Distal Skin Research Articles

Debridement: From Bloodletting to Selective Tissue Removal

In the past, bloodletting was used to “cure” almost every disease.1 The procedure was recommended in ancient civilizations by the famous healers Papyrus in Egypt and Hippocrates in Greece. Before lower limb amputations, bloodletting included the removal of a quantity of blood equal to the amount perfusing the limb that was scheduled to be removed. Bloodletting was performed for many years by barbers (hence the red-striped pole) as an extension of their razor use; later this was undertaken by surgeons.2 The bloodletting procedure remained in Dr William Osler’s classic book The Principles and Practice of Medicine until 1923.3 In modern medicine, bloodletting is still performed selectively when patients have overabundant red blood cells because of hematologic disorders. As outlined in this month’s continuing education article, several methods of modern debridement are available to wound care clinicians (biological, autolytic, mechanical, enzymatic, conservative and acute surgical) and some patients require more than one option. The most important step prior to debridement is to determine (1) if there is an adequate blood supply to heal and (2) if the cause of the wound has been corrected. If debridement is attempted surgically without first treating the cause of the wound, a larger wound is created that advantages bacterial tissue invasion and disadvantages host tissue. Conservative surgical debridement removes slough/necrotic tissue, foreign material, and bacterial surface organisms including biofilms. A biofilm contains a protective glycocalyx that is difficult for topical antimicrobial agents to penetrate. Iodine is a small molecule and penetrates biofilm glycocalyx more efficiently than silver or other larger molecular weight antiseptic agents.4 Active surgical debridement (such as bloodletting) also removes viable cells, but it is a selective process adjacent to the wound surface, creating an acute wound within the chronic wound that accelerates wound healing. In a randomized controlled study, Steed et al5 found that wound bed preparation with regular active surgical debridement was more effective for healing diabetic neurotropic foot ulcers than conservative debridement. Further, the addition of adjunctive therapy (platelet-derived growth factor) was more effective when combined with regular active surgical debridement.5 The ability to perform active surgical debridement depends on the healthcare professional’s scope of practice and expertise as well as institutional, state, or province regulations. Mechanical debridement, which refers to tissue removal by an external force, can be performed by several methods, including running water in a jet stream, whirlpool bath, shower, or syringe/catheter. In this issue of Advances, Xu and colleagues report using negative-pressure wound therapy as a mechanical debridement procedure. This procedure lasted 3 months and the time to prepare for skin grafting may have been even shorter with active surgical debridement between dressing reapplications. Sterile maggots from the green bottle fly (Lucilla sericata) ingest dead tissue, release antibacterial substances, and may eliminate antibiotic-resistant bacteria. They offer a useful alternative in the debridement toolkit if maggots can be obtained in a timely fashion and the cost is covered by the patient’s healthcare system. There is an “ick” factor for many patients, and even some professionals, that may be partly addressed by containment in a mesh bag; however, debridement is slower in a containment device versus free range activity. Leeches have also been FDA-approved to pierce distal skin with their teeth, release anticoagulant saliva, and extract blood for 20 to 45 minutes (eg, to treat a patient’s toe that has a diabetes-related microvascular clot). Autolytic debridement from dressings is slower than biologic, mechanical, or surgical debridement methods. This process can be facilitated by any moisture exchanging, non-fluid-lock dressings including calcium alginates, foams, hydrocolloids, and films. The sixth selective method of debridement is accomplished by applying an enzyme (eg, collagenase) to the wound bed. A prescription is required (enzymes are classified as drugs) and clinicians need to follow the FDA-approved product labeling regarding dosage, application, precautions, and contraindications. This method of debridement usually requires daily dressing changes and is an alternative option when methods requiring licensed clinical expertise are not available. When indicated, debridement methods are a key component of wound bed preparation.R. Gary Sibbald, MD, MEd, FRCPC, FAAD, JMElizabeth A. Ayello, PhD, MS, RN, CWON, FAAN

Association between circadian skin temperature rhythms and actigraphic sleep measures in real-life settings.

