Efficacy of Blanketrol III and Arctic Sun in Cooling Non-shivering Humans

This study compares three medical cooling devices for effectiveness of cooling the core of non-shivering subjects. This relates to common protocols to cool patients experiencing myocardial infarctions or stokes.

Study Overview

• Status: Completed
• Conditions: Body Temperature Changes
• Intervention / Treatment: Device: Blanketrol cooling device and water-perfused blankets; Device: Blanketrol and Kool Kit; Device: Arctic Sun

Detailed Description

Body core and brain cooling by 1-3°C has been used as an adjunct in treatment of stroke and myocardial infarction (MI) patients. Body surface cooling is simple and non-invasive however this process is difficult to implement effectively because skin cooling stimulates shivering heat production, a defense mechanism that protects the body core from cooling. It is sometimes necessary to pharmacologically inhibit shivering in order to cool the body from surface cooling strategies such as application of cold packs or cold water-perfused blankets or pads.

Two commercial cooling units that are currently used are: 1) the Blanketrol III with standard Gel Pad (Gentherm Inc.); and 2) the Arctic Sun with hydrogel coated pads (Arctic Sun). A new cooling attachment system has been developed for the Blanketrol III. The new Kool Kit includes a head wrap, and a vest and lower body blanket. The effectiveness of the Kool Kit has not been quantified or compared to the current two systems mentioned above.

Since shivering heat production attenuates core cooling, it must be eliminated in clinical or research settings where core cooling effectiveness is the main dependent variable. Previous studies from this laboratory (Laboratory for Exercise and Environmental Medicine) have used a human model for severe hypothermia which meperidine (Demerol) is infused to inhibit shivering. Under these conditions the primary core cooling capacity of a cooling system can be determined.

The investigators intend to evaluate the Tco cooling rate, in hospital treatment conditions, [ambient temperature (Ta) = 22ºC] during surface cooling of non-shivering subjects with either: 1) Blanketrol with Gel Pads; 2) Blanketrol with Kool Kit; or 3) an Arctic Sun cooling system.

The purpose is to compare the core cooling rates induced by three commercial surface cooling devices in non-shivering subjects. Because of the increased total surface area of the cooling pads and blankets, the investigators hypothesize that the Blanketrol with Kool Kit will have a greater rate of core cooling than the other two cooling systems tested.

• Study Type: Interventional
• Enrollment (Actual): 12
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Manitoba
    • Winnipeg, Manitoba, Canada, R3T 2N2
      • 211 Max Bell Centre, 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:

• Healthy adults, who answer "No" to all the questions on a Get Active Questionnaire (GAQ) and the "Medical Screening Questionnaire for Hypothermia Study'.
• Participants will also be interviewed to determine that they are free of any cardio- respiratory disease, Raynaud's Syndrome, or any other conditions that can be aggravated by cold exposure.
• Also, the study will include women of child bearing potential willing to use highly effective birth control during the trial. All women of child bearing potential will complete the "Research participant information for female subjects" and undergo a pregnancy test at screening.

Exclusion Criteria:

• Anyone who gives a positive answer to any question in the GAQ or Medical Screening Questionnaire for Hypothermia Study, or who has any cardio-respiratory disease, renal dysfunction, Raynaud's Syndrome, past recreational drug use or any other conditions that can be aggravated by cold exposure will be excluded.
• Subjects contraindicated for meperidine administration or who have any of the conditions listed below will also be excluded from the study.
• hypersensitivity to meperidine or any ingredients in the formulation
• known or suspected mechanical GI obstruction or any diseases/conditions that affect bowel transit
• suspected surgical abdomen (i.e. acute appendicitis or pancreatitis)
• severe CNS depression, head injury, increased cerebrospinal or intracranial pressure
• convulsive disorder, delirium tremens
• hypothyroidism
• prostatic hypertrophy or urethral stricture
• sickle cell anemia
• Addison's disease
• Pheochromocitoma
• Known sensitivity or intolerance to the drug metoclopramide
• Use of medications that might interact negatively with meperidine. Examples should include MAO inhibitors at the time of screening or within 14 days of screening; CNS depressants; phenytoin; cimetidine; ritonavir; aclyclovir; skeletal muscle relaxants.
• pregnant women, breastfeeding women, and women planning on becoming pregnant

Study Plan

How is the study designed?

Design Details

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

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Non-shivering cooling group; Cooling devices	Device: Blanketrol cooling device and water-perfused blankets; Blanketrol and water-perfused blankets; Device: Blanketrol and Kool Kit; Blanketrol cooling device with water-perfused vest, hood and lower body blanket; Device: Arctic Sun; Arctic Sun cooling device with gel cooling pads

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Esophageal temperature cooling rate	Rate at which esophageal temperature decreases	120 minutes
Skin heat exchange	Body surface heat flux	120 minutes

Collaborators and Investigators

• Sponsor: University of Manitoba

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2020
• Primary Completion (Actual): April 30, 2022
• Study Completion (Actual): April 30, 2022

Study Registration Dates

• First Submitted: March 26, 2020
• First Submitted That Met QC Criteria: March 31, 2020
• First Posted (Actual): April 2, 2020

Study Record Updates

• Last Update Posted (Actual): January 23, 2023
• Last Update Submitted That Met QC Criteria: January 19, 2023
• Last Verified: March 1, 2021

More Information

Terms related to this study

• Keywords: hypoxia; brain cooling; medical body cooling devices; Brain protection
• Additional Relevant MeSH Terms: Body Temperature Changes
• Other Study ID Numbers: HS23118 (B2019:076)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No