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Trial registered on ANZCTR

Registration number
Ethics application status
Not yet submitted
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
A comparative trial of a new disposable laryngeal mask airway (LMA® SupremeTM) during anaesthesia in spontaneously breathing adult patients
Scientific title
A randomised, single-blinded, controlled trial of the LMA® SupremeTM disposable laryngeal mask versus LMA® ClassicTM during anaesthesia in spontaneously breathing adult patients
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Supralaryngeal device in spontaneuosly breathing patients 3120 0
Condition category
Condition code
Anaesthesiology 3283 3283 0 0

Study type
Description of intervention(s) / exposure
The intervention groups will receive either the LMA® SupremeTM (LMAS) or LMA® ClassicTM (LMAC) L aryngeal Mask Airway (LMA) for airway maintenance. We hypothesise that the LMA Supreme will provide superior cuff seal pressure than the classic LMA. We also believe the success rate on first attempt will be higher with the LMA Supreme. The ease of insertion, time to achieve effective airway, success rate on subsequent attempts, and incidence of oro-pharyngeal trauma will be measured and we believe they will be similar in all groups. The LMAC is a reusable supraglottic airway device that has been available since 1998 and is widely used during elective general anaesthesia where endotracheal intubation is not thought necessary. Newer single-use disposable supraglottic airway devices are now available, which potentially reduce the risk of infection transfer. The laryngeal mask is the most commonly used supraglottic device; its silicone construction ensures that it is easy to insert and minimises airway trauma. The Therapeutics Goods Administration in Australia has recently assessed a number of newer disposable LMAs, and they are now available for use in Australia. The LMAC is easy to insert, creates an effective airway seal but provides only limited protection against aspiration. The LMAC is silicone construction. The single use LMA Supreme is a new supraglottic airway device, which is a hybrid of the LMA Prosealâ„¢ (modified cuff for high seal pressures, integrated bite block and gastric access channel) and the LMA Fastrachâ„¢ (fixed curvature airway tube and guiding handle). These features should in theory enhance insertion,fixation, ventilation, airway protection and airway protection.Anaesthetic technique Routine anaesthetic monitoring, as per Australian and New Zealand College of Anaesthetists guidelines for general anaesthesia, will be instituted. A standardised general anaesthetic technique will be employed. Patients will not be pre-medicated. Induction of anaesthesia will utilise propofol 1-2 mg/kg, fentanyl (1-3 mg/kg), and midazolam (0.025-0.05 mg/kg), at the discretion of the anaesthetist concerned, to produce a loss of lash reflex. Following induction of anaesthesia patients undergo controlled ventilation using an anaesthetic facemask and 100% oxygen with sevoflurane (end tidal concentration at discretion of the anaesthetist). Following insertion of supraglottic airway device and return of spontaneous ventilation, maintenance of anaesthesia is to be achieved using sevoflurane (end tidal concentration at discretion of the anaesthetist) and a fresh gas flow with an inspired oxygen concentration of 70-100%. No nitrous oxide will be used. Small doses of metaraminol or phenylephrine can be administered to control systemic arterial blood pressure. Maintenance of general anaesthesia will be with sevoflurane in an oxygen:air mixture to achieve an inspired oxygen level of 70-100%. Insertion of supraglottic airway device A practitioner experienced in the use of LMA devices will carry out insertion. Routine recommended preinsertion tests of the control and study device will be performed. The airway device will be inserted when loss of lash reflex and jaw tone allows. Successful device placement will be confirmed by: · resistance to further downward movement of the device · cuff inflation with the appropriate volume of gas to achieve an intracuff pressure of 60cmH20. · effective ventilation as defined by assisted ventilation with chest wall movement, observance of a square wave capnograph trace and assisted ventilation without a leak at airway pressure of at least 10cmH20. At the conclusion of surgery the anaesthetic gases will be replaced by 100% oxygen to allow patient recovery. When protective reflexes are noted to have returned to normal, the airway device will be removed after deflation of the cuff. The device will be inspected for secretions and blood.
Intervention code [1] 2866 0
Treatment: Devices
Comparator / control treatment
LMA® SupremeTM disposable laryngeal mask (comparator) versus LMA® ClassicTM (control)
Control group

