FRCA Notes

Rhinological Surgery

Resources

  • These common, minimally-invasive and often day-case surgeries include functional endoscopic sinus surgery (FESS), nasal polypectomy and septorhinoplasty
  • They are typically performed to reduce symptoms of nasal obstruction and/or treat medically refractory rhinosinusitis

Perioperative management of the patient undergoing rhinological surgery


History & examination

  • Patients are often young and otherwise well, though one should target a history towards more commonly co-existing comorbidities such as:
    • Sleep-disordered breathing inc. OSA
    • Airways disease e.g. asthma, COPD, bronchiectasis (present in up to 2/3rds of patients with chronic rhinosinusitis)
    • Obesity
  • One should also elicit any contraindication to hypotensive anaesthesia, namely significant hypertensive disease, vascular insufficiency or sickle cell disease

  • A standard airway assessment suffices, acknowledging BVM ventilation may be more difficult in nasal obstruction

Medications

  • Check for NSAID intolerance, as it is more prevalent in patients with chronic sinus disease and nasal polyps
  • Check not on MAO-I's, which may interact with topical vasoconstrictors
  • Ascertain whether patient is on anti-platelet or -coagulant medication and hold accordingly

Monitoring

  • AAGBI as standard
  • More invasive monitoring is rarely required
  • Eyes should be left untaped/unpadded but lubricated, which aids surgical assessment of whether the orbit wall has been breached

Airway choice

  • This is shared airway surgery with one's airway both distal to the anaesthetic machine and relatively inaccessible
  • Armoured LMA's benefit from:
    • Avoiding need for NMBA in (often) day-case patient
    • Large cuff protecting against aspiration of blood and surgical debris
    • Minimally stimulating on removal vs. ETT which will reduce bleeding risk
  • They may be inappropriate owing to patient (obesity, reflux) or surgical (long surgery, bleeding ++) factors
  • Either an armoured ETT or south-facing RAE tube are appropriate choices for a definitive airway

  • NB the surgeons may insert a throat pack to help mop up blood and debris from the airway

Limiting blood loss

  • Surgery to the vascular mucosa of the nose and sinuses can cause a fair amount of bleeding
  • Limiting said bleeding is beneficial as it:
    • Improves surgical endoscopic views
    • Reduces risk of airway soiling/aspiration/'coroner's clot'
    • Limits blood loss and risk of anaemia
    • Reduces need for post-operative packing

  • There are multiple strategies for limiting bleeding:
Non-pharmacological methods Pharmacological methods
Position head up 10-20° Local anaesthetic ± adrenaline
Limit PEEP to ~5cmH2O Topical vasoconstrictors (see below)
Avoid profound hypercapnoea Steroids e.g. dexamethasone
Hypotensive anaesthesia (see below) TXA (topical/IV)

Topical vasoconstrictors

  • A number of agents are available:
    • Cocaine (as Moffett's solution: 1–2 ml cocaine 5% + 1 ml adrenaline 1:1000 + 2 ml sodium bicarbonate 8.4%, made up to 10 ml with 0.9% NaCl)
    • Adrenaline (typically in combination with local anaesthetic)
    • Phenylephrine (e.g. as co-phenylcaine)
    • Sympathomimetics i.e. the imidazole derivatives xylometolazine and oxymetolazine, which are ɑ1 agonists

  • Cocaine is less frequently used owing to its propensity to cause cardiovascular side-effects, though it is exceptionally effective at preventing epistaxis
  • Adrenaline too can cause cardiovascular sequelae due to systemic absorption
  • This makes the ɑ1 agonist agents preferable i.e. phenylephrine, xylometolazine
  • Anecdotally, mixing xylometolazine into co-phenylcaine and administering it topically leads to excellent results

Hypotensive anaesthesia

  • Intraoperative bleeding arises due to higher arterial (MAP) or raised venous pressures
    • The latter is addressed by steps in the table above addressing positioning and PEEP

  • Induced hypotension to a MAP approximately 20 - 30% below baseline (or 50 - 65mmHg) and a low-normal HR (e.g. 60bpm) can reduce blood loss and improve visibility in the surgical field
  • This approach is contraindicated in those <1yr, those with vascular insufficiency, sickle cell disease or significant hypertensive disease (i.e. shifted auto-regulatory curves)
  • There are multiple methods to achieve this:
Technique Notes
TIVA anaesthetic ↓ blood loss and better surgical field vs. inhalational agents
Recommended by 2020 European Position Paper on Rhinosinusitis & Nasal Polyps
Remifentanil ↓ HR and ↓ MAP
Blunts response to (airway) stimuli
ɑ2 agonists Added benefit of analgesic properties
Sedative properties may be unsuitable for day cases
β-blockers Bradycardia and negative inotropy reduce MAP
↑ diastolic time may improve venous return
Vasodilators (CCBs, nitrates) Reduce SVR and MAP
Vasodilation may ↑ bleeding
Reflex tachycardia


Extubation

  • Inspection and thorough suction of oro- and laryngo-pharynx at end of case
  • Ensure suction behind soft palate/nasopharynx to remove 'coroner's clot'
  • Ensure full NMBA reversal if used
  • Extubate head-up to reduce bleeding
  • Avoid coughing/bucking/straining during airway removal e.g. use LMA, extubate with remifentanil running, IV lidocaine etc.

Analgesia

  • Simple analgesia
  • Perioperative short-acting opioids e.g. fentanyl
  • Local anaesthetic in the form of topical application or local injection
  • Dexamethasone may provide analgesia by reducing oedema

Other

  • Standard rules of day case surgery apply with regards to PONV prophylaxis