Heat-related changes in the velocity and kinetic energy of flowing blood influence the human heart's output during hyperthermia.

Passive whole-body hyperthermia increases limb blood flow and cardiac output ( Q ̇ $\dot Q$ ), but the interplay between peripheral and central thermo-haemodynamic mechanisms remains unclear. Here we tested the hypothesis that local hyperthermia-induced alterations in peripheral blood flow and blood kinetic energy modulate flow to the heart and Q ̇ $\dot Q$ . Body temperatures, regional (leg, arm, head) and systemic haemodynamics, and left ventricular (LV) volumes and functions were assessed in eight healthy males during: (1) 3 h control (normothermic condition); (2) 3 h of single-leg heating; (3) 3 h of two-leg heating; and (4) 2.5 h of whole-body heating. Leg, forearm, and extracranial blood flow increased in close association with local rises in temperature while brain perfusion remained unchanged. Increases in blood velocity with small to no changes in the conduit artery diameter underpinned the augmented limb and extracranial perfusion. In all heating conditions, Q ̇ $\dot Q$ increased in association with proportional elevations in systemic vascular conductance, related to enhanced blood flow, blood velocity, vascular conductance and kinetic energy in the limbs and head (all R2 ≥ 0.803; P < 0.001), but not in the brain. LV systolic (end-systolic elastance and twist) and diastolic functional profiles (untwisting rate), pulmonary ventilation and systemic aerobic metabolism were only altered in whole-body heating. These findings substantiate the idea that local hyperthermia-induced selective alterations in peripheral blood flow modulate the magnitude of flow to the heart and Q ̇ $\dot Q$ through changes in blood velocity and kinetic energy. Localised heat-activated events in the peripheral circulation therefore affect the human heart's output. KEY POINTS: Local and whole-body hyperthermia increases limb and systemic perfusion, but the underlying peripheral and central heat-sensitive mechanisms are not fully established. Here we investigated the regional (leg, arm and head) and systemic haemodynamics (cardiac output: Q ̇ $\dot Q$ ) during passive single-leg, two-leg and whole-body hyperthermia to determine the contribution of peripheral and central thermosensitive factors in the control of human circulation. Single-leg, two-leg, and whole-body hyperthermia induced graded increases in leg blood flow and Q ̇ $\dot Q$ . Brain blood flow, however, remained unchanged in all conditions. Ventilation, extracranial blood flow and cardiac systolic and diastolic functions only increased during whole-body hyperthermia. The augmented Q ̇ $\dot Q$ with hyperthermia was tightly related to increased limb and head blood velocity, flow and kinetic energy. The findings indicate that local thermosensitive mechanisms modulate regional blood velocity, flow and kinetic energy, thereby controlling the magnitude of flow to the heart and thus the coupling of peripheral and central circulation during hyperthermia.

Storylines of family medicine VIII: clinical approaches.

Storylines of Family Medicine is a 12-part series of thematically linked mini-essays with accompanying illustrations that explore the many dimensions of family medicine as interpreted by individual family physicians and medical educators in the USA and elsewhere around the world. In 'VIII: clinical approaches', authors address the following themes: 'Evaluation, diagnosis and management I-toward a working diagnosis', 'Evaluation, diagnosis and management II-process steps', 'Interweaving integrative medicine and family medicine', 'Halfway-the art of clinical judgment', 'Seamless integration in family medicine-team-based care', 'Technology-uncovering stories from noise' and 'Caring for patients with multiple long-term conditions'. May readers recognise in these essays the uniqueness of a family medicine approach to care.

Cross-adaptation from heat stress to hypoxia: A systematic review and exploratory meta-analysis.

