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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
A randomised controlled trial of forced air warming for patients undergoing interventional cardiology procedures with sedation
Scientific title
Maintaining normoTHERMIa during SEDation in the cardiac catheterisation laboratory: A randomised controlled trial
Secondary ID [1] 288196 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
sedation 297102 0
hypothermia 297103 0
Condition category
Condition code
Anaesthesiology 297341 297341 0 0
Other anaesthesiology
Cardiovascular 297342 297342 0 0
Other cardiovascular diseases

Study type
Description of intervention(s) / exposure
Participants randomised to the intervention group will receive forced air warming for the duration of the procedure. The WarmTouchTM WT 6000 Warming Unit (Covidien, USA) will be used. The ‘upper body’ blanket attachment will be used for percutaneous coronary interventions and ablation of cardiac arrhythmias. The ‘lower body’ blanket attachment will be used for cardiac rhythm management device implantation procedures. Device temperature will be initially set at 43 degrees C. Participants will be monitored for sweating, flushing and thermal discomfort so that the device temperature can be titrated accordingly. The step-down protocol will be followed if a participant complains of feeling uncomfortable (Appendix A). Temperature will also be monitored at 30 minute intervals using an infrared aural canal thermometer for warming device titration purposes. If temperature rises above 37.5 degrees C, active warming will be ceased. Active warming will be ceased at the end of procedures.
Intervention code [1] 293498 0
Treatment: Devices
Comparator / control treatment
All randomised participants will receive usual care, which involves passive warming with heated cotton blankets throughout the peri-procedural period that will be applied at the discretion of the nurses.
Control group

Primary outcome [1] 296901 0
Hypothermia defined as temperature less than 36 degrees C (measured non-invasively with an oral digital thermometer placed in the left or right sublingual pocket)
Timepoint [1] 296901 0
As soon as possible post-procedure (within 5 minutes)
Secondary outcome [1] 319659 0
mean change in temperature (measured non-invasively with an oral digital thermometer placed in the left or right sublingual pocket)
Timepoint [1] 319659 0
pre to post procedure (on entry to department for pre-procedural measurement and as soon as possible post procedure, within 5 minutes)
Secondary outcome [2] 319660 0
Thermal comfort (Research assistant will ask participants, using a standardised script, to score how comfortable they are with their body temperature on a five point scale with the indicators 'Too cold', 'cool', 'just right', 'warm', 'too warm')
Timepoint [2] 319660 0
As soon as possible post-procedure (within 5 minutes)
Secondary outcome [3] 319661 0
Major complications (from a medical chart review), defined as:
a. Local infection that required re-intervention (not just antibiotics); or
b. Systemic infection/endocarditis.

c. Bleeding (TIMI major [symptomatic intracranial haemorrhage, clinically overt signs of bleeding associated with a drop in haemoglobin of more than 4g/dL or fatal bleeding] or required blood transfusion or procedural/surgical re-intervention)

d. Cardiovascular complications
i. Cardiac arrest (defined as ventricular fibrillation, asystole, electromechanical dissociation or ventricular tachycardia without cardiac output that required cardiopulmonary resuscitation and cardioversion)
ii. Myocardial infarction (defined as confirmed myocardial infarction distinct from index event)
Timepoint [3] 319661 0
30 days post-procedure
Secondary outcome [4] 319662 0
Cost-effectiveness (The net monetary benefit (NB) for the alternate treatment options will be calculated by multiplying the effect by the willingness-to-pay threshold minus the cost. The cost-effective intervention will be the one that yields the highest expected NB.)
Timepoint [4] 319662 0
30 days post-procedure
Secondary outcome [5] 319663 0
Disability-free survival (measured with the World Health Organization Disability Assessment Schedule 2.0)
Timepoint [5] 319663 0
30 days post-procedure
Secondary outcome [6] 319664 0
Feasibility of conducting a larger clinical trial (Descriptive statistics will be used to calculate rate of recruitment, the number of eligible patients who agreed to participate, the number of patients who received the correct protocol and the number of patients who completed the trial. Acceptability of the intervention will be evaluated by using descriptive statistics to determine the number of intervention group participants who did not tolerate the active warming device for the whole procedure.)
Timepoint [6] 319664 0
30 days post-procedure

Key inclusion criteria
Patients undergoing an interventional procedure for cardiovascular disease in the Cardiac Catheter Theatres at The Wesley Hospital and the Cardiac Catheter Laboratory at St Vincent’s Private Hospital, Sydney that is expected to require sedation and be of more than 30 minutes duration will be included. Interventional procedures include percutaneous coronary interventions, implantation of cardiac rhythm management devices (e.g. permanent pacemaker, implantable cardioverter-defibrillator) and ablation of cardiac arrhythmias.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Patients will be excluded from the study if they:

