Airway Flashcards
What is the treatment of laryngospasm?
- Removal of airway irritants
- Deepen anaesthesia (Propofol)
- CPAP
- Paralysis
What are predictors of difficult BVM?
OBESE MM
Obese
Beard
Elderly
Snoring/OSA
Edentulousness
Mallampati 3 or 4
Male
What are pre-op issues with patients having laryngeal surgery?
- Assess lesion location, size, extent and mobility (imaging, nasendoscopy)
- Assess for obstruction - signs, symptoms, positioning
- Feasibility of laryngoscopy and intubation
- Consideration of backup plan
What are induction/intra-operative issues with patients having laryngeal surgery?
- consider antisialogogue
- consider use of topical local anaesthetics
- ensure all equipment is ready before induction
- Consider TIVA as maintenance with remi
- Consider airway devices i.e MLT, Jet ventilation, spont vent GA
What are post-operative issues with patients having laryngeal surgery?
- Laryngospasm
- Aspiration
- Airway obstruction due to oedema (give dexa, can give nebulised adrenaline if stridor)
What are signs of airway trauma?
- Subcut emphysema
- Dyspnoea
- Stridor
- Inability to tolerate the supine position
Minor signs:
- Local swelling and tenderness
- Hoarse voice
- Dysphagia
- Haemoptysis
What is the classification of laryngeal injuries?
Schaefer’s classification most commonly used:
- Minor endolaryngeal haematomas or lacerations, without detectable laryngeal fractures
- Laryngeal oedema or haematoma, or minor mucosal disruption without exposed cartilage
- Massive oedema, large mucosal lacerations, exposed cartilage, displaced fractures, and vocal cord immobility
- As per group 3 but with comminuted or unstable fractures
What is the management of laryngeal injuries?
- Schaefer class 1: Observation
- Other classes:
- Surgical tracheo under local
- Oral ETT under GA
- Awake fibreoptic intubation
What is the technqiue of awake fibreoptic intubation?
- Patient sitting up at 45 degrees, operator facing patient
- Nasal easier than oral
- Glyco 200mcg - 10 min prior
- Sedation (Prop TCI or Remi)
- Topicalising agent:
- calculate total amount of lignocaine you can use (~8mg/kg)
What are risk factors for difficult intubation?
Patient:
- Previous difficult intubation
- Arthritis
- Congenital disorders
- Obesity
Pathology:
- Infections
- Tumours
- Iatrogenic eg radiation
- Trauma
Surgery:
- Emergency
- Obstetric patients
What are signs on examination for difficult intubation?
LEMON
L - Look - obvious deformity, large teeth, limited mouth opening, macroglossia, C-spine collar
E - Evaluate - TMD <3 fingers
M - Mallampatti score
O - Obstruction i.e tumour, OSA
N - ROM, circumference
What are the fasting guidelines for adults?
- Clear fluids up to 2 hours pre op
- Solid food 6 hours
What are the fasting guidelines for children (over 6 months)?
- Clear fluids up to 1 hour pre op
- Breast milk 4 hours
- Food/formula 6 hours
What are the fasting guidelines for infants under 6 months?
- Clear fluids 1 hour preop
- Breast milk up to 3 hours
- Formula up to 4 hours
What are recommendations for aspiration management and prevention?
- All patients must be assessed before surgery
- Airway management should be consistent with the risk
- RSI is the technique for airway protection
- Cricoid must be done properly
Mx:
- Suction trachea once airway is secured, ideally before PPV is commenced
- CXR (may show RLL collapse/consolidation)
- Early bronch can be considered
- Early antibiotics not indicated (may increase ABx resistance)
What are lung ventilation stratigies for ARDS?
- Lung protective ventilation
- VT ~4mls/kg, higher RR
- Maximal PEEP to prevent alectotrauma
- Plateau pressures of <30cm H20
- Allow permissive hypercapnoea to pH 7.2
What are the ventilation strategies for bronchospasm?
- Issue with dynamic hyperinflation + high peak airway pressures
- Aim for prolonged I:E ratio
- Low resp rate
- No PEEP
- Permissive hypercapnoea to pH 7.2
What are the ventilation strategies for Pulm HTN?
- Normothermia, normoxia, normocarbia, normal acid/base
- Avoid N20, ketamine, high PEEP or high Vt
What are risk factors for difficult LMA insertion?
RODS
R - restricted mouth opening
O - OSA/obstructive
D - Disrupted/distorted airway
S - Stiff C spine
What is a Mccoy blade?
- Mac blade with a levering tip to lift the epiglottis
What are important pre op considerations for patient with tracheostomy?
- What trache tube it is (size, presence of inner cannula)
- Indication originally for trache
- Whether there is patent upper airway
What are the key principles of manageing a blocked/displaced trache in an emergency?
- Waveform capnography is vital to confirm -> if not present
- Oxygenation is prioritised
- Trials of ventilation via a potentially displaced trache is avoided
- Suction is only attempted after removing a potentially blocked inner tube
- Blocked/displaced trache is removed as soon as identified, not a last resort
- Apply oxygen to both face and neck
What is the algorithm for emergency trache management?
- Is the patient breathing? If no Code blue
- Assess trache patency (remove speaking valve and inner tube)
- try and pass suction catheter
- if can’t deflate the cuff - look listen feel at mouth and trache and waveform capnography -> if nothing remove the trache tube - Primary and secondary emergency oxygentation (standard BMV, LMA intially, applied paeds mask to stoma then secondary attempt to orally intubate then finally stoma intubation)
What are the clinical features that indicate that a patient is safe for extubation?
- Awake and following commands
- Neuromuscular blockade reversed
- Adequate spont ventilation (oxygenated, regular respiration with adequate volumes with minimal support, not excessively Hypercarbic)
What are possible complications of extubation?
- Mechanical i.e trauma to larynx
- CVS response (decrease in EF in patients with IHD)
- Resp complications (coughing, sore throat, hypoxia, bronchospasm, laryngospasm, obstruction i.e oedema, upper airway tone, negative pressure pulm oedema, aspiration)
What are the risk factors for complicated extubation?
Patient:
- severe cardioresp disease
- Congential/acquired airway pathology
- Morbid obesity
- OSA
- Severe GORD
Anaesthetic:
- multiple intubation attempts
- aspiration risk
Surgical:
- recurrent laryngeal nerve damage
- haematoma
- Oedema
What are components required for airway fire?
- fuel eg surgical prep, ETT
- source eg lasers, diathermy
- Oxidiser eg Oxygen
What is the immediate management of airway fires?
- Remove source of fire, ETT and flammable/burning materials from the airway
- extinguish fire with water/saline
- stop flow of all gases to airway
- once fire is extinguished, mask ventilate with air and increase Oxygen as required
- Maintain anaesthesia with TIVA
- early reintubation
What is the short-long term management of patient with airway fires?
- IV steroids
- CXR, ABG for smoke inhalational assessment
- Consider delayed extubation +/- ICU post op
What is the cuff leak test and what value is predictive of post op stridor
- deflate the cuff and should have a leak as the upper airway patency is maintained
- Value <110ml is predictive of post op stridor
What are some strategies for high risk extubations?
- Use of airway adjunct upon wakeup
- Extubation where intubated i.e operating table with equipment available
- Use of CPAP and high flow straight away
Advanced technqiues:
- Switch to LMA at the end
- Remifentanil technique
- Airway exchange catheter/staged extubation
What is the management of post extubation stridor?
- Sit patient up
- Nebulized adrenaline (1mg in 5ml normal saline)
- IV steroids