Cross-adaptation (CA) refers to the successful induction of physiological adaptation under one environmental stressor (e.g., heat), to enable subsequent benefit in another (e.g., hypoxia). This systematic review and exploratory meta-analysis investigated the effect of heat acclimation (HA) on physiological, perceptual and physical performance outcome measures during rest, and submaximal and maximal intensity exercise in hypoxia. Database searches in Scopus and MEDLINE were performed. Studies were included when they met the Population, Intervention, Comparison, and Outcome criteria, were of English-language, peer-reviewed, full-text original articles, using human participants. Risk of bias and study quality were assessed using the COnsensus based Standards for the selection of health status Measurement INstruments checklist. Nine studies were included, totalling 79 participants (100 % recreationally trained males). The most common method of HA included fixed-intensity exercise comprising 9 ± 3 sessions, 89 ± 24-min in duration and occurred within 39 ± 2 °C and 32 ± 13 % relative humidity. CA induced a moderate, beneficial effect on physiological measures at rest (oxygen saturation: g = 0.60) and during submaximal exercise (heart rate: g = -0.65, core temperature: g = -0.68 and skin temperature: g = -0.72). A small effect was found for ventilation (g = 0.24) and performance measures (peak power: g = 0.32 and time trial time: g = -0.43) during maximal intensity exercise. No effect was observed for perceptual outcome measures. CA may be appropriate for individuals, such as occupational or military workers, whose access to altitude exposure prior to undertaking submaximal activity in hypoxic conditions is restricted. Methodological variances exist within the current literature, and females and well-trained individuals have yet to be investigated. Future research should focus on these cohorts and explore the mechanistic underpinnings of CA.

Remote vision-based digital patient monitoring of pulse and respiratory rates in acute medical wards.

Remote Vision-Based digital Patient Monitoring (VBPM) of pulse (PR) and respiratory rate (RR) was set up in six single rooms in an acute medical and an orthopaedic ward. We compared 102 PR and 154 RR VBPM measurements (from 27 patients) with paired routine nurse measurements. VBPM measurements of RR were validated by reviewing video footage. Nurse measurements of RR were often 16-18 breaths/minute, and did not match VBPM RR (overestimating at low RR and underestimating at high RR). Nurse measurements of pulse were on average 3.9 beats per minute greater than matched VBPM measurements. VBPM was unobtrusive and well accepted.

An Innovative Resource to Guide and Track Medical Resident Activity and Wellness During At-Home Assignments.

Background and objectives Medical residents may work from home for various reasons, including study electives, isolation due to exposure to illness, or during parental leave when they choose to work at home instead of taking extended time off. The University of Arkansas for Medical Sciences (UAMS) Little Rock Family Medicine residency program recognized the need for a tool that provided residents with a list of resources and approved activities for at-home work and a means of tracking their performance in those activities. Methods The administration team at the UAMS Little Rock Family Medicine residency program custom-designed a Daily Activities Log that served multiple purposes. Family medicine residents used it to choose what activities to participate in from a comprehensive list of activities and resources including virtual conferences, recorded didactics, modules, and other online materials. The program provided the framework on the log, while residents used it to document time spent on those activities. The log also gave the program a daily update on the resident's health, as one question specifically asked about well-being. Since it was built in an electronic survey format already owned by the residency program, it was completely customizable and available at no additional cost. Results In the two years covered by this project, residents logged a total of 593 hours of at-home work. In response to a survey, 76% of participating residents (N=14) rated the log as extremely or very easy to use; 64% indicated that it was a helpful resource; and 50% said that it simplified the reporting of their daily status. The residency program faculty found that having one source to track all off-site residents was an efficient means of monitoring their well-being and their work. Conclusions The Daily Activities Log is a versatile tool that provides comprehensive information, resources, and approved activities for residents, documents their work, and provides updates to residency management. It can be readily modified for use in other programs that have residents working at home.

Critical illness aspects of heatstroke: A hot topic.

Heatstroke represents the most severe end of the heat illness spectrum, and is increasingly seen in those undergoing exercise or exertion ('exertional heatstroke') and those exposed to high ambient temperatures, for example in heatwaves ('classical heatstroke'). Both forms may be associated with significant thermal injury, leading to organ dysfunction and the need for admission to an intensive care unit. The process may be exacerbated by translocation of bacteria or endotoxin through an intestinal wall rendered more permeable by the hyperthermia. This narrative review highlights the importance of early diagnosis, rapid cooling and effective management of complications. It discusses the incidence, clinical features and treatment of heatstroke, and discusses the possible role of intestinal permeability and advances in follow-up and recovery of this condition. Optimum treatment involves an integrated input from prehospital, emergency department and critical care teams, along with follow-up by rehabilitation teams and, if appropriate, sports or clinical physiologists.

Skeletal muscle angiogenic, regulatory, and heat shock protein responses to prolonged passive hyperthermia of the human lower limb.

