Airway  Anaesthesia  for  Final  FRCA

Final  FRCA  Teaching  July  2018

Dr  Kate  Henderson

Learning  Outcomes

• Popular  exam  topics• Anatomy• Case  based  discussions• Exam  questions

Potential  Topics

Recent  publications

BJA  Education• Paediatric  airway  infections• Management  of  elective  laryngectomy• Postoperative  management  of  the  difficult  

airway• Anaesthesia  for  laryngo-­‐tracheal  surgery,  

including  tubeless  field  techniques• Anaesthesia  for  head  and  neck  cancer  surgery• Management  of  airway  obstruction

Anaesthesia  2018• Anaesthetist  inserted  throat  packs

BJA• DAS  Intubation  in  the  critically  ill  guideline

Airway  emergencies:• Bleeding  tonsil• Inhaled  foreign  body• Croup/epiglottitis

Anatomy:• Nose• Larynx• Tracheobronchial   tree

ENT:• Laser  airway  surgery• Jet  ventilation• Airway  imaging• Middle  ear  surgery• Thyroidectomy

Maxfacs:• Bimaxillary osteotomy• Dental  damage• Intraoral   abscesses• Facial  trauma  • AFOI• Head  and  neck  cancers

Equipment:• Supraglottic  airways• Various  ET  tubes• Tracheostomy• Bronchoscopes• Fibre-­‐optic  scope• HFNOT

Anatomy  Quiz

① Identify  anatomical  structures

② Nerve  supply  to  each  area

① How  would  you  anaesthetise  each  area  for  an  AFOI?

Indications  and  contraindications  for  AFOI

Indications Contraindications

Known/  anticipated  difficult  mask  ventilation

LA  allergy

Known/anticipated  difficult   intubation Patient  refusal/lack  of  co-­‐operation

Patients  with  difficult  airway  and  aspiration  risk

Lack  of  experienced  operator

Cervical  spine  instability(NB  video   laryngoscopy)

Narrow  glottis/subglottis-­‐airway  obstruction  with  scopeNasal  intubation:  basal  skull  #

Upper  airway  bleeding

Case  based  discussionsKey  concerns?  Intubation  options?

1. 17  year  old  female  with  fractured  mandible  requiring  ORIF.  MO  1cm.  

2. 27  year  old  male  with  facial  swelling  due  to  intra-­‐oral  abscess  requiring  I  &D  in  theatre.  MO  1cm.

3. 54  year  old  male  for  microlaryngoscopy  for  biopsy  of  laryngeal  lesion.  Normal  MO.  Previous  surgery  abandoned  due  to  failed  direct  laryngoscopy.  PMH  radiotherapy  for  tonsillar  cancer.

Case  One

17  year  old  female  with  fractured  mandible  requiring  ORIF.  MO  1cm.  

Key  Concerns• Head  injury/trauma• Alcohol/drugs• Fasting• Nasal  patency/CI  nasal  intubation• Blood  in  airway

Facial  fractures

Case  Two

27  year  old  male  with  facial  swelling  due  to  intra-­‐oral  abscess  requiring  I  &D  in  theatre.  MO  1cm.

Key  Concerns• Anatomy  of  abscess• Tongue  protrusion• CI  nasal  intubation• Co-­‐operation/explanation  AFOI• Sepsis

Fascial  Plane  Infections

Cervical  space  infectionAirway  Management  Considerations

Superficial•Reduced  nasal  patency•Trismus  related  to  pain  unless  spread  to  other  spaces

Floor  of  mouth•Trismus•Raised  floor  of  mouth  (can’t  protrude  tongue)•Reduced  oro-­‐pharyngeal  space•Potential  rupture  on  airway  manipulation•Dysphagia,  drooling•Supraglottitis-­‐oedema   of  laryngeal  structures•Difficult  tracheal  access

Masticator• Severe  trismus• Rupture  on  manipulation

Pharyngeal• Neck  stiffness• Reduced  oro-­‐pharyngeal   space• Rupture• Dysphagia,  drooling• Airway  distortion/oedema   and  stridor• Distant  spread  (mediastinitis)

Case  Three54  year  old  male  for  microlaryngoscopyfor  excision  of  laryngeal  lesion.  

