Wound Bed Preparation 2024: Delphi Consensus on Foot Ulcer Management in Resource-Limited Settings.

GENERAL PURPOSE: To review a practical and scientifically sound application of the wound bed preparation model for communities without ideal resources. TARGET AUDIENCE: This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and registered nurses with an interest in skin and wound care. LEARNING OBJECTIVES/OUTCOMES: After participating in this educational activity, the participant will:1. Summarize issues related to wound assessment.2. Identify a class of drugs for the treatment of type II diabetes mellitus that has been shown to improve glycemia, nephroprotection, and cardiovascular outcomes.3. Synthesize strategies for wound management, including treatment in resource-limited settings.4. Specify the target time for edge advancement in chronic, healable wounds.

Chronic wound management in low-resource settings deserves special attention. Rural or underresourced settings (ie, those with limited basic needs/healthcare supplies and inconsistent availability of interprofessional team members) may not have the capacity to apply or duplicate best practices from urban or abundantly-resourced settings. The authors linked world expertise to develop a practical and scientifically sound application of the wound bed preparation model for communities without ideal resources. A group of 41 wound experts from 15 countries reached a consensus on wound bed preparation in resource-limited settings. Each statement of 10 key concepts (32 substatements) reached more than 88% consensus. The consensus statements and rationales can guide clinical practice and research for practitioners in low-resource settings. These concepts should prompt ongoing innovation to improve patient outcomes and healthcare system efficiency for all persons with foot ulcers, especially persons with diabetes.

Improvements in Orthostatic Tolerance with Exercise Are Augmented by Heat Acclimation: A Randomized Controlled Trial.

INTRODUCTION: Heat adaptation is protective against heat illness; however, its role in heat syncope, due to reflex mechanisms, has not been conclusively established. The aim of this study was to evaluate if heat acclimation (HA) was protective against heat syncope and to ascertain underlying physiological mechanisms. METHODS: Twenty (15 males, 5 females) endurance-trained athletes were randomized to either 8 d of mixed active and passive HA (HEAT) or climatically temperate exercise (CONTROL). Before, and after, the interventions participants underwent a head up tilt (HUT) with graded lower body negative pressure (LBNP), in a thermal chamber (32.0 ± 0.3°C), continued until presyncope with measurement of cardiovascular parameters. Heat stress tests (HST) were performed to determine physiological and perceptual measures of HA. RESULTS: There was a significant increase in orthostatic tolerance (OT), as measured by HUT/LBNP, in the HEAT group (preintervention; 28 ± 9 min, postintervention; 40 ± 7 min) compared with CONTROL (preintervention; 30 ± 8 mins, postintervention; 33 ± 5 min) ( P = 0.01). Heat acclimation resulted in a significantly reduced peak and mean rectal and skin temperature ( P < 0.01), peak heat rate ( P < 0.003), thermal comfort ( P < 0.04), and rating of perceived exertion ( P < 0.02) during HST. There was a significantly increased plasma volume (PV) in the HEAT group in comparison to CONTROL ( P = 0.03). CONCLUSIONS: Heat acclimation causes improvements in OT and is likely to be beneficial in patients with heat exacerbated reflex syncope. Heat acclimation-mediated PV expansion is a potential physiological mechanism underlying improved OT.

The effect of water temperature on orthostatic tolerance: a randomised crossover trial.

