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33 Cards in this Set
- Front
- Back
Anatomy of Larynx
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1. Bone
a. Hyoid bone C3 2. Cartilage (3 unpaired and 3 paired) a. Unpaired i. Epiglottis ii. Thyroid cartilage iii. Cricoid cartilage b. Paired i. Arytenoid cartilages ii. Corniculate cartilages iii. Cuneiform cartilages 3. Ligaments (4 extrinsic and minor intrinsic) a. Thyrohyoid membrane b. Hyo-epiglottic ligament c. Cricothyroid ligament d. Cricotracheal ligament 4. Muscles (3 extrinsic and 6 intrinsic) a. Extrinsic i. Sternothyroid ii. Thyrohyoid iii. Inferior constrictor b. Intrinsic i. Posterior cricoarytenoid ii. Lateral cricoarytenoid iii. Interarytenoid iv. Thyroarytenoid v. Vocalis vi. Cricothyroid 5. Vascular supply a. Arterial i. Superior laryngeal (from superior thyroid artery) ii. Inferior laryngeal (from inferior thyroid artery) b. Venous i. Into corresponding superior and inferior thyroid veins 6. Nerve Supply a. Branches of vagus (X) nerve i. Superior laryngeal nerve I. External branch: motor to Cricothyroid II. Internal branch: sensory above vocal cords and inferior surface of epiglottis (surface of epiglottis supplied from glossopharyngeal) ii. Recurrent (inferior) laryngeal nerve I. Motor to all intrinsic muscles of larynx (except Cricothyroid) II. Sensation below vocal cords |
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Laryngectomy and Radical Neck Dissection Issues
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Anaesthetic Factor
1. Airway a. Mass effect of tumour b. Shared airway (remote anaesthesia) 2. Circulation a. IV access b. Maintain blood pressure with 20% of normal c. Blood loss d. Fluid management 3. Pressure areas 4. Length of procedure 5. Fatigue 6. Pain usually not a problem Patient 1. Co-existing disease 2. Nutrition Surgical 1. Position: head up to reduce bleeding 2. Casual vandalism a. Airway b. Eyes c. Lips d. teeth 3. Damage to adjacent structure a. Blood vessels b. Nerves: i. recurrent laryngeal, phrenic, vagus ii. Carotid stimulation c. Muscles d. Thyroid/parathyroid e. Pneumothorax f. Air embolus |
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Remote Anaesthesia Issues
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1. Airway
2. Access 3. Casual vandalism a. Airway b. Eyes c. Lip d. Teeth e. Brachial plexus |
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Tonsillectomy Issues
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Background
Common surgical procedure in children with bimodal peaks age 4 and 16-17. Respiratory complications are common in less than 3 years Secondary haemorrhage is common Issues Indication for procedure: airway obstruction or recurrent infection Obstruction Apnoea URTI: risk of respiratory complication and bleeding Bleeding Post operative analgesia Paediatrics: separation anxiety, cooperation and parent anxiety |
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Rebleeding Tonsillectomy Issues and management
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Issues
1. Full stomach 2. Hypovolaemia 3. Airway 4. Location and time a. Peripheral hospital b. Middle of the night Management History: General health: infection Surgical: when was tonsillectomy done, known complication, timing and quantifying amount of bleeding. Respiratory: breathing, stridor and ability to lie flat CVS: hydration status, amount of resuscitation to date Prev anaesthetic: ease of intubation, IV access, allergy Examination Airway assessment Respiratory effort Fluid status: BP, HR, Urine output and capillary refill Investigation Hb, PLT, COAG, G&S Preparation Resuscitation: 2 large bore cannula, IV fluid titrates to HR, BP and urinary output. Assistant and surgeon in OT Drug prepared for RSI Monitoring: routine Equipment: difficult airway trolley, two bright laryngoscope, assorted size of ETT, with a smaller size available, bougie, video laryngoscope, two suction devices, NGT Induction Two methods described 1. RSI: allow rapid airway protection but laryngoscope may be difficult. It is my referred method. 2. Inhalational induction on left lateral position: takes longer, with a non-fasted patient and unfamiliar technique. |
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Nasal surgery intraoperative HTN Differential Diagnosis
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Differential Diagnosis
Physiological 1. Nociception 2. Inadequate anaesthesia 3. Hypoxia 4. Hypercapnia Pathological 1. ICP: check Cushing response 2. Pre-eclampsia 3. Endocrine a. Thyroid storm b. Conn syndrome/Cushings c. Phaeochromocytoma Iatrogenic 1. Anaesthetic: vasopressor, inotropes, MH 2. Surgical: adrenaline in LA, cocaine 3. Measurement error |
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HTN intraoperative management
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Management of HTN
