Laryngoscopy Procedure: Indications, Preparation, Technique, and Post-Procedure Management
Overview of Laryngoscopy Modalities
Laryngoscopy can be performed using three primary techniques: indirect mirror laryngoscopy, flexible transnasal laryngoscopy, and rigid oral laryngoscopy, with flexible laryngoscopy being the most reliable method for office-based examination and rigid laryngoscopy reserved for therapeutic interventions requiring general anesthesia. 1
Indications
Flexible (Transnasal) Laryngoscopy
- Diagnostic evaluation of vocal fold mobility in patients with voice changes, suspected laryngeal pathology, or preoperative assessment before thyroid surgery 1
- Assessment of subtle vocal fold motion abnormalities that cannot be detected with mirror examination 1
- Evaluation during running speech and motion-directed tasks (e.g., "eee-sniff," whistle, laugh, deep inspiration, cough, speaking, singing) 1
- Preoperative laryngeal assessment in patients with thyroid cancer with suspected extra-thyroidal extension or prior neck surgery 1
- Video documentation for repeat evaluation and slow-motion analysis 1
Rigid (Oral) Laryngoscopy
- Management of massive hemoptysis requiring immediate airway control 1
- Treatment of tracheobronchial stenosis and airway obstruction 1
- Foreign body removal from the airway 1
- Tumor resection and mechanical debulking 1
- Deep bronchial-wall biopsy requiring larger tissue samples 1
- Central airway obstruction (proximal and critical obstruction) where rigid bronchoscopy is favored due to distinct multimodality procedural advantages 1
Contraindications
Specific to Rigid Laryngoscopy
- Unstable cervical spine 1
- Severe maxillofacial trauma or deformity 1
- Obstructing oral or laryngeal disease 1
Pre-Procedure Preparation
For Flexible Laryngoscopy
- No specific anesthesia required for office-based examination; topical anesthesia may be applied to nasal passages if needed 1
- Patient positioning: seated upright or semi-reclined 1
- Equipment check: ensure flexible laryngoscope is functional with adequate light source and video recording capability 1
For Rigid Laryngoscopy
- General anesthesia is mandatory, administered intravenously (preferred) or by inhalation 1
- Anesthesia team required: anesthesiologists, nurses, and assistants familiar with the procedure must be present 1
- Ventilation planning: options include spontaneous ventilation, spontaneous assisted ventilation, controlled ventilation with Venturi Jet, high-frequency ventilation, or circuit positive pressure ventilation 1
- Equipment preparation: select appropriate rigid bronchoscope (classic ventilating bronchoscopes with beveled distal ends, telescopes for visualization, and instruments for therapeutic procedures) 1
- Physiological monitoring: continuous multi-modal monitoring including oxygen saturation, electrocardiogram, blood pressure, peak inspiratory pressure, and exhaled tidal volume 2
- Airway assessment: if patient is intubated, ensure endotracheal tube is at least 1.5 mm larger than the external diameter of the bronchoscope 2
- Oxygenation optimization: administer 100% FiO2 and reduce positive end-expiratory pressure as tolerated 2
- Sedation and paralysis: provide adequate sedation with consideration of short-acting paralytic agents to prevent coughing 2
Technique
Flexible (Transnasal) Laryngoscopy
- Insertion: pass the flexible laryngoscope through the nose (typically the more patent nostril) and advance posteriorly along the floor of the nasal cavity 1
- Visualization: advance the scope to visualize the nasopharynx, oropharynx, hypopharynx, and larynx 1
- Functional assessment: perform directed tasks (e.g., phonation with "eee," sniffing, whistling, laughing, deep inspiration, coughing, speaking, singing) to assess vocal fold mobility and identify subtle motion abnormalities 1
- Video recording: document findings for review and comparison 1
- Learning curve: on average, only 6 attempts are necessary for a novice to become competent in performing flexible laryngoscopy 1
Rigid (Oral) Laryngoscopy
- Patient positioning: after induction of anesthesia, partially extend the patient's head 1
- Insertion: insert the bronchoscope in the midline with the bevel anterior 1
- Tooth protection: use the operator's finger or a plastic tooth protector to protect the upper teeth 1
- Epiglottis passage: advance the bronchoscope to and pass under the epiglottis, then rotate 90 degrees to pass atraumatically through the vocal cords 1
- Tracheal entry: once the trachea is entered, rotate the bronchoscope back 90 degrees and advance toward the lower airways 1
- Bronchial tree examination: to examine one of the bronchial trees, rotate the patient's head toward the contralateral shoulder 1
- Alternative technique for intubated patients: advance the bronchoscope along the endotracheal tube to the level of the vocal cords, remove the endotracheal tube, and pass the bronchoscope into the trachea 1