Skin temperature manipulation with little or no change in core body temperature affects sleep-wake states; however, the association of 24-hour skin temperature variation with sleep quality has not been investigated in a large-scale population. We examined the association between the circadian rhythm of distal skin temperature and sleep quality in real-life settings and aimed to provide additional evidence of the link between thermoregulation and sleep-wake states. In this cross-sectional study of 2,187 community-dwelling adults, we measured distal skin temperature at the ventral forearm at 3-minute intervals for 7 consecutive days to calculate nonparametric indicators of a circadian skin temperature rhythm, including intradaily variability, interdaily stability, and relative amplitude. Participants underwent simultaneous 7-day wrist actigraphy to objectively measure sleep quality. The association between nonparametric circadian skin temperature rhythm indicators and 7-day sleep measures was evaluated using multivariable linear regression models. Lower intradaily variability and higher interdaily stability and relative amplitude of distal skin temperature were significantly associated with higher sleep efficiency, shorter wake after sleep onset, and longer total sleep time (all P < .001). After adjusting for demographic, clinical, and environmental factors, the coefficients for the linear trend of sleep efficiency were -1.20 (95% confidence interval: -1.53, -0.87), 1.08 (95% confidence interval: 0.80-1.36), and 1.47 (95% confidence interval: 1.04-1.89) per quartile increase in intradaily variability, interdaily stability, and relative amplitude, respectively (all P < .001). Distal skin temperature with lower fluctuations and higher regularity and rhythm amplitudes was associated with better sleep quality. Our results could be applied in chronobiological interventions to improve sleep quality. Tai Y, Obayashi K, Yamagami Y, Saeki K. Association between circadian skin temperature rhythms and actigraphic sleep measures in real-life settings. J Clin Sleep Med. 2023;19(7):1281-1292.

Circadian rhythmicity in schizophrenia male patients with and without substance use disorder comorbidity

Circadian rhythmicity is associated to clinical variables that play an important role in both schizophrenia (SZ) and substance use disorders (SUD), although the characteristics of the coexistence of these two diagnoses (SZ +) remain mostly unknown. Hence, we studied a sample of 165 male patients divided in three groups each of 55, according to their diagnoses (SZ + , SZ, and SUD), as well as a healthy control (HC; n = 90) group. Alongside with sociodemographic and clinical variables, circadian rhythms were registered through a sleep–wake data structured interview, a circadian typology questionnaire, and distal skin temperature (DST) using the Thermochron iButton every 2 min during 48 h. Analyses showed that SZ + and SZ patients presented a longer sleep (delay in wake-up time) and mostly an intermediate circadian typology, while SUD patients slept less hours, displaying a morning typology. The DST showed the highest daily activation and stability for the SUD group, even when compared with the HC group. The presence of schizophrenia (SZ + and SZ) was related to a DST pattern with a reduced amplitude determined by a wakefulness impairment, which was more pronounced for SZ patients whose sleep period was adequate. The assessment of circadian rhythms in under treatment male patients with SZ should be focused on the diurnal period as a possible marker of either treatment adherence or patient's recovery, irrespective of the presence of a comorbid SUD. Further research with additional objective measures may provide knowledge transferable to therapeutic strategies and could be useful to establish possible endophenotypes in the future.

Benefits of medially based perichondrio-adipo-dermal flap in cartilage sparing prominent ear surgery

BackgroundCartilage-cutting and cartilage-sparing techniques are the two types of otoplasty procedures. Because of the significant risk of haematoma, skin necrosis, and ear deformity, cartilage-cutting techniques have been questioned. As a result; suture-based cartilage-sparing procedures such as Mustarde and Furnas suture procedures have grown in popularity. However, these techniques have a tendency for deformity recurrence due to cartilage memory and suture fatigue, as well as the possibility of suture extrusion and pinpricking sensation of the sutures. MethodsIn this study, we used a medially based adipo-dermal flap including perichondrium which is elevated from the back of the auricle to cover and support a cartilage-sparing otoplasty, thirty-four patients (14 female and 20 male) were operated using this technique. The medially based perichondrio-adipo-dermal flap is advanced anteriorly and fixed to the helical rim under cover of the distal skin flap. This procedure sought to cover the suture line preventing suture extrusion and support in the repair of the deformity preventing its recurrence. ResultsThe average operative time was 80min, ranging from 65 to 110min. The patients passed the early postoperative period uneventfully except for 2 patients; one patient (2.9%) developed haematoma, and the other patient developed a small area of necrosis on the new antihelical fold. In late the postoperative period recurrence of the deformity developed in one patient. No patients developed suture extrusion or granuloma. ConclusionThe treatment to repair prominent ears is easy and safe, with benefits such as a natural-looking antihelical fold and minimal tissue stress. The medially or proximally based adipo-dermal flap may help to lower recurrence rates and suture extrusion.

