Forced-air Warming in Endovascular Surgery: Testing Effectiveness of Two Different Blanket Models

• Sponsor: Nelson Wolosker (Other)
• Overall Status: Completed
• CT.gov ID: NCT02742818
• Collaborator: (none)
• Enrollment: 50
• Arms: 2
• Duration (Months): 18

Study Details

Study Description

Brief Summary

Prospective randomized trial comparing effectiveness of two different forced-air warming blankets in patients undergoing lower extremity angioplasty (LEA) and endovascular abdominal aortic aneurysm repair (EVAR).

Condition or Disease	Intervention/Treatment	Phase
Hypothermia	Device: Upper body blanket, Bair Hugger; Device: Underbody blanket, Bair Hugger	N/A

Detailed Description

Fifty patients undergoing LEA and EVAR will be randomized into two groups: Group upper body blanket and Group underbody blanket. All patients will receive general anesthesia and body temperature will be measured and registered by an esophageal thermometer with 15 minutes interval beginning immediately after tracheal intubation up to tracheal extubation. The warming unit used (Bair Hugger 750 warming unit, Arizant Healthcare) will be the same for both groups and the blankets tested will be: upper body blanket (Bair Hugger 522 upper body blanket, 3M) and underbody blanket (Bair Hugger 635 full acess underbody blanket, 3M). Surgical and anesthetic complications will be noted. Only surgeries with minimum 45 minutes duration will be accepted for the purposes of this study.

Study Design

• Study Type: Interventional
• Actual Enrollment: 50 participants
• Allocation: Randomized
• Intervention Model: Parallel Assignment
• Masking: None (Open Label)
• Primary Purpose: Prevention
• Official Title: Forced-air Warming in Endovascular Surgery: Testing Effectiveness of Two Different Blanket Models
• Study Start Date: Sep 1, 2014
• Actual Primary Completion Date: Jun 1, 2015
• Actual Study Completion Date: Mar 1, 2016

Arms and Interventions

Arm	Intervention/Treatment
Other: Upper body blanket, Bair Hugger Patients undergoing EVAR and LEA will use this type of warming blanket.	Device: Upper body blanket, Bair Hugger; Upper body warming blanket will be used in patients undergoing LEA and EVAR.
Other: Underbody blanket, Bair Hugger Patients undergoing EVAR and LEA will use this type of warming blanket.	Device: Underbody blanket, Bair Hugger; Underbody warming blanket will be used in patients undergoing LEA and EVAR.

Outcome Measures

Primary Outcome Measures

1. Values of Body Temperature ( in Celsius Degree ) in Two Groups of Patients Undergoing EVAR and LEA That Will Use Two Different Types of Bair Hugger 3M Body Warming Blankets, Namely: 522 Upper Body Blanket and 635 Full Access Underbody Blanket. [Across duration of surgery (up to 210 minutes)]

   After tracheal intubation, upper body or underbody blanket will be turned on at the highest temperature of the warming unit ( 43 celsius degree) and the body temperatures will be measured and registered with an esophageal thermometer every 15 minutes until tracheal extubation. Temperatures will be compared with the purposes of determining which one of the two models tested are more effective in keeping patient warm. Values of body temperature across duration of surgery will be compared by models of variance analysis with repeated measurements. Duration of surgery will be used as a control variable.

Secondary Outcome Measures

1. Age ( in Years) [At time of surgery ( in minutes)]

   The investigators will observe the profile of the patients and the mean of age in two groups.

2. Gender [At time of surgery ( in minutes)]

   The investigators will observe gender distribution in the two groups studied.

3. Type of Surgery ( LEA and EVAR ) [At time of surgery ( in minutes)]

   The investigators will observe the type of surgery distribution profile in the two groups studied.

4. Duration of Surgery ( in Minutes) [Across duration of surgery ( in minutes)]

   The investigators will observe the duration of surgery (in minutes) in the two groups studied.

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years and Older
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Inclusion Criteria:

• Patients undergoing LEA and EVAR

• American Society of Anesthesiologists physical status (ASA) : 1-4

Exclusion Criteria:

• Non-endovascular surgery

• pregnant patients

• patient refusal

• less than 45 minutes duration of surgery

Contacts and Locations

Locations

No locations specified.

Sponsors and Collaborators

• Nelson Wolosker

Investigators

None specified.