Aim: prevent myocardial ischaemia and hypertensive stroke 1. ABC 2. FiO2 3. Deepen anaesthesia and given analgesia 4. Pharmacological a. HR: high β-blockers: metoprolol 1-2 mg, labetalol 5-10mg, Esmolol 0.5 mg/kg b. HR: low vasodilator: hydralazine, GTN, SNP i. β-blocker may cause unopposed -vasoconstriction ii. Generally vasodilator first 5. Recovery a. ECG and troponin if suspect myocardial injury 6. Subsequent a. General physician referal b. Secondary HTN i. 24 hour urinary catecholamine ii. TFT |
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Throat Pack: prevention
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1. Inform surgeon and nursing staff
2. Tie to tube 3. Mark on the forehead 4. Include in the count 5. Inform changeover staff |
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Mastoidectomy Issues
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Surgical:
1. Monitoring of facial nerve and nerve stimulation: normal neuromuscular function at the time of surgery. Anaesthetic: 1. Remote anaesthesia 2. Pressure area 3. Nitrous oxide should not be used 4. Analgesia usually not an issue 5. Preference Propofol TIVA and remifentanil Patient: 1. PONV: Apefel a. Female b. Previous PONV c. Non-smoker d. Opioid use (not so much for Mastoidectomy) |
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Myringotomy and Grommets Issues
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Common procedure in children aged 6 months to 3 years that is performed as a day case.
Indications Recurrent otitis media Persistent middle ear fluid, glue ear Hearing loss Speech delay Issues 1. Shared airway 2. Obstruction 3. Laryngospasm Patient 1. Craniofacial syndromes 2. Sleep apnoea: may have respiratory insufficiency and require overnight hospitalisation 3. Recent URTI Anaesthetic 1. Shared airway |
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Risk with URTI
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1. Increased laryngospasm
a. Hyper-reactivity and respiratory muscle weakness for 2 weeks (JAMA 1974) b. 3 x increase in bronchospasm and laryngospasm with recent URTI (Tait and Knight Can J Anaes 1987) c. ETT in child with URTI increase risk of adverse event by 11x (Cohen A&A 1991) d. More common in less than 1 year old (Anaesthesiology 1991) 2. Coughing 3. Breath holding 4. Obstructed airway 2-7 x 5. Increased risk of hypoxia a. Recent URTI and GA with face mask no increase rate of complications in the URTI group compared with control (Tait Anaesthesiology 1987) but increased desaturations (Anaesthesia 1992) |
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When to cancel with URTI
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1. < 1 year old
2. Lethargic and look unwell 3. Temp > 38 4. Production cough 5. Green/yellow nasal discharge 6. Chest infection 7. Need for intubation |
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When to reschedule URTI
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Wait 4-6 weeks
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Epiglottitis Assessment
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Inflammation of the epiglottis commonly caused by haemophilus influenza.
It is now rare to see as people are vaccinated against H. influenza History Clinical triad: drooling, dysphagia and distress classic presentation. High fever 40C. Abrupt onset of stridor and laboured breathing Dysphagia Sore throat and anxiety Examination Toxic, shock, anxiety Chin hyperextended and body leaning forward. (tripod sniffing position) Stridor, marked suprasternal, subcostal and intercostal retractions |
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Epiglottitis Management
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This is an emergency:
Securing the airway is of upmost priority. Transfer patient to OTAsse Management of patient 1. DO NOT examine or insert iv 2. Immediate transfer to theatre 3. Call for help a. Senior anaesthetist b. ENT surgeon 4. Keep sitting up 5. Inhalational induction with 100% O2 6. Once obtunded a. Monitoring on b. Iv access c. Atropine d. Bloods e. CPAP 7. Make sure patient is in a deep plane of anaesthesia 8. Intubate patient with ETT 1-2 size smaller 9. If unable to see larynx press on the chest to see air bubbles 10. Change to nasal tube if it was an easy intubation 11. Transfer to ICU and Ceftriaxone 12. Extubate once temp settles and leak around the tube |
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Tracheostomy Issues
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This is generally an elective procedure
Airway fires Bleeding Hazardous times 1. Changing the trachy 2. Insertion of trachy 3. During transport and on return to ward |
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Tracheostomy Assessment
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Elective or emergency
Airway: 1. Short fat necks 2. grade of intubation 3. Type of tube at present Breathing 1. Ventilator dependence 2. Setting: VT, airway pressure, frequency 3. Oxygenation Circulation 1. Inotrope dependence as low as possible COAG 1. Correction to avoid airway bleeding 2. Normal INR, platelets Timing 1. Out of hours |
