Condition category
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Dr JE Smith


Contact details

Selly Oak Hospital
B29 6JD
United Kingdom
+44 (0)121 627 1627

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title


Study hypothesis

The object of the study is to determine whether laryngoscope-assisted fibreoptic intubation results in better airway clearance and a shorter intubation time than other methods of fibreoptic intubation, and also to determine if laryngoscope-assisted fibreoptic intubation reduces the cardiovascular response to intubation.

Ethics approval

Not provided at time of registration

Study design

Randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting

Not specified

Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Surgery: Intubation


The investigators will carry out the normal bedside assessment of the airways of patients who require orotracheal intubation as part of their anaesthetic management. If a patient presents one of the criteria for difficult intubation {viz Mallampati class III or IV, thyromental distance <6.5 cm, interincisor distance between 3 and 5 cm, protruding upper teeth, small mouth or mandible or reduced neck mobility) he or she will be invited to take part in the trial. He or she will then be scheduled for an orotracheal fibreoptic intubation, since this is the most appropriate treatment when there is an increased risk of difficult intubation.

A normal general anaesthetic will be given comprising pre-oxygenation with 100% oxygen, induction with fentanyl (l mcg/kg) and propofol (2.5 mg/kg) and ventilation of the lungs with oxygen, nitrous oxide and isoflurane (0.5% end-tidal) with the aid of a Guedel airway. After confirmation of easy ventilation of the lungs, atracurium (0.5 mg/kg) will be given and mask ventilation will be continued until muscular relaxation is complete.

Immediately before intubation, patients will be randomised to have one of three manoeuvres to facilitate fibreoptic intubation:
1. Jaw thrust while keeping the mouth open together with lingual traction applied using Duval's forceps.
2. The insertion of a Berman airway into the mouth.
3. The insertion of a Macintosh size 3 laryngoscope into the mouth, placing its tip into the vallecula and lifting the tongue anteriorly.

The following timings will be made on every patient:
1. Endoscopy time - the time for the fibrescope to pass from the lips to the carina and
2. Intubation time - the time from the fibrescope passing between the lips to the detection of carbon dioxide by the gas analyser.

Heart rate, non-invasive blood pressure and pulse oximetry will be measured and recorded at 1 min intervals throughout the procedure. After intubation, the patient's surgery will commence. The patients will be reviewed in the Recovery area and on the first postoperative day, on the general ward. The presence of pharyngeal or lingual discomfort will be assessed and graded as mild, moderate or severe.

If the oxygen saturation falls below 97% at any time, or the electrocardiogram (ECG) or blood pressure (BP) readings fall outside normal limits, or if the endoscopy is not completed with 60 s, or if there is any concern for the patient's safety, the study period will end and appropriate action will be taken to treat the patient and facilitate endotracheal intubation.

Intervention type



Not Specified

Drug names

Primary outcome measures

Not provided at time of registration

Secondary outcome measures

Not provided at time of registration

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

45 Patients will be recruited to the study.

1. Aged 16-65
2. American Society of Anesthesiologists (ASA) 1 or 2
3. Undergoing elective procedures requiring orotracheal intubation
4. Presenting one clinical sign predicting difficult intubation
5. Giving informed written consent.

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Cardiovascular or cerebrovascular disease
2. Diabetes
3. Autonomic neuropathy
4. Patients taking vasoactive drugs
5. Oesophageal reflux
6. Morbid obesity (Body Mass Index [BMI] >35)
7. Fixed flexion deformity of the spine
8. Patients known to be difficult intubations
9. Patients demonstrating multiple clinical signs which in combination strongly predict difficult intubation

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

B29 6JD
United Kingdom

Sponsor information


Department of Health (UK)

Sponsor details

Richmond House
79 Whitehall
United Kingdom

Sponsor type




Funder type


Funder name

University Hospital Birmingham NHS Trust (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

1. 1991 comparison of two methods of fibrescope-guided tracheal intubation in

Publication citations

  1. Smith JE, Mackenzie AA, Scott-Knight VC, Comparison of two methods of fibrescope-guided tracheal intubation., Br J Anaesth, 1991, 66, 5, 546-550.

Additional files

Editorial Notes