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: Nelson Wolosker, MD, PHD, Hospital Israelita Albert Einstein
• ClinicalTrials.gov Identifier: NCT02742818
• Other Study ID Numbers: Forced-air warming in ES
• First Posted: Apr 19, 2016
• Last Update Posted: Dec 30, 2019
• Last Verified: Dec 1, 2019

• Keywords provided by Nelson Wolosker, MD, PHD, Hospital Israelita Albert Einstein: forced-air warming; hypothermia; endovascular surgery; blanket
• Additional relevant MeSH terms: Hypothermia

Study Results

Participant Flow

Arm/Group Title	Upper Body Blanket	Underbody Blanket
Arm/Group Description	Patients undergoing EVAR and LEA will use this type of warming blanket. 522 upper body blanket, Bair Hugger, 3M	Patients undergoing EVAR and LEA will use this type of warming blanket. 635 full access underbody blanket, Bair Hugger, 3M
Period Title: Overall Study
STARTED	25	25
COMPLETED	25	23
NOT COMPLETED	0	2

Baseline Characteristics

Arm/Group Title	Underbody Blanket	Upper Body Blanket	Total
Arm/Group Description	Patients undergoing EVAR and LEA will use this type of warming blanket. 635 full access underbody blanket, Bair Hugger, 3M	Patients undergoing EVAR and LEA will use this type of warming blanket. 522 upper body blanket, Bair Hugger, 3M	Total of all reporting groups
Overall Participants	23	25	48
Age (years) [Median (Inter-Quartile Range) ]
Median (Inter-Quartile Range) [years]	71	70	70.5
Sex: Female, Male (Count of Participants)
Female	8 34.8%	6 24%	14 29.2%
Male	15 65.2%	19 76%	34 70.8%

Outcome Measures

1. Primary Outcome

Title	Values of Body Temperature ( in Celsius Degree ) in Two Groups of Patients Undergoing EVAR and LEA That Will Use Two Different Types of Bair Hugger 3M Body Warming Blankets, Namely: 522 Upper Body Blanket and 635 Full Access Underbody Blanket.
Description	After tracheal intubation, upper body or underbody blanket will be turned on at the highest temperature of the warming unit ( 43 celsius degree) and the body temperatures will be measured and registered with an esophageal thermometer every 15 minutes until tracheal extubation. Temperatures will be compared with the purposes of determining which one of the two models tested are more effective in keeping patient warm. Values of body temperature across duration of surgery will be compared by models of variance analysis with repeated measurements. Duration of surgery will be used as a control variable.
Time Frame	Across duration of surgery (up to 210 minutes)

Outcome Measure Data

Analysis Population Description

In the Underbody blanket group 2 patients were excluded from analysis. One of the patients due to anaphylactic reaction and the other framed exclusion criteria (Surgery time lesser than 45 minutes)

Arm/Group Title	Upper Body Blanket	Underbody Blanket
Arm/Group Description	Patients undergoing EVAR and LEA will use this type of warming blanket. 522 upper body blanket, Bair Hugger, 3M	Patients undergoing EVAR and LEA will use this type of warming blanket. 635 full access underbody blanket, Bair Hugger, 3M
Measure Participants	25	23
Median (Full Range) [Celsius degrees]	36.2	36.1

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Upper Body Blanket, Underbody Blanket
	Comments
	Type of Statistical Test	Other
	Comments
Statistical Test of Hypothesis	p-Value	0.190
	Comments
	Method	Generalized Estimation Equations (GEE)
	Comments	Model assuming Gaussian distribution and AR-1 correlation structure, considering repeated measures in time.
Other Statistical Analysis		Through inference, changes in body temperature and proportional occurrence of hypothermia during surgery were evaluated using general models of estimating equations (GEE, Liang e Zeger, 1986). Binominal and normal distributions were taken into account, respectively, and assumptions for errors normalities were verified using residual plot graphs and fitted values. The significance of other associated factors and probable outcomes were verified, including gender, age, surgery type and total surgery duration, in minutes. Since analyses were longitudinal, AR-1 working correlation matrix was created.

