The Fibre Optic Bronchoscope and Airway Topicalisation

04_The-fibre-optic-bronchoscopeThis Skill Station covers:

-Description, assembly and steering of the bronchoscope

-Aftercare of the bronchoscope

-Topicalisation of the airway

The Equipment - Bronchoscopes

The Olympus BFP-180

1 Steering lever

2 Working channel

3 Insertion cord

4 Suction / oxygen port

The Ambu aScope 3

1 Steering lever

2 Working channel

3 Insertion cord

4 Suction / oxygen port

The Essentials - Bronchoscopes

Visually guided techniques are preferable to blind techniques when appropriate equipment is available. The fibre optic bronchoscope can be used as an adjunct for the unanticipated difficult airway in a “can’t intubate can ventilate” situation (Plan B of DAS guidelines). It can also be used electively in the patient with a known difficult airway to facilitate intubation using one of the following techniques:

-Oral or nasal awake or asleep fiber optic intubation

-Fibre optically guided intubating LMA (Fastrach) technique

-Asleep fibre optic intubation via a conduit (the LMA or Berman airway)

It has been suggested that a learning curve can be constructed to predict the number of fibre optic intubations that are necessary to become competent. One study showed that trainees can become “reasonably proficient” after 18 supervised intubations and expert after 45 intubations.1 However, research suggests that preliminary practice on simple bronchial models allows trainees to gain the manual dexterity required to perform fibre optic intubations, and improves performance when confronted with real patients.2 Various home-made models have been described, as well as the Dexter™ training model3 and the more lifelike airway training manikins such as the Laerdal Airway Trainer™ and the Trucorp Airsim™, which have been found to be superior for teaching simple and advanced airway management skills.4 Video monitors are especially useful in the early stages of teaching and allow for feedback and guidance.5

Most fibre optic bronchoscopes are 60cm in length (some are 55cm). They are available in 1.8 – 6.4mm diameters, but commonly 4-5mm diameter:

Bronchoscope
Diameter (mm)
Working channel (mm)
Olympus BFP-180 4.9 2.0
Ambu aScope 3 5.0 2.2
Ambu aScope 3 Slim * 3.8 1.2

Of these, only the aScope 3 Slim can be used with an Aintree catheter (which has an internal diameter of 4.7mm)

-All multi-use bronchoscopes contain glass fibres to transmit light from a light source to the distal end of the insertion cord. Fibre optic bronchoscopes also transmit the image via glass fibres. Higher diameter scopes produce a larger picture with better definition and have larger working channels, but are more difficult to manipulate and cause more trauma. Many hospitals are replacing fibre-optic systems with bronchovideoscopes, which contain glass fibres to transmit the light source, but have a digital camera in the distal end of the insertion port to transmit the image. They are more robust and even small diameter scopes can produce a high definition image. The Ambu aScopes use a digital camera and LED light source, both in the distal end of the device, and contain no fibre optics

-Older fibre optic systems contain an eyepiece, so that the scope can be used without a screen, and some have cameras which fit onto this eyepiece

-Bronchoscopes can be flexed and retro-flexed due to the Bowden cable system– a flexible cable that converts a mechanical force by movement of an inner cable relative to the outer housing). Generally bronchoscopes have a 120° field of view with 180° up and 130° down angulation

Top Tips

-Assistant applies jaw thrust to increase space in posterior pharynx

-Maintain straight scope at all times

-Orientate yourself using the triangular 12 o’clock marker (if present)

-Aim for black, and bring target into flexion plane (i.e in line with marker, between 6 and 12 o’clock) by rotating, then advance towards it by flexing / extending

-Keep target in the centre of the field of vision

-If you see red, withdraw until re-orientated, don’t push further

-Failure to negotiate nares – ensure good topicalisation, check nostril patency beforehand

-Don’t advance tube too early – advance bronchoscope to carina before carefully advancing tube

The Video

The Equipment - Airway Topicalisation

The Essentials - Airway Topicalisation

There are four main components to successful fibre optic intubation:

-Topicalisation

-IV drugs

-Communication with the awake patient

-Good motor skills

Topicalisation refers to the application of topical local anaesthetic agents and vasoconstrictors. This has three main aims: patient comfort; decreased coughing and gagging; and decreased bleeding, all of which make the procedure more difficult. There are many recipes and methods available for airway topicalisation, below is a summary of the better options. Remember, topicalisation takes time – don’t rush it.

Airway Topicalisation

Bronchcoscopy Road Map

FOAM Resources

References

  1. Smith JE, Jackson AP, Hurdley J, Clifton PJ. Learning curves for fibreoptic nasotracheal intubation when using the endoscopic video camera. Anaesthesia. 1997;52(2):101-106.
  2. Ovassapian A, Yelich SJ, Dykes MH, Golman ME. Learning fibreoptic intubation: use of simulators v. traditional teaching. British journal of anaesthesia. 1988;61(2):217-220.
  3. Marsland CP, Robinson BJ, Chitty CH, Guy BJ. Acquisition and maintenance of endoscopic skills: developing an endoscopic dexterity training system for anesthesiologists. Journal of clinical anesthesia. 2002;14(8):615-619.
  4. Jordan GM, Silsby J, Bayley G, Cook TM, Difficult Airway S. Evaluation of four manikins as simulators for teaching airway management procedures specified in the Difficult Airway Society guidelines, and other advanced airway skills. Anaesthesia. 2007;62(7):708-712.
  5. Smith JE, Fenner SG, King MJ. Teaching fibreoptic nasotracheal intubation with and without closed circuit television. British journal of anaesthesia. 1993;71(2):206-211.