PURPOSE: Bolus water drinking, at room temperature, has been shown to improve orthostatic tolerance (OT), probably via sympathetic activation; however, it is not clear whether the temperature of the water bolus modifies the effect on OT or the cardiovascular responses to orthostatic stress. The aim of this study was to assess whether differing water temperature of the water bolus would alter time to presyncope and/or cardiovascular parameters during incremental orthostatic stress. METHODS: Fourteen participants underwent three head-up tilt (HUT) tests with graded lower body negative pressure (LBNP) continued until presyncope. Fifteen minutes prior to each HUT, participants drank a 500 mL bolus of water which was randomised, in single-blind crossover fashion, to either room temperature water (20 °C) (ROOM), ice-cold water (0-3 °C) (COLD) or warm water (45 °C) (WARM). Cardiovascular parameters were monitored continuously. RESULTS: There was no significant difference in OT in the COLD (33 ± 3 min; p = 0.3321) and WARM (32 ± 3 min; p = 0.6764) conditions in comparison to the ROOM condition (31 ± 3 min). During the HUT tests, heart rate and cardiac output were significantly reduced (p < 0.0073), with significantly increased systolic blood pressure, stroke volume, cerebral blood flow velocity and total peripheral resistance (p < 0.0054), in the COLD compared to ROOM conditions. CONCLUSIONS: In healthy controls, bolus cold water drinking results in favourable orthostatic cardiovascular responses during HUT/LBNP without significantly altering OT. Using a cold water bolus may result in additional benefits in patients with orthostatic intolerance above those conferred by bolus water at room temperature (by ameliorating orthostatic tachycardia and enhancing vascular resistance responses). Further research in patients with orthostatic intolerance is warranted.

Relative changes in brain and kidney biomarkers with Exertional Heat Illness during a cool weather marathon.

BACKGROUND: Medical personnel may find it challenging to distinguish severe Exertional Heat Illness (EHI), with attendant risks of organ-injury and longer-term sequalae, from lesser forms of incapacity associated with strenuous physical exertion. Early evidence for injury at point-of-incapacity could aid the development and application of targeted interventions to improve outcomes. We aimed to investigate whether biomarker surrogates for end-organ damage sampled at point-of-care (POC) could discriminate EHI versus successful marathon performance. METHODS: Eight runners diagnosed as EHI cases upon reception to medical treatment facilities and 30 successful finishers of the same cool weather marathon (ambient temperature 8 rising to 12 ºC) were recruited. Emerging clinical markers associated with injury affecting the brain (neuron specific enolase, NSE; S100 calcium-binding protein B, S100ß) and renal system (cystatin C, cysC; kidney-injury molecule-1, KIM-1; neutrophil gelatinase-associated lipocalin, NGAL), plus copeptin as a surrogate for fluid-regulatory stress, were sampled in blood upon marathon collapse/completion, as well as beforehand at rest (successful finishers only). RESULTS: Versus successful finishers, EHI showed significantly higher NSE (10.33 [6.37, 20.00] vs. 3.17 [2.71, 3.92] ug.L-1, P<0.0001), cysC (1.48 [1.10, 1.67] vs. 1.10 [0.95, 1.21] mg.L-1, P = 0.0092) and copeptin (339.4 [77.0, 943] vs. 18.7 [7.1, 67.9] pmol.L-1, P = 0.0050). Discrimination of EHI by ROC (Area-Under-the-Curve) showed performance that was outstanding for NSE (0.97, P<0.0001) and excellent for copeptin (AUC = 0.83, P = 0.0066). CONCLUSIONS: As novel biomarker candidates for EHI outcomes in cool-weather endurance exercise, early elevations in NSE and copeptin provided sufficient discrimination to suggest utility at point-of-incapacity. Further investigation is warranted in patients exposed to greater thermal insult, followed up over a more extended period.

Growth factors for treating chronic venous leg ulcers: A systematic review and meta-analysis.

Chronic venous leg ulcers (VLU) are wounds that commonly occur due to venous insufficiency. Many growth factors have been introduced over the past two decades to treat VLU. This systematic review and meta-analysis evaluates the impact of growth factor treatments of VLU in comparison to control for complete wound healing, percent reduction in wound area, time to wound healing, and adverse events. A systematic review and meta-analysis of randomised trials was conducted. MEDLINE and EMBASE were searched up to December 2020. Studies were included if they compared a growth factor versus placebo or standard care in patients with VLU. From 1645 articles, 13 trials were included (n = 991). There was a significant difference between any growth factor and placebo in complete wound healing (P = 0.04). Any growth factor compared to placebo significantly increased the likelihood of percent wound reduction by 48.80% (P = <0.00001). There was no difference in overall adverse event rate. Most comparisons have low certainty of evidence according to Grading of Recommendations, Assessment, Development, and Evaluation. This meta-analysis suggests that growth factors have a beneficial effect in complete wound healing of VLU. Growth factors may also increase percent reduction in wound area. The suggestion of benefit for growth factors identified in this review is not a strong one based on the low quality of evidence.