PD-L1 Enhanced by cis-Urocanic Acid on Langerhans Cells Inhibits Vγ4+ γδT17 Cells in Imiquimod-Induced Skin Inflammation

Psoriasis is an IL-23/IL-17-mediated inflammatory autoimmune dermatosis, and UVB may contribute to immunosuppression and ameliorate associated symptoms. One of the pathophysiology underlying UVB therapy is the production of cis-urocanic acid (cis-UCA) by keratinocytes. However, the detailed mechanism is yet to be fully understood. In this study, we found FLG expression and serum cis-UCA levels were significantly lower in patients with psoriasis than in healthy controls. We also noted that cis-UCA application inhibited psoriasiform inflammation through the reduction of Vγ4+ γδT17 cells in murine skin and draining lymph nodes. Meanwhile, CCR6 was downregulated on γδT17 cells, which would suppress the inflammatory reaction at a distal skin site. We revealed that the 5-hydroxytryptamine receptor 2A, the known cis-UCA receptor, was highly expressed on Langerhans cells in the skin. cis-UCA also inhibited IL-23 expression and induced PD-L1 on Langerhans cells, leading to the attenuated proliferation and migration of γδT-cells. Compared to the isotype control, α-PD-L1 treatment invivo could reverse the antipsoriatic effects of cis-UCA. PD-L1 expression on Langerhans cells was sustained through the cis-UCA-induced mitogen-activated protein kinase/extracellular signal-regulated kinase pathway. These findings uncover the cis-UCA-induced PD-L1-mediated immunosuppression on Langerhans cells, which facilitates the resolution of inflammatory dermatoses.

Hypoxia-induced CCL2/CCR2 axis in adipose-derived stem cells (ADSCs) promotes angiogenesis by human dermal microvascular endothelial cells (HDMECs) in flap tissues.

Flap expansion has become an important method widely used in wound repair and organ reconstruction. However, distal skin flap ischemic necrosis remains a problematic complication. In this study, integrative bioinformatics analyses indicated the upregulation of C-C motif chemokine ligand 2 (CCL2) and C-C motif chemokine receptor 2 (CCR2) in reperfusion-exposed skin flap tissues. In adipose-derived stem cells (ADSCs, CD90-positive, CD29-positive, CD34-negative, and CD106-negative) exposed to hypoxia, HIF-1α and CCL2 levels were significantly elevated. Conditioned medium (CM) from hypoxia-stimulated ADSCs promoted HDMEC proliferation, migration, and tube formation, partially inhibited by sh-CCL2-induced CCL2 knockdown or neutralized antibody-induced CCL2 depletion in ADSCs. Consistently, CCL2, CCR2, TNF-α, TLR2, and TLR4 protein levels in HDMECs were significantly increased by hypoxia-treated ADSCs CM, and partially decreased by sh-CCL2-induced CCL2 knockdown or neutralizing antibody-induced CCL2 knockdown in ADSCs. In the flap expansion model, ADSCs transplantation significantly improved flap survival and angiogenesis by endothelial cells in flap tissues, whereas CCL2 knockdown in ADSCs partially eliminated the improvement by ADSCs transplantation; overexpression of CCL2 in ADSCs further promoted the effects of ADSCs transplantation on skin flap. In conclusion, the CCL2/CCR2 axis in ADSCs could be induced by hypoxia, promoting HDMEC proliferation, migration, and tube formation and improving flap survival and angiogenesis in flap tissues.

Testing the circulation of expanded flaps-prevention of necrosis of expanded flaps (a clinic study).

