Evaluation of the Ambu ® aScope® for Tracheal Intubation in Difficult Airways

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01467739
Recruitment Status : Completed
First Posted : November 9, 2011
Last Update Posted : December 16, 2013
Information provided by (Responsible Party):
Patrick Schoettker,MD PD, University of Lausanne Hospitals

Brief Summary:
The purpose of this study is to evaluate a disposable fiberscope (Ambu ® aScope®) for tracheal intubation in difficult airways due to cervical immobilization by a cervical collar, and compare it to a conventional reusable fiberscope.

Condition or disease Intervention/treatment Phase
Surgical Intervention Endotracheal Intubation Device: Ambu ® aScope® Device: a conventional reusable fiberscope Not Applicable

Detailed Description:

Any general anesthesia requiring tracheal intubation for controlled ventilation includes the likelihood of intubation failure and, in case of difficult or impossible mask ventilation, can be life-threatening. In patients with diagnosed or suspected disease of the cervical spine, airway control can be tricky. Indeed, the cervical collar used to secure the cervical spine makes direct laryngoscopy impossible. In elective surgery, the most commonly used technique is fiberoptic intubation, achievable without removing of the cervical collar.

A new disposable fiberscope was recently developed by Ambu ®: the aScope®. It consists of a disposable flexible fiberscopic device, whose distal end is fitted with a camera that can be directed. This device is connected to a separate reusable LCD display. The aScope® is used as a conventional flexible fiberscope to guide the instrumentation of the airway.

With the exception of case reports, all studies of this device in difficult conditions were performed on mannequins.

The investigators propose to assess and validate this device on real patients with difficult airways caused by a rigid cervical collar and compare intubation conditions and time to the gold standard technique, the classical reusable fiberscope.

Induction of general anesthesia is performed by the anesthesiologist responsible for the patient, according to the standards in the anesthesiology department.

The cervical collar is fitted and positioned once the patient is asleep in addition to a dedicated oropharyngeal cannula (Ovassapian fiberoptic intubating airway cannula) in order to guide the aScope® or fiberscope in the oropharynx. The timer is activated once the investigating physician takes the aScope® or fiberscope in his hands. The device is advanced into the airway with visual control on the LCD screen for the aScope® or on an external dedicated screen for the fiberscope. Once in the trachea, the device will serve as a guide for introduction of the orotracheal tube, according to standard fiberscopic intubation technique. Tracheal intubation is confirmed through visualization of the distal end of the tube into the trachea, the onset of an end tidal CO2 curve and auscultation. The timer will be stopped at the onset of the end tidal CO2 curve.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 100 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Official Title: Evaluation of the Ambu ® aScope® for Tracheal Intubation During Cervical Spine Immobilization With a Cervical Collar, in Comparison With a Conventional Reusable Fiberscope.
Study Start Date : June 2011
Actual Primary Completion Date : November 2011
Actual Study Completion Date : November 2011

Arm Intervention/treatment
Active Comparator: Ambu ® aScope® Device: Ambu ® aScope®
Active Comparator: a conventional reusable fiberscope. Device: a conventional reusable fiberscope

Primary Outcome Measures :
  1. Effectiveness of the Ambu ® aScope® for tracheal intubation in difficult airways.
    Time to reach the carina and Time to obtain an end tidal CO2 curve by aScope in comparison to conventional reusable fiberscope.

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Ages Eligible for Study:   16 Years and older   (Child, Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Patients older than 16 years
  • ASA 1-2
  • BMI < 35 kg/m2
  • Surgery requiring general anesthesia with intubation of the trachea

Exclusion Criteria:

  • Emergency operation
  • Patient ASA 3 or more
  • BMI above 35 kg/m2
  • History of difficult airways
  • History of surgery or radiotherapy in head and neck
  • Presence of gastro esophageal reflux

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01467739

University of Lausanne Hospitals
Lausanne, Vaud, Switzerland, 1011
Sponsors and Collaborators
University of Lausanne Hospitals

Publications of Results:
Responsible Party: Patrick Schoettker,MD PD, MD, University of Lausanne Hospitals Identifier: NCT01467739     History of Changes
Other Study ID Numbers: 88/11
First Posted: November 9, 2011    Key Record Dates
Last Update Posted: December 16, 2013
Last Verified: December 2013