Passive hyperthermia induces a range of physiological responses including augmenting skeletal muscle mRNA expression. This experiment aimed to examine gene and protein responses to prolonged passive leg hyperthermia. Seven young participants underwent 3 h of resting unilateral leg heating (HEAT) followed by a further 3 h of rest, with the contralateral leg serving as an unheated control (CONT). Muscle biopsies were taken at baseline (0 h), and at 1.5, 3, 4, and 6 h in HEAT and 0 and 6 h in CONT to assess changes in selected mRNA expression via qRT-PCR, and HSP72 and VEGFα concentration via ELISA. Muscle temperature (Tm) increased in HEAT plateauing from 1.5 to 3 h (+3.5 ± 1.5°C from 34.2 ± 1.2°C baseline value; P < 0.001), returning to baseline at 6 h. No change occurred in CONT. Endothelial nitric oxide synthase (eNOS), Forkhead box O1 (FOXO-1), Hsp72, and VEGFα mRNA increased in HEAT (P < 0.05); however, post hoc analysis identified that only Hsp72 mRNA statistically increased (at 4 h vs. baseline). When peak change during HEAT was calculated angiopoietin 2 (ANGPT-2) decreased (-0.4 ± 0.2-fold), and C-C motif chemokine ligand 2 (CCL2) (+2.9 ± 1.6-fold), FOXO-1 (+6.2 ± 4.4-fold), Hsp27 (+2.9 ± 1.7-fold), Hsp72 (+8.5 ± 3.5-fold), Hsp90α (+4.6 ± 3.7-fold), and VEGFα (+5.9 ± 3.1-fold) increased from baseline (all P < 0.05). At 6 h Tm were not different between limbs (P = 0.582; CONT = 32.5 ± 1.6°C, HEAT = 34.3 ± 1.2°C), and only ANGPT-2 (P = 0.031; -1.3 ± 1.4-fold) and VEGFα (P = 0.030; 1.1 ± 1.2-fold) differed between HEAT and CONT. No change in VEGFα or HSP72 protein concentration were observed over time; however, peak change in VEGFα did increase (P < 0.05) in HEAT (+140 ± 184 pg·mL-1) versus CONT (+7 ± 86 pg·mL-1). Passive hyperthermia transiently augmented ANGPT-2, CCL2, eNOS, FOXO-1, Hsp27, Hsp72, Hsp90α and VEGFα mRNA, and VEGFα protein.

Increased air temperature decreases high-speed, but not total distance, in international field hockey.

This study investigated the effect of heat stress on locomotor activity within international field hockey at team, positional and playing-quarter levels. Analysis was conducted on 71 matches played by the Malaysia national men's team against 24 opponents. Fixtures were assigned to match conditions, based on air temperature [COOL (14 ± 3°C), WARM (24 ± 1°C), HOT (27 ± 1°C), or VHOT (32 ± 2°C), p < 0.001]. Relationships between locomotor metrics and air temperature (AIR), absolute and relative humidity, and wet bulb globe temperature (WBGT) were investigated further using correlation and regression analyses. Increased AIR and WBGT revealed similar correlations (p < 0.01) with intensity metrics; high-speed running (AIR r = -0.51, WBGT r = -0.45), average speed (AIR r = -0.48, WBGT r = -0.46), decelerations (AIR r = -0.41, WBGT r = -0.41), sprinting efforts (AIR r = -0.40, WBGT r = -0.36), and sprinting distance (AIR r = -0.37, WBGT r = -0.29). In comparison to COOL, HOT, and VHOT matches demonstrated reduced high-speed running intensity (-14-17%; p < 0.001), average speed (-5-6%; p < 0.001), sprinting efforts (-17%; p = 0.010) and decelerations per min (-12%; p = 0.008). Interactions were found between match conditions and playing quarter for average speed (+4-7%; p = 0.002) and sprinting distance (+16-36%; p < 0.001), both of which were higher in the fourth quarter in COOL versus WARM, HOT and VHOT. There was an interaction for "low-speed" (p < 0.001), but not for "high-speed" running (p = 0.076) demonstrating the modulating effect of air temperature (particularly >25°C) on pacing within international hockey. These are the first data demonstrating the effect of air temperature on locomotor activity within international men's hockey, notably that increased air temperature impairs high-intensity activities by 5-15%. Higher air temperatures compromise high-speed running distances between matches in hockey.

Non-contact physiological monitoring of post-operative patients in the intensive care unit.