What do environment-related illnesses tell us about the character of military medicine and future clinical requirements?

Extreme environments present medical and occupational challenges that extend beyond generic resuscitation, to formulating bespoke diagnoses and prognoses and embarking on management pathways rarely encountered in civilian practice. Pathophysiological complexity and clinical uncertainty call for military physicians of all kinds to balance intuition with pragmatism, adapting according to the predominant patterns of care required. In an era of smaller operational footprints and less concentrated clinical experience, proposals aimed at improving the systematic care of Service Personnel incapacitated at environmental extremes must not be lost to corporate memory. These general issues are explored in the particular context of thermal stress and metabolic disruption. Specific focus is given to the accounts of military physicians who served on large-scale deployments into the heat of Iraq and Kuwait (Operation TELIC) and Oman (Exercise SAIF SAREEA). Generalisable insights into the enduring character of military medicine and future clinical requirements result.

Safer care for patients with adrenal insufficiency: weighing the evidence, balancing risks and acknowledging uncertainties.

The National Patient Safety Alert supporting early recognition and treatment of adrenal crisis is a vital new component of care for adults affected by primary adrenal insufficiency. Benefits for patients with secondary and tertiary adrenal insufficiency need to be weighed alongside other considerations such as security of the diagnosis, relative likelihood of adrenal crisis and potential for anxiety and distress from assigning 'physical dependency' in relation to glucocorticoid therapy. All clinicians must be vigilant for and responsive to managing risks of adrenal crisis in at-risk patients, while avoiding diagnostic anchoring in the context of acute illness. More research is required to help define who is at greatest risk of adverse outcomes (including avoidance of therapeutic glucocorticoid therapy for fear of adrenal insufficiency) and a cross-specialty approach is advocated.

Changes in gastrointestinal cell integrity after marathon running and exercise-associated collapse.

PURPOSE: Endurance exercise and hyperthermia are associated with compromised intestinal permeability and endotoxaemia. The presence of intestinal fatty acid-binding protein (I-FABP) in the systemic circulation suggests intestinal wall damage, but this marker has not previously been used to investigate intestinal integrity after marathon running. METHODS: Twenty-four runners were recruited as controls prior to completing a standard marathon and had sequential I-FABP measurements before and on completion of the marathon, then at four and 24 h later. Eight runners incapacitated with exercise-associated collapse (EAC) with hyperthermia had I-FABP measured at the time of collapse and 1 hour later. RESULTS: I-FABP was increased immediately on completing the marathon (T0; 2593 ± 1373 ng·l-1) compared with baseline (1129 ± 493 ng·l-1; p < 0.01) in the controls, but there was no significant difference between baseline and the levels at four hours (1419 ± 1124 ng·l-1; p = 0.7), or at 24 h (1086 ± 302 ng·l-1; p = 0.5). At T0, EAC cases had a significantly higher I-FABP concentration (15,389 ± 8547 ng.l-1) compared with controls at T0 (p < 0.01), and remained higher at 1 hour after collapse (13,951 ± 10,476 ng.l-1) than the pre-race control baseline (p < 0.05). CONCLUSION: I-FABP is a recently described biomarker whose presence in the circulation is associated with intestinal wall damage. I-FABP levels increase after marathon running and increase further if the endurance exercise is associated with EAC and hyperthermia. After EAC, I-FABP remains high in the circulation for an extended period, suggesting ongoing intestinal wall stress.

Echocardiographic changes following active heat acclimation.

