Bullard laryngoscopy

Bullard laryngoscopy

The Bullard laryngoscope was invented by James Roger Bullard of Augusta, GA, in 1993 and was patented for use in 1995. It was a breakthrough in the area of fiberoptic medical devices for visualization and minimally invasive procedures. The Bullard laryngoscope refined manipulation and visualization in the field of laryngoscopy. 

Bullard laryngoscopy uses a rigid fiberoptic laryngoscope that was designed for use with patients who are difficult to intubate. In certain patients, it is not possible to visualize and access a target area, such as the glottis, without considerable effort and distortion of the internal anatomy of the patient. The Bullard laryngoscope (see the image below) resolves this problem with its simple and effective design. Bullard laryngoscopy allows visualization of the larynx without requiring alignment of the pharyngeal, laryngeal, and oral axes.

Bullard laryngoscope. 

Laryngoscopy is a procedure whereby the airway and the passage into the airway (the glottis) is visualized or exposed to provide a route for the administration of anesthetic gases, introduce an endotracheal tube for securing the airway, allow a detailed examination of the larynx and its structures, or perform minor endolaryngeal procedures (eg, obtaining tissue specimens for biopsy).

In the resting human larynx, the epiglottis usually protects, and thus covers, the opening of the glottis. Therefore, it needs to be retracted out of the way when doing any of the other procedures. This retraction of the epiglottis is facilitated by laryngoscopy with the help of the blade of the laryngoscope.

Relevant Anatomy

The larynx is located within :

1.anterior aspect of the neck

2.anterior to the inferior portion of the pharynx

3.superior to the trachea. 

primary function of larynx is :

1. To protect the lower airway by closing abruptly upon mechanical stimulation

2. Thereby halting respiration and preventing the entry of foreign matter into the airway.

3. The production of sound (phonation)

4. Coughing,

5. The Valsalva maneuver,

6. Control of ventilation,

7. Acting as a sensory organ. 

The larynx is composed of 3 large: 

1. Unpaired cartilages (cricoid, thyroid, epiglottis)

2. 3 pairs of smaller cartilages (arytenoids, corniculate, cuneiform)

3. Some of intrinsic muscles (see the image below).

L

Indications

Indications for Bullard laryngoscopy include the following:

• Inability to position the patient optimally for intubation, such as in disease and/or instability of the cervical spine (eg, kyphosis with barrel-chest deformity, spinal fractures)
• An obese or overweight patient with a thick, short neck
• Limited mouth opening due to structural problems, such as temporomandibular joint syndrome, ankylosis, large tongue, or facial fractures
• Breast hypertrophy
• Prominent incisors, receding mandible, anterior larynx, intraoral masses, edema, secretions, scar, or bleeding

Bullard laryngoscopy has some advantages in patients 

1. who are difficult to intubate

2. Have limited or undesirable head and neck movements

3. Have limited mouth openings

4. Have facial fractures, or are morbidly obese. 

Contraindications

No absolute contraindications exist for the use of Bullard laryngoscope. However, there is a considerable learning curve and inexperienced persons are not encouraged to use this laryngoscope in difficult situations. 

Technical Considerations

Best Practices

Constant positioning and repositioning while changing the tip extender blade may increase the costs and risks of the surgical procedure being undertaken.

If a tracheal tube larger than 7.5 mm is used, the introducing stylet may be pushed posteriorly and thus obscure the view.

Sometimes, the orotracheal tube may hit against the right arytenoid cartilage and a large epiglottis, leading to problems.

If laser is to be used, the metallic laser tube cannot be fitted over the introducing stylet. In these cases, a standard tube has to positioned first and then the metal laser tube should be introduced using a tube exchanger. 

Procedure Planning

Before use, the tip of the laryngoscope blade housing the image bundle at the end of the sheath should be cleaned thoroughly. 

Periprocedural Care

Equipment

The Bullard laryngoscope is specifically designed for difficult intubation and has a rigid, anatomically curved blade.

In addition to the Bullard laryngoscope, the standard equipment for difficult intubation includes the following:

• Fiberscope
• Fiberoptic light source
• Video head
• Videocassette recorder
• Defogging solution
• Swivel fiberoptic adaptors
• Local anesthetic spray
• Patil-Syracuse endoscopic mask
• Fiberoptic intubation airways
• Fiberoptic stylet laryngoscope
• Lighted intubation stylet
• Special laryngoscope
• Pediatric Bullard laryngoscope
• Bougies
• Flexible suction catheters
• Yankauer suction tips
• Laryngeal mask airways
• Cricothyrotomy device
• Device for tracheal tube ventilation
• Combitubes
• Retrograde intubation kit
• Tracheostomy kit
• Binasal airway

Patient Preparation

Anesthesia

Bullard laryngoscopy may be performed in the awake patient under topical or local anesthesia, or in the anaesthetized patient who is paralyzed or breathing spontaneously. For local anesthetic may be sprayed through the working channel to optimize the anesthesia. 

Positioning

The user is positioned at the patient’s head, with the laryngoscope held in the left hand, keeping the handle horizontal. The patient's head is kept in the neutral position.

Technique

Approach Considerations

For intubation, any of the following may be used:

• Styletted tracheal tube
• Bullard stylet
• Tracheal tube with a directional tip
• Reinforced (anode) tracheal tube
• Pediatric introducing stylet
• Multifunctional stylet

General Approach

1. Insert the blade of the Bullard laryngoscope into the oral cavity. Rotate it from horizontal to vertical, which will allow the blade to move around the tongue. With the laryngoscope fully vertical, allow the blade to drop momentarily to the patient’s posterior pharynx.

