Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12615000431527
Ethics application status
Approved
Date submitted
10/04/2015
Date registered
6/05/2015
Date last updated
16/02/2018
Type of registration
Retrospectively registered

Titles & IDs
Public title
Prewarming of surgical patients to prevent hypotension on induction of anaesthesia
Scientific title
Prewarming of neurosurgical patients to prevent hypotension on induction of anaesthesia
Secondary ID [1] 286503 0
Nil
Universal Trial Number (UTN)
U1111-1169-1635
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Hypotension on anaesthetic induction 294718 0
Condition category
Condition code
Anaesthesiology 295007 295007 0 0
Anaesthetics
Surgery 295192 295192 0 0
Other surgery

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Prewarming of neurosurgical patients for one hour at 46 degrees Celsius with a forced air warmer (Cocoon Convective Warming System 4000, Care Essentials, North Geelong, Victoria, Australia) prior to anaesthetic induction, after placement of intra-arterial blood pressure monitoring. The patient's temperature is measured prior to and at conclusion of warming
Intervention code [1] 291597 0
Treatment: Devices
Intervention code [2] 291755 0
Prevention
Comparator / control treatment
No prewarming of control group
Control group
Active

Outcomes
Primary outcome [1] 294761 0
Absolute difference in immediate pre- and nadir post-induction mean arterial pressure (MAP) using an arterial line
Timepoint [1] 294761 0
Immediately prior to laryngoscopy
Secondary outcome [1] 314008 0
Vasopressor dose and type used, composite secondary outcome. Contemporaneously recorded
Timepoint [1] 314008 0
Immediately prior to laryngoscopy
Secondary outcome [2] 314009 0
Incidence of hypotension defined as a decrease in mean blood pressure > 20% from immediate pre-induction value.
Timepoint [2] 314009 0
Immediately prior to laryngscopy

Eligibility
Key inclusion criteria
1. Neurosurgical patients aged 18 years and over
2. Craniotomy for any indication
3. American Society of Anesthesiologists’ (ASA) physical status 1-3
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
1. Inadequate English comprehension due to a language barrier, cognitive deficit or intellectual disability
2. Significant cardiorespiratory impairment (i.e. ASA 4-5 patients)
3. Severe hypertension (systolic BP > 180 mmHg, diastolic BP > 110 mmHg in the operating suite admission bay)
4. Antihypertensive therapy with ACE inhibitor/angiotensin II receptor antagonist if administered on the day of surgery
5. Secondary hypertension (e.g. renal artery stenosis, phaeochromocytoma, Cushing's syndrome)
6. Temperature > 37.5 degrees Celcius at baseline
7. Thyroid dysfunction
8. Otitis media/externa (preventing accurate tympanic membrane temperature measurement)

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Sealed opaque envelopes
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by computer software (computerised sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?


The people assessing the outcomes
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
The difference in mean arterial blood pressures between pre- and post- anaesthetic induction values between groups of equal or greater than 20 mmHg, assuming a standard deviation of 20 mmHg (accepted population standard deviation), an alpha error of 0.05 and power of 0.8 will require 16 patients in each group (32 patients total).

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
2/02/2015
Actual
29/01/2015
Date of last participant enrolment
Anticipated
Actual
22/06/2015
Date of last data collection
Anticipated
Actual
22/06/2015
Sample size
Target
32
Accrual to date
Final
32
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment hospital [1] 3687 0
Royal Melbourne Hospital - City campus - Parkville

Funding & Sponsors
Funding source category [1] 291070 0
Charities/Societies/Foundations
Name [1] 291070 0
Australian and New Zealand College of Anaesthetists
Country [1] 291070 0
Australia
Primary sponsor type
Individual
Name
Jai Darvall
Address
Department of Anaesthesia and Pain Management
Royal Melbourne Hospital
300 Grattan St
Parkville 3050
Country
Australia
Secondary sponsor category [1] 289750 0
None
Name [1] 289750 0
Address [1] 289750 0
Country [1] 289750 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 292654 0
Melbourne Health Human Research Ethics Committee
Ethics committee address [1] 292654 0
Office for Research
Royal Melbourne Hospital
300 Grattan St
Parkville VIC 3050
Ethics committee country [1] 292654 0
Australia
Date submitted for ethics approval [1] 292654 0
Approval date [1] 292654 0
02/12/2014
Ethics approval number [1] 292654 0
2014.211

Summary
Brief summary
General anaesthesia, whilst very safe, has some undesirable side effects. Two of these, a fall in body temperature and a fall in blood pressure, are usually very mild and require little treatment. Occasionally, more severe changes can result requiring significant intervention by the anaesthetist. Whilst prewarming of patients prior to surgery is sometimes employed to reduce the drop in body temperature seen with anaesthesia, it is not known whether this warming may also help reduce the fall in blood pressure.

Warming patients results in dilation of blood vessels, with some of the circulating blood volume then moving into more peripheral tissues. This is similar to the process that happens under anaesthesia, with the relaxation of blood vessels caused by anaesthetic drugs resulting in lowered blood pressure. This is usually mild and easily correctable with medications and intravenous fluid administered by the anaesthetist, though occasionally can be more serious.

This study aims to answer the question of whether prewarming patients may reduce the fall in blood pressure seen with the onset of anaesthesia, due to blood vessels already being dilated, and hence reduce the need for intervention by the anaesthetist.
Trial website
Trial related presentations / publications
Published in the Canadian Journal of Anesthesia (Can J Anaesth. 2016 May;63(5):577-583)
Public notes

Contacts
Principal investigator
Name 56414 0
Dr Jai Darvall
Address 56414 0
Department of Anaesthesia and Pain Management
Royal Melbourne Hospital
300 Grattan St
Parkville VIC 3050
Country 56414 0
Australia
Phone 56414 0
+61393427136
Fax 56414 0
Email 56414 0
jai.darvall@mh.org.au
Contact person for public queries
Name 56415 0
Jai Darvall
Address 56415 0
Department of Anaesthesia and Pain Management
Royal Melbourne Hospital
300 Grattan St
Parkville VIC 3050
Country 56415 0
Australia
Phone 56415 0
+61393427136
Fax 56415 0
Email 56415 0
jai.darvall@mh.org.au
Contact person for scientific queries
Name 56416 0
Jai Darvall
Address 56416 0
Department of Anaesthesia and Pain Management
Royal Melbourne Hospital
300 Grattan St
Parkville VIC 3050
Country 56416 0
Australia
Phone 56416 0
+61393427136
Fax 56416 0
Email 56416 0
jai.darvall@mh.org.au

No information has been provided regarding IPD availability


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
SourceTitleYear of PublicationDOI
EmbasePrewarming neurosurgical patients to minimize hypotension on induction of anesthesia: a randomized trial.2016https://dx.doi.org/10.1007/s12630-016-0601-6
N.B. These documents automatically identified may not have been verified by the study sponsor.