Heat adaption through acclimatisation or acclimation improves cardiovascular stability by maintaining cardiac output due to compensatory increases in stroke volume. The main aim of this study was to assess whether 2D transthoracic echocardiography (TTE) could be used to confirm differences in resting echocardiographic parameters, before and after active heat acclimation (HA). Thirteen male endurance trained cyclists underwent a resting blinded TTE before and after randomisation to either 5 consecutive daily exertional heat exposures of controlled hyperthermia at 32°C with 70% relative humidity (RH) (HOT) or 5-days of exercise in temperate (21°C with 36% RH) environmental conditions (TEMP). Measures of HA included heart rate, gastrointestinal temperature, skin temperature, sweat loss, total non-urinary fluid loss (TNUFL), plasma volume and participant's ratings of perceived exertion (RPE). Following HA, the HOT group demonstrated increased sweat loss (p = 0.01) and TNUFL (p = 0.01) in comparison to the TEMP group with a significantly decreased RPE (p = 0.01). On TTE, post exposure, there was a significant comparative increase in the HOT group in left ventricular end diastolic volume (p = 0.029), SV (p = 0.009), left atrial volume (p = 0.005), inferior vena cava diameter (p = 0.041), and a significant difference in mean peak diastolic mitral annular velocity (e') (p = 0.044). Cardiovascular adaptations to HA appear to be predominantly mediated by improvements in increased preload and ventricular compliance. TTE is a useful tool to demonstrate and quantify cardiac HA.

Post-exertional increase in first-phase ejection fraction in recreational marathon runners.

OBJECTIVES: Running a marathon has been equivocally associated with acute changes in cardiac performance. First-phase ejection fraction is a novel integrated echocardiographic measure of left ventricular contractility and systo-diastolic coupling which has never been studied in the context of physical activity. The aim of this study was to assess first-phase ejection fraction following recreational marathon running along with standard echocardiographic indices of systolic and diastolic function.Design and participants: Runners (n = 25, 17 males), age (mean ± standard deviation) 39 ± 9 years, were assessed before and immediately after a marathon race which was completed in 4 h, 10 min ± 47 min. MAIN OUTCOME MEASURES: Central hemodynamics were estimated with applanation tonometry; cardiac performance was assessed using standard M-mode two-dimensional Doppler, tissue-doppler imaging and speckle-tracking echocardiography. First-phase ejection fraction was calculated as the percentage change in left ventricular volume from end-diastole to the time of peak aortic blood flow. RESULTS: Conventional indices of systolic function and cardiac performance were similar pre- and post-race while aortic systolic blood pressure decreased by 9 ± 8 mmHg (P < 0.001) and first-phase ejection fraction increased by approximately 48% from 16.3 ± 3.9% to 22.9 ± 2.5% (P < 0.001). The ratio of left ventricular transmitral Doppler early velocity (E) to tissue-doppler imaging early annular velocity (e') increased from 5.1 ± 1.8 to 6.2 ± 1.3 (P < 0.01). CONCLUSION: In recreational marathon runners, there is a marked increase in first-phase ejection fraction after the race despite no other significant change in cardiac performance or conventional measure of systolic function. More detailed physiological studies are required to elucidate the mechanism of this increase.

Biomarker directed chronic wound therapy - A new treatment paradigm.

AIM: To develop a treatment paradigm for chronic leg ulcers that incorporates new biomarkers of wound healing with currently available therapies. METHODS: Recently published data on GM-CSF and MMP-13 as biomarkers of venous leg ulcer (VLU) healing status with accuracies of 92% and 78% respectively, was reviewed along with the wound bed preparation (WBP) theoretical framework for treatment of chronic wounds. The broad categories of wound treatments that align with the WBP concepts were identified. These were then considered in a hierarchical order that initially improves the wound bed and subsequently incorporates more complex advanced wound therapies. Identification of the non-healing status of the wound is the driver to advance through the different treatments. RESULTS: A point of care test of wound healing status is the key to the systematic use of currently available therapies for chronic leg ulcers in a timely fashion. The different therapies address - debridement, moisture control, bacterial contamination, protease inhibition, formation of granulation tissue, application of growth factors, application of matrix constructs, and application of cellular components. Progression through this hierarchical order of therapies is directed by the leg ulcer remaining in a non-healing state with the previous therapies having been implemented. CONCLUSION: Combining a validated point of care test of wound healing with a systematic approach to wound therapies, has the potential to create a new paradigm of chronic leg ulcer treatment - biomarker directed wound therapy.

A Scoping Review on the Use of Antibiotic-Impregnated Beads and Applications to Vascular Surgery.

