Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12613000531718
Ethics application status
Approved
Date submitted
12/04/2013
Date registered
13/05/2013
Date last updated
14/10/2015
Type of registration
Prospectively registered

Titles & IDs
Public title
Cerebral oxygenation in the beachchair surgical patient
Scientific title
The effect of vasopressor therapy versus a placebo saline infusion on cerebral oxygen saturation during shoulder surgery in the beachchair position.
Secondary ID [1] 282324 0
NIL
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Intraoperative cerebral ischaemia 288867 0
Beachchair position during shoulder surgery 288868 0
Condition category
Condition code
Anaesthesiology 289209 289209 0 0
Anaesthetics
Surgery 289210 289210 0 0
Surgical techniques
Stroke 289211 289211 0 0
Ischaemic

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This study will investigate the effects of clinically used vasopressor drugs versus saline infusion on cerebral blood flow and oxygenation, in patients placed into beach chair position for shoulder surgery. Following interscalene brachial plexus anaesthesia with 20-30 ml ropivicaine 0.75%, general anaesthesia will be induced with propofol 50-200mg and maintained on sevoflurane 2-3%. Following stabilisation an infusion of either noradrenaline (20 microg/ml), phenylephrine (100 microg/ml), ephedrine (300 microg/ml) or vasopressin (0.3 U/ml) will be commenced. Infusions are equipotent in concentration and will initially commence at a rate of 6 ml/hr. At 2.5 minutely intervals, the infusion rate will be increased stepwise to 15, 30, 45 and 60 ml/hr. Infusion is titrated until the mean arterial pressure increases to 120 % baseline/or cerebral desaturation decreases to 80% baseline. Infusion is maintained within these limits whilst patient placed into beachchair position for surgery. The duration of intervention is 1 hour.
Intervention code [1] 286939 0
Treatment: Surgery
Intervention code [2] 286940 0
Treatment: Drugs
Comparator / control treatment
In control patients saline will be infused at the same rate as the vasopressor infusion, and for the same duration. Infusions will be unmarked and contents unknown to the observer making measurements.
Control group
Placebo

Outcomes
Primary outcome [1] 289321 0
Cerebral oxygen delivery in the beach chair position. Measurement of frontal lobe cerebral oxygenation by near infra-red spectroscopy.
Timepoint [1] 289321 0
The primary timepoint is beachchair positioning, which occurs following induction and at completion of vasopressor infusion.
Secondary outcome [1] 302236 0
Change in arterial blood pressure using intra-arterial pressure monitoring with transducer placed at tragus, and heart rate from ECG.
Timepoint [1] 302236 0
The secondary timepoint is beachchair positioning, which occurs following induction and at completion of vasopressor infusion.
Secondary outcome [2] 318261 0
An ipsilateral change in cerebral oxygen saturation following interscalene blockade. Measurement of frontal lobe cerebral oxygenation by near infra-red spectroscopy.
Timepoint [2] 318261 0
Following interscalene blockade until post-induction before vasopressor infusion.

Eligibility
Key inclusion criteria
>18 years of age
Shoulder surgery suitable for beach chair position
Able to provide informed consent
Minimum age
18 Years
Maximum age
80 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Previous cerebrovascular event
Current cardiac disease including pacemaker Cerebrovascular disease
Significant cardiac or respiratory impairment
Contraindications to interscalene block
Inadequate understanding of English
Body Mass Index (BMI) > 35

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)
Discussion of the study with patient prior to surgery, followed by informed, written consent.
Placement in control or intervention groups will be decided via sealed envelopes on day of procedure. Patients will be randomised to one of five groups:
Arm 1: Normal saline control
Arm 2: Noradrenaline (20 microg/ml)
Arm 3: Phenylephrine (100 microg/ml))
Arm 4: Ephedrine ( 300 microg/ml)
Arm 5: Vasopressin ( 0.3 U/ml)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Equal numbers of randomisation pairs using a randomisation table created by computer software,and assigned in this order to sealed envelopes by an independent person.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
Intervention assignment
Parallel
Other design features
The anaesthetist is blinded to the infusion and an independent observer will record study measurements
Phase
Not Applicable
Type of endpoint/s
Safety/efficacy
Statistical methods / analysis
Data are presented as mean (SD). In a previous study vasopressor infusion was shown to have significant effects on MAP and ScO2 during BCP, with PE (100microgram.kg-1.min-1) increasing MAP by 38 mmHg, and decreasing ScO2 by 7%. Analysis indicated that a sample size of n = 40 (8 each group) was required to compare vasopressors (alpha 0.05, power 0.8). This sample number was particularly feasible for our resources and time commitment.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
21/05/2013
Actual
21/05/2013
Date of last participant enrolment
Anticipated
30/04/2014
Actual
26/08/2014
Date of last data collection
Anticipated
Actual
Sample size
Target
40
Accrual to date
Final
40
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment hospital [1] 886 0
The Avenue Private Hospital - Windsor
Recruitment hospital [2] 887 0
Glenferrie Private Hospital - Hawthorn
Recruitment postcode(s) [1] 6689 0
3181 - Windsor
Recruitment postcode(s) [2] 6690 0
3122 - Hawthorn

