Publications by authors named "Luke N Belval"
Article Synopsis
- The study investigates how different cooling methods can help manage heat stress and core temperature during exercise in individuals with varying degrees of burn injuries.
- Participants included non-burned adults and those with moderate and large burn injuries, who exercised under controlled conditions while experiencing different cooling treatments.
- Results showed that while cooling modalities helped reduce feelings of exertion, they had a limited effect on core temperature, especially beneficial for those with larger burn injuries when exercising in hotter conditions.
Article Synopsis
- Trauma-induced hemorrhage is a major cause of death before reaching the hospital, and studies show that females have a lower tolerance to simulated blood loss compared to males.
- This study compared the cardiovascular responses of 17 females and 19 males during a simulated hemorrhage by using lower-body negative pressure (LBNP) to assess their tolerance levels.
- Results indicated that females demonstrated a significantly lower tolerance to hypovolemia, with lower blood pressures and muscle sympathetic nerve activity compared to males, suggesting a sex difference in response to blood loss.
Context: A high number of exertional heat stroke (EHS) cases occur during the Falmouth Road Race.
Objectives: To extend previous analyses of EHS cases during the Falmouth Road Race by assessing or describing (1) EHS and heat exhaustion (HE) incidence rates, (2) EHS outcomes as they relate to survival, (3) the effect of the environment on these outcomes, and (4) how this influences medical provider planning and preparedness.
Design: Descriptive epidemiologic study.
This project tested the hypothesis that burn survivors can perform mild/moderate-intensity exercise in temperate and hot environments without excessive elevations in core body temperature. Burn survivors with low (23 ± 5%TBSA; N = 11), moderate (40 ± 5%TBSA; N = 9), and high (60 ± 8%TBSA; N = 9) burn injuries performed 60 minutes of cycle ergometry exercise (72 ± 15 watts) in a 25°C and 23% relative humidity environment (ie, temperate) and in a 40°C and 21% relative humidity environment (ie, hot). Absolute gastrointestinal temperatures (TGI) and changes in TGI (ΔTGI) were obtained.
View Article and Find Full Text PDFOlder adults are at greater risk for heat-related morbidity and mortality, due in part to age-related reductions in heat dissipating capabilities. Previous studies investigating the impact of age on responses to heat stress used approaches that lack activities of daily living and therefore may not accurately depict the thermal/physiological strain that would occur during actual heatwaves. We sought to compare the responses of young (18-39 yr) and older (≥65 yr) adults exposed to two extreme heat simulations.
View Article and Find Full Text PDFIn humans, elevated body temperatures can markedly increase the ventilatory response to exercise. However, the impact of changing the effective body surface area (BSA) for sweat evaporation (BSA) on such responses is unclear. Ten healthy adults (9 males, 1 female) performed eight exercise trials cycling at 6 W/kg of metabolic heat production for 60 min.
View Article and Find Full Text PDFIntroduction: An uncontrollably rising core body temperature (T C ) is an indicator of an impending exertional heat illness. However, measuring T C invasively in field settings is challenging. By contrast, wearable sensors combined with machine-learning algorithms can continuously monitor T C nonintrusively.
View Article and Find Full Text PDFHemorrhage is a leading cause of preventable battlefield and civilian trauma deaths. Ketamine, fentanyl, and morphine are recommended analgesics for use in the prehospital (i.e.
View Article and Find Full Text PDFArticle Synopsis
- Research on low-dose morphine's impact on cardiovascular regulation mainly comes from animal studies, leaving a gap in understanding its effects in conscious humans during pain.
- A study tested whether low-dose morphine can decrease pain perception and sympathetic cardiovascular responses during a controlled cold pressor test with 29 participants.
- Results showed that morphine significantly lowered perceived pain and mean blood pressure compared to a placebo, but did not affect measures of muscle sympathetic nerve activity, indicating its specific impact on pain rather than overall autonomic response.
Article Synopsis
- Hemorrhage is a major cause of preventable deaths in both military and civilian contexts, and low-dose morphine is often used for pain relief in prehospital settings.
- A study involving thirty adults tested whether intravenous morphine (5 mg) impacts hemorrhagic tolerance by comparing it to a placebo in a controlled environment using a lower-body negative pressure protocol.
- Results showed that low-dose morphine significantly reduced hemorrhagic tolerance and lowered blood pressure, indicating it may not be the best option for managing pain in individuals experiencing significant bleeding.