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Tracheostomy anaesthetic
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1. General anaesthesia with relaxant: provide optimal surgical condition
2. Severe airway compromise: LA 3. Position: a. Supine with head extension b. Semi-upright for severe airway obstructions 4. For difficult intubation grade 3-4: bougie prior to pulling out tube |
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Jet Ventilation Complications
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1. Barotrauma
a. Pneumothorax b. Pneumomediastinum c. Pneumopercardium d. Subcutaneous emphysema e. Necrotizing tracheobronchitis 2. Malposition a. Gastric distension and rupture b. Necrotizing enterocolitis in neonates c. Dysrhythmia 3. Inadequate gas exchange a. Hypoxaemia b. hypercapnia |
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Microlaryngoscopy Issues
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1. Short stimulating procedure
2. Shared airway 3. Whether laser is going to be used or not 4. Awake patient at the end of the procedure |
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Unfamiliar Environment Issues
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1. Assistant: unfamiliar and expectation
2. Drugs: preparation and location 3. Monitoring: different monitors and availability 4. Equipment: location, suction, advanced airway equipment may be lacking, ventilator |
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Airway tumour Assessment
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Routine airway assessment
Mass: friable, bleeding, size, location (retrosternal involvement), invasion to nearby structure, Metabolic: electrolytes, hormonal effects Metastasis: Medication: chemotherapy or radiotherapy Remember often airway tumour: 1. heavy smokers, alcoholics 2. Cardiac, respiratory and hepatic issues |
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Airway Trauma Issues
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Patient
1. Patient full stomach 2. Psychology/EtOH/Drugs/cooperation from patient Anaesthesia 1. Unfamiliar environment (ED) 2. Difficult airway 3. Airway trauma: airway manipulation needs to be under direct vision (fibreoptic) Surgical 1. Unclear of actual procedure 2. ENT surgeon needs to be scrubbed and available Management Principle 1. Spontaneous breathing patient 2. Visualise airway as further airway injury possible |
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Inhaled Foreign Body Assessment
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Epidemiology
FB aspiration is one of the leading causes of death in young children. 300 deaths per year in US Commonly in 1-3 years old Most die at the time of aspiration due to complete airway obstruction. Most common object is food with nuts most common. (Peanuts account of 1/3 of all FB aspiration) History 1. Early vs late presentation a. Time of presentation since event b. Early can go from well pink child to severe acute upper airway obstruction. c. Late: signs of lower respiratory tract infection. 2. Size, shape and type of object inhaled: a. suggest site of lodgement b. likelihood of visibility on CXR c. Urgency: battery corrosive 3. Site of object within airway (trachea, main bronchus, distal airways) Sudden choking followed by coughing and wheezing Examination Early 1. Respiratory distress: cyanosis, stridor, severe intercostal/sternal recession 2. Change of voice/barking cough: laryngeal oedema/upper airway obstruction 3. Consciousness: reduced → of upper airway obstruction Late 1. Pneumonia: fever, cough, tachycardia, tachypnoea and focal chest signs Investigation CXR: include neck: sensitivity 67-82% specificity 44-74% Normal CXR especially within 24 hours does not exclude diagnosis of FB 1. Normal 2. Gas trapping 3. Mediastinal shift 4. Atelectasis 5. Lobar collapse/consolidation |
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Foreign objection in airway management
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Immediate
1. Does the child have effective cough? a. If yes encourage cough b. Physiotherapy/intervention (back blows or chest/abdominal thrust) i. Less effective ii. Risk of dislodging the FB and worsens the obstruction 2. Is the child conscious? a. No cough but conscious i. 5 back blows followed by 5 chest thrusts b. Unconscious i. BSL Anaesthesia Technique Preparation 1. Adequate Staff a. Senior anaesthetist (paediatric anaesthetist) b. ENT surgeon with ridged bronchoscope ready 2. Fasting a. Don’t worry about it too much especially in compromised situations b. Premedication i. Generally no premed: maintain perioperative respiratory drive ii. Atropine/glycopyrrolate: I. reduce bradycardia via vagal stimulation II. reduced airway secretions 3. Antibiotics: especially in late and pneumonia 4. Intravenous access: may insert after induction Induction 5. Inhalational induction a. Sevo + 100% oxygen b. No nitrous due to gas trapping 6. Lignocaine 4% a. Reduce cardiovascular and tussive response to bronchoscopy Maintenance 1. Spontaneous ventilation a. Catheter to the sidearm of a Storz bronchoscope i. Allow volatile, oxygenation and ventilation b. Possible to run low dose TIVA to maintain deep anaesthesia 2. Paralyse and positive pressure ventilation a. Decrease amount of coughing b. However, jet ventilation may push foreign object further down. Postoperative 7. Depend on child 8. CXR to exclude pneumonthorax 9. Antibiotics if there is delayed treatment such as pneumonia |