Normal  MO.  Previous  surgery  abandoned  due  to  failed  direct  laryngoscopy.  PMH  radiotherapy  for  tonsillarcancer.

Key  Concerns• Previous  chart-­‐ease  of  FMV• AFOI  vs videolaryngoscopy• Inhalational  vs  intravenous  induction• Type  of  ETT,  ventilatoryconsiderations

Implications  of  radiotherapySite  of  cancer Pathology Problems ImplicationsFace  &  Buccal  mucosa Necrosis

MucositisOral  thrushOrofacial  painUlcerationFistula  formation

Difficult  mask  ventilationMucosal  bleeding

TMJ Fibrosis Trismus Difficult  laryngoscopy

Tongue FibrosisInflammation

GlossitisGlossomegalyReduced  tongue  mobility

Difficult  laryngoscopy

Dentition Increased  risk  caries Loose  teethDental  loss

Difficulty  mask  ventilationRisk  of  dental  trauma

Floor  of  mouth Fibrosis Reduced  mobility Difficult  laryngoscopy

Mandible Osteonecrosis MicrognathiaMandibular  recession

Difficult  mask  ventilationDifficult  laryngoscopy-­‐reduction   in  mandibular  space

Suprahyoid  region FibrosisOedema

Firm/woody  neck   tissueSkin  tethering

Difficult  laryngoscopy-­‐limited  atlanto-­‐axial  flexion/extension

Lower  airway Epiglottic  &  glottic  oedema SnoringHoarsenessCough

Difficult  laryngoscopyDifficult  endotracheal  intubation

SAQ

A  54  year  old  patient  with  base  of  tongue  cancer  presents  for  a  hemiglossectomy  and  radial  forearm  free  flap  reconstruction.  

a)  What  conditions/procedures  require  the  formation  of  a  free  flap?(2  marks)b)  Which  specific  factors  must  the  anaesthetist  consider  when  assessing  this  patient  prior  to  surgery  (10  marks)  c)  List  the  benefits  of  a  free  flap  reconstruction  (2  marks)d)  What  are  the  causes  of  f lap  failure  and  how  may  they  be  prevented  in  the  perioperative  period?  (6  marks)  

Free  Flap  Surgery

Conditions  requiring  free  flap

Reconstructive  surgery  headand  neck  cancers

Breast reconstructive  surgery

Reconstructive  hand  surgery

Burns

Trauma

Donor  Sites

Intra-­‐oral  defects• Radial  forearm• Anterolateral  thigh

Mandibular  reconstruction• Fibula• Iliac  crest  (DCIA)• Scapula

Pre-­‐operative  assessment

Patient:• Smoking• Alcohol• NutritionAnaesthetic:• Airway-­‐previous  surgery/radiotherapy,  site  of  lesion• Side  of  flap  and  surgery  (venous/arterial/central  access)Surgical:• Duration• Positioning• Temperature  (core  and  peripheral)• DVT  prophylaxis• NGT/PEG• Tracheostomy  formation• Post  op  HDU

Benefits  of  free  flap

① Integrity② Function③ Aesthetics

• Benefits  of  taking  tissue  from  a  distant  site• Better  outcomes  if  future  radiotherapy  needed• Minimal  donor  site  morbidity

Causes  of  flap  failure

• Primary  ischaemia

• Reperfusion  injury

• Secondary  ischaemia

Free  flap  physiology

• Intact  arterial  and  venous  system• Denervated• No  lymphatic  drainage

Physiological  principles• Hagen-­‐Poiseuille• Laplace

Causes  of  flap  failure

Flap  Failure

Arterial  occlusion§ Flat§ Pale§ Cool§ Decreased  or  absent  CRT§ No  bleeding  on  pinprick§ Loss  of  arterial  Doppler  signal

Venous  occlusion§ Oedematous§ Congested  (pink-­‐purple)§ CRT  brisk§ Dark  bleeding  on  pinprick§ Loss  of  venous  Doppler  

signal

HFNOT

a)  What  are  the  benefits  of  high  flow  nasal  oxygen  therapy?  b)  Describe  the  physiological  basis  for  HFNOTc)  What  are  the  indications  for  HFNOT?  d)  What  are  the  contraindications?  