Expanded flaps are commonly used in plastic surgery. Although expanded flaps are more resistant to hypoxia than unexpanded flaps, flap necrosis can sometimes occur, particularly with skin incisions of regular proportion. Distal skin necrosis of the expansion flap can be avoided by careful design; however, the utilization rate of the expansion flap decreases. Consequently, successfully avoiding distal skin flap necrosis remains a challenge. In this study, we designed a device for testing the circulation of the expanded flap that can decrease the risk of expanded flap necrosis, thus maximizing the use of an expanded flap. A total of 128 patients who underwent surgical repair between 2011 and 2019 and were retrospectively examined with the device for testing the circulation of the expanded flap were included in the study. The procedure included (1) making a device for testing the circulation, (2) implanting a skin expander, (3) injecting normal saline into the skin expander, (4) testing the circulation of the expanded flap, and (5) transferring the expanded flap to repair the defect. One hundred forty-eight expanded flaps were implanted in 128 patients. The expanded flap that was transferred to repair the defect had no necrosis or infection. None of the expanded flaps with separated blood supply, which could be observed during operations, revealed complications. The survival rates of the expanded flap were increased by testing the circulation of the expanded flap. Expanded flaps designed by this method showed no swelling or paleness and no obvious temperature changes. In addition, the length-to-width ratio could be extended to 3:1. Our proposed method resulted in an effective surgical procedure for the repair of tissue defects. This approach could effectively change the direction of the blood vessel of the expanded skin flap and prevent necrosis of the expanded flap, thus representing a practical way to increase the use of expanded flaps and the flap survival rate, making the whole expanded flap transfer procedure more convenient.

Infective endocarditis with systemic bacterial embolism caused by Staphylococcus aureus in a free-ranging Amami rabbit (Pentalagus furnessi)

The Amami rabbit (Pentalagus furnessi) is found only on the two islands of Amami-Ōshima and Tokunoshima in southwest Japan. It has a primitive appearance and ecology, is an evolutionarily valuable animal and has been assigned to the International Union for Conservation of Nature Red List of Threatened Species. We describe a case with mild purulent wounds on the distal digital skin of both forelimbs and multiple nodular lesions in various organs, including the heart and kidney. Microscopically, the heart lesions were characterized by disruption of the mitral valve and multifocal myocardial necrosis and abscesses due to infection with gram-positive cocci. Similar bacterial infarctions were also found in other organs, including the kidneys. The bacteria were identified as Staphylococcus aureus by immunohistochemical and molecular biological examinations. This first report of infective endocarditis and systemic infarctions caused by S.aureus in an Amami rabbit indicates the importance of monitoring purulent injuries, even if mild, to prevent secondary infections in this species.

Distal skin temperature in patients with substance use disorder: exploring sex-related differences in circadian parameters

Distal skin temperature in patients with substance use disorder: exploring sex-related differences in circadian parameters

Diabetic foot treatment using oxygen-ozone therapy.

Diabetic, arteriopathic and/or neuropathic foot, either ulcerated or not, is a major problem for any health system, requiring significant allocations of funds. The diabetic patient often gets complications, through an inadequate lifestyle or by giving up treatment, most often due to polypragmasia. Oxygen-ozone treatment has remarkable effects in patients with diabetic foot (DFN or DFU).&#x0D; A retrospective study of 50 patients with type 2 diabetes (25 with DFU and 25 with DFN), treated with oxygenozone mixture for a minimum duration of 3 months, showed the positive effect of treatment with accelerated wound healing, 70% of them having a skin lesion for more than one year. Decreased glycosylated hemoglobin, blood pressure regulation and increased distal skin sensitivity were added to the healing of skin lesions, using only oxygen-ozone therapy (systemic and local) combining personalized diet, physical activity and the correction of vitamin D levels. Most patients avoided amputation or it was minimal, only in the case of necrotic tissues without vascularization.&#x0D; The results obtained recommend the use of oxygen-ozone therapy, especially in the case of patients proposed for amputation, but especially in the prevention of the dreaded complications of diabetes.

Evaluation of distal skin temperature and tissue oxygen saturation determined by near-infrared spectroscopy for predicting ultrasound-guided lateral infraclavicular block success.

Changes in tissue oxygen saturation determined by near-infrared spectroscopy (NIRS) may help predict and determine the success of a lateral infraclavicular (LIC) block.We investigated whether evaluation of tissue oxygen saturation determined by NIRS couldbe an indicator of LIC block success. Forty patients scheduled for hand or forearm surgery under LIC block were studied. NIRS sensors were placed on the ventral aspect of both mid-forearms, and the contralateral hand was used as the control group. NIRS values were recorded before the block andat regular intervals during the following 30 min. NIRS values were significantly higher in the successfully blocked patients whencompared to the complete failure, partial failure, and contralateral hand groups at the 10thmin. In the successfully blocked patients, NIRS values (mean ± SD [change in %]) increasedby 11.09 ± 4.86 (16.03%), 15.00 ± 4.53 (21.76%), 16.35 ± 5.14 (23.77%), 16.38 ± 4.88(23.85%), 16.67 ± 5.04 (24.29%), and 16.96 ± 5.71 (24.78%), respectively, from baselineto 5, 10, 15, 20, 25, and 30 min. ΔTs values were significantly higher in the successfullyblocked patients than in the complete failure patients and contralateral hand at the 30thmin. However, there was no statistically significant difference when comparing ΔTs values ofsuccessful block and partial failure block patients at the 30th min. We conclude that measurement of tissue oxygen saturation by NIRS withinthe scope of evaluation of the lateral infraclavicular block is a rapid, effective, and applicabletechnique.