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Thyroid Surgery issues
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Preoperatively
1. Thyroid activity 2. Potential airway problem Intraoperatively 1. Remote anaesthesia from airway 2. Thyroid storm 3. Coughing 4. Surgeon a. Vascular: i. Bleeding ii. Air embolism b. Nerves: vagus, recurrent laryngeal, phrenic, carotid reflexes i. View cords at the end of surgery ii. Special ETT: required neuromuscular function: no relaxant and no coughing c. Parathyroid d. pneumothorax Postoperative 1. Airway (stridor) 2. Pneumothorax 3. Post-operative bleeding 4. Thyroid storm/Myxoedema coma 5. Hypocalcaemia |
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Post-thyroidectomy Stridor Differential Diagnosis
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Anaesthetic
1. Foreign object 2. Laryngospasm 3. Residual NMB 4. Decreased LOC Surgical 1. Bleeding 2. Nerves (recurrent laryngeal nerve injury) 3. Tracheomalacia 4. Parathyroid (hypocalcaemia) |
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Dental Abscess issues
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Patient:
1. Trismus 2. Airway contamination Anaesthetic 1. Shared airway 2. Difficult airway Surgeon 1. ?local anaesthetic |
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Advantage of laser surgery
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1. Good haemostasis
2. Minimal perioperative oedema 3. Preservation of normal tissue 4. Surgical precision 5. Rapid healing 6. Minimal scar formation |
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Laser Safety
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Patient:
1. Safety glasses and eye protection 2. Water based lubricants and flame resistant draps Surgical: 1. Non-alcoholic prep 2. Instruments: matte finish 3. Laser: minimal power, smallest spot size and shortest exposure time 4. Bucket of water Anaesthetic: 1. Lowest FiO2 and no nitrous 2. Special ETT/no ETT 3. Double cuff: inflate with dye 4. Staff: a. Training b. glasses c. Warning sign outside d. laser safety officer |
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Airway Management for Laser
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1. Protected conventional tube (aluminium foil)
2. Non-combustible tube a. Benjet tube b. Mallincrodt laser flex c. Xomed laser shield II 3. No tube a. Venturi jet ventilation b. High frequency jet ventilation |
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Airway Fire management
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1. Remove source of fire (the laser!).
2. Stop ventilating, disconnect circuit, extubate. 3. Extinguish fire in bucket of water (MUST have one ready!). 4. Mask ventilate with 100% O2, 5. Continue anaesthesia i.v. 6. Direct laryngoscopy & rigid bronchoscopy for damage and debris. 7. Reintubate if damage. 8. Blowtorch fire may need distal fibreoptic bronchoscopy and lavage. 9. Severe damage may need low tracheostomy. 10. Assess oropharynx and face. 11. CXR. 12. ?Steroids. 13. ICU |
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Special ETT's.
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Some special tubes have been made to deal with the problems of flammability and cuff rupture. From the literature it doesn't appear that these are much better than a taped tube but I'll describe them anyway.
Bivona Fome-Cuff. This is an aluminium spiral tube with a silicone polyurethane foam cuff in a silicone envelope. The foam is self inflating (it has to be sucked down) thus preventing deflation in the event of cuff rupture. It should nonetheless be filled with coloured saline to identify rupture. Its problem is the trauma an undeflated cuff will cause in the event of perforation. It also has a high incidence of sore throat and is only recommended for use with a CO2 pulsed laser. Xomed Laser-Shield. A silicone elastomer tube containing metallic powder only for use with pulsed CO2 laser less than 25W. There is still a risk of perforation and fragmentation into silica ash and wet pledgets should be placed around the cuff. Mallinckrodt Laser-Flex. An airtight stainless steel spiral wound tube with two PVC cuffs which should be filled with coloured saline. The distal cuff maintains the seal if the proximal one is ruptured. It is only recommended for CO2 and KTP-Nd-YAG, not the ordinary YAG. |