- Laryngoscope-assisted technique: use a laryngoscope to lift the epiglottis anteriorly and allow passage of the bronchoscope to the level of the vocal cords, then guide it through the vocal cords under direct visualization 1
- Telescope use: use a telescope through the bronchoscope to provide adequate visualization to the level of the segmental airways 1
- Therapeutic procedures: mechanical resection and dilation can be accomplished with the barrel of the scope alone; tools such as laser fibers, cryotherapy and electrocautery probes, balloon dilators, stents, suction catheters, and various biopsy and retrieval forceps can be inserted through the barrel 1
Rigid Bronchoscopy for Mucous Plug Removal (Specific Technique)
- Systematic inspection: perform systematic inspection of the tracheobronchial tree to identify the location and extent of mucous plugging 2
- Direct suctioning: begin with direct suctioning through the bronchoscope's working channel to remove loose secretions and smaller plugs 2
- Wire basket retrieval: use a wire basket retrieval device for larger or more cohesive plugs 2
- Mechanical removal: if flexible bronchoscopy fails, the barrel of the rigid bronchoscope itself can be used for mechanical removal of obstructing material 2
Post-Procedure Management
For Flexible Laryngoscopy
- Minimal post-procedure care required for office-based examination 1
- Documentation: accurately document findings, including vocal fold mobility and any abnormalities 1
- Follow-up: arrange follow-up as indicated based on findings 1
For Rigid Laryngoscopy
- Continued physiological monitoring: monitor for at least 2-4 hours post-procedure 2
- Oxygenation and compliance monitoring: assess for improvement in oxygenation and compliance 2
- Complication surveillance: monitor for injury to lips, teeth, gums, larynx, and the tracheobronchial wall 1
- ICU patients: consider high risk for complications and maintain close monitoring 2
- Equipment cleaning: maintain detailed records of which bronchoscope was used on each patient and clean and disinfect all reusable equipment according to institutional protocols 2
Training Requirements and Competency
Flexible Laryngoscopy
- Rapid learning curve: novices require only 6 attempts on average to become competent 1
- Ongoing use: diagnostic accuracy improves with continued use 1
Rigid Laryngoscopy
- Prerequisites: training should be reserved for physicians with extensive experience in flexible bronchoscopy and endotracheal intubation 1
- Initial training: trainees should first practice on mannequins or animal models 1
- Supervised procedures: perform at least 20 supervised rigid bronchoscopy procedures before attempting the procedure alone 1
- Maintenance of competency: perform the procedure at least 10-15 times per year to maintain competency 1
Complications and Safety Considerations
Flexible Laryngoscopy
- Minimal complications when performed correctly 1
- Patient discomfort: nasal passage irritation or gagging may occur 1
Rigid Laryngoscopy
- Trauma: injury to lips, teeth, gums, larynx, and the tracheobronchial wall 1
- Bleeding complications: more bleeding-related complications and deaths may occur with flexible bronchoscopy under moderate sedation compared to rigid bronchoscopy under general anesthesia 1
- High-risk patients: ICU patients and those with clotting abnormalities are at higher risk for complications 2
- Neonates and infants: require particular attention to sedation, analgesia, and airway monitoring 2
Anesthesia Considerations for Rigid Laryngoscopy
General anesthesia with deep sedation is suggested over moderate sedation for therapeutic bronchoscopy, as it is associated with fewer complications. 1
- Intravenous anesthesia is preferred over inhalation anesthesia 1
- Ventilation options: spontaneous ventilation, spontaneous assisted ventilation, controlled ventilation with Venturi Jet, high-frequency ventilation, or circuit positive pressure ventilation 1
Common Pitfalls and How to Avoid Them
- Inadequate visualization with mirror laryngoscopy: if the larynx cannot be examined using a mirror or if vocal fold movement abnormality is unclear, proceed to flexible laryngoscopy 1
- Multiple intubation attempts: limit the number of laryngoscope insertions to a maximum of four to prevent trauma and development of a "can't ventilate" situation 1
- Failure to protect teeth: always use the operator's finger or a plastic tooth protector to prevent dental injury during rigid laryngoscopy 1
- Inadequate anesthesia: ensure general anesthesia is properly administered before rigid laryngoscopy to prevent patient movement and complications 1
- Insufficient training: do not attempt rigid laryngoscopy without adequate supervised experience (at least 20 supervised procedures) 1