Radial Flap in Reconstructions of the Hand - Case Series Study

Abstract Radial forearm flap is an axial flap that has become an important technique in reconstructive surgery as a free flap or as a pedicled flap. Defects of the skin and other tissues on the hand are very common and most often they are work-related injuries. In deep defects, flap must be used, as well as in reconstruction of the amputated thumb. There are many flaps that provide adequate soft tissue coverage for the hand. Therefore, the aim of this paper is to present the results of the use of radial forearm flap in various reconstructions on the hand. The retrospective study included 35 patients who underwent reconstruction with radial forearm flaps due to defects of the skin and other tissues on the hand, in the period 1997-2019. Results and complications of the surgery were analyzed. The functional and aesthetic outcome was assessed using Michigan Hand Outcome Qusteionnarire. All patients were followed for a minimum of 1 year. Fasciocutaneous flap was the most commonly used (65.71%), followed by adiposofascial (20%) and osteocutaneous (14.29%). The size of the fasciocutaneous flap ranged from 2.2×3.1cm to 9×13.5cm. The majority of donor sites were closed with split-thickness skin grafts (56.52%), and less frequently with direct suture, local skin flap, and full-thickness skin graft. There were no complete flap losses in the study. Marginal necrosis was noted in 8.57%, and graft failure at the donor site in 14.29%. Secondary surgical procedures were performed in 13 patients. The functional-aesthetic result of the operation, based on the MHQ score, ranged from 31 (1/35) to 130 points (3/35). The ultimate aim of hand reconstruction is to restore sufficient function and form, also, closing the wound within three days following the injury is desirable. Meticulous intraoperative dissection of radial flap and early physical therapy after surgery are mandatory. The radial flap is a suitable method, especially for large and more distal skin defects on the hand, and a very good method for thumb reconstruction.

Cardiovascular responses to orthostasis during a simulated 3-day heatwave

Global warming has caused an increase in the frequency, duration, and intensity of summer heatwaves (HWs). Prolonged exposure to hot environments and orthostasis may cause conflicting demands of thermoregulation and blood pressure regulation on the vasomotor system, potentially contributing to cardiovascular complications and occupational heat strain. This study assessed cardiovascular and skin blood flow (SkBF) responses to orthostasis before, during and after a 3-day simulated HW. Seven male participants maintained a standard work/rest schedule for nine consecutive days split into three 3-day parts; thermoneutral pre-HW (25.4 °C), simulated HW (35.4 °C), thermoneutral post-HW. Gastrointestinal (Tgi) and skin (Tsk) temperatures, cardiovascular responses, and SkBF were monitored during 10-min supine and 10-min 60° head-up tilt (HUT). SkBF, indexed using proximal–distal skin temperature gradient (∆TskP-D), was validated using Laser-Doppler Flowmetry (LDF). The HW significantly increased heart rate, cardiac output and SkBF of the leg in supine; HUT increased SkBF of the arm and leg, and significantly affected all cardiovascular variables besides cardiac output. Significant regional differences in SkBF presented between the arm and leg in all conditions; the arm displaying vasodilation throughout, while the leg vasoconstricted in non-HW before shifting to vasodilation in the HW. Additionally, ∆TskP-D strongly correlated with LDF (r = −.78, p < 0.001). Prolonged HW exposure and orthostasis, individually, elicited significant changes in cardiovascular and SkBF variables. Additionally, varying regional blood flow responses were observed, suggesting the upper and lower vasculature receives differing vasomotor control. Combined cardiovascular alterations and shifts towards vasodilation indicate an increased challenge to industrial workers during HWs.

Reversing painful and non-painful diabetic neuropathy with the capsaicin 8% patch: Clinical evidence for pain relief and restoration of function via nerve fiber regeneration.

