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Comparison of a Single Use (Ambu aScope) and a Reusable Flexible Optical Scope for Intubation Through a Supraglottic Airway Device (Aura-i)

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified May 2014 by Rigshospitalet, Denmark.
Recruitment status was:  Recruiting
Information provided by (Responsible Party):
Michael Seltz Kristensen, Rigshospitalet, Denmark Identifier:
First received: November 24, 2013
Last updated: May 20, 2014
Last verified: May 2014

In patient who are predicted to be difficult to intubate with a standard direct laryngoscope well use flexible optical intubation via a supraglottic airway devise (the Ambu Aura-i). Patients are randomly assigner to a single- or a multiple- use flexible optical scope.

We hypothesize that intubation is obtained equally effective with both types of flexible scopes

Condition Intervention
General Anesthesia
Procedure: tracheal intubation

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: A Comparison Between Flexible Single Use Endoscopes (Ambu aScopes) and Reusable Flexible Endoscopes Used as a Standard of Car When Intubation the Trachea Via an Aura-I Supraglottic Airway Device

Further study details as provided by Rigshospitalet, Denmark:

Primary Outcome Measures:
  • Duration of intubation. From the endoscope enters the supraglottic-airway-device to CO2-curve is seen [ Time Frame: Measured during tracheal intubation at induction of anesthesia ]

Secondary Outcome Measures:
  • Number of attempts at placing the supraglottic-airway-device (SAD) [ Time Frame: From anesthesia induction and the following 10 minutes during securing of the airway ]
    an attempt is defined as the tip of the SAD passing the upper front teeth

  • number of attempts at placing the flexible endoscope in the trachea [ Time Frame: From anesthesia induction and the following 10 minutes ]
  • number of attempts at intubation [ Time Frame: From anesthesia induction and during the following 10 minutes during airway management ]
    An intubation attempt starts when the tip of the endotracheal tube passes the entrance to the SAD

  • Total time for placement of SAD and endoscopy and intubation [ Time Frame: During induction of anesthesia and the following 10 minutes during airway management ]
  • The best glottic view obtained [ Time Frame: After anesthesia induction and during the following 10 minutes during airway management ]
  • The ease of passage of the flexible endoscope via the SAD [ Time Frame: During induction and airway management ]
  • The anesthesiologists' satisfaction with the procedure [ Time Frame: During induction of anesthesia and within the 30 minutes hereafter ]
  • The quality of the endoscopically obtained image [ Time Frame: During induction of anesthesia and the following 10 minutes during airway management ]
  • Postoperative sore throat, dysphonia or dysphagia one hour after extubation [ Time Frame: AT the time 1 hour after extubation of the trachea ]

Estimated Enrollment: 100
Study Start Date: November 2013
Estimated Primary Completion Date: December 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Single use flexible optical scope
Single use flexible optical scope , Ambu aScope
Procedure: tracheal intubation
Active Comparator: Multiple use flexible optical scope
Multiple use flexible optical scope
Procedure: tracheal intubation


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • ASA physical status 1-3 and evaluated pre-operatively and found suitable for tracheal intubation with a flexible optical scope via the SAD and scheduled for elective surgery/anesthesia and are conscious about their rights and consequences of participating in the study.
  • The patient must have one or two of the following predictors of difficult tracheal intubation:

    1. Modified Mallampati score > 2 (= "no parts of the Uvula is visible")
    2. a thyromental distance of less then or equal to 6.5 cms
    3. Combined movement in head and neck < 90 degrees
    4. Mouth-opening less the 4 cm (but must be larger then 2.5 cm)
    5. Inability to protrude the teeth n the lower jaw beyond the upper incisors
    6. BMI > 40 combined with a neck-circumference > 43 cms
    7. Upper-lip-bite-test > 2
    8. Previous difficult intubation or laryngoscopy (If more then two criteria are fulfilled the patient should be considered intubated awake instead. . But the upper-lip-bite-test and the prognation-beyond the incisors test represents a similar thing, namely the inability to sub-luxate the lower jaw, the if both these findings are positive it is only considered as counting for one.

Exclusion Criteria:

  • ASA physical status 4 or 5
  • contraindications for use of the SAD
  • Patients in whom intubation via a SAD has previously failed
  • Patients at risk of aspiration from the gastrointestinal channel
  • diseases in mouth, pharynx or larynx that precludes the use of a SAD
  • Patients in whom the cricothyroid membrane cannot be localized preanaesthetically
  • Patients in whom the doctor making the pre-anaesthetic evaluation finds in need of an awake intubation
  • Patients with possible Creutzfeldt-Jacobs disease or contraindication against the use of non-autoclavable equipment r risk of cross contamination with prions
  Contacts and Locations
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Please refer to this study by its identifier: NCT02002364

Contact: Michael S Kristensen, M.D. 0045 35458033

Rigshospitalet, Denmark Recruiting
Copenhagen, Denmark, 2100
Contact: Michael S Kristensen, M.D.    0045 3445 8033   
Principal Investigator: Michael S Kristensen, M.D.         
Service d'anesthesie-reanimation 1 avenue Moliere Hopiatl de Hautepierre Not yet recruiting
Strasbourg, France, 67098
Contact: Pierre Diemunsch, M.D.    0033 3 88 12 70 76   
Principal Investigator: Pierre Diemunsch, M.D.         
Sponsors and Collaborators
Rigshospitalet, Denmark
Principal Investigator: Michael S Kristensen Rigshospitalet, Denmark
  More Information

Responsible Party: Michael Seltz Kristensen, Consultant anaesthetist, Rigshospitalet, Denmark Identifier: NCT02002364     History of Changes
Other Study ID Numbers: Journal nr. H-3-2012-001
Study First Received: November 24, 2013
Last Updated: May 20, 2014

Keywords provided by Rigshospitalet, Denmark:
tracheal intubation processed this record on April 28, 2017