Comparison of a New Patient Warming System Using Polymer Conductive Warming With Forced Air Warming During Surgery (HDV)

This study has been completed.
Sponsor:
Information provided by:
Medical University of Vienna
ClinicalTrials.gov Identifier:
NCT00772460
First received: October 14, 2008
Last updated: September 18, 2009
Last verified: September 2009
  Purpose

Two patient warming systems will be compared with 40 patients each in a convective warming group (BairHugger, Arizant) and in a conductive warming group (HotDog, Augustine Biomedical).

The patients will undergo small to medium trauma surgery and will be warmed with the randomized device - the hypothesis is, that the area under the standardized core temperature / time curve is significantly greater in the conductive warming group. Secondary outcome is the mean skin temperature / time area under the curve.


Condition Intervention Phase
Hypothermia
Device: Patient Warming with conductive / convective warming
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Single Blind (Subject)
Primary Purpose: Treatment
Official Title: Comparison of a New Patient Warming System Using Polymer Conductive Warming With Forced Air Warming During Surgery

Resource links provided by NLM:


Further study details as provided by Medical University of Vienna:

Primary Outcome Measures:
  • Area under the standardized "core temperature * time" curve [ Time Frame: intraoperatively ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Area under "mean skin temperature * time" curve [ Time Frame: intraoperatively ] [ Designated as safety issue: No ]

Enrollment: 80
Study Start Date: October 2008
Study Completion Date: June 2009
Primary Completion Date: June 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Forced Air
Warming with forced air (BairHugger)
Device: Patient Warming with conductive / convective warming
Warming device set to maximum (43 °C)
Experimental: Conductive Warming
Warming with the conductive device (HotDog)
Device: Patient Warming with conductive / convective warming
Warming device set to maximum (43 °C)

Detailed Description:

General study design We will study 200 patients (18-90 years) undergoing elective orthopedic surgery at the trauma surgery unit. The patients must have normal weight (20-30 BMI), the duration of surgery should last between 3 - 4 hours. There will be no other exclusion criteria (except severe peripheral arterial disease in the warmed extremity), as forced air patient warming is routinely used for all patients during this procedure.

The patients will be randomly assigned via a computer generated randomization list to treatment with either polymer or forced air warming. Anaesthesia and fluid management will be administered as desired by the anaesthesiologist.

Before warming four skin temperature probes will be attached to the upper arm, chest, abdomen and back of the patients to calculate mean body temperature. A probe (Mallinckrodt Anesthesiology Products, Inc., St. Louis, MO) will be introduced in the ear to measure core temperature. Afterwards, treatment with BairHugger or HotDog will be started.

The measurements will be recorded every five minutes until the end of surgery when intraoperative warming is stopped.

Differences between core temperatures will be analyzed both by using the summary measure of AUC (area under the curve) and by comparing the core-temperature at the end of surgery in the polymer and the forced air group with two-tailed, unpaired t tests if normally distributed and with a Wilcoxon test, if not normally distributed (distribution tested by K-S-test).

Results are expressed as means ± standard deviations if normally distributed, as median (IQ-Range) when not normally distributed.

Differences will be considered statistically significant when P < 0.05. We consider a difference in core temperature at the end of surgery of 0.5°C as clinically important. Considering this difference as well as a known standard deviation of approximately 1.5°C we will have to study 40 patients in each arm of the study to achieve statistical significance using a power of 90% and a p-value of 0.05.

  Eligibility

Ages Eligible for Study:   18 Years to 90 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • The patients must have normal weight (20-30 BMI), the duration of surgery should last between 3 - 4 hours.
  • There will be no other exclusion criteria , as forced air patient warming is routinely used for all patients during this procedure.

Exclusion Criteria:

  • Severe peripheral artery disease in the warmed extremity
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00772460

Locations
Austria
Medical University of Vienna
Vienna, Austria, 1090
Sponsors and Collaborators
Medical University of Vienna
Investigators
Principal Investigator: Oliver Kimberger, M.D. Medical University of Vienna
  More Information

No publications provided by Medical University of Vienna

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Dr. Oliver Kimberger, Medical University of Vienna
ClinicalTrials.gov Identifier: NCT00772460     History of Changes
Other Study ID Numbers: HotDogVienna
Study First Received: October 14, 2008
Last Updated: September 18, 2009
Health Authority: Austria: Ministry of Health

Keywords provided by Medical University of Vienna:
patient warming
convective warming
conductive warming
intraoperative normothermia
accidental hypothermia
intraoperative hypothermia

Additional relevant MeSH terms:
Hypothermia
Body Temperature Changes
Signs and Symptoms

ClinicalTrials.gov processed this record on October 29, 2014