FRCA Notes

Bronchoscopy

The curriculum asks for knowledge on 'commonly used methods of local and general anaesthesia for bronchoscopy including techniques of ventilation'.

This page covers both flexible and rigid bronchoscopy, although it's usually the latter which requires the involvement of anaesthetists.

Resources

  • Bronchoscopy is a common diagnostic and therapeutic procedure, performed by ENT, thoracic surgeons and respiratory physicians
  • It is sub-divided into:
    • Flexible bronchoscopy, which can be used for most procedures and is generally well tolerated
    • Rigid bronchoscopy, which may be required for certain procedures (foreign body removal, relief of tracheal stenosis or placement of airway stents)

Diagnostic Therapeutic
Investigate respiratory disease Removal of foreign body (rigid bronchoscopy)
BAL Removal of secretions causing lobar collapse/consolidation
Assessment of airway injuries e.g. burns/trauma Respiratory toilet
Assessment of tracheal tube placement e.g. DLT, percutaneous tracheostomy To facilitate awake tracheal intubation
Tumour biopsy for cancer staging Tumour debulking or resection
Assessment of lung tumour position prior to resection Massive haemoptysis
Endobronchial ultrasound Tracheal stenting or dilatation

Contraindications

  • Patient refusal
  • Failure to maintain oxygenation
  • Unstable haemodynamic status including dysrhythmia
  • Non-correctable coagulopathy or bleeding disorders
  • Inadequate facilities or staff

  • Choice of technique will depend on:
    • Planned procedure
    • Whether flexible or rigid bronchoscope is being used, with the latter generally mandating GA
    • Patient factors including severity of lung disease, comorbidities and preferences

Topical anaesthesia

  • Generally suitable for:
    • Basic, short-duration diagnostic procedures
    • Cooperative patients with minimal respiratory comorbidities
  • Similar process of airway topicalisation as with awake tracheal intubation, but without the need to topicalize the nasal passages

  • Benefits from being the least invasive, but still has issues such as:
    • Risk of aspiration due to relaxation of the pharyngeal & laryngeal muscles, and thus depression of airway reflexes
    • Intolerable as the sole source of anaesthesia, requiring procedural sedation or other modes of anaesthesia
    • Unsuitability for rigid bronchoscopy

Regional anaesthesia

  • The superior laryngeal nerve block is a putative technique for bronchoscopy
  • It aims to block the internal branch of the superior laryngeal nerve as it passes below the greater cornu of the hyoid
  • In doing so it blocks the cough reflex, which may reduce other anaesthetic requirements
  • Has a number of complications:
    • Superior laryngeal artery injury
    • Neck haematoma
    • Aberrant injection of LA into e.g. the trachea, thyroid gland, intra-arterial or intraneural injection
    • Local anaesthetic toxicity

Procedural sedation

  • Suitable for flexible bronchoscopy, as an adjunct to topical anaesthesia
  • Often requires at least moderate sedation
  • Most non-anaesthetists seem to use a combination of midazolam (1-2mg) and fentanyl (50-100μg) ± further boluses
  • Other options include:
Drug Advantages Disadvantages
Propofol Familiar
Good sedation
Titrateable		 Risk of apnoea
Haemodynamic effects
Remifentanil Blunts airway reflexes Risks adverse respiratory effects
Dexmedetomidine Less respiratory depression
Fewer respiratory adverse events		 Haemodynamic effects
Longer time to discharge
Ketamine Maintains airway reflexes ↑Secretion burden
Hallucinogenic

General anaesthesia

  • GA is required for:
    • Patients in whom other techniques are unacceptable, contra-indicated or have failed
    • Rigid bronchoscopy
    • Longer, or more complex, procedures
    • Procedures in which neuromuscular blockade is needed
  • Options include volatile anaesthesia or a TIVA technique
Maintenance Advantages Disadvantages
Volatile anaesthesia Bronchodilator effect
Maintain SV in patients if
ability to rapidly secure the airway is in doubt		 Difficulty controlling anaesthetic depth
Room pollution
High FGF required
TIVA Uncouples ventilation & anaesthesia
Suitable if volatile contra-indicated		 Requires depth of anaesthesia monitoring
if NMBA required
Standard TIVA issues

  • If volatile anaesthesia is used, isoflurane may be superior as its longer duration means there is lower risk of awareness/awakening if ventilation is interrupted

  • Shared airway surgery with risk of aspiration

Airway options

  • Laryngeal mask airway
    • Suitable in flexible bronchoscopy; may expedite the procedure as the bronchoscope can be inserted through the LMA via an adaptor
    • May be used at the end of rigid bronchoscopy to maintain the airway after the bronchoscope is removed, prior to the patient waking
    • May be preferential for shorter, less invasive procedures

  • Endotracheal tube
    • Suitable in flexible bronchoscopy; may expedite the procedure as the bronchoscope can be inserted through the LMA via an adaptor
    • May be needed in patients:
      • Undergoing longer and/or more complex procedures
      • Those at risk of aspiration
    • Associated with less atelectasis than using an LMA (VESPA trial, 2022)
    • Generally require a size 8.0 tube, if not greater, to accomodate the bronchoscope

  • Tubeless surgery e.g. using THRIVE

Ventilatory management

  • Spontaneously ventilating patient

  • Standard PPV by connecting the anaesthetic circuit to the side-port of the rigid bronchoscope

  • Jet ventilation

  • THRIVE