Current oral treatments for pain in diabetic peripheral neuropathy (DPN) do not affect the progression of DPN i.e., "disease modification." We assessed whether Capsaicin 8% patch treatment can provide pain relief and also restore nerve density and function via nerve regeneration, in both painful (PDPN) and non-painful (NPDPN) diabetic peripheral neuropathy. 50 participants with PDPN were randomized to receive Capsaicin 8% patch Qutenza with Standard of Care (SOC) (PDPN Q+SOC group), or SOC alone (PDPN SOC group). Pain symptoms were assessed with a diary (Numerical Pain Rating Scale, NRPS) and questionnaires. Investigations included quantitative sensory testing (QST) and distal calf skin biopsies, at baseline and 3 months after baseline visit; subsequent options were 3-monthly visits over 1 year. 25 participants with NPDPN had tests at baseline, and 3 months after all received Capsaicin 8% patch treatment. At 3 months after baseline, PDPN Q+SOC group had reduction in NPRS score (p = 0.0001), but not PDPN SOC group. Short-Form McGill Pain Questionnaire (SF-MPQ) showed significant reductions in scores for overall and other pain descriptors only in the PDPN Q+SOC group. Warm perception thresholds were significantly improved only in the PDPN Q+SOC group (p = 0.02), and correlated with reduction in SF-MPQ overall pain score (p = 0.04). NPDPN Q+SOC group did not report pain during the entire study. Density of intra-epidermal nerve fibers (IENF) with PGP9.5 was increased at 3 months in PDPN Q+SOC (p = 0.0002) and NPDPN Q+SOC (p = 0.002) groups, but not in the PDPN SOC group. Increased sub-epidermal nerve fibers (SENF) were observed with GAP43 (marker of regenerating nerve fibers) only in PDPN Q+SOC (p = 0.003) and NPDPN Q+SOC (p = 0.0005) groups. Pain relief in the PDPN Q+SOC group was correlated with the increased PGP9.5 IENF (p = 0.0008) and GAP43 (p = 0.004), whereas those with lack of pain relief showed no such increase; in some subjects pain relief and increased nerve fibers persisted over months. PGP9.5 IENF increase correlated with axon-reflex vasodilatation in a NPDPN Q+SOC subset (p = 0.006). Capsaicin 8% patch can provide pain relief via nerve regeneration and restoration of function in DPN (disease modification). It may thereby potentially prevent diabetic foot complications, including ulcers.

Repairing large skin defect of hand with modified dorsal metacarpal artery reverse island flap

To investigate the effectiveness of modified dorsal metacarpal artery reverse island flap based on two adjacent recurrent branches of dorsal metacarpal arteries in repairing large skin defect of the hand. Between September 2017 and March 2021, 15 cases of large skin defect of the hand were treated. There were 11 males and 4 females with an average age of 42 years (range, 24-66 years). The injury causes included machine twist injury in 6 cases, pound injury in 5 cases, and crush injury in 4 cases. The injured parts included 6 cases of finger skin defect and 9 cases of distal skin defect of palm and dorsum of hand, all of which had tendon, joint, and bone exposure. The interval from injury to operation ranged from 2 to 6 hours (mean, 4 hours). The defect sizes after thorough debridement ranged from 3.5 cm×3.0 cm to 8.0 cm×4.5 cm. The modified dorsal metacarpal artery reverse island flap with a range of 3.8 cm×3.3 cm to 9.0 cm×5.0 cm was used to repair the defect, and the flap donor site was repaired with full-thickness skin graft. All the flaps survived successfully after operation, and the wounds in the recipient site and the skin grafts in the donor site healed by first intention. All patients were followed up 9-24 months, with an average of 14 months. The appearance of the flap was good, and its texture and color were similar to those of the surrounding normal tissue. There was no obvious scar contracture, depression, and pigmentation in the donor site. At last follow-up, the static two-point discrimination of the flap was 8-20 mm, with an average of 13.6 mm. According to the Michigan Hand Outcome Questionnaire, 5 patients were very satisfied with the appearance of the flap, and 10 patients were satisfied. The modified dorsal metacarpal artery reverse island flap based on two adjacent recurrent branches of dorsal metacarpal arteries has reliable blood supply, larger harvested area, simple procedure, and minimal donor site damage, which is suitable for emergency repair of large skin defect of the hand.

