Direct Laryngoscopy/ Bronchoscopy

Background:

• Direct Laryngoscopy and Bronchoscopy may be performed for a variety of reasons. Diagnostic evaluation of the airway may be performed to diagnose laryngotracheomalacia, subglottic stenosis, vascular rings or to identify a tracheoesophageal fistula. Interventions may also be performed. This includes supraglottoplasty for laryngomalacia, laser treatment of subglottic stenosis or papillomas, injection of laryngeal cleft and removal of a tracheal foreign body.

Patient Considerations:

• Patients presenting for direct laryngoscopy and bronchoscopy may have a high degree of airway obstruction at baseline. A detailed history of obstructive symptoms should be obtained prior to induction of general anesthesia. Additionally, patients frequently have comorbid conditions such as bronchopulmonary dysplasia. This increases airway reactivity and decreases the patients’ tolerance of apnea.

• Anesthetic Management:

  • Case Planning:

    • Thorough Pre-Anesthetic Evaluation including identification and optimization of comorbid conditions

  • Specific or Unique Room Set-Up Requirements

    • Airway

      • Mask induction with maintenance of spontaneous ventilation,

      • Open/shared airway

  • Drugs/Infusions

    • Steroids

  • Dexamethasone (0.2-0.5mg/kg)

    • PONV Prophylaxis

  • Ondansetron (0.1-0.15mg/kg)- Max

    • Emergence Delirium Prophylaxis

  • Dexmetomedine (0.5mcg/kg)

  • Many options/combinations for maintenance

    • Inhalational

      • A 4.0-5.0 uncuffed OETT in the side of mouth allows insufflation of volatile anesthetic while the surgeon is working

      • Dr. Borders may ask you to ventilate through the bronchoscope by attaching your circuit to the scope

    • Precedex

      • Bolus or infusion

    • Ketamine

      • 1mg/kg boluses

    • Remifentanil

    • Propofol

      • Start at 100mcg/kg/min and titrate to effect

  • Monitors

    • Standard ASA monitors

    • EtCO2 unreliable during open airway

      • SpO2 and Chest Movement must be observed to confirm oxygenation/ventilation

  • Blood Availability

    • Not usually required

  • PICU Bed Availability

    • Should be available for:

      • Prolonged procedures (edema)

      • High risk of post-op obstruction (supraglottoplasty)

• Anesthetic Considerations

  • Laryngoscopy is VERY stimulating, anesthetic depth should be deep enough to tolerate this, considering that removal of stimulation may lead to deep anesthesia and apnea

  • Surgeon will apply topical local anesthetic to vocal cords to minimize risk of laryngospasm

  • Maintain spontaneous ventilation is goal

  • Avoid light anesthesia to prevent laryngospasm and bronchospasm

  • Role of apneic oxygenation

    • Healthy patients can tolerate prolonged apnea if 100% O2 is insufflated during bronchoscopy

    • PaCO2 will continue to rise in the absence of effective ventilation

• Induction

  • Mask induction with maintenance of spontaneous ventilation

• Positioning

  • Frequently supine with bed turned 90*

• Maintenance

  • Drugs as above

• Hemodynamic/Physiologic goals

  • Optimize oxygenation

  • Maintain spontaneous ventilation

  • Minimize increases in Pulmonary Artery pressures

    • Avoid significant hypoxia and hypercapnia

• Surgical Considerations

  • Spontaneous ventilation

  • Continuous communication with surgeon

    • May require asking surgeon to back out to mask

  • Ventilation through rigid bronchoscope

  • Limit FiO2 if laser involved (avoid airway fire)

• Emergence/Disposition

  • Appropriate patients may be brought to PACU deep if PACU able to handle such patients

  • Consider awakening any patient with intervention in OR

• Post-Op Pain Management

  • Very stimulating intra-op, usually not painful post-op

• Case-Specific Complications

  • Hypoxia

  • Hypercarbia

  • Pulmonary Hypertension

    • Both hypoxia and hypercarbia increase PVR.

      • Patients with pre-existing pulmonary HTN or cardiac defects may not tolerate this

  • Laryngospasm

    • May occur due to light anesthesia and/or surgical manipulation of vocal cords

  • Bronchospasm

    • Difficult to treat with open airway

    • Have a low threshold for administering small boluses of IV epinephrine

  • Stridor

    • Edema from surgical manipulation can cause obstruction

      • Generous steroid administration may help mitigate this

      • Racemic epinephrine may be given to decrease edema