INTRODUCTION: Surgical site infection (SSI) presents a ubiquitous concern to surgical specialties, especially in the presence of prosthetic material. Antibiotic-impregnated beads present a novel and evolving means to combat this condition. This review aims to analyze the quality of evidence and methods of antibiotic bead use, particularly for application within vascular surgery. METHODS: A systematic scoping review was conducted within Embase, MEDLINE, and the Cochrane Registry of Randomized Controlled Trials. Articles were evaluated by 2 independent reviewers. Level of evidence was evaluated using the Oxford Center for Evidence-Based Medicine Criteria and the Cochrane Risk of Bias Tool for Randomized Controlled Trials. RESULTS: The search yielded 6951 papers, with 275 included for final analysis. Publications increased in frequency from 1978 to the present. The most common formulation was polymethyl methacrylate; however publications on biodegradable formulations, including calcium sulfate beads, have been published with increasing frequency. Most publications had positive conclusions (94.2%); however, the data was mainly subjective and may be prone to publication bias. Only 11 randomized controlled trials were identified and all but one was evaluated to be at a high risk of bias. The most common indication was for osteomyelitis (52%), orthopedic prosthetic infections (20%), and trauma (9%). Within vascular surgery, beads have been used primarily for the treatment of graft infection, with freedom from recurrence rates being reported from 41% to 87.5%. CONCLUSIONS: Antibiotic-impregnated beads provide a means to deliver high doses of antibiotic directly to a surgical site, without the risks of parenteral therapy. There has yet to be significant high-level quality data published on their use. There is a large body of evidence that suggests antibiotic beads may be used in SSIs in high-risk patients, prosthetic infections, and other complex surgical infections. Important potential areas of application in vascular surgery include graft infection, prevention of wound infection in high-risk patients, and diabetic foot infection.

Adapting the Social-Ecological Framework for Chronic Pain Management and Successful Opioid Tapering.

CONTEXT: In 2015, Solano County's Medi-Cal insurer implemented a new policy to taper patients using high-dose opioids (≥120-mg morphine equivalent dose) to a safer level to follow best practices to address the opioid epidemic. OBJECTIVE: To evaluate the effect of the 2015 Solano County Medi-Cal prescribing policy, gain insight into the patient experience of undergoing opioid tapering, and generate hypotheses for further study. METHODS: Using a case series approach, researchers completed medical record reviews of affiliated clinical records, Solano County Vital Statistics, and California's prescription monitoring program in 2018. After exclusions, eligible patients were asked to participate in a comprehensive qualitative interview. RESULTS: Medical record reviews of 38 patients found the majority were not using opioids using them at a morphine equivalent dose of 90 mg or less. The reviews also found that mental illness and obesity prevalence were higher than Solano county baseline levels. Furthermore, naloxone was not prescribed to any of the 38 patients. Researchers reached 15 of the 38 patients by phone, and ultimately 6 completed the interview process. Themes and emergent concepts from interviews identified a lack of empathetic connection with health care professionals, poor understanding of overdose risks, persistent pain, and confirmed naloxone underuse. CONCLUSION: Safer prescribing policies may take multiple years to fully implement and need to be employed across the jurisdiction to minimize doctor-shopping and adverse effects on patients with chronic pain. Approaching pain management through the social-ecological model can address potential root causes of addiction and establish a framework for doctors to provide compassionate care, community leadership, and advocacy for these patients.

Variation in renal responses to exercise in the heat with progressive acclimatisation.