HFNOT

• Triad  of  humidity,  high  Fi02  and  patient  compliance• Reduces  anatomical  dead  space  • Up  to  7cmH20  PEEP  ,  60L/min

Uses:1. Acute  respiratory  failure2. Preoxygenation3. Post  extubation4. Tubeless  surgery

• CI:  as  for  NIV

SBA

You  are  called  to  see  a  patient  with  tracheostomy  .  His  saturation  dropped  from  98%  to  86%  on  50%  oxygen.  What  will  be  your  next  immediate  step?

a. Call  for  helpb. Connect  the  tracheostomy  tube  to  a  circuit  and  do  manual  

baggingc. Give  100%  oxygend. Pass  suction  catheter  through  tracheostomy  tubee. Remove  tracheostomy  tube

SBA

70  year  old  male  undergoes  radical  neck  dissection  for  malignancy.  Patient  becomes  unstable  when  tumour  is  being  dissected  from  carotid  sheath.  SBP  drops  to  60,  HR  110,  SpO2 87%  and  ETCO2 1.9kpa.  The  most  likely  cause  is:

a.   Anaphylaxisb.   Carotid  sinus  manipulationc.   Myocardial  ischaemiad.   Tension  pneumothoraxe.   Venous  air  embolism

SBA

Following  a  difficult  intubation  but  easy  bag  and  mask  ventilation  in  an  obese  lady  you  cannot  hand  ventilate.  What  will  you  do  first?  

a. Take  out  ETTb. Look  at  capnograph  trace  c. Look  at  oxygen  saturationd. Give  nebuliser  e. Give  muscle  relaxant  

SBA

You  are  called  to  see  a  patient  in  recovery  one  hour  following  a  thyroidectomy  operation.  He  has  difficulty  breathing  and  his  O2saturation  has  dropped  to  89%  from  97%  despite  a  FiO2 of  60%.  The  front  of  his  neck  appears  swollen  despite  no  blood  in  the  suction  drain.  What  will  be  your  next  line  of  action:

a. Get  the  surgeons  to  re-­‐explore  the  woundb. Open  the  clips  in  the  front  of  the  neckc. Give  CPAP  using  NIVd. Nebulised  Adrenalinee. Urgent  USS  

MCQ

A  man  is  referred  by  his  General  Practitioner  to  the  Ear  Nose  and  Throat  (ENT)  ward  with  a  three  month  history  of  hoarseness.  There  is  now  stridor  and  dyspnoea  but  no  hypoxia.  Nasendoscopy  shows  a  glottic  mass  with  significant  narrowing  of  the  airway.  Appropriate  statements  regarding  his  management  include:  

a)  Given  the  stridor,  he  is  likely  to  be  taken  to  theatre  to  have  his  airway  secured.  b)  Epinephrine  10  mg  should  be  nebulised  to  alleviate  his  symptoms.  c)  Awake  fibreoptic  intubation  is  likely  to  be  performed.  d)  Given  the  absence  of  hypoxia,  high  flow  nasal  oxygen  is  unlikely  to  be  administered.  e)  A  computerised  tomographic  (CT)  scan  should  be  arranged

MCQ

A  42-­‐year-­‐old  obese  man  attends  hospital  with  a  large  retrosternal  goitre  and  significant  tracheal  compression.  He  is  short  of  breath  on  exertion  and  has  obstructive  sleep  apnoea.  His  is  on  your  list  for  total  thyroidectomy.  Appropriate  statements  regarding  his  management  include:  

a)  To  optimise  his  airway  before  surgery,  high  dose  steroids  are  likely  to  be  prescribed  b)  Tracheostomy  is  likely  to  be  part  of  his  airway  strategy  c)  Patients  with  head  and  neck  disease  are  under-­‐represented  in  the  assessment  of  adverse  outcomes  in  the  National  Audit  Project  4  d)  The  lack  of  airway  symptoms  such  as  stridor  is  likely  to  be  reassuring  e)  Fibreoptic  intubation  after  induction  of  general  anaesthesia  is  likely  to  be  indicated

