Airway - ACEM Fellowship Notes

> *see also:* [ACEM - Airway management](x-devonthink-item://9125BB84-B3C0-42F2-93D9-2C5533BC9216), [Dunn - penetrating neck trauma](x-devonthink-item://0F8FCCB8-7CC7-4B82-97BE-1A16E79A074F) > **special populations:** > - [[Pregnant trauma#Pregnancy effect on resus]] > - [[Obesity resus considerations]] > - [[Geriatric Trauma]] and [[Geriatric resus considerations]] > - [[paediatric airway management]] & [[Tracheostomy#CICO age <10|CICO age <10]] > > **resus considerations:** > - [[Peri-intubation collapse]] (also includes special populations tables), [[Aortic stenosis#intubation and RSI with aortic stenosis|aortic stenosis RSI]] > - [[Awake fiberoptic intubation]] > - [[Ventilator strategies]] eg ARDS, asthma, etc > - [[Tracheostomy|CICO]], [[jet insufflation]] > - [[Delayed sequence intubation]] > - [[Induction agents]] > > **Other related topics:** > - [[Extubation in ED]] for **paeds:** [[paediatric airway management]] & [[Tracheostomy#CICO age <10|CICO age <10]] Thanks Jana! source: [ED Fellowship Land](https://edfellowshipland.webnode.page) #tables > [!pearl]- Reflection > In Emergency Medicine, there are two types of ED Doctors: those who have confronted each of the following airway situations, and those who are *yet* to confront these situations: > 1. An airway is unexpectedly difficult during intubation > 2. A pending airway emergency is undersold or under-appreciated during handover > > The near ubiquity of the above clinical scenarios in ED clinicians’ memory explains how “Airway” became the tip top of the resuscitation hierarchy, and why so much attention is given in this section to potentially-difficult scenarios, anticipated problems, and management solutions. > > For a previous generation of airway practitioners, a Mac 4 and a 8.0 ETT was the equipment adjunct to the strong arm and 14g cannula needed to reach any other body cavity. Due in large part to the stack of coroner cases and anaesthetic root cause analyses that resulted from this hubristic heuristic, we now have an array of strategies, checklists, communication seminars and hospital policies about “graded escalation,” and backup plans for difficult airway emergencies. Whether or not you subscribe to the hyper-angulated video laryngoscopy backup, or prefer to structure plans “a, b, and c” over the Vortex shared mental model, the point is to know how to recognise difficult airway or [[Peri-intubation collapse|peri-intubation physiology]], develop a strategy for dealing with it, have a plan for failure, and to communicate that plan to your team. > > Broadly-speaking, the exam — both written and OSCE — has moved away from the “never be consulting” approach to difficult airway. While they do still want you to know how YOU as the airway doctor might approach any of these situations (especially if you were rural or retrieving a patient), they tend to be far more interested in your assessment of the nuances of what makes a situation difficult and what *modifications* you might make to a standard approach to address to difficulties. They know you love giving 100mg of rocuronium; when is this the wrong dose? (Hint, usually it isn’t; it’s dosed for ideal body weight, so don’t need to overdo it if they are obese!). They know you see ketamine as the only induction agent you ever need, so when is this the wrong answer? Finally, they know you love intubating and teaching intubation, so when should you ask for help from anaesthetics or ENT? How would you supervise if they start getting task-focused? Etc etc. > > In honesty, there were very few airway questions on the fellowship exams I’ve sat across the written and the OSCE, but you need to know this stuff back-to-front because it is considered “core” knowledge and knowing the basics will be the expected basis for how they might construct a question, or the only “easy” or straightforward question on your exam. # Trauma airway See also [[#neck trauma airway]], [[Facial trauma radiology#management|Le Fort management]] | | considerations | | ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | indications | - facilitate