Prolonged non-contact camera-based monitoring in critically ill patients presents unique challenges, but may facilitate safe recovery. A study was designed to evaluate the feasibility of introducing a non-contact video camera monitoring system into an acute clinical setting. We assessed the accuracy and robustness of the video camera-derived estimates of the vital signs against the electronically-recorded reference values in both day and night environments. We demonstrated non-contact monitoring of heart rate and respiratory rate for extended periods of time in 15 post-operative patients. Across day and night, heart rate was estimated for up to 53.2% (103.0 h) of the total valid camera data with a mean absolute error (MAE) of 2.5 beats/min in comparison to two reference sensors. We obtained respiratory rate estimates for 63.1% (119.8 h) of the total valid camera data with a MAE of 2.4 breaths/min against the reference value computed from the chest impedance pneumogram. Non-contact estimates detected relevant changes in the vital-sign values between routine clinical observations. Pivotal respiratory events in a post-operative patient could be identified from the analysis of video-derived respiratory information. Continuous vital-sign monitoring supported by non-contact video camera estimates could be used to track early signs of physiological deterioration during post-operative care.

Regional thermal hyperemia in the human leg: Evidence of the importance of thermosensitive mechanisms in the control of the peripheral circulation.

Hyperthermia is thought to increase limb blood flow through the activation of thermosensitive mechanisms within the limb vasculature, but the precise vascular locus in which hyperthermia modulates perfusion remains elusive. We tested the hypothesis that local temperature-sensitive mechanisms alter limb hemodynamics by regulating microvascular blood flow. Temperature and oxygenation profiles and leg hemodynamics of the common (CFA), superficial (SFA) and profunda (PFA) femoral arteries, and popliteal artery (POA) of the experimental and control legs were measured in healthy participants during: (1) 3 h of whole leg heating (WLH) followed by 3 h of recovery (n = 9); (2) 1 h of upper leg heating (ULH) followed by 30 min of cooling and 1 h ULH bout (n = 8); and (3) 1 h of lower leg heating (LLH) (n = 8). WLH increased experimental leg temperature by 4.2 ± 1.2ºC and blood flow in CFA, SFA, PFA, and POA by ≥3-fold, while the core temperature essentially remained stable. Upper and lower leg blood flow increased exponentially in response to leg temperature and then declined during recovery. ULH and LLH similarly increased the corresponding segmental leg temperature, blood flow, and tissue oxygenation without affecting these responses in the non-heated leg segment, or perfusion pressure and conduit artery diameter across all vessels. Findings demonstrate that whole leg hyperthermia induces profound and sustained elevations in upper and lower limb blood flow and that segmental hyperthermia matches the regional thermal hyperemia without causing thermal or hemodynamic alterations in the non-heated limb segment. These observations support the notion that heat-activated thermosensitive mechanisms in microcirculation regulate limb tissue perfusion during hyperthermia.

Exercise hyperthermia induces greater changes in gastrointestinal permeability than equivalent passive hyperthermia.

Hyperthermia and exertional heat illness increase gastrointestinal (GI) permeability, although whether the latter is only via hyperthermia is unclear. The aim of this pilot study was to determine whether different changes in GI permeability, characterized by an increased plasma lactulose:rhamnose concentration ratio ([L:R]), occurred in exercise hyperthermia in comparison to equivalent passive hyperthermia. Six healthy adult male participants (age 25 ± 5 years, mass 77.0 ± 6.7 kg, height 181 ± 6 cm, peak oxygen uptake [ V·O2peak ] 48 ± 8 ml.kg-1 .min-1 ) underwent exercise under hot conditions (Ex-Heat) and passive heating during hot water immersion (HWI). Heart rate (HR), rectal temperature (TCORE ), rating of perceived exertion (RPE), and whole-body sweat loss (WBSL) were recorded throughout the trials. The L:R ratio, peak HR, change in HR, and change in RPE were higher in Ex-Heat than HWI, despite no differences in trial duration, peak core temperature or WBSL. L:R was strongly correlated (p < 0.05) with HR peak (r = 0.626) and change in HR (r = 0.615) but no other variable. The greater L:R in Ex-Heat, despite equal TCORE responses to HWI, indicates that increased cardiovascular strain occurred during exercise, and exacerbates hyperthermia-induced GI permeability at the same absolute temperature.

Volume and Intensity of Locomotor Activity in International Men's Field Hockey Matches Over a 2-Year Period.