OBJECTIVES: To investigate changes in renal status from exercise in the heat with acclimatisation and to evaluate surrogates markers of Acute Kidney Injury. DESIGN: Prospective observational cohort study. METHODS: 20 male volunteers performed 60 min standardised exercise in the heat, at baseline and on four subsequent occasions during a 23-day acclimatisation regimen. Blood was sampled before and after exercise for serum creatinine, copeptin, interleukin-6, normetanephrine and cortisol. Fractional excretion of sodium was calculated for corresponding urine samples. Ratings of Perceived Exertion were reported every 5 min during exercise. Acute Kidney Injury was defined as serum creatinine rise ≥26.5 µmol L-1 or fall in estimated glomerular filtration rate >25%. Predictive values of each candidate marker for developing Acute Kidney Injury were determined by ROC analysis. RESULTS: From baseline to Day 23, serum creatinine did not vary at rest, but showed a significant (P<0.05) reduction post-exercise (120 [102, 139] versus 102 [91, 112] µmol L-1). Acute Kidney Injury was common (26/100 exposures) and occurred most frequently in the unacclimatised state. Log-normalised fractional excretion of sodium showed a significant interaction (exercise by acclimatization day), with post-exercise values tending to rise with acclimatisation. Ratings of Perceived Exertion predicted AKI (AUC 0.76, 95% confidence interval 0.65-0.88), performing at least as well as biochemical markers. CONCLUSIONS: Heat acclimatization is associated with reduced markers of renal stress and AKI incidence, perhaps due to improved regional perfusion. Acclimatisation and monitoring Ratings of Perceived Exertion are practical, non-invasive measures that could help to reduce renal injury from exercise in the heat.

Evaluation of wound fluid biomarkers to determine healing in adults with venous leg ulcers: A prospective study.

Clinical practice guidelines recommend using repeated wound surface area measurements to determine if a chronic ulcer is healing. This results in delays in determining the healing status. This study aimed to evaluate whether any of a panel of biomarkers can determine the healing status of chronic venous leg ulcers. Forty-two patients with chronic venous leg ulcers had their wound measured and wound fluid collected at weekly time points for 13 weeks. Wound fluid was analyzed using multiplex enzyme-linked immunosorbent assay to determine the concentration of biomarkers in the wound fluid at each weekly time point. Healing status was determined by examining the change in wound size at the previous and subsequent weeks. Predictive accuracy with 95% confidence intervals (CI) is reported. Of 42 patients, 105 evaluable weekly time points were obtained, with 32 classified as healing, 27 as nonhealing, and 46 as indeterminate. Thirteen biomarkers significantly differed between healing and nonhealing wounds (p < 0.1) and were included in a multivariate logistic regression model. Granulocyte macrophage-colony stimulating factor (p < 0.001) and matrix metalloprotease-13 (p = 0.004) were the best predictors of wound healing. Receiver operating characteristic curves indicated 92% accuracy (95% CI: 85%,100%) for granulocyte macrophage-colony stimulating factor, and 78% accuracy (95% CI: 65%,90%) for matrix metalloprotease-13 in discriminating between healing and nonhealing wounds. This study found that two biomarkers from wound fluid can predict healing status in chronic venous leg ulcers. These findings may lead to the ability to determine the future trajectory of a wound and the ability to modify treatment accordingly.

Steroids in cardiac surgery trial: a substudy of surgical site infections.

PURPOSE: Postoperative infection, particularly in cardiac surgery, results in significant morbidity, mortality, and healthcare cost. Identification of novel predictors of postoperative infection can target high-risk populations for prophylactic intervention. METHODS: Steroids in cardiac surgery (SIRS) was a multi-centre randomized-controlled trial assessing intraoperative administration of methylprednisone during cardiac surgery, which enrolled 7,507 patients across 80 centres in 18 countries. It demonstrated that administration of steroids had no effect on mortality or major morbidity after cardiac surgery. Our primary objective was to identify risk factors for postoperative surgical site infections using SIRS participants as a cohort. We excluded patients who did not undergo surgery, died intraoperatively, or died within 48 hr of the operation. Patients were assessed for development of "surgical site infection" over the first 30 days postoperatively. Using theoretical and previously identified risk factors, we used forward stepwise entry to create a binary logistic regression model. RESULTS: Follow-up at 30 days was complete for all patients; 7,406 were included in the cohort. Surgical site infection occurred in 180 (4.8%) and 184 (5.0%) of patients in the placebo and steroid arms respectively. Significant risk factors (P < 0.05 level) included: diabetes managed with insulin (adjusted odds ratio [aOR]: 1.55; 95% confidence interval [CI] 1.13 to 2.12), oral hypoglycemics (aOR 1.60; 95% CI 1.18 to 2.16), or diet (aOR 1.81; 95% CI 1.16 to 2.83), female sex (aOR 1.34; 95% CI 1.05 to 1.71), renal failure with (aOR 2.03; 95% CI 1.06 to 3.91), and without (aOR 1.50; 95% CI 1.04 to 2.14) dialysis, > 96 min cardiopulmonary bypass (CPB) time (aOR 1.84; 95% CI 1.44 to 2.35), body mass index (BMI) < 22.3 (aOR 0.44; 95% CI 0.28 to 0.71) or > 30 (aOR 1.49; 95% CI 1.17 to 1.89), peak intensive care unit blood glucose (aOR 1.02 per mmol·L-1; 95% CI 1.00 to 1.04), and coronary artery bypass grafting (CABG) operation type (aOR 2.59; 95% CI 1.87 to 3.59). CONCLUSIONS: Patients undergoing CABG, requiring longer CPB, with higher BMI, or with diabetes, are at elevated risk of surgical site infection. Strategies to mitigate this risk warrant further investigation.