Low-dose fentanyl does not alter muscle sympathetic nerve activity, blood pressure, or tolerance during progressive central hypovolemia.
Am J Physiol Regul Integr Comp Physiol
January 2022
Article Synopsis
- * The research involved 28 volunteers participating in a controlled trial where some received fentanyl and others received a placebo while undergoing a simulated hemorrhage test (LBNP).
- * Results showed no significant differences in blood pressure regulation or tolerance to blood loss between the fentanyl and placebo groups, indicating that fentanyl does not impair the body's response to severe hemorrhage.
Low-dose fentanyl reduces pain perception, muscle sympathetic nerve activity responses, and blood pressure responses during the cold pressor test.
Am J Physiol Regul Integr Comp Physiol
January 2022
Article Synopsis
- - The study investigates the effects of low-dose fentanyl on pain perception and cardiovascular responses during a painful stimulus in humans, as most previous knowledge is based on animal studies.
- - In a controlled trial with 23 participants, the researchers used a cold pressor test to assess pain sensitivity and cardiovascular changes before and after administering either fentanyl or a placebo.
- - Results showed that low-dose fentanyl significantly reduced perceived pain, muscle sympathetic nerve activity, and blood pressure response during the test compared to the placebo, suggesting it effectively modulates autonomic cardiovascular responses in humans.
Objective: This study aimed at assessing the risks associated with human exposure to heat-stress conditions by predicting organ- and tissue-level heat-stress responses under different exertional activities, environmental conditions, and clothing.
Methods: In this study, we developed an anatomically detailed three-dimensional thermoregulatory finite element model of a 50th percentile U.S.
Objective: To provide best-practice recommendations for developing and implementing heat-acclimatization strategies in secondary school athletics.
Data Sources: An extensive literature review on topics related to heat acclimatization and heat acclimation was conducted by a group of content experts. Using the Delphi method, action-oriented recommendations were developed.
Context: Hypohydration has been shown to alter neuromuscular function. However, the longevity of these impairments remains unclear.
Objective: To examine the effects of graded exercise-induced dehydration on neuromuscular control 24 hours after exercise-induced hypohydration.
Exertional heat stroke (EHS) survivors may be more susceptible to subsequent EHS; however, the occurrence of survivors with subsequent EHS episodes is limited. Therefore, the purpose of this study was to evaluate the incidence of participants with repeated EHS (EHS-2+) cases in a warm-weather road race across participation years compared to those who experienced 1 EHS (EHS-1). A retrospective observational case series design was utilized.
View Article and Find Full Text PDFContext: Sex, age, and wet-bulb globe temperature (WBGT) have been proposed risk factors for exertional heat stroke (EHS) despite conflicting laboratory and epidemiologic evidence.
Objective: To examine differences in EHS incidence while accounting for sex, age, and environmental conditions.
Design: Observational study.
Context: Lightning-related injuries are among the top 10 causes of sport-related death at all levels of sport, including the nearly 8 million athletes participating in US secondary school sports.
Objective: To investigate the adoption of lightning safety policies and the factors that influence the development of comprehensive lightning safety policies in United States secondary schools.
Design: Cross-sectional study.
Huggins, RA, Giersch, GEW, Belval, LN, Benjamin, CL, Curtis, RM, Sekiguchi, Y, Peltonen, J, and Casa, DJ. The validity and reliability of GPS units for measuring distance and velocity during linear and team sport simulated movements. J Strength Cond Res 34(11): 3070-3077, 2020-This experimental study aimed to assess the validity and reliability of shirt-mounted 10-Hz global positioning system (GPS) units (Polar Team Pro) for measuring total distance (TD), constant velocity (VelC), and instantaneous velocity (VelI) during linear running and a team sport simulation circuit (TSSC).
View Article and Find Full Text PDFExertional heat stroke (EHS) is a potentially lethal, hyperthermic condition that warrants immediate cooling to optimize the patient outcome. The study aimed to examine if a portable cooling vest meets the established cooling criteria (0.15 °C·min or greater) for EHS treatment.
View Article and Find Full Text PDFArticle Synopsis
- * Research suggests that low dose ketamine reduces pain perception and blood pressure during painful stimuli in healthy adults, but does not significantly affect muscle sympathetic nerve activity.
- * The findings from a study involving 22 participants indicate that low dose ketamine can blunt responses during a cold pressor test, providing important insights for healthcare professionals considering its use.