The locomotor demands of international men's field hockey matches were investigated across positions (DEF, MID, FWD) and playing quarters. Volume (i.e., total values) and intensity (i.e., relative to playing time) data were collected using 10-Hz GPS/100-Hz accelerometer units from the #11 world-ranked (WR) team, during 71 matches, against 24 opponents [WR 12 ± 11 (range, 1-60)]. Mean ± SD team total distance (TD) was 4,861 ± 871 m, with 25% (1,193 ± 329 m) "high-speed running" (>14.5 km h-1) and 8% (402 ± 144 m) "sprinting" (>19.0 km h-1). Reduced TD (range, -3 to 4%) and average speed (range, -3.4 to 4.7%) occurred through subsequent quarters, vs. Q1 (p < 0.05). A "large" negative relationship (r = -0.64) was found between playing duration and average speed. Positional differences (p < 0.05) were identified for all volume metrics including; playing duration (DEF, 45:50 ± 8:00 min; MID, 37:37 ± 7:12 min; FWD, 33:32 ± 6:22 min), TD (DEF, 5,223 ± 851 m; MID, 4,945 ± 827 m; FWD, 4,453 ± 741 m), sprinting distance (DEF, 315 ± 121 m; MID, 437 ± 144 m; FWD, 445 ± 129 m), and acceleration efforts (>2 m s-2; DEF, 48 ± 12; MID, 51 ± 11; FWD, 50 ± 14). Intensity variables similarly revealed positional differences (p < 0.05) but with a different pattern between positions; average speed (DEF, 115 ± 10 m min-1; MID, 132 ± 10 m min-1; FWD, 134 ± 15 m min-1), sprinting (DEF, 7 ± 3 m min-1; MID, 12 ± 4 m min-1; FWD, 14 ± 4 m min-1), and accelerations (DEF, 1.1 ± 0.3 n min-1; MID, 1.4 ± 0.2 n min-1; FWD, 1.5 ± 0.3 n min-1). Physical outputs reduced across playing quarters, despite unlimited substitutions, demonstrating the importance of optimizing physical preparation prior to international competition. Volume and intensity data highlight specific positional requirements, with forwards displaying shorter playing durations but greater high-intensity activities than defenders.

Exercise heat acclimation and post-exercise hot water immersion improve resting and exercise responses to heat stress in the elderly.

OBJECTIVES: To investigate the efficacy of heat acclimation (HA) in the young (YEX) and elderly (EEX) following exercise-HA, and the elderly utilising post-exercise hot water immersion HA (EHWI). DESIGN: Cross-sectional study. METHOD: Twenty-six participants (YEX: n = 11 aged 22 ±â€¯2 years, EEX:n = 8 aged 68 ±â€¯3 years, EHWI: n = 7 aged 73 ±â€¯3 years) completed two pre-/post-tests, separated by five intervention days. YEX and EEX exercised in hot conditions to raise rectal temperature (Trec) ≥38.5 °C within 60 min, with this increase maintained for a further 60 min. EHWI completed 30 min of cycling in temperate conditions, then 30 min of HWI (40 °C), followed by 30 min seated blanket wrap. Pre- and post-testing comprised 30 min rest, followed by 30 min of cycling exercise (3.5 W·kg-1 Hprod), and a six-minute walk test (6MWT), all in 35 °C, 50% RH. RESULTS: The HA protocols did not elicit different mean heart rate (HR), Trec, and duration Trec ≥ 38.5 °C (p > 0.05) between YEX, EEX, and EHWI groups. Resting Trec, peak skin temperature, systolic and mean arterial pressure, perceived exertion and thermal sensation decreased, and 6MWT distance increased pre- to post-HA (p < 0.05), with no difference between groups. YEX also demonstrated a reduction in resting HR (p < 0.05). No change was observed in peak Trec or HR, vascular conductance, sweat rate, or thermal comfort in any group (p > 0.05). CONCLUSIONS: Irrespective of age or intervention, HA induced thermoregulatory, perceptual and exercise performance improvements. Both exercise-HA (EEX), and post-exercise HWI (EHWI) are considered viable interventions to prepare the elderly for heat stress.

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.

Non-contact vital sign monitoring of patients in an intensive care unit: A human factors analysis of staff expectations.