Primary outcome [1] 4171 0
Airway pressure leading to cuff leakage immediately after induction of general anesthesia and placement of LMA, measured in cmH20. The LMAC sealing pressures are between 20-25cmH20. No study to date has directly compared the sealing pressures between the LMAC and other silicone based LMAs. This may have important consequences with the use of these devices in patients where it is considered difficult to maintain a patient airway during general anaesthesia. A standardised amount of air will be injected to achieve cuff inflation pressure of 60cmH20. A manometric stability test (to a maximum pressure of 40 cm H20) will be performed to determine LMA leak pressure.
Timepoint [1] 4171 0
Immediately after induction of anaesthesia
Secondary outcome [1] 7034 0
Failure to establish an adequate airway (maximum of three attempts, intra-op)
Timepoint [1] 7034 0
Secondary outcome [2] 7035 0
First attempt insertion (intra-operative).
Timepoint [2] 7035 0
Based on observation intraoperatively.
Secondary outcome [3] 7036 0
Ease of insertion (intra-operative).
Timepoint [3] 7036 0
Assessed and reported by the Clinician at the end of the intervention period.
Secondary outcome [4] 7037 0
Time to achieve effective airway
Timepoint [4] 7037 0
intra-operative from induction of anaesthesia to time to achieve effective ventilation
Secondary outcome [5] 7038 0
Intra-cuff volume at standardized pressure or maximum intracuff pressure (intra-operative).
Timepoint [5] 7038 0
Measured at time of inflation of laryngeal mask.
Secondary outcome [6] 7039 0
Post-anaesthesia sore throat, hoarse voice and dysphagia in recovery (PACU).
Timepoint [6] 7039 0
Measured in recovery when the patient is awake and orientated and at 24 hours through question over telephone at 24 hours post-operatively.

Key inclusion criteria
Adult undergoing spontaneous ventilation general anaesthesia in whom a supraglottic airway device would have been chosen for maintenance of airway patency by the Anaesthetist responsible for the individual patient.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Individuals undergoing general anaesthesia in whom it would not have been appropriate to insert a supraglottic airway device for airway patency as determined by the anaesthetist responsible for that patient will be excluded. Such patients include:· Patients with morbid obesity (Body Mass Index 35 kg/m2)· Risk of aspiration· Limited interincisor distance (2.5 cm)· Known difficult airway.Patients who are unable to communicate in English, because of a language barrier, cognitive deficit or intellectual disability will not be approached.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Randomisation results will be concealed in opaque envelopes until after patient consent has been obtained.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Computer generated random sequence.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Blinding: subjects, data analyst. Un-blinded: Anaesthetist and assessor.
Phase 4
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Not yet recruiting
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)

Funding & Sponsors
Funding source category [1] 3363 0
Name [1] 3363 0
Royal Melbourne Hospital
Address [1] 3363 0
Grattan Street
Victoria 3050
Country [1] 3363 0
Primary sponsor type
Investigator Initiated (Daryl Williams)
Grattan Street
Victoria 3050
Secondary sponsor category [1] 3010 0
Name [1] 3010 0
Address [1] 3010 0
Country [1] 3010 0

Ethics approval
Ethics application status
Not yet submitted
Ethics committee name [1] 5388 0
Ethics committee address [1] 5388 0
Ethics committee country [1] 5388 0
Date submitted for ethics approval [1] 5388 0
Approval date [1] 5388 0
Ethics approval number [1] 5388 0
Ethics committee name [2] 5389 0
Melbourne Health HREC
Ethics committee address [2] 5389 0
Grattan Street
Victoria 3050
Ethics committee country [2] 5389 0
Date submitted for ethics approval [2] 5389 0
Approval date [2] 5389 0
Ethics approval number [2] 5389 0

Brief summary
Patients presenting for surgery at RMH eligible for LMA general anaesthesia
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 28573 0
Address 28573 0
Country 28573 0
Phone 28573 0
Fax 28573 0
Email 28573 0
Contact person for public queries
Name 11730 0
Daryl Williams
Address 11730 0
Grattan Street
Victoria 3050
Country 11730 0
Phone 11730 0
613 9342 7540
Fax 11730 0
Email 11730 0
Contact person for scientific queries
Name 2658 0
Daryl Williams
Address 2658 0
Grattan Street
Victoria 3050
Country 2658 0
Phone 2658 0
613 9342 7540
Fax 2658 0
Email 2658 0

No information has been provided regarding IPD availability
Summary results
No Results