Hypothermia Rewarming With Distal Limb Warming

Hypothermia Rewarming Effectiveness of Distal Limb Warming With Either Fluidotherapy or Warm Water Immersion

The study will compare the rewarming effectiveness of heat donation through the distal arms and legs during rewarming of mildly hypothermic subjects. Warming will be accomplished through either warm water immersion; and fluidotherapy. The investigators hypothesize that fluidotherapy will be as, or more, effective compared to warm water immersion

Study Overview

• Status: Completed
• Conditions: Rewarming by Shivering Heat Production Only; Rewarming by Arm and Leg Immersion in Warm Water; Rewarming by Arm and Leg Exposure to Fluidotherapy
• Intervention / Treatment: Device: Fluidotherapy warming device

Detailed Description

Dr. Gordon Giesbrecht is studying/comparing the effectiveness of heat donation through the distal arms and legs in rewarming a mildly hypothermic individual. Warming will be accomplished through either warm water immersion; and fluidotherapy.

Procedure. Eight participants will be cooled in 8°C water on three occasions and then warmed by each of three warming conditions. The study will include following specific procedures: Anthropometric data which includes age, weight, height, and measurements of skinfold thickness at four sites- biceps, triceps, subscapularis, and suprailiac will be collected. Participant's heart rate and electrocardiogram will be monitored continuously throughout the experiment.

Participants will be instrumented as follows:

1. About 12 heat flux disks (2 cm in diameter) will be taped to the skin on the arms, legs, torso, head etc. to measure skin temperature and heat transfer from the skin.
2. Three ECG leads will be affixed to the skin.
3. Core temperature will be measured with a disposable esophageal thermocouple. A thin, flexible tube will be inserted through the nose, to midway down the esophagus at the level of the heart.
4. Oxygen consumption will be continuously measured with a metabolic cart. Participants will be asked to wear a face mask which will collect the expired breath during the cooling as well as the rewarming periods.

Conditions: The three treatment methods are as follows.

A. Spontaneous rewarming (Shivering only) - In this control condition, no external heat will be provided and the participant will rewarm spontaneously with the heat produced from shivering.

B. Warm water distal extremities immersion - Distal arms and legs will be immersed in warm water at 45°C for rewarming.

C.Fluidotherapy distal extremities rewarming - Distal arms and legs will be immersed in Fluidotherapy equipment for rewarming at 50°C.

Rewarming procedures will be administered either for a period of 60 minutes or until core temperature returns to normal values ( ̴ 36.5-37˚C). Following that, participants will be placed in a warm water bath (40-42˚C).

Research Design: Each of the three experimental trials, separated by at least 48 hours. On each of the three trials, participants will be immersed up to the level of the sternal notch in 8˚C for up to 60 minutes or until the core temperature falls to 35˚C. The participant will then exit the water, be dried off and rewarmed with either lie inside a vapor barrier within a hooded sleeping bag with the head inside the hood, or sitting with their distal arms and legs immersed in either Fluidotherapy at 50°C or warm water at 45°C. The rewarming will be administered for 60 minutes or until the core temperature returns to normal values (̴36.5-37˚C). The order of warming methods will follow a balanced design.

• Study Type: Interventional
• Enrollment (Actual): 8
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Manitoba
    • Winnipeg, Manitoba, Canada, R3T 2N2
      • University of Manitoba

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• 18-45 yrs old, males or females, healthy

Exclusion Criteria:

• cardiopulmonary disease
• any symptoms caused by cold exposure

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Core temperature rewarming rate	Esophageal temperature will be measured to determine the rate of core temperature increase during rewarming periods	Sixty minutes post-cooling

Collaborators and Investigators

• Sponsor: University of Manitoba

Study record dates

Study Major Dates

• Study Start: May 1, 2013
• Primary Completion (Actual): December 1, 2013
• Study Completion (Actual): December 1, 2013

Study Registration Dates

• First Submitted: April 4, 2013
• First Submitted That Met QC Criteria: April 4, 2013
• First Posted (Estimate): April 9, 2013

Study Record Updates

• Last Update Posted (Estimate): December 3, 2015
• Last Update Submitted That Met QC Criteria: December 2, 2015
• Last Verified: December 1, 2015

More Information

Terms related to this study

• Keywords: hypothermia; rewarming; core cooling; afterdrop; hospital treatment
• Additional Relevant MeSH Terms: Body Temperature Changes; Hypothermia
• Other Study ID Numbers: B2013:039; NSERC 2011-6 (Other Grant/Funding Number: NSERC Discovery Grant)