Endotracheal Intubation

Indications

• Hypoxia

• Respiratory distress

• Protection of the airway

• Cardiopulmonary arrest

• Need to maintain hyperventilation (e.g., with traumatic brain injury)

Contraindications

• Cervical spine injury (may use video and optical laryngoscopes, fiberoptic laryngoscope, or digital [tactile] technique)

• Cervical spine severely immobilized due to arthritis (may use video and optical laryngoscopes, fiberoptic laryngoscope, or digital [tactile] technique)

• Expanding neck hematoma (relative, must use caution but may require surgical airway)

• Uncontrolled oropharyngeal hemorrhage (relative, may require surgical airway)

• Intact tracheostomy or stoma (replace tracheostomy tube)

• Combative patient (consider rapid-sequence intubation [RSI]—described in this chapter)

• Trismus (consider RSI or nasotracheal intubation)

• Severe facial or neck trauma (consider needle or surgical cricothyroidotomy)

Equipment

See Figure 63-1-1 .

• Laryngoscope (and fresh batteries)

• Laryngoscope blades (at least two different types)

• Endotracheal tubes

  • Adult men sizes 7 to 9

  • Adult women sizes 6 to 8

  • Nasotracheal intubation sizes 5 to 7

  • Pediatrics – consult Broselow tape or use the size equal to the width of the fingernail of the little finger. Use uncuffed tubes in infants and small children up to 8 years of age.

• Water-soluble lubricant

• 10-mL syringe

• Umbilical tape or endotracheal tube holding device

• Scissors

• Bag-valve-mask device (Ambu-bag) with 100% oxygen delivery system

• Pulse oximeter

• Capnograph, carbon dioxide detector, esophageal detector or other device to confirm tube placement

• Suction system with dental or Yankauer tip in children and adults, DeLee suction in neonates

• Stethoscope

• Cardiac monitor and defibrillator

• Blood pressure monitor

• Gloves

• Face mask, goggles or eye shield, and any other equipment necessary to follow universal blood and body fluid precautions

• Intravenous line (if possible)

• Ventilator

• Cricothyroidotomy kit

• Sedative medication to use for chemical restraint (e.g., propofol, benzodiazepines)

Cricoid Pressure (Sellick Maneuver)

Providing or performing cricoid pressure may help protect against regurgitation of gastric contents; it also increases visibility by moving the trachea into the visual field of the person intubating. To perform cricoid pressure (Sellick maneuver), first find the thyroid cartilage (Adam's apple), and then the small indentation beneath it (cricothyroid membrane). The cartilage beneath this small indentation is the cricoid bone. Cricoid pressure is performed by pinching the extended thumb, index, and middle finger together into a double “V,” or tripod. This is then placed on the cricoid bone and pressed down with enough pressure to occlude the esophagus ( Figure 63-1-2 ). The pressure should be applied toward the patient's back and the head somewhat. Cricoid pressure should not be released until intubation is completed and confirmed and the cuff inflated.

note : The effectiveness of the Sellick maneuver has been questioned. Because of the wide variation in pressure applied by operators, cricoid pressure should be removed if there is difficulty in visualizing the airway.

Airway Assessment

Begin with the patient on 100% nonrebreather mask if spontaneously breathing. The jaw thrust maneuver can be used to keep the airway open ( Figure 63-1-3 ), or begin bag-valve-mask breathing with a second assistant providing cricoid pressure (Sellick maneuver). The practitioner should be familiar with the anatomic landmarks ( Figure 63-1-4 ). Many airway management failures can be traced to lack of airway assessment. Patients can be classified into three groups (shades) based on two criteria: anticipated difficulty in intubation and ability to maintain oxygen saturation greater than 90% by bag-valve-mask ventilation. Airway assessment is critical. An experienced person can assess an airway in less than 4 seconds, and an inexperienced person should be able to do so in less than 8 seconds.

The mnemonic for assessing difficulty in intubation is 332-NUTS:

• 3 – fingerbreadths, mouth opening

• 3 – fingerbreadths, mentum (distance from the tip of the chin to the anterior soft tissue of the neck)

• 2 – fingerbreadths, thyromental distance (distance from the top of the thyroid cartilage to the upper soft tissue angle of the neck)

• N – Normal neck flexion

• U – Uvula visible when opening the mouth

• T – no Tension pneumothorax

• S – no “Soup” (foreign body in the airway)

Meeting all these criteria indicates a low-risk intubation; conversely, the fewer the criteria present, the higher the risk. Although the last two categories, tension pneumothorax and “soup,” do not strictly determine the anatomic difficulty of intubation, establishing their absence is a vital part of early airway assessment. The Mallampati system has previously been used to assess the uvular portion of the mnemonic; however, it is important to note that this classification was designed to assess a patient sitting upright with voluntary mouth opening – a condition rarely encountered in clinical practice outside anesthesiology. A simpler method is to open the mouth with the thumb while standing to either side of the patient's head. (Standing at the head of the patient changes the angle of view, and may produce a false result). If any portion of the uvula can be seen, then intubation will likely be unimpeded by this factor. The three risk groups (shades) are as follows:

• Pink – able to keep the oxygen saturation greater than 90%; anticipate easy intubation and use standard technique.

• Purple – able to keep the oxygen saturation greater than 90%, but anticipate difficult intubation. Attempt awake laryngoscopy. If successful, perform an assisted intubation with a gum elastic bougie, intubating or fiberoptic laryngoscope, lit stylet, or similar device. If not, use an intermediate airway (laryngeal mask airway [LMA] or King LTS-D) if possible, and obtain expert assistance for further management.

• Blue – unable to keep the oxygen saturation greater than 90%. If possible, perform a single attempt at an intermediate airway (LMA or King LTS-D). If successful and easy intubation is anticipated, attempt assisted intubation as in the purple patient. If difficulty is anticipated, obtain expert assistance for further management if time permits. If not, needle or surgical cricothyroidotomy may be needed.