Funding & Sponsors
Funding source category [1] 287081 0
Charities/Societies/Foundations
Name [1] 287081 0
Melbourne Orthopaedic research group
Country [1] 287081 0
Australia
Primary sponsor type
Charities/Societies/Foundations
Name
Melbourne Orthopaedic Research Group
Address
33 The Avenue Windsor Vic 3181
Country
Australia
Secondary sponsor category [1] 285856 0
University
Name [1] 285856 0
University of Melbourne
Address [1] 285856 0
The Department of Pharmacology
Level 8, Medical Building (No. 181)
Corner of Grattan Street and Royal Parade
University of Melbourne
Victoria 3010 Australia
Country [1] 285856 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 289097 0
The Avenue Hospital Human Research Ethics comittee
Ethics committee address [1] 289097 0
40 The Avenue
Windsor 3181
Victoria
Ethics committee country [1] 289097 0
Australia
Date submitted for ethics approval [1] 289097 0
Approval date [1] 289097 0
12/08/2012
Ethics approval number [1] 289097 0
127

Summary
Brief summary
During shoulder surgery patients are positioned into an upright sitting position for optimal access to the shoulder joint.

In some patients blood pressure may decrease and a concern of the anaesthetist is whether sufficient blood reaches the brain during such surgery. Even though this can be routinely treated with cardiac drugs, the exact effect of this treatment on the brain is unknown.

This study plans to investigate the changes in flow to the brain when patients are anaesthetised and placed upright. The surgery will be performed using the anaesthetic technique that we use for the majority of the surgeon’s cases.

Special monitoring of the oxygen level within the brain, using reflected light waves, will be used. This technique is non-invasive and presents no harm to the patient. The study will investigate whether the administration of medication to gently increase blood pressure has an effect on blood flow to the brain, and on recovery following surgery. A number of commonly used drugs will be studied by infusing them into a large vein within the arm.

By agreeing to the study patients will give us permission to make these extra measurements during anaesthesia. This will help us understand whether we are protecting the brain during surgery.
Trial website
Trial related presentations / publications
Effect of phenylephrine on the haemodynamic state and cerebral oxygen saturation during anaesthesia in the upright position. P. F. Soeding, S. Hoy, G. Hoy, M. Evans and C. F. Royse
Br. J. Anaesth. (2013) 111 (2): 229-234 doi:10.1093/bja/aet024
Public notes

Contacts
Principal investigator
Name 39230 0
A/Prof Paul Soeding
Address 39230 0
Department of Pharmacology
Faculty of Medicine, Dentistry and Health Science
University of Melbourne
Grattan St
Parkville 3010
Victoria
Country 39230 0
Australia
Phone 39230 0
+61 3 8344 7483
Fax 39230 0
Email 39230 0
[email protected]
Contact person for public queries
Name 39231 0
A/Prof Paul Soeding
Address 39231 0
Department of Pharmacology
Faculty of Medicine, Dentistry and Health Science
University of Melbourne
Grattan St
Parkville 3010
Victoria
Country 39231 0
Australia
Phone 39231 0
+61 3 83447483
Fax 39231 0
Email 39231 0
[email protected]
Contact person for scientific queries
Name 39232 0
A/Prof Paul Soeding
Address 39232 0
Department of Pharmacology
Faculty of Medicine, Dentistry and Health Science
University of Melbourne
Grattan St
Parkville 3010
Victoria
Country 39232 0
Australia
Phone 39232 0
+61 3 8344 7483
Fax 39232 0
Email 39232 0
[email protected]

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No Supporting Document Provided



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