The length of distal skin incision of the postero-lateral approach affects the cup inclination during the total hip arthroplasty

Aim: The primary aim of the study was to determine whether the length of the distal skin incision of the posterolateral approach affects the cup inclination during total hip arthroplasty (THA).&#x0D; Material and Method: In this study, a cohort of 71 consecutive patients who performed between January 2017 and December 2021 with unilateral THA using a posterolateral approach was retrospectively assessed. Two groups were formed according to acetabular cup inclination with normal anteversion angle. There were 56 hips in the inside group and 17 in the outside group. A curvilinear skin incision of around 13 cm was performed. Component position evaluation was carried out through a radiographic assessment of the acetabular component on an anteroposterior pelvis radiograph. The rate of an outlier was compared between groups according to the safe zone defined as 30° to 50° of inclination and 5° to 25° of anteversion, which was described by Lewinnek et al. &#x0D; Results: No significant difference in the average total incision length was found between the two groups (p=0.207). While the average distal incision length was 7.91±0.62 cm (range, 6.8-9 cm) in the inside group and 6.37±0.21 cm (range, 6-6.7 cm) in the outside group. According to ROC analysis, a patient with ≤6.7 cm of the distal length of incision (DLI) was 5.71 times more likely to be outside than a patient with &gt;6.7 cm of DLI. Seventeen hips (23.3%) were found outside the safe range. Substantial differences were observed regarding radiographic cup inclination between the two groups (p=0.0001). In the inside group, the average cup inclination was 44.11°±3.44° (range, 37°-50°), whereas, in the outside group, it was 55.41°±2.5° (range, 52°-59°). However, there were no significant differences in the average radiographic cup anteversion between the two groups (p=0.960). Although 11 of 17 (64.5%) patients were classified as obese (BMI ≥30) in the outside group experienced higher rates of inaccurate cup orientation, logistic regression analysis showed that the individual effects of obesity on the occurrence of the inaccurate cup position were not observed (p=0.884). One posterior hip dislocation occurred after one month postoperative in the outside group. &#x0D; Conclusions: Longer distal portion of the skin incision of the posterolateral approach should be performed to achieve optimal operative inclination angles of the acetabular cup during THA. The surgeon must have no hesitation in extending the distal skin incision when adopting the posterolateral approach.

Warm ears, a red flag for sleepiness?

Core body and skin temperatures are intimately linked to sleep and alertness. The distal-to-proximal skin temperature gradient has been described as a good physiological predictor for sleep onset. Increased ear skin temperature is often caused by increased blood flow reflected in redness, which is commonly noticed in people who are sleepy, especially anecdotally in children. Nonetheless, no prior study investigated the possible relation between sleepiness and ear skin temperature as a separate measurement. We assessed the relation between ear skin temperature and sleepiness in patients undergoing regular electroencephalographic examinations, because of suspicion of epilepsy, both without and after sleep deprivation. Subjective sleepiness was measured using the Stanford Sleepiness Scale, and objective sleepiness by determining sleep onset with electroencephalography. Distal, proximal and ear skin temperature were measured repeatedly using wireless measurement devices (iButtons). Forty-four adult patients were included. Ear skin temperature correlates weakly with distal skin temperature (r= 0.174, p< 0.001) and distal-to-proximal gradient (r= 0.160, p< 0.001), but not with proximal skin temperature (r= -0.001, p= 0.975). Ear skin temperature increased significantly in a subgroup of 13 patients, between 5 and 1 min before sleep onset (p= 0.002; η2 = 0.059), even though this increase was also associated with supine posture. iButtons is a valid method to measure ear skin temperature, which appears to function partly like a distal and partly like a proximal skin temperature measurement. Change in ear skin temperature is associated with sleep onset and supine posture.

Bright Light Decreases Peripheral Skin Temperature in Healthy Men: A Forced Desynchrony Study Under Dim and Bright Light (II).

Human thermoregulation is strictly regulated by the preoptic area of the hypothalamus, which is directly influenced by the suprachiasmatic nucleus (SCN). The main input pathway of the SCN is light. Here, thermoregulatory effects of light were assessed in humans in a forced desynchrony (FD) design. The FD experiment was performed in dim light (DL, 6 lux) and bright white light (BL, 1300 lux) in 8 men in a semi-randomized within-subject design. A 4 × 18 h FD protocol (5 h sleep, 13 h wake) was applied, with continuous core body temperature (CBT) and skin temperature measurements at the forehead, clavicles, navel, palms, foot soles and toes. Skin temperature parameters indicated sleep-wake modulations as well as internal clock variations. All distal skin temperature parameters increased during sleep, when CBT decreased. Light significantly affected temperature levels during the wake phase, with decreased temperature measured at the forehead and toes and increased navel and clavicular skin temperatures. These effects persisted when the lights were turned off for sleep. Circadian amplitude of CBT and all skin temperature parameters decreased significantly during BL exposure. Circadian proximal skin temperatures cycled in phase with CBT, while distal skin temperatures cycled in anti-phase, confirming the idea that distal skin regions reflect heat dissipation and proximal regions approximate CBT. In general, we find that increased light intensity exposure may have decreased heat loss in humans, especially at times when the circadian system promotes sleep.