oxygenation and ventilation - protect airway - prevent impending obstruction - facilitate safe transfer, procedures - intractable pain - neuroprotection | | pitfalls | - aspiration risk; may have posterior *bleeding* or vomiting - laryngeal trauma - MILS can limit view - blood and swelling can limit view - difficult BVM ventilation if facial injuries - difficult surgical airway - haemodynamic instability - difficult positive-pressure ventilation if pneumothorax or result in tension | | strategies | - MILS protect C spine - video laryngoscopy and direct view if camera obscured by blood - suction ++ - double set up for surgical airway - pre-empty haemodynamic collapse -- metaraminol, blood transfusion, avoid vasodilators (eg propofol) | > ***Tip:*** > Never under-estimate the issues from bleeding! It can obscure your camera on video making indirect “D-blade” laryngoscopy impossible, or lying for hours on back in spinal precautions with facial injuries bleeding into stomach can result in precipitous vomiting and aspiration and a rapidly-deteriorating situation. > > ABC is not just “airway, breathing, circulation”; it is also **Any Bleeding Considered?** (this applies for everything besides airway; in any uncertain situation, always think: could bleeding either be the cause of this problem or make the problem worse? # neck trauma airway see: [[Neck and spine trauma]] - [Question 4 Geelong trauma laryngotracheal injury](x-devonthink-item://67A32A80-4A95-4B9A-A369-C341A08C1AD7?page=14&start=328&length=11&search=Question%204) - [Deranged physiology - approach patient with severe airway injuries](https://derangedphysiology.com/main/required-reading/airway-management/Chapter%20311/approach-patient-severe-airway-injuries) - [cubox link](cubox://card?id=7219056439300458501) - [Dunn - Laryngotracheal trauma](x-devonthink-item://E843E991-371F-4AFC-8B09-819F8DF5DE63) see [tintinalli neck trauma](x-devonthink-item://1ADC8D20-7826-44D0-9DEE-31D41057C9A3?page=53) - keep patient calm and upright and apply oxygen - early intubation if: - airway obstruction/stridor - expanding neck haematoma - visible defect in trachea - haemoptysis - ↓ GCS - hypoxia - smaller size ETT - risk of damaging structures if using cricoid pressure or positive pressure ventilation prior to intubation - awake fibre optic in co-operative patient - if BVM contra-indicated, appropriate for awake orotracheal intubation with sedative + local without parlytic - FONA failing above unless extensive airway injuries → early preparation and "double airway" setup for this | change | rationale | | --------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------- | | no cricoid pressure | risk of damaging structures if cricoid pressure used | | pre-oxygenate with atmospheric pressure rather than positive pressure | positive pressure can dissect through broken tissue planes → s/c emphysema → make airway impossible also risks of air embolism | | upright often | avoid blood pooling back of airway | | no positive pressure until cuff is up | risks of destroying larynx | | awake fibreoptic may not be possible | obtunded / uncooperative / too much blood / no time | | double airway setup | | | ETT 1 size smaller than usual | swelling | | Cricothyrotomy is relatively contraindicated | altered anatomy, may result in complete airway separation | | gas induction and laryngoscopy | - maintain spont breathing - does not require face mask ventilation | issues with emergency cricothyroidotomy in patients with possible laryngotracheal injury: - complete laryngotracheal separation - inability to find cricothyroid membrane due to haemorrhage or s/c emphysema - bougie finding inferior false passage - neck or mediastinal emphysema from ventilating superior to tracheal injury - expanding emphysema/ swelling/haematoma displacing tube - pre-tracheal tissue too deep for tracheostomy tube due to emphysema/swelling/haematoma # Pregnant Airway see [[Pregnant trauma#Pregnant effect on assessment]] and [[Pregnant trauma#Pregnancy effect on resus]] | | considerations | | ------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Difficulties | - high risk aspiration (gravid uterus & increase pressures on upper abdo lying flat, reduced gastric emptying) - BVM difficult due to engorged nasal mucosa and oedemetous upper airway - laryngoscopy difficult due to breast enlargement, ↑ mallampati grade - desaturate quickly due to ↓ FRC and increased O2 consumption | | strategies | - short handle macintosh - ramping ear to sternal notch - RSI and best operator - external laryngeal manipulation | # Obese Airway see [[Obesity resus considerations]] | | consideration | | ------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | difficulties | - similar to pregnancy - quick desaturation time - drug dose need to be considered for ideal body weight - difficult IV access - difficult airway anatomy for front of neck access - difficult laryngoscopy, large breasts and neck | | strategies | similar to preg - preoxygenation is key - +/- [[Delayed sequence intubation]] - external laryngeal manipulation - addequate IV access pre-induction | | drugs | - propofol: LBW for induction; TBW for maintenance - Rocuronium: IBW - midazolam: TBW for induction; LBW for maintenance - sux: TBW | # Paediatric airway see: [[APLS]], [paediatric airway Rosen](x-devonthink-item://E2A70D5A-9657-4EC9-B118-925065B4EA17) | | consideration | | ------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | difficulties | - large tongue - wide/floppy epiglottis - anterior/superior larynx - anterior vocal cords - narrow cricoid ring - high risk bradycardia - large occiput - reduced FRC | | anatomical difference | implications | solution | | -------------------------------------------------------------------- | ------------------------------------------------------------------ | ---------------------------------------------------------------- | | large occiput and head | neck position flexed when lying supine and flat on stretcher | shoulder roll required for optimal positioning of young infant | | large tongue | may occlude airway in unconscious or obtunded child | jaw thrust and OPA or NPA useful adjuncts | | high, anterior airway | visualisation of vocal cords may be difficult | correct positioning prior to laryngoscopy | | upper airway anatomy and narrow subglottic region | upper airway prone to dynamic collapse and inflammation (eg croup) | cuffed tubes safe, monitor cuff pressure | | large tonsils and adenoids | prone to bleeding with manipulaiton | blind nasotracheal intubation relatively contraindicated age <10 | | small cricothyroid membrane | surgical cricothyrotomy difficult | needle cricothyrotomy recommended in infants and young children | | large stomach, dependence on diaphragmatic excursion for ventilation | insufflation of stomach during BVM can compromise ventilation | use orogastric or nasogastric tube for decompression | **Infant airway differences** - large tongue - wide/floppy epiglottis - anterior and superior larynx and anterior vocal cords - narrow cricoid ring - high risk bradycardia - large occiput - reduced functional reserve volume # Laryngospasm see: [[Laryngospasm]], [[Tracheostomy|CICO]] **causes** - local -- intubation/airway manipulation, blood, fb, aspiration, drowning - systemic -- drugs, hypocalcaemia, strychnine poisioning, epilepsy **features** - no chest wall movement/breath sounds - loss of capnography - no stridor/airway sounds - inability to BVM **Management** PPPP - stop and call for help - PEEP 100% fiO2 tight seal to force cords open - suction airway clear secretions - painful inward and anterior pressure at larson's point while doing a jaw thrust - deep sedation with propofol - suxamethonium of hypoxia persists; if severe give full dose and intubate **special considerations** - bradycardia in children: atropine 20mcg/kg - recurrence of laryngospasm # anaphylaxis and angioedema - treat underlying cause - bradykinin mediated → FFP or C1 inhibitor - histamine → adrenaline - ACE-i → FFP - HAE → icatibant (bradykinin 2 receptor inhibitor), ecallantide (kallekrein inhibitor), C1 inhiitor concentrate - fibreoptic exam prior - consider awake fibreoptic intubation # epistaxis | | consideration | | ------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | difficulties | - blood makes video laryngoscopy impossible - posterior source of bleeding more likely to cause airway compromise as difficult to tamponade in ED - hypovolaemia needs simultaneous resus + intubation - ALOC → aspiration - attempt to control bleeding prior to intubation for better view - swallow blood → vomit or aspiration | | strategies | - nasal packing - merocel: dehydrated polyvinyl polymer that expands 3x its size - rapid rhino - promotes platelet aggregation - posterior packing - double balloon catheter inflate posterior balloon first and bring forward (*high risk* for hypoxia and hypoventilation) - alternative is foley catheter | # Burns airway see also [[Burns#possible ventilation issues high pressures|Burns ventilation issues]] *indications for intubation* - impending complete airway obstruction (stridor, oligophonia) - hypoxia on max O2 via face mask - significant hypoventilation consider urgent intubation for: - painful swallow (odynophagia) - hoarse voice / voice change - oral erythema or blistering methods: - ketamine usually induction agent of choice due to analgesic properties and effects on BP - progressive oedema may make intubation or surgical airway difficult to perform later; may need gaseous induction or fibre optic intubation **Ventilator settings** Tidal volume - 6-8 mL/kg RR - 8-12 adults (12-45 children) plateau pressure < 35cm H2O I/E 1:1 to 1:30 flow rate - 40-100L/min PEEP - 8 cm H2O *5 reasons for climbing airway pressures in a burns patient* - trauma causes: pneumothorax 2/2 blast injury, primary pulm contusion, haemothorax - burns-related: thoracic burns requiring escharotomy, pulm oedema 2/2 fluid resus or third-spacing, ARDS - ETT obstruction from burn secretions or blood - patient-ventilator dyssynchrony - obstructive lung disease # Airway assessment ## LEMON **L**ook externally - small/long mandible, big tongue **E**valuate - 332: 3 cm mouth opening, 3 cm thyromental ,2cm thyrohyoid **M**allampati **O**besity/obstruction - blood/emesis in mouth **N**eck mobility TMJ dysfunction experience (prior history of difficulty) ![[Pasted image 20240512200442.jpg]] ## Difficult surgical airway assessment see: [[Tracheostomy#surgical cricothyroidotomy|surgical airway]] > [!quote] " You're SMART if you prepare for surgical airway difficulties" ***SMART*** **S**urgery (previous to area) **M**ass (abscess, haematoma) **A**ccess / anatomy issues (obesity, oedema) **R**adiation (previous to area) **T**umour # Rapid Sequence intubation (RSI) see: [Dunn - endotracheal intubation](x-devonthink-item://3A5D82EC-3F37-40CE-A635-D62BDC539271) **indications in ED** - airway protection - patient requires invasive ventilation / ventilatory assistance - hyperventilation required (eg TCA OD, head injury) - selective lung ventilation ( massive haemoptysis, bronchopleural fistula) - volatile hydrocarbon injection - to facilitate urgent treatments (eg MDAC for carbamazapine overdose) - life-threatening hyperthermia -- in conjunction with muscle relaxation **Steps for RSI in ED** 1. staff -- airway doctor + nurse, medications doctor, scribe 2. equipment -- monitoring equipment, CMAC, FONA equipment, BVM, adjuncts , suction 3. space -- resus room, alarms 4. patient optimisation (eg IFV, pressors, etc) 5. pre-intubation checklist 6. position patient sniffing air 7. pre-oxygenate at least 3 minutes high flow 15L (8 quick breaths if very quick) 8. medication administration + muscle relaxant 9. apoenic oxygenation HFNC 10. laryngoscopy +/- BURP 11. insert bougie → ETT 21-23 cm in males 12. cuff 20 cm H2O 13. ensure Ett placement EtCO2 14. secure ETT 15. post intubation care: ongoing sedation, NGT ![[Pasted image 20241004194725.png| line up oral axis, pharyngeal axis, and laryngeal axis]] ![[Pasted image 20241004194810.png| a. before and B. after cricoid pressure / BURP]] # Hyperangulated “D Blade” intubation - [good video](https://m.youtube.com/watch?v=aYo7kqu9QpA) # Post-intubation care see [Dunn - post intubation care](x-devonthink-item://F6FAD3E7-3CDE-4DCE-BC2E-A945B2FE444B)