2. Elevate the blade against the tongue’s dorsal surface. Upward movement along the axis of the handle should be minimal and results in the blade of the laryngoscope lifting the epiglottis. The glottis opening is now fully visible.

3. In some patients it may be necessary to remove the laryngoscope, mount a blade tip extender, and then reinsert the laryngoscope to achieve an effective blade length because the location of the glottis and epiglottis differs from patient to patient.

4. Jet ventilation may be used or oxygen may be delivered from the working channel on the side. If needed, apply suction through the working channel to clear secretions. Oxygen administration also helps to clear secretions and prevent fogging.

5. If using a pediatric or multifunctional stylet, disengage the tracheal tube connector and backload it over the stylet. Position pediatric and multipurpose stylets near the tip of the tracheal tube but not protruding through the end.

6. Apply a small amount of lubricant to the stylet and tube before placing the tracheal tube over the stylet. Thread the adult tracheal tube over the lubricated stylet so that the stylet tip protrudes through the Murphy eye.

7. Alternatively, an endotracheal tube can be mounted on the exterior of the stylet. Pass a guide member through the interior of the stylet and advance it through the patient's vocal cords into the trachea. Then advance the endotracheal tube along the guide member until it is in a desired location in the patient's trachea to permit ventilation.

8. Fasten the stylet-tracheal tube combination to the laryngoscope, which brings the vertical part of the stylet behind and to the right side of the laryngoscope in the groove formed by the blade anteriorly and by the lens housing in the middle. When properly loaded, the tip of the introducing stylet should be visible at the four-o'clock position through the eyepiece or video camera. The tip of the multipurpose stylet is usually not visible.

Oral Intubation

For oral intubation, insert the blade midline into the oral cavity, with the handle horizontal, either by manually opening the mouth or with the aid of a tongue blade. The handle sometimes impinges upon the chest during insertion, especially in obese patients. In these cases, remove it prior to insertion and reconnect after the laryngoscope is positioned in the pharynx.

As the blade is advanced, rotate the handle to the vertical position so that the blade slides over the tongue. Once the blade has been rotated around the tongue, exert upward movement along the axis of the handle to visualize the larynx. If properly placed, either the epiglottis or glottis should come into view through the eyepiece. Occasionally, slight displacement of the blade posteriorly followed by use of the blade (directly or indirectly) to lift the epiglottis vertically may be necessary to optimize visualization.

In some cases, the tip of the tracheal tube will impact on the right arytenoid. If this occurs, reposition the laryngoscope and the stylet to the left. If this does not work, consider one of the following approaches:

• The tube may be rotated 180 degrees on the stylet
• The end of the bevel can be positioned near the blade
• The tip of the stylet may be allowed to protrude through the central opening of the tracheal tube

If the tube passes through the vocal cords but cannot be advanced past the level of the cricoid cartilage, angle the laryngoscope slightly forward.

The Bullard laryngoscope can also be used for oral intubation without the stylet by passing the catheter through the channel where the introducing stylet normally attaches.

Nasotracheal Intubation

For nasotracheal intubation, no stylet is used. A directional tip tracheal tube may be especially useful. Use the Bullard laryngoscope to visualize the larynx. Manipulate the patient’s head position and thyroid cartilage to allow advancement of the tube between the vocal cords.

Another method of nasal intubation involves oral intubation first. Place a small tube changing catheter through the nose. Under direct vision, manipulate it alongside the oral tracheal tube. Then remove the oral tube and pass the nasal tube over the catheter into the larynx.

In difficult cases, the introducing stylet may sometimes be used. Once the larynx is visualized, manipulate the stylet tip until it points between the cords. Under visualization, advance the tube off the stylet until the cuff passes beyond the vocal cords. Then remove the laryngoscope and stylet. If the tube does not enter the larynx, withdraw the tube along with the stylet and once again place the tube over the stylet before another attempt at intubation is made.

When using the multifunctional stylet, visualize the larynx first and advance the tube until it is visible. If possible, advance the tube between the vocal cords. If this is not possible, a catheter can sometimes be threaded through the stylet into the larynx followed by advancement of the tracheal tube over the catheter. The tracheal tube is then threaded over the catheter into the larynx.

Referances

1.      Rionda E, Diaz A, Jimenez A, Quintero M, Ortega J. Orotracheal intubation with Bullard laryngoscope. A report of 65 cases. An Med Asoc Med Hosp ABC. 2008. 53 (3):

2.      Ghouri AF, Bernstein CA. Use of the Bullard laryngoscope blade in patients with maxillofacial injuries. Anesthesiology. 1996 Feb. 84(2):490. [Medline].

3.      Spain K. Use of the Bullard laryngoscope in the adult patient with epiglottitis: a case report. AANA J. 2002 Apr. 70(2):127-9. [Medline].

4.      Zamora JE, Nolan RL, Sharan S, Day AG. Evaluation of the Bullard, GlideScope, Viewmax, and Macintosh laryngoscopes using a cadaver model to simulate the difficult airway. J Clin Anesth. 2011 Feb. 23(1):27-34. [Medline].

5.      http://emedicine.medscape.com/article/1999835-overview#showall