0086 Unobtrusive Sensing of Skin Temperature During Sleep Using a Mattress Sensor

Abstract Introduction Sleep is associated with temperature changes in the human body. At sleep onset, distal (hands and feet) and proximal (abdomen) temperatures increase by ~1°C and ~0.5°C, respectively, forming a distal-to-proximal gradient that increases throughout the first half of a night’s sleep. However, core temperature decreases during this period. Few devices can measure these temperatures unobtrusively. Our aim was to estimate distal skin temperature unobtrusively during sleep using a temperature sensor array on a mattress. Methods Three male volunteers participated in the study. Skin temperatures were measured using an array of 5 equally spaced thermistors distributed laterally across the mattress region aligning with the torso. Participants wore an Empatica smart watch to provide benchmark distal skin temperatures.Data from 249 sleep hours were used to build predictive models estimating distal skin temperature. The preprocessed data were grouped by participant and segmented into training and test sets (~60%/40%, respectively), with earlier sleep sessions selected for training and later sessions selected for testing. Using the Automated Machine Learning (AutoML) feature in Databricks, a model was developed that optimized R2. This model was applied to the test set and its performance evaluated by Bland-Altman analysis, using predicted and benchmark distal temperatures. Results The AutoML selected an XGBoost decision-tree model to predict distal skin temperature for each minute. The mean difference in temperature between predicted and benchmark readings was 0.13°C (R2=0.35), with lower and upper limits of agreement (LOA) of -1.59 and 1.84, respectively. Next, all minute-level data were averaged by sleep session, and model performance was re-evaluated across all sleep sessions. This approach resulted in smaller LOAs (-0.58, 0.91), with a mean difference in temperature of 0.16°C (R2=0.73). Conclusion Our results suggest that a temperature sensor array, coupled with an optimized decision-tree model, can predict mean distal skin temperature for each sleep session with reasonable accuracy. Our system enabled unobtrusive, ecologically valid collection of distal skin temperatures during sleep and may be useful for future studies of overnight temperature dynamics. Support (If Any) This study was funded by Sleep Number Corporation. Medical writing support, by Sandra J. Page, PhD, Oxford PharmaGenesis Inc., was funded by Sleep Number Corporation.

Periocular Skin Warming Promotes Sleep Onset Through Heat Dissipation From Distal Skin in Patients With Insomnia Disorder.

Study ObjectivesPeriocular skin warming before bedtime has been demonstrated to improve subjective sleep initiation in healthy adults with sleep difficulties scored six or higher in the Pittsburgh Sleep Questionnaire Index. This study aimed to investigate the effects of periocular skin warming on sleep initiation and thermoregulation processes in patients with insomnia disorder.MethodsParticipants included those with sleep difficulty (n = 22) and those with insomnia disorder (n = 16). Individuals from both groups were assessed at baseline (habitual sleep-wake schedule) and after two intervention conditions (use of a warming eye mask or a sham eye mask before habitual bedtime). The subjective and electroencephalographic sleep onset latency, along with proximal and distal skin temperature after periocular skin warming, were evaluated.ResultsPeriocular skin warming reduced objective sleep onset latency in independently of the group. Foot temperature and foot-proximal temperature gradient after getting into bed increased with periocular skin warming in independently of the group. However, the increase in hand temperature was observed only in the insomnia disorder group. Periocular skin warming also increased the normalized high frequency component of heart rate variability in independently of the group. The reduction of objective sleep onset latency was strongly associated with heat dissipation from the foot skin region.ConclusionThese results suggest that periocular skin warming promotes sleep initiation by enhancing heat dissipation from the distal skin regions in individuals with sleep difficulty and insomnia disorder. Periocular skin warming could thus be a novel non-pharmacological therapy for insomnia disorder.