MCQ

A  56  year-­‐old  lady  presents  to  the  Emergency  Department  in  a  District  General  Hospital  with  presumed  angio-­‐odema  after  taking  lisinopril.  She  has  developed  massive  tongue  swelling,  as  well  as  a  weak  voice  and  cough.  She  seems  to  be  hypoxic  on  room  air.  Appropriate  statements  regarding  this  situation  include:  

a)  She  has  signs  of  laryngeal  oedema  b)  She  is  likely  to  be  transferred  by  ambulance  to  the  ear,  nose  and  throat  ward  for  a  formal  assessment  c)  Awake  standard  fibreoptic  intubation  of  the  trachea  is  more  likely  to  be  successful  than  intubation  by  awake  videolaryngoscopy  d)  Surgeons  are  likely  to  be  standing  ready  to  carry  out  surgical  cricothyroidotomy  during  attempts  to  secure  the  airway  e)  After  failure  of  tracheal  intubation  under  general  anaesthesia  that  includes  rocuronium,  the  next  step  is  likely  to  be  reversal  of  muscle  relaxation  for  return  of  spontaneous  ventilation

MCQ

Awake  videolaryngoscopy:  

a)  Is  likely  to  be  useful  in  the  presence  of  epiglottic  cysts  b)  Is  well  tolerated  when  hyper-­‐angulated  devices  are  usec)  Is  likely  to  be  followed  by  use  of  a  tracheal  tube  containing  a  stylet  d)  Is  a  skill  that  is  more  difficult  to  acquire  than  standard  fibreoptic  laryngsocopy  e)  Causes  the  “cork  in  the  bottle  phenomenon”

Perioperative  dental  injury:

A    Has  an  incidence  of  1  in  4500  general  anaestheticsB    Is  most  commonly  associated  with  the  use  of  a   laryngeal  mask  airwayC    May  be  avoided  by  using  oropharyngeal  airways  as  bite   blocksD    Most  commonly  affects  the  left  central  mandibular  incisorE    Is  not  recognized  by  the  anaesthetist  in  up  to  15%  of  cases

MCQ  2

Correct  management  after  dental  injury  should  include:

A Immediate  replacement  of  the  avulsed  tooth  in  it’s  socket

B Placement  of  the  tooth  or  fragments  into  an  osmolality  balanced  solution

C Avoiding  a  ‘dry  time’ of  less  than  90  minD Preservation  of  the  periodontal  ligament  cells  by  

avoiding  handling  of  the  crown,  where  these  cells  are  located

E Location  of  missing  fragments  using  a  chest  radiograph

MCQ  1

What  we’ve  covered:

• Anatomy  of  the  upper  airways• Relevance  of  intra-­‐oral  abscesses  &  facial  #• Implications  of  head  and  neck  radiotherapy• Free  flap  surgery• High  flow  nasal  oxygen  therapy

References

Pathak  et  al.  Ventilation  and  anaesthetic  approaches  for  rigid  bronchoscopy.    Annals  American  Thoracic  Society.  2014,  4:  628-­‐634.Conlon,  C.  High  frequency  jet  ventilation.  Anaesthesia  Tutorial  of  the  Week  271.  2012.Evans  et  al.  Jet  Ventilation.  CEACCP.  2007,  7:  2-­‐5.Darshane et  al.  Responsive  contingency  planning:  a  novel  system  for  anticipated  difficulty  in  airway  management.  BJA  2007,  99(6):  898-­‐905.Adams  J  and  Charlton  P.  Anaesthesia  for  microvascular free  tissue  transfer.  BJA  CEPD  2003,3:33-­‐37.Nimalan N.  Anaesthesia  for  free  flap  breast  reconstruction.  BJA  Education.  2015.Kabadayi.  S  Bronchoscpy in  critical   care.  BJA  Education  2016.Ashraf-­‐Kashani,  N  and  Kumar  R.  High  flow  nasal  oxygen  therapy.  BJA  Education  2017,  17  (2):  63-­‐67Abeysundara L  and  Creedon A.  Dental  Knowledge  for  anaesthetists.  BJA  Education  2016,  16  (11);  362-­‐368.