2. Secondary Outcome

Title	Age ( in Years)
Description	The investigators will observe the profile of the patients and the mean of age in two groups.
Time Frame	At time of surgery ( in minutes)

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Upper Body Blanket	Underbody Blanket
Arm/Group Description	Patients undergoing EVAR and LEA will use this type of warming blanket. 522 upper body blanket, Bair Hugger, 3M	Patients undergoing EVAR and LEA will use this type of warming blanket. 635 full access underbody blanket, Bair Hugger, 3M
Measure Participants	25	23
Median (Inter-Quartile Range) [years]	70	71

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Upper Body Blanket, Underbody Blanket
	Comments
	Type of Statistical Test	Other
	Comments
Statistical Test of Hypothesis	p-Value	0.820
	Comments
	Method	Wilcoxon (Mann-Whitney)
	Comments

3. Secondary Outcome

Title	Gender
Description	The investigators will observe gender distribution in the two groups studied.
Time Frame	At time of surgery ( in minutes)

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Underbody Blanket	Upper Body Blanket
Arm/Group Description	Patients undergoing EVAR and LEA will use this type of warming blanket. 635 full access underbody blanket, Bair Hugger, 3M	Patients undergoing EVAR and LEA will use this type of warming blanket. 522 upper body blanket, Bair Hugger, 3M
Measure Participants	23	25
Male	15 65.2%	19 76%
Female	8 34.8%	6 24%

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Upper Body Blanket, Underbody Blanket
	Comments
	Type of Statistical Test	Other
	Comments
Statistical Test of Hypothesis	p-Value	0.529
	Comments
	Method	Chi-squared
	Comments

4. Secondary Outcome

Title	Type of Surgery ( LEA and EVAR )
Description	The investigators will observe the type of surgery distribution profile in the two groups studied.
Time Frame	At time of surgery ( in minutes)

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Upper Body Blanket	Underbody Blanket
Arm/Group Description	Patients undergoing EVAR and LEA will use this type of warming blanket. 522 upper body blanket, Bair Hugger, 3M	Patients undergoing EVAR and LEA will use this type of warming blanket. 635 full access underbody blanket, Bair Hugger, 3M
Measure Participants	25	23
EVAR	13 56.5%	12 48%
LEA	12 52.2%	11 44%

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Upper Body Blanket, Underbody Blanket
	Comments
	Type of Statistical Test	Other
	Comments
Statistical Test of Hypothesis	p-Value	0.999
	Comments
	Method	Chi-squared
	Comments

5. Secondary Outcome

Title	Duration of Surgery ( in Minutes)
Description	The investigators will observe the duration of surgery (in minutes) in the two groups studied.
Time Frame	Across duration of surgery ( in minutes)

Outcome Measure Data

Analysis Population Description

Models of generalized estimation equations will be used to evaluate the evolution of body temperature across duration of surgery (in minutes)

Arm/Group Title	Upper Body Blanket	Underbody Blanket
Arm/Group Description	Patients undergoing EVAR and LEA will use this type of warming blanket. 522 upper body blanket, Bair Hugger, 3M	Patients undergoing EVAR and LEA will use this type of warming blanket. 635 full access underbody blanket, Bair Hugger, 3M
Measure Participants	25	23
Median (Inter-Quartile Range) [minutes]	180	210

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Upper Body Blanket, Underbody Blanket
	Comments
	Type of Statistical Test	Other
	Comments
Statistical Test of Hypothesis	p-Value	0.462
	Comments
	Method	Wilcoxon (Mann-Whitney)
	Comments

Adverse Events

Arm/Group Title	Upper Body Blanket		Underbody Blanket
Arm/Group Description	Patients undergoing EVAR and LEA will use this type of warming blanket. 522 upper body blanket, Bair Hugger, 3M		Patients undergoing EVAR and LEA will use this type of warming blanket. 635 full access underbody blanket, Bair Hugger, 3M
All Cause Mortality
	Upper Body Blanket		Underbody Blanket
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	/ (NaN)		/ (NaN)
Serious Adverse Events
	Upper Body Blanket		Underbody Blanket
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/25 (0%)		1/25 (4%)
Immune system disorders
Anaphylatic reaction	0/25 (0%)	0	1/25 (4%)	1
Other (Not Including Serious) Adverse Events
	Upper Body Blanket		Underbody Blanket
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/25 (0%)		1/25 (4%)
Immune system disorders
Anaphylatic reaction	0/25 (0%)	0	1/25 (4%)	1

Limitations/Caveats

[Not Specified]

More Information

Certain Agreements

Principal Investigators are NOT employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.