BACKGROUND: Infra-red and thermal imaging enable wireless systems to monitor patients' vital signs and absence of wires may improve patient experiences. No studies have explored staff perceptions of the concept of this specific type of technology in the adult population. Understanding existing working systems before introducing technology could improve adoption. METHODS: We conducted semi-structured interviews with Intensive Care Unit (ICU) staff exploring perceptions of wireless patient monitoring. We used the Systems Engineering Initiative for Patient Safety (SEIPS) model to guide thematic analysis. RESULTS: We identified usability themes relating to staff perceptions of current patient monitoring experiences, staff perceptions of patient/relative expectations of ICU care, troubleshooting, hierarchy of monitoring, and consensus of trust. CONCLUSION: The concept of wireless monitoring has perceived benefits for patients and staff. The Systems Engineering Initiative for Patient Safety model guided a systems-based exploratory evaluation. Results highlight the social and environmental factors which may influence usability, adoption, or abandonment of wireless technology in the ICU.

Systemic but not local rehydration restores dehydration-induced changes in pulmonary function in healthy adults.

Water transport and local (airway) hydration are critical for the normal functioning of lungs and airways. Currently, there is uncertainty regarding the effects of systemic dehydration on pulmonary function. Our aims were 1) to clarify the impact of exercise- or fluid restriction-induced dehydration on pulmonary function in healthy adults; and 2) to establish whether systemic or local rehydration can reverse dehydration-induced alterations in pulmonary function. Ten healthy participants performed four experimental trials in a randomized order (2 h exercise in the heat twice and 28 h fluid restriction twice). Pulmonary function was assessed using spirometry and whole body plethysmography in the euhydrated, dehydrated, and rehydrated states. Oral fluid consumption was used for systemic rehydration and nebulized isotonic saline inhalation for local rehydration. Both exercise and fluid restriction induced mild dehydration (2.7 ± 0.7% and 2.5 ± 0.4% body mass loss, respectively; P < 0.001) and elevated plasma osmolality (P < 0.001). Dehydration across all four trials was accompanied by a reduction in forced vital capacity (152 ± 143 mL, P < 0.01) and concomitant increases in residual volume (216 ± 177 mL, P < 0.01) and functional residual capacity (130 ± 144 mL, P < 0.01), with no statistical differences between modes of dehydration. These changes were normalized by fluid consumption but not nebulization. Our results suggest that, in healthy adults: 1) mild systemic dehydration induced by exercise or fluid restriction leads to pulmonary function impairment, primarily localized to small airways; and 2) systemic, but not local, rehydration reverses these potentially deleterious alterations.NEW & NOTEWORTHY This study demonstrates that, in healthy adults, mild systemic dehydration induced by exercise in the heat or a prolonged period of fluid restriction leads to negative alterations in pulmonary function, primarily localized to small airways. Oral rehydration, but not nebulized isotonic saline, is able to restore pulmonary function in dehydrated individuals. Our findings highlight the importance of maintaining an adequate systemic fluid balance to preserve pulmonary function.

The efficacy of steroids in reducing morbidity and mortality from extreme hyperthermia and heatstroke-A systematic review.

Severe hyperthermia from classical or exertional heatstroke, or from drug ingestion or other noninfective pyrogens, is associated with a high mortality and morbidity. A systemic pro-inflammatory response occurs during heatstroke, characterized by elevated cytokines with endotoxemia from elevated lipopolysaccharide (LPS) levels. Corticosteroids reduce LPS and cytokine levels, suggesting that they may improve outcome. A systematic review searching Embase, MEDLINE, and PubMed from the earliest date available until September 2019 was conducted, according to the PRISMA guidelines, with five papers identified. In four studies, systemic steroids administered before or at the onset of heat stress improved mortality or reduced organ dysfunction. Survival time was greatest when steroid administration preceded heat stress. In one study, a nonsignificant increase in mortality was seen. A dose response was observed, with higher doses extending survival time. Animal studies suggest that steroids improve mortality and/or organ dysfunction after an episode of heat stress or extreme hyperthermia.

Heat alleviation strategies for athletic performance: A review and practitioner guidelines.

