Microlaryngoscopy with Jet Ventilation
Patient phenotype
Vocal cord lesion (polyp, papilloma, dysplasia, early carcinoma), subglottic stenosis. Often: smoker, GERD, CAD. Shared airway with surgeon; high-stakes airway management.
Procedure
Surgeon places suspension laryngoscope, microscopic excision of lesion. Anesthesia maintains oxygenation without obstructing surgical view — typically jet ventilation through small catheter or surgeon's laser-resistant tube. ~30-60 min.
Anesthetic plan
GA TIVA (propofol + remifentanil) — total IV avoids volatile pollution + smoothest emergence. Shared airway: jet ventilation OR small laser-resistant ETT. Eye protection essential. NMB throughout to prevent cord movement.
Setup
- ·Standard ASA + ETCO₂ (challenging with jet)
- ·PIV
- ·Eye protection — wet gauze + tape (laser cases)
- ·Small ETT 4.5-5.5 (laser-resistant Mallinckrodt or similar) OR jet catheter
- ·Jet ventilator if used (Sanders or Manujet)
- ·Suction immediately available
- ·Wet drapes + non-flammable solution (laser cases)
- ·FiO₂ ≤ 30% if laser in use (fire risk)
Biggest concerns by phase
Difficult airway anticipated — laryngeal pathology
Anatomic lesion may obstruct view + ventilation. Awake fiberoptic if pre-op exam concerning. Have multiple airway plans + small ETT sizes available. Surgical airway plan documented.
Smooth induction + intubation through pathology
Standard induction (propofol + fentanyl + roc 1.0 mg/kg). Intubate with smallest ETT that ventilates (5.0 typical for adult woman, 5.5-6.0 for man). Surgeon may direct visualization via DL while you intubate.
Jet ventilation principles
High-pressure (1-3 bar) brief pulses through small catheter (suprahyoid, transtracheal, or via supraglottic catheter). 100-120 pulses/min, 30-50% inspiratory time. CRITICAL: ensure egress (no trapping → pneumothorax). Monitor chest rise + SpO₂; ETCO₂ unreliable. PaCO₂ rises during case (ABG q15-20 min for long case).
Laser airway fire prevention
Three-element fire: O₂ + fuel (ETT, drapes) + ignition (laser). Reduce FiO₂ to ≤ 30% (room air + N₂O blend or air/O₂). Use laser-resistant ETT (wrapped Mallinckrodt with double cuff filled with saline + methylene blue). If fire: stop O₂, remove ETT, flood with saline, ventilate by mask, re-intubate, evaluate airway with bronch.
Hypercapnia during jet — managed
Jet ventilation washes out CO₂ less efficiently than conventional ventilation. PaCO₂ rises gradually. Tolerate PaCO₂ to 50-60 in healthy patients (permissive hypercapnia). If higher, plan recovery breaks of conventional ventilation between jet runs.
Smooth emergence — avoid coughing on tube + laryngospasm
Cord pathology + manipulation = laryngospasm + bleeding risk on emergence. Lidocaine 1.5 mg/kg pre-extubation. Suction blood + secretions. Deep extubation if airway favorable, awake otherwise. Have re-intubation kit ready.
Mock-defense scenarios
Practice answering these out loud. The probes show what an examiner is listening for.
Mid-microlaryngoscopy under jet ventilation for vocal cord polyp. SpO₂ has been 99%. You note ETCO₂ now reads 65 (was 45 at start), and the patient's chest is rising less symmetrically. What's happening and what do you do?
What an examiner probes for
- ▹Differential: hypercapnia from inadequate jet, gas trapping, mainstem migration of jet catheter, pneumothorax
- ▹Pause jet, switch to conventional ventilation via bag, assess chest movement + auscultation
- ▹Stat ABG, CXR if pneumothorax suspected
- ▹Communication with surgeon — pause for stabilization
Sources
- Miller's Ch 66 (ENT)
- ASA Practice Advisory: Operating Room Fires
- Bourgain BJA jet ventilation
Anatomy reference
Sourced reference images. 4 matches for "larynx vocal cords trachea".
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