Exercise in Burn Survivors: Cooling Modalities

University of Texas Southwestern Medical Center70 enrolled

Overview

This project will identify the efficacy of cooling modalities aimed to attenuate excessive elevations in skin and internal body temperatures during physical activity in well-healed burn survivors. The investigators will conduct a randomized crossover design study. Non-burned control subjects, subjects who experienced burns covering \~20% to 40% of their body surface area, and subject having burns \>40% of their body surface area will be investigated. Subjects will exercise in heated environmental conditions while receiving the following cooling modalities: no cooling, fan only, skin wetting only, and a combination of fan and skin wetting.

Within the United States, 500,000+ individuals are enduring the long-term consequences of severe burn injuries covering 20% or more of their body surface area, with upwards to 11,000 individuals experiencing such an injury per year. These burn injuries can severely compromise body temperature regulation, owing to permanent impairments in the primary thermoeffectors necessary to dissipate heat, namely profoundly blunted skin blood flow and sweating responses in the injured skin. The investigators propose that this heat intolerance deters burn survivors from participating in physical activity, including activities of daily living, necessary to avoid the adverse cardiovascular and metabolic sequela of a sedentary lifestyle. Consistent with hypothesis, years after the injury burn survivors have a very low aerobic capacity; greater all-cause mortality rates; greater hospitalization days for circulatory diseases; and suffer from greater incidences of ischemic heart disease, heart failure, diabetes, and cerebrovascular disease (including stroke) relative to matched non-burned cohorts. The primary goal of this project is to identify modalities to attenuate excessive elevations in skin and core body temperatures during physical activity in well-healed burn survivors. The implementation of such modalities will eliminate heat intolerance as a barrier to participation in activities that are necessary to improve/maintain cardiovascular health in this vulnerable population. This project will investigate whether increased skin wetness, with and without accompanying fan use, will restore otherwise impaired evaporative cooling of well-healed burn survivors, with the extent of that improvement predicated on the environmental conditions and the percentage of body surface area burned.

Study Type

INTERVENTIONAL

Allocation

Interventions

Control (no cooling modalities)OTHER

Subjects will exercise for 60 minutes in the indicated environmental condition while being exposed to no cooling modality.

Water Spray OnlyOTHER

Subjects will exercise for 60 minutes in the indicated environmental condition while being exposed to the skin wetting modality. Skin wetting will be performed by spraying water onto the skin throughout the exercise bout.

Fan OnlyOTHER

Subjects will exercise for 60 minutes in the indicated environmental condition while being exposed to the fan cooling modality. The fan will be a commercially available fan will be directed to the research subject throughout the exercise bout.

Water Spray and FanOTHER

Subjects will exercise for 60 minutes in the indicated environmental condition while being exposed to both the skin wetting and fan cooling modalities. The fan will be a commercially available fan will be directed to the research subject throughout the exercise bout. Skin wetting will be performed by spraying water onto the skin throughout the exercise bout.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 65 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria (non-burned individuals): * Healthy male and female subjects * 18-65 years of age. * Free of any underlying medical conditions Exclusion Criteria (non-burned individuals): * Any burn-related injuries resulting in at least one night of hospitalization. * Heart disease or any other chronic medical condition requiring regular medical therapy including cancer, diabetes, and hypertension. * Abnormalities detected on routine screening * Individuals who participate in a structured aerobic exercise training program at moderate to high intensities. * Current smokers, as well as individuals who regularly smoked within the past 3 years. * Body mass index of greater than 30 kg/m\^2. * Pregnant individuals Inclusion Criteria (burn survivors): * Healthy male and female subjects * 18-65 years of age. * Free of any underlying medical conditions * Having a burn injury covering 20-40% or \>40% of the participant's body surface area; at least 50% of those burn injuries must be full thickness that required skin grafting. * Participants must have been hospitalized due to the burn injury for a minimum of 15 days Exclusion Criteria (burn survivors): * Any burn-related injuries resulting in at least one night of hospitalization. * Heart disease or any other chronic medical condition requiring regular medical therapy including cancer, diabetes, and hypertension. * Abnormalities detected on routine screening * Individuals who participate in a structured aerobic exercise training program at moderate to high intensities. * Current smokers, as well as individuals who regularly smoked within the past 3 years. * Body mass index of greater than 30 kg/m\^2. * Pregnant individuals * Extensive unhealed injured skin

Outcomes

Primary Outcomes

Change in Core Temperature (°C) During Control Intervention

The subject's core body temperature will be measured from gastrointestinal temperature via an ingestible telemetric pill.

Time frame: At 0 minutes and 60 minutes into the intervention.

Change in Core Temperature (°C) During Fan Intervention

The subject's core body temperature will be measured from gastrointestinal temperature via an ingestible telemetric pill.

Time frame: At 0 minutes and 60 minutes into the intervention.

Change in Core Temperature (°C) During Water-Spray Intervention

The subject's core body temperature will be measured from gastrointestinal temperature via an ingestible telemetric pill.

Time frame: At 0 minutes and 60 minutes into the intervention.

Change in Core Temperature (°C) During Water-Spray and Fan Intervention

The subject's core body temperature will be measured from gastrointestinal temperature via an ingestible telemetric pill.

Time frame: At 0 minutes and 60 minutes into the intervention.

Secondary Outcomes

Skin Temperature (°C) Following Control Intervention

The subject's skin temperature will be measured from small temperature sensitive electrodes attached to the participant's skin.