-are less than 18 years of age;
-are cognitively impaired (due to inability to provide informed consent);
-are unable to understand and speak English (due to inability to provide written informed consent);
-are undergoing an emergency procedure (e.g. percutaneous coronary intervention for ST elevation myocardial infarction);
-are undergoing a diagnostic procedure (e.g. coronary angiogram, electrophysiology study without ablation);
-have a current temperature above 37.5 degrees C;
-are scheduled for general anaesthesia.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Sealed opaque envelopes organized in sequential order will be used to conceal the allocation to intervention and control groups. The RA will hand the envelope to the Scout nurse only once eligibility and consent has been confirmed.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
All consented eligible patients will be allocated randomly to intervention and control groups. A statistician from the Institute of Health and Biomedical Innovation’s Research Methods Group with no clinical involvement in the trial will generate a stratified (by site and into groups where an anaesthetist is going to be present during the procedure or not) block randomised sequence. Participants will be grouped into these strata because it will be important for the use of propofol to be balanced between the intervention and control groups. In our previous study we identified that the administration of propofol, which is only used when an anaesthetist is present, was an independent predictor of hypothermia.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 4986 0
The Wesley Hospital - Auchenflower
Recruitment hospital [2] 4987 0
St Vincent's Private Hospital (Darlinghurst) - Darlinghurst

Funding & Sponsors
Funding source category [1] 292589 0
Name [1] 292589 0
St Vincent's Clinic Foundation
Address [1] 292589 0
St Vincent’s Clinic Foundation
Level 4
St Vincent’s Clinic
438 Victoria Street
Darlinghurst NSW 2010
Country [1] 292589 0
Funding source category [2] 292590 0
Government body
Name [2] 292590 0
National Health and Medical Research Council
Address [2] 292590 0
National Health and Medical Research Council

GPO Box 1421

Canberra ACT 2601
Country [2] 292590 0
Funding source category [3] 292591 0
Commercial sector/Industry
Name [3] 292591 0
Address [3] 292591 0
Covidien LP, a Medtronic company, located at 6135 Gunbarrel Avenue, Boulder, Colorado 80301 USA (“Covidien”)
Country [3] 292591 0
United States of America
Primary sponsor type
Queensland University of Technology
Institute of Health & Biomedical Innovation
60 Musk Ave
Kelvin Grove QLD 4059
Secondary sponsor category [1] 291311 0
Name [1] 291311 0
Address [1] 291311 0
Country [1] 291311 0

Ethics approval
Ethics application status
Ethics committee name [1] 294073 0
Uniting Care Health HREC
Ethics committee address [1] 294073 0
Ground Floor Moorlands House
The Wesley Hospital
451 Coronation Drive, Auchenflower QLD 4066
Ethics committee country [1] 294073 0
Date submitted for ethics approval [1] 294073 0
Approval date [1] 294073 0
Ethics approval number [1] 294073 0
Ethics committee name [2] 294074 0
St Vincent's Hospital HREC
Ethics committee address [2] 294074 0
390 Victoria St
Darlinghurst NSW 2010
Ethics committee country [2] 294074 0
Date submitted for ethics approval [2] 294074 0
Approval date [2] 294074 0
Ethics approval number [2] 294074 0

Brief summary
Hypothermia is a known adverse effect of general and regional anaesthesia. It is associated with increased risk of complications including surgical site infections and bleeding. For this reason, it is recommended that strategies are implemented to prevent hypothermia. The most effective strategy is forced-air warming. Of note, with advances in medical technology continuing to expand the indications for minimally invasive surgical techniques, sedation is likely to be increasingly used for many procedures that once could only be performed with general anaesthesia. Interventions to prevent hypothermia from occurring, such as forced air warming, are not currently used for sedated patients. Yet, we recently observed in one of our previous studies that about one quarter of patients undergoing procedures with sedation were hypothermic after their procedure. Sedated patients who become hypothermic may be at similar risk of developing complications, like infections and bleeding, to those patients who undergo a general or regional anaesthetic. As such, investigation of the clinical benefits of preventing hypothermia in sedated patients is required. This research aims to determine whether forced air warming reduces hypothermia in sedated patients. The results could potentially benefit the large number of patients undergoing interventional procedures with sedation.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 62334 0
Dr Aaron Conway
Address 62334 0
Queensland University of Technology
Institute of Health and Biomedical Innovation
60 Musk Ave
Kelvin Grove QLD 4059
Country 62334 0
Phone 62334 0
Fax 62334 0
Email 62334 0
Contact person for public queries
Name 62335 0
Dr Aaron Conway
Address 62335 0
Queensland University of Technology
Institute of Health and Biomedical Innovation
60 Musk Ave
Kelvin Grove QLD 4059
Country 62335 0
Phone 62335 0
Fax 62335 0
Email 62335 0
Contact person for scientific queries
Name 62336 0
Dr Aaron Conway
Address 62336 0
Queensland University of Technology
Institute of Health and Biomedical Innovation
60 Musk Ave
Kelvin Grove QLD 4059
Country 62336 0
Phone 62336 0
Fax 62336 0
Email 62336 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary