BMJ July 24 1880 pp 123 “He sat in bed supporting himself with stiffened arms: his head was thrown forwards, and he had the distressed anxiety so characteristic of impending suffocation …. His inspirations were crowing and laboured, and there was a very frequent forced attempt to swallow, attended by extreme pain, … He spoke in a muffled whisper, and confined his answers, when possible, to monosyllables, or substituted signs by head or hand. …” Sir William MacEwen 1848-1924
Laryngeal Trauma: incidence Rare – Why? –under reported - paucity of peer reviewed data - »American Association Oral Maxillofacial Surgeons 2006: 203-214 »Current Opinion Otolaryngology 2000 8(6):497- 502 –patients die before reaching hospital – not reported in data –larynx well protected & flexible mandible - superiorly; sternocleidomastoids – laterally; clavicles – inferiorly. »American Association Oral Maxillofacial Surgeons 2006: 203-214 »Current Opinion Otolaryngology 2000 8(6):497- 502
Laryngeal Trauma: Diagnosis DIAGNOSIS OF SUSPICION –laryngeal trauma NEEDS to be excluded –diagnosis may not be obvious in a patient with an uncompromised airway –symptoms & signs unrelated to degree of trauma this may also be reason for under reporting Once diagnosed the extent of injury must be defined before any attempt at intubation –ETT across injured larynx can convert mucosal laceration to a more complex problem ETT can cause complete laryngo-tracheal separation
Laryngeal Trauma: Morbidity/mortality Mortality –0-18% »J Trauma 1990 30(1):87-93 Delay in diagnosis increases morbidity & mortality –pharyngeal, oesophageal & vessel injury must be excluded Concurrent occult oesophageal injury significantly contributes to morbidity & mortality –evaluation of oesophagus mandatory - NB before placement N/G tube
Laryngeal trauma: Diagnosis of Suspicion HISTORY Hoarseness - 90% Tenderness - 90% Subcutaneous emphysema - 60% Anterior neck contusion - 40% SOB - 40% Current Opinion Otolaryngology 2000 8(6):497-502
Associated injuries Chest trauma - 40% Facial #s - 30% Facial laceration - 30% Long Bone #s - 30% Oesophageal laceration - 10% Head injury - 10% Pharyngeal trauma/perforation - rare None - 30% Current Opinion Otolaryngology 2000 8(6):497-502
Laryngeal trauma: History may give some idea of injury Complete L-T separation associated with: –hyperextension injuries: avulsion of larynx – tearing of fibrous ring between CC & 1 st tracheal ring –strangulation –rarely associated with blunt trauma –ASSOCIATED WITH # CRICOID CARTILAGE # Thyroid Cartilage: –neck hyperflexion Knife or Gunshot wounds –evaluate the oesophagus
Multiple threats to airway: Direct penetration Distorted tissue planes Haematoma Oedema Excessive blood & secretions
Multiple threats to airway:..2 IPPV & coughing: –worsen air leaks –s/c emphysema Cricoid pressure: –lead to laryngo-tracheal separation
Fractured Larynx: Management Tracheostomy under LA vs GA Management is NOT A LEARNING EXPERIENCE HELIOX FOB & Cricothyroidotomy may not be appropriate Intubation may not be appropriate –may cause complete separation
WHY HELIOX? 1.Less dense – work of breathing less. 2.Decrease amount of subcutaneous emphysema
Helium - Upper airway obstruction “When it is available an even better effect can be expected from inhalation of 79% Helium with 21% Oxygen” –Wylie Churchill Davidson 1960 pp 382
Turbulent flow –F ~ P 1/2 /Lρ 1/2 F = flow; P = pressure; ρ = density; L = length. (Radius important but not expressible as a power of the diameter - as radius decreases flow decreases also) Turbulent flow: flow greater with Heliox than air or O 2 Density important
Relationship between pressure and flow during turbulent flow Even if flow is turbulent there is less work of breathing and greater flow with given pressure change Comparison between Heliox (black) & air or O 2 (yellow) Heliox O2O2
Why Helium? Hylegaard et al O 2 breathing initial bubble growth –O 2 > He solubility in fat –build up O 2 around bubble in tissue Helium breathing bubble constantly shrunk
Helium mixtures: Physics /Gas flux GAS FLUX = diffusion x solubility coefficient –He>N 2 diffusibility (smaller atomic wt) –He He flux HENSE ANY AIR POCKETS WILL SHRINK.
WHY HELIOX? HELIOX WILL GAIN PATIENT’S CONFIDENCE AND MAKE BREATHING EASIER AND MAY DECREASE THE AMOUNT OF S/C EMPHYSEMA.
5 Case Histories Maybe others – but not recognised. trauma patients on ICU ventilator – laryngeal oedema when extubated a couple of days later – ‘floppy epiglottis’ on intubation 1. Walker in mountains –hoarse voice in GP’s surgery –GA - laryngoscopy – unable to identify any structures, unable to intubate (fortunately!!) –obstructed during tracheostomy with retractors 2. Motorcyclist on farmer’s property –intubated at scene
5 Case Histories 3. MVA – car rolled. –hanged by seat belt upside down –complete tracheal/laryngeal separation –partial obstruction with palpation of neck - GA 4. Motorcyclist – MVA – Modbury Hospital –gaseous induction –complete obstruction during tracheostomy – retractors again 5. And ….
Head extended exposing the neck. Neck palpated. LA injected. Horizontal 6 cm incision to anterior borders sternocleidomastoid muscles. Skin, subcut tissue, platysma to deep fascia. May not be able to extend the head. Palpation of structures may press on trachea & cause anxiety. LA stings – may increase anxiety. Veins may be enlarged due to inspiratory/expiratory pressures SURGICAL TRACHEOSTOMY
Self retaining retractor placed, dissection to strap muscles Strap muscles divided & retracted. Langerbech retractors placed. Retractor placement important – to much pressure can obstruct airway.
Thyroid isthmus exposed, clamped, divided and ligated, rotated externally & sutured. Trachea is exposed Retractor placement again important – to much pressure can obstruct airway.
Tracheal incision sited over 2nd & 3rd or 3rd & 4th tracheal rings. Tracheostomy tube inserted Placement of tube may cause some distress
Summary: Rare – diagnosis of suspicion Mortality ~20% –increases if unrecognised Concurrent oesophageal injury increases morbidity & mortality –needs to be excluded Inability to lie supine – indication immediate tracheostomy
Summary:.. 2 Consider Heliox if available Avoid coughing – may make s/c emphysema worse and airway impossible Awake tracheostomy vs SV GA? –careful palpation –care with retractors
3rd SIG Airway Meeting Lorne March 9-11 2012 “Everything airways including problems outside the OT”