RéSUMé: OBJECTIF: L'infection postopératoire, en particulier en chirurgie cardiaque, entraîne une morbidité, une mortalité et des coûts en soins de santé significatifs. L'identification de nouveaux éléments prédictifs de l'infection postopératoire permettrait de cibler les populations à risque élevé pour offrir une intervention prophylactique. MéTHODES: L'étude des corticostéroïdes en chirurgie cardiaque (SIRS) était un essai multicentrique, randomisé et contrôlé évaluant l'administration de méthylprednisolone en peropératoire au cours de la chirurgie cardiaque; l'étude avait inclus 7 507 patients dans 80 centres répartis dans 18 pays. Elle a démontré que l'administration de stéroïdes n'avait aucun effet sur la mortalité ou morbidité majeure après la chirurgie cardiaque. Notre objectif principal était d'identifier les facteurs de risque d'infections postopératoires du site chirurgical en utilisant une cohorte constituée des participants à l'étude SIRS. Nous avons exclu les patients n'ayant pas subi de chirurgie, décédés en cours d'intervention ou dans les 48 heures suivant l'intervention. Les patients ont été évalués en fonction de l'apparition d'une « infection du site chirurgical ¼ au cours des 30 premiers jours postopératoires. Utilisant des facteurs de risque théoriques et précédemment identifiés, nous avons utilisé une introduction par étape ascendante pour créer un modèle de régression logistique binaire. RéSULTATS: Le suivi à 30 jours a été complet pour tous les patients; 7 406 patients ont été inclus dans la cohorte. Une infection du site chirurgical est survenue chez 180 (4,8 %) et 184 (5,0 %) des patients dans, respectivement, le groupe placebo et le groupe corticostéroïdes. Les facteurs de risque significatifs (pour P < 0,05) étaient notamment : un diabète géré avec de l'insuline (rapport de cotes ajusté [aOR] : 1,55; intervalle de confiance [IC] à 95 % : 1,13 à 2,12), les hypoglycémiants par voie orale (aOR : 1,60; IC à 95 % 1,18 à 2,16) ou un régime alimentaire (aOR : 1,81; IC à 95 % : 1,16 à 2,83), le sexe fémnin (aOR : 1,34; IC à 95 % : 1,05 à 1,71), une insuffisance rénale avec (aOR : 2,03; IC à 95 % : 1,06 à 3,91) et sans (aOR : 1,50; IC à 95 % : 1,04 à 2,14) dialyse, une durée de circulation extracorporelle (CEC) > 96 minutes (aOR : 1,84; IC à 95 % : 1,44 à 2,35), un indice de masse corporelle (IMC) < 22,3 (aOR : 0,44; IC à 95 % : 0,28 à 0,71) ou > 30 (aOR : 1,49; IC à 95 % : 1,17 à 1,89), un pic d'hyperglycémie en unité de soins intensifs (aOR : 1,02 par mmol·L−1; IC à 95 % : 1,00 à 1,04) et une intervention de type pontage coronarien (aOR : 2,59; IC à 95 % : 1,87 à 3,59). CONCLUSIONS: Les patients subissant des pontages coronariens, nécessitant une CEC prolongée, avec un IMC plus élevé ou un diabète sont à plus grand risque d'infection du site chirurgical. Des stratégies de limitation de ce risque justifient des investigations complémentaires.

