Post on 13-Feb-2018
transcript
Common questions
Airway emergencies:
• Bleeding tonsil
• Inhaled foreign body
• Croup/epiglottitis
Topical airway stuff:
• Tracheostomy/DAS guidelines
• NAP 4
• BJA Education
ENT:
• Laser airway surgery
• Jet ventilation
• Airway imaging
Maxfacs:
• Intraoral abscesses
• Facial fractures
Equipment:
• Supraglottic airways
• Fibreoptic scope
Discuss intubation options
17 year old female with fractured mandible requiring ORIF. MO 1cm. Very anxious. Requesting EMLA for cannulation.
27 year old male with facial swelling due to intra-oral abscess requiring I &D in theatre. MO 1cm.
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.
Airway 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)
Implications of radiotherapy
Site of cancer Pathology Problems Implications
Face & Buccal mucosa Necrosis
Mucositis
Oral thrush
Orofacial pain
Ulceration
Fistula formation
Difficult mask ventilation
Mucosal bleeding
TMJ Fibrosis Trismus Difficult laryngoscopy
Tongue Fibrosis
Inflammation
Glossitis
Glossomegaly
Reduced tongue mobility
Difficult laryngoscopy
Dentition Increased risk caries Loose teeth
Dental loss
Difficulty mask ventilation
Risk of dental trauma
Floor of mouth Fibrosis Reduced mobility Difficult laryngoscopy
Mandible Osteonecrosis Micrognathia
Mandibular recession
Difficult mask ventilation
Difficult laryngoscopy-
reduction in mandibular
space
Suprahyoid region Fibrosis
Oedema
Firm/woody neck tissue
Skin tethering
Difficult laryngoscopy-
limited atlanto-axial
flexion/extension
Lower airway Epiglottic & glottic
oedema
Snoring
Hoarseness
Cough
Difficult laryngoscopy
Difficult endotracheal
intubation
SAQ One
A 71-year-old patient requires a rigid bronchoscopy for biopsy
and possible resection of an endobronchial tumour.
a) What are the possible indications for rigid bronchoscopy
under GA?
b) What are the options for anaesthesia and ventilation during
bronchoscopy?
c) What are the possible complications of rigid bronchoscopy?
d) What are the indications for bronchoscopy on the intensive
care unit?
Diagnostic Therapeutic
Massive haemoptysis
Massive haemoptysis
Biopsy tumour Stent insertion
Tracheal dilation
Removal inhaled FB
Tumour debulking
Indications for rigid bronchoscopy
Options for anaesthesia/ventilation?
• Apnoeic oxygenation
• Spontaneous assisted ventilation
• Controlled ventilation
• Manual jet ventilation
• High frequency jet ventilation
Jet ventilation
• Low frequency vs high frequency
• Jet stream from high pressure source
generates tidal volume
• Passive expiration from lung and chest
wall recoil (NB HFOV)
High frequency jet ventilation
Small Vt (1-3 ml/kg) from a high pressure jet at supra-physiological frequencies 1-10Hz
• Gas exchange: pendelluft/
laminar flow/longitudinal dispersion
• Facilitate surgical access
• Lower mean airway pressure
(useful if gas leak)
Complications
Bronchoscopy related Anaesthesia related
Airway bleeding Hypoxaemia
Trauma to vocal cords Hypercarbia
Laryngospasm Barotrauma/Pneumothorax
Aspiration Surgical emphysema
Bronchospasm Awareness?
Oedema-post op stridor Gastric distension
Bronchoscopy in ICU
Inspection Sampling Therapy
Aspiration x x x
Infection x x x
Lobar
collapse/atelect
asis
x x x
Airway
management
x x
Airway
assessment
x x
Foreign Body x x
Strictures/steno
sis
x x
Haemoptysis/h
aemorrhage
x x
SAQ Two
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 flap failure and how may they be prevented in the perioperative period? (6 marks)
Free Flap Surgery
Conditions requiring free flap
Reconstructive surgery head and
neck cancers
Breast reconstructive surgery
Reconstructive hand surgery
Burns
Trauma
Donor Sites in H&N
Intra-oral defects
• Radial forearm
• Anterolateral thigh
Mandibular reconstruction
• Fibula
• Iliac crest (DCIA)
• Scapula
Pre-operative assessment
Patient:
Smoking
Alcohol
Pre-op BP
Nutrition
Anaesthetic:
Airway-previous radiotherapy, site of lesion
Side of flap (venous/arterial access)
Surgical:
Duration
Positioning
Temperature
DVT prophylaxis
Tracheostomy formation
Benefits of free flap
① Integrity
② Function
③ Aesthetics
• Benefits of taking tissue from a distant site
• Better outcomes if future radiotherapy
needed
• Minimal donor site morbidity
Free flap physiology
• Intact arterial and venous system
• Denervated
• No lymphatic drainage
Physiological principles?
• Hagen-Pouiselle
• Laplace
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
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 help
b. Connect the tracheostomy tube to a circuit and do manual bagging
c. Give 100% oxygen
d. Pass suction catheter through tracheostomy tube
e. 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
is:
a. Anaphylaxis
b. Carotid sinus manipulation
c. Myocardial ischaemia
d. Tension pneumothorax
e. 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 ETT
b. Look at capnograph trace
c. Look at oxygen saturation
d. 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 O2 saturation 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 wound
b. Open the clips in the front of the neck
c. Give CPAP using NIV
d. Nebulised Adrenaline
e. Urgent USS
MCQ
Complication of percutaneous tracheostomy
are:
a. Tracheal stenosis
b. Surgical emphysema
c. Endobronchial intubation
d. Hypothyroidism
e. Trachea-oesophageal fistula
MCQ
With regards to high frequency ventilation:
a. I:E ratio 1:3 is used
b. It is used in management of broncho-pleural fistula
c. Increases FRC
d. Requires continuous infusion of muscle relaxants
e. Reduces the risk of barotrauma
What we’ve covered:
Anatomy and nerve supply of the upper airways
Relevance of intra-oral abscesses & facial #
Implications of head and neck radiotherapy
Bronchoscopy/principles of jet ventilation
Free flap surgery
References
Pathak et al. Ventilation and anaesthetic approaches for rigid bronchoscopy. Annals American Thoracic Society. 2014, 4: 628-634.
Conclon, 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.