Extubation Strategies and Criteria

Extubation Strategies

Extubation Criteria

Routine Extubation Criteria (Normal Airway)

1. CNS Criteria:

   • Patient must be awake and cooperative.

   • Protective reflexes (cough, gag, and swallow) must be present.

2. Ventilation and Oxygenation Criteria:

   • Patient is breathing spontaneously.

   • Respiratory rate less than 25/min.

   • Tidal volume at least 5 ml/kg.

   • Vital capacity at least 15 ml/kg.

   • Arterial pH greater than 7.35.

   • Arterial $PaCO_2$ less than or equal to 50 mmHg.

   • Oxyhemoglobin saturation greater than or equal to 90%.

3. Neuromuscular Criteria:

   • Patient has unassisted head lift greater than 5 seconds.

   • Full reversal from neuromuscular relaxant drug blockade documented via nerve stimulator testing.

Terminology

• Tidal Volume: The amount of air inhaled and exhaled during normal breathing.

• Vital Capacity: The maximum amount of air exhaled after a full inhalation.

• Residual Volume: The amount of air remaining in the lungs after a maximal exhalation.

Extubation Criteria Following a Difficult Intubation

Type I Causes (Reversible)

• If the difficult intubation was caused by a reversible phenomenon, that cause must be eliminated, and the airway returned to its normal anatomical configuration prior to extubation.

• Examples:

  • Trauma

  • Bleeding

  • Laryngeal edema (trauma, burns, angioedema, toxic irritation)

  • Airway distorted by a foreign body

  • Airway distorted by abscess, infection, hematoma, or tumor

• Reversal of transient causes can be verified by:

  • Physical examination

  • Direct laryngoscopy

  • Fiberoptic evaluation

  • Video laryngoscope observation

  • Review of appropriate radiographic tests

• Criterion for extubation: Resolution of the pathology or abnormality to normal airway anatomy.

Type II Causes (Irreversible)

• If the difficult intubation was caused by an irreversible phenomenon, the practitioner must define the cause of the difficulty and its exact effect on the patient’s airway anatomy, prior to extubation.

• A detailed plan to deal with all anticipated contingencies must be made, and all special airway equipment and personnel must be on hand prior to extubation.

• Sometimes, establishing an elective surgical airway prior to extubation is the best or only plan.

• Examples:

  • Craniofacial abnormalities

  • Arthritis affecting neck mobility and positioning and/or the laryngeal anatomy

  • Obesity affecting neck mobility as well as oral and pharyngeal anatomy

  • Laryngeal pathology (cricoarytenoid arthritis, laryngomalacia, postoperative surgical changes)

  • Tracheomalacia

  • Contractures after burn injury

  • Permanent airway distortion after trauma, infection, or tumor

  • Tumor mass in the airway itself

  • Lingual tonsils at the base of the tongue

Summary: Strategy for Extubating a Patient with a Difficult Airway

• Intubation, ventilation, respiratory care, and extubation carry inherent risks that can cause additional airway trauma and/or distortion, iatrogenic pathology must be kept in mind when planning an extubation strategy.

1. The patient meets all routine extubation criteria.

2. The patient meets all extubation criteria following a difficult intubation.

3. A contingency plan to deal with anticipated and unanticipated difficulties is in place.

4. All airway equipment is on hand and in working order. Backup equipment is readily available.

5. Extra assistance is on hand. Each person knows his role in the extubation strategy.

6. Personnel and equipment are on hand, should an emergency surgical airway be required.

7. "Cuff Leak test" confirms airway patency around the endotracheal tube. This test is used to assess the risk of post-extubation stridor, a high-pitched breathing sound that can indicate airway obstruction.

8. All visual and radiographic evaluations of the airway predict successful extubation.