Heat Adaptation in Military Personnel: Mitigating Risk, Maximizing Performance.

The study of heat adaptation in military personnel offers generalizable insights into a variety of sporting, recreational and occupational populations. Conversely, certain characteristics of military employment have few parallels in civilian life, such as the imperative to achieve mission objectives during deployed operations, the opportunity to undergo training and selection for elite units or the requirement to fulfill essential duties under prolonged thermal stress. In such settings, achieving peak individual performance can be critical to organizational success. Short-notice deployment to a hot operational or training environment, exposure to high intensity exercise and undertaking ceremonial duties during extreme weather may challenge the ability to protect personnel from excessive thermal strain, especially where heat adaptation is incomplete. Graded and progressive acclimatization can reduce morbidity substantially and impact on mortality rates, yet individual variation in adaptation has the potential to undermine empirical approaches. Incapacity under heat stress can present the military with medical, occupational and logistic challenges requiring dynamic risk stratification during initial and subsequent heat stress. Using data from large studies of military personnel observing traditional and more contemporary acclimatization practices, this review article (1) characterizes the physical challenges that military training and deployed operations present (2) considers how heat adaptation has been used to augment military performance under thermal stress and (3) identifies potential solutions to optimize the risk-performance paradigm, including those with broader relevance to other populations exposed to heat stress.

Emerging Roles of the Membrane Potential: Action Beyond the Action Potential.

Whilst the phenomenon of an electrical resting membrane potential (RMP) is a central tenet of biology, it is nearly always discussed as a phenomenon that facilitates the propagation of action potentials in excitable tissue, muscle, and nerve. However, as ion channel research shifts beyond these tissues, it became clear that the RMP is a feature of virtually all cells studied. The RMP is maintained by the cell's compliment of ion channels. Transcriptome sequencing is increasingly revealing that equally rich compliments of ion channels exist in both excitable and non-excitable tissue. In this review, we discuss a range of critical roles that the RMP has in a variety of cell types beyond the action potential. Whereas most biologists would perceive that the RMP is primarily about excitability, the data show that in fact excitability is only a small part of it. Emerging evidence show that a dynamic membrane potential is critical for many other processes including cell cycle, cell-volume control, proliferation, muscle contraction (even in the absence of an action potential), and wound healing. Modulation of the RMP is therefore a potential target for many new drugs targeting a range of diseases and biological functions from cancer through to wound healing and is likely to be key to the development of successful stem cell therapies.

Changes in northern hemisphere male international rugby union players' body mass and height between 1955 and 2015.

OBJECTIVES: We sought to establish the effects of professionalism, which officially began in 1995, on the body mass and height of northern hemisphere male international rugby union (RU) players. We hypothesised that mass would significantly increase following professionalism. We also investigated the changes in size of players according to their playing position, and we compared changes to rugby league (RL) players and the public. METHODS: The body mass and height of players representing their international team for that country's first game of the Five Nations in 1955, 1965, 1975, 1985 and 1995 and, for 2005 and 2015, the Six Nations, were collected from matchday programmes. RL players' data were collected from the Challenge Cup final games played in the same years. RESULTS: International RU player body mass has significantly increased since 1995. In 1955 mean (±SD) player body mass was 84.8 kg (±8.2); in 2015, it was 105.4 kg (±12.1), an increase of 24.3%. Between 1955 and 2015, the body mass of forwards increased steadily, whereas that of backs has mostly gone up since 1995. RU player body mass gain has exceeded that of RL, but the age-matched difference between RU players and the public has remained relatively constant. CONCLUSIONS: The factors influencing the gain in body mass of rugby players are legion; however, we believe that the interpretation of the law relating to the scrum put-in and changes allowing substitutions have, at least in part, contributed to the observed changes. Injury severity is increasing, and this may be linked to greater forces (caused by greater body mass) occurring in contact. RU law makers should adjust the rules to encourage speed and skill at the expense of mass.