaluating systemic and local inflammatory responses and signs of pain. A total of 12 cutaneous wounds, three on each shoulder and each metatarsus, were created in a standing surgical procedure. Wounds were biopsied on days 2, 4, 7, 14, 21, and 28 after surgery. Clinical parameters (rectal temperature, heart rate, respiratory frequency) and blood levels of white blood cell, serum amyloid A, fibrinogen, and iron were monitored to evaluate the systemic inflammatory response. Local signs of inflammation (swelling, heat, pain) were subjectively assessed, the limb circumference recorded, and temperature of the wound measured by thermometry. Pain was evaluated by a composite measure pain scale (CMPS). The results demonstrated that the wounding procedure elicits an inflammatory response. Day 1 after surgery, two horses scored 2 and 7 units (of 27 units), respectively, on the CMPS, and day 8 after surgery, one horse scored 3 units. The biopsy procedure did not elicit local or systemic signs of inflammation. Based on these findings, it appears that the equine experimental wound model causes mild discomfort and pain manifestations. This information is important for researchers, who consider using the model. To justify the use of an animal model, it should be demonstrated that the expected benefits of the research outweigh the discomfort imposed to the animal.

Measurement of pH, exudate composition and temperature in wound healing: a systematic review

OBJECTIVE

To assess the potential of measurements of pH, exudate composition and temperature in wounds to predict healing outcomes and to identify the methods that are employed to measure them.

METHOD

A systematic review based on the outcomes of a search strategy of quantitative primary research published in the English language was conducted. Inclusion criteria limited studies to those involving in vivo and human participants with an existing or intentionally provoked wound, defined as 'a break in the epithelial integrity of the skin', and excluded in vitro and animal studies. Data synthesis and analysis was performed using structured narrative summaries of each included study arranged by concept, pH, exudate composition and temperature. The Evidence Based Literature (EBL) Critical Appraisal Checklist was implemented to appraise the quality of the included studies.

RESULTS

A total of 23 studies, three for pH (mean quality score 54.48%), 12 for exudate composition (mean quality score 46.54%) and eight for temperature (mean quality score 36.66%), were assessed as eligible for inclusion in this review. Findings suggest that reduced pH levels in wounds, from alkaline towards acidic, are associated with improvements in wound condition. Metalloproteinase-9 (MMP-9), matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase (TIMP), neutrophil elastase (NE) and albumin, in descending order, were the most frequently measured analytes in wounds. MMP-9 emerged as the analyte which offers the most potential as a biomarker of wound healing, with elevated levels observed in acute or non-healing wounds and decreasing levels in wounds progressing in healing. Combined measures of different exudate components, such as MMP/TIMP ratios, also appeared to offer substantial potential to indicate wound healing. Finally, temperature measurements are highest in non-healing, worsening or acute wounds and decrease as wounds progress towards healing. Methods used to measure pH, exudate composition and temperature varied greatly and, despite noting some similarities, the studies often yielded significantly contrasting results. Furthermore, a limitation to the generalisability of the findings was the overall quality scores of the research studies, which appeared suboptimal.

CONCLUSION

Despite some promising findings, there was insufficient evidence to confidently recommend the use of any of these measures as predictors of wound healing. pH measurement appeared as the most practical method for use in clinical practice to indicate wound healing outcomes. Further research is required to increase the strength of evidence and develop a greater understanding of wound healing dynamics.

A Study of Thermistor Performance within a Textile Structure

Textiles provide an ideal structure for embedding sensors for medical devices. Skin temperature measurement is one area in which a sensor textile could be particularly beneficial; pathological skin is normally very sensitive, making the comfort of anything placed on that skin paramount. Skin temperature is an important parameter to measure for a number of medical applications, including for the early detection of diabetic foot ulcer formation. To this end an electronic temperature-sensor yarn was developed by embedding a commercially available thermistor chip into the fibres of a yarn, which can be used to produce a textile or a garment. As part of this process a resin was used to encapsulate the thermistor. This protects the thermistor from mechanical and chemical stresses, and also allows the sensing yarn to be washed. Building off preliminary work, the behaviour and performance of an encapsulated thermistor has been characterised to determine the effect of encapsulation on the step response time and absolute temperature measurements. Over the temperature range of interest only a minimal effect was observed, with step response times varying between 0.01–0.35 s. A general solution is presented for the heat transfer coefficient compared to size of the micro-pod formed by the encapsulation of the thermistor. Finally, a prototype temperature-sensing sock was produced using a network of sensing yarns as a demonstrator of a system that could warn of impending ulcer formation in diabetic patients.