International competition inevitably presents logistical challenges for athletes. Events such as the Tokyo 2020 Olympic Games require further consideration given historical climate data suggest athletes will experience significant heat stress. Given the expected climate, athletes face major challenges to health and performance. With this in mind, heat alleviation strategies should be a fundamental consideration. This review provides a focused perspective of the relevant literature describing how practitioners can structure male and female athlete preparations for performance in hot, humid conditions. Whilst scientific literature commonly describes experimental work, with a primary focus on maximizing magnitudes of adaptive responses, this may sacrifice ecological validity, particularly for athletes whom must balance logistical considerations aligned with integrating environmental preparation around training, tapering and travel plans. Additionally, opportunities for sophisticated interventions may not be possible in the constrained environment of the athlete village or event arenas. This review therefore takes knowledge gained from robust experimental work, interprets it and provides direction on how practitioners/coaches can optimize their athletes' heat alleviation strategies. This review identifies two distinct heat alleviation themes that should be considered to form an individualized strategy for the athlete to enhance thermoregulatory/performance physiology. First, chronic heat alleviation techniques are outlined, these describe interventions such as heat acclimation, which are implemented pre, during and post-training to prepare for the increased heat stress. Second, acute heat alleviation techniques that are implemented immediately prior to, and sometimes during the event are discussed. Abbreviations: CWI: Cold water immersion; HA: Heat acclimation; HR: Heart rate; HSP: Heat shock protein; HWI: Hot water immersion; LTHA: Long-term heat acclimation; MTHA: Medium-term heat acclimation; ODHA: Once-daily heat acclimation; RH: Relative humidity; RPE: Rating of perceived exertion; STHA: Short-term heat acclimation; TCORE: Core temperature; TDHA: Twice-daily heat acclimation; TS: Thermal sensation; TSKIN: Skin temperature; V̇O2max: Maximal oxygen uptake; WGBT: Wet bulb globe temperature.

The efficacy of antibiotics in reducing morbidity and mortality from heatstroke - A systematic review.

Severe hyperthermia, for example, classical heatstroke or exertional heatstroke from heatwaves or exercise respectively, or from drug ingestion or other non-infective pyrogens, is associated with a high mortality and morbidity, which may be chronic or permanent. Abolition of lipopolysaccharide, from gram-negative intestinal bacteria translocating into the systemic circulation via an intestinal wall rendered permeable from the hyperthermia, reduces the adverse effects, suggesting that antibiotics against the intestinal bacteria may have a similar effect. A systematic review searching Embase, MEDLINE and PubMed from the earliest date available until 2019 was conducted, according to PRISMA guidelines. Two papers were found which fit the criteria. In one, non-absorbable oral antibiotics were administered prior to the onset of heat stress, which reduced the cardiovascular dysfunction and rise in endotoxaemia, but animals succumbed at a lower temperature. In the second, non-absorbable oral antibiotics, in combination with a laxative and enema, given prior to the onset of heat stress, improved mortality; antibiotics administered after the heat stress did not, but the antibiotics used may have limited action against intestinal bacteria. Only two papers were found; both suggest an improvement in organ dysfunction or mortality after an episode of heat stress. No papers were found that investigate the sole use of antibiotics effective against intestinal bacteria given after the onset of heat stress, although biological plausibility suggest they warrant further research.

Introducing artificial intelligence in acute psychiatric inpatient care: qualitative study of its use to conduct nursing observations.

BACKGROUND: All patients admitted to an acute inpatient mental health unit must have nursing observations carried out at night either hourly or every 15 minutes, to ascertain that they are safe and breathing. However, while this practice ensures patient safety, it can also disturb patients' sleep, which in turn can impact negatively on their recovery. OBJECTIVE: This article describes the process of introducing artificial intelligence ('digitally assisted nursing observations') in an acute mental health inpatient ward, to enable staff to carry out the hourly and the 15 minutes observations, minimising disruption of patients' sleep while maintaining their safety. FINDINGS: The preliminary data obtained indicate that the digitally assisted nursing observations agreed with the observations without sensors when both were carried out in parallel and that over an estimated 755 patient nights, the new system has not been associated with any untoward incidents. Preliminary qualitative data suggest that the new technology improves patients' and staff's experience at night. DISCUSSION: This project suggests that the digitally assisted nursing observations could maintain patients' safety while potentially improving patients' and staff's experience in an acute psychiatric ward. The limitations of this study, namely, its narrative character and the fact that patients were not randomised to the new technology, suggest taking the reported findings as qualitative and preliminary. CLINICAL IMPLICATIONS: These results suggest that the care provided at night in acute inpatient psychiatric units could be substantially improved with this technology. This warrants a more thorough and stringent evaluation.