5th Congress of WUWHS Abstract book Florence, Italy September 25–29 2016

The abstract book contains the abstracts of keynote lectures, focus sessions, symposia, workshops, AIUC annual meeting, AISLEC annual meeting, EPUAP annual meeting, ETRS special session, sponsor symposia, oral presentations, poster presentations and the subject index.

Looking Beyond the Cell in Cellulitis

BACKGROUND

Patients with erythematous skin are likely to receive a diagnosis of cellulitis; however, the accuracy of this diagnosis is approximately only 33%. The diagnosis of cellulitis should be made only after a thorough evaluation of all possible differential diagnoses. Cellulitis may be a primary process (superficial spreading infective process involving only the epidermis and dermis) versus a secondary (reactive) process incited by a subcutaneous process, such as an abscess, tenosynovitis, necrotizing fasciitis, and osteomyelitis.

CASE PRESENTATION

A 50-year-old man was admitted to a general hospital with the diagnosis of cellulitis. He was initially treated with systemic antibiotics without improvement. Following consultation with a wound management physician, the patient received a diagnosis of a pretibial abscess and was treated with surgical evacuation and postoperative systemic antibiotic therapy guided by tissue cultures. A postoperative wound was successfully treated with inelastic compression therapy.

CONCLUSIONS

This case demonstrates the potential for misdiagnosis when evaluating erythematous skin. Furthermore, concluding that the erythema is due to a primary cellulitis may result in monotherapy with systemic antimicrobial agents. In such cases, making a correct diagnosis through a skillful and complete physical examination of the patient, coupled with appropriate investigations, will lead to the best possible outcome. A comprehensive treatment approach may include systemic antimicrobials, as well as surgical options and compression therapy.

Heat delays skin wound healing in mice

In vivo studies have shown that the combination of infrared radiation (IR) and visible light (VIS) is responsible for the activation of metaloproteinases, causing matrix degradation and damage to healthy skin. However, the role of heat originating from the VIS spectrum on wound healing remains poorly understood. Our objective was to investigate the macroscopic, microscopic and biochemical effects of heat induced by visible light on cutaneous wound healing in mice. Male mice were anesthetized, subjected to a cutaneous excisional wound and divided into two groups ( n = 10/group) exposed to 23℃ or 43℃ in a thermal chamber for 30 min every other day, for 13 days. On day 14, the animals were sacrificed, and their lesions were processed for histochemistry, immunohistochemistry and protein expression analysis. The wound area was 42% greater 11 days ( p < 0.01) and 29% greater 14 days ( p < 0.001) after wounding in the 43℃ group than in the 23℃ group. The 43℃ group presented a lower (17%) percentage of reepithelialized wounds ( p < 0.001) 14 days after wounding. The length of the epidermal gap was greater in the 43℃ group ( p < 0.01). The volume density of myofibroblasts and the number of F4/80-positive macrophages was greater in the 43℃ group ( p < 0.05). The 43℃ group showed increased protein expression of type III collagen ( p < 0.001), decreased protein expression of type I collagen ( p < 0.05), increased MMP-1 expression ( p < 0.05), and decreased MMP-2 activity ( p < 0.001). The protein expression of fibrillin-1 ( p < 0.001), MMP-12 ( p < 0.05), TGF-β 1/2/3 ( p < 0.01) and ERK activation ( p < 0.05) was increased in the 43℃ group. Our results suggest that heat delays the stages of wound healing in mice.