Airway Management Flashcards
The three management issues in airway assessment?
Is mask ventilation going to be difficult?
Is laryngeal visualisation going to be difficult?
Is cricothyroidotomy going to be difficult?
(Can’t ventilate, can’t intubate, can’t rescue with surgical airway).
Who will be difficult to mask ventilate?
(BONES) Beard Obesity No teeth Elderly Snoring
Who will be difficult to intubate?
(4 xD’s)
Disproportion (Macroglossia, macrognathia, high arched palate, bony abnormalities, short thick neck)
Distortion (airway trauma, epiglottitis, abnormal larynx)
Dysmobility (limited mouth opening)
Dentition (passion gap, buck teeth)
What are the 3 most commonly bedside tests to predict the possibility of a difficult intubation?
Mallampati Score
Thyro-mental distance
Extension at the atlanto-occipital joint
(Inidividually - poor predictive value, but good when used in combination)
Mallampati Score/Classification:
Performed with patient in sitting position, head in neutral position, mouth wide open and tongue protruding to maximum.
I: Soft palate, fauces, whole uvula, anterior and posterior pillars (best)
II: Soft palate, fauces, most of uvula
III: Soft palate and base of the uvula
IV: Only hard palate visible (worst)
Thyromental Distance:
Distance from lower mandible (in the midline from the chin) to the thyroid notch (when patients neck fully extended).
What thyro-mentral distance is predictive of a difficult intubation?
Less than 3 finger-breadths/less than 6cm
What maneuvers can be performed to provide a patent airway?
Head tilt and chin lift.
Jaw thrust.
Effective mask ventilation in a spontaneously breathing patient can be determined by?
Good expansion of the chest during inspiration.
Absence of accessory muscle use and tracheal tug.
Inspection of the reservoir bag of the breathing circuit to gain an indication of tidal volume.
Signs of upper airway obstruction:
Stridor
Tracheal tug
Accessory muscle use
“See-saw movement” of the abdomen and chest:
Complete upper airway obstruction
Severe or complete upper airway obstruction may lead to:
Negative pressure pulmonary oedema (which may necessitate re-intubation and ventilation in ICU)
Severe or complete upper airway obstruction usually occurs in:
Otherwise fit strong and healthy individuals.
Advantages of tracheal intubation?
- Guaranteed airway
- Protection from aspiration of gastric contents
- Ability to provide effective positive pressure ventilation
- Ability to clear secretions from respiratory tract by suctioning
Indications for tracheal intubation?
- Controlled ventilation (gold standard for isolating trachea and bronchial tree) - i.e. if patient is to be paralysed and cannot breathe spontaneously
- Protection of the airway (cuffed tube provides protection from aspiration and allows for suctioning)
- Maintenance of a patent airway - in an unusual operative position, if airway inaccessible, anesthetist and surgeon operating in same airway, anticipated difficulties with facemask/LMA ventilation
- Postoperative ventilation in ICU
Equipment needed for intubation?
(IMALES) Introducer Mask, Magill's forceps Airways, Ambubag, Alternative airway (LMA) Laryngoscopes Endotracheal tubes Suction
ETT internal diameter sizing in adults?
Orotracheal intubation: 7,5-8,0 mm in males, 7,0-7,5 mm in females.
Nasotracheal intubation: size usually reduced by 0,5-1,0 mm
ETT internal diameter sizing in children (until puberty)?
(Age in years/4) + 4
How do you calculate the correct depth of an ETT?
22+/- 2cm mark at teeth for adult males.
20+/- 2cm mark at teeth for adult females
In children: (age in years/2) + 12
Orotracheal intubation technique?
- Patient in sniffing position (cervical spine flexed and atlanto-occipital joint extended).
- Laryngoscope in L hand, introduce to R side of mouth.
- Advance blade posteriorly and towards the midline, sweeping tongue to L.
- When epiglottis in view, advance blade into vallecula.
- Lift laryngoscope to bring larynx into view (cricoid pressure can be applied).
- When larynx in view, introduce ETT tube from R.
- Once in place, apply positive pressure to the lungs while assistant inflates cuff during inspiratory phase.
How to tell if ETT is in the trachea?
Watch the tubes go through vocal cords
Capnography (correct hole, rather than correct position)
Osophogeal detector devices
Misting
Chest movement on both sides
Auscultation (axilla, lung bases and epigastrium)
CXR for long-term intubations
When is naso-tracheal tube used?
ENT
Dentistry
Maxillo-facial surgery
In ICU for LT ventilation (controversial - sinus infection, but tolerated better than ETT and requires less sedation)
Extubation technique?
- Check that patient recovering and breathing spontaneously with good tidal volumes.
- Allow patient to breath high flow 40% O2 for 1-2minutes to wash out any ISO and/or N2O.
- Remove secretions by suctioning.
- Check that patient is NOT in excitable state (light anaesthesia).
- Deflate cuff slowly.
- Remove ETT at end of inspiration with a positive pressure breath.
- Supplemental facemask O2
- If satisfied, monitor O2 SATS on room air
Complications of intubation?
Trauma (nose, lips, teeth, soft tissues) Bronchial intubation (ETT too deep) Physiological responses to intubation Increased resistance to breathing ETT obstruction (collapse, foreign body, secretions, biting) Oesophageal intubation Dislodgement into pharynx or bronchus (inadequate securing) Failed intubation
What are the physiological responses to intubation?
Tachycardia HPT Dysrythmias Bronchospasm Increased ICP Increased intra-occular pressure
Complications after extubation?
Laryngospasm Aspiration of gastric contents Hoarseness Sore throat Oedema of trachea and larynx Ulceration of vocal cords and/or trachea (LT intubation) Tracheal stenosis (LT intubation)
Management of laryngospasm?
Apply 02 via tight fitting mask
Apply CPAP
If necessary, use small dose of Suxamethonium (25mg) to re-intubate
LMA stands for:
Laryngeal Mask Airway
LMA sizing in adults:
Size 3-4 for females
Size 4-5 for males
Indications for the use of an LMA?
- Starved patients without gastric reflux
- Failed intubation (a holding measure)
- Plan B in a resuscitation when one cannot intubate
LMA advantages?
Easy High success rate Less stimulation than intubation Lower incidence sore throat Relieves anesthetists hands Can ventilate patient with a pressure
LMA disadvantages?
Does NOT protect airway from aspiration
Ventilation not always possible
Laryngospasm may occur
Indications for a surgical airway/trachostomy/cricothyroidotomy?
Prolonged ICU ventilation Head and neck deformity/trauma The "impossible" airway Tracheal toilet Emergency rescue airway
Those at risk for regurgitation of gastric contents?
Morbid obesity Pregnant women after first trimester History of reflux or hiatus hernia Emergency surgery in unstarved patients Bowel obstruction Any suggestion of delayed gastric emptying Abdominal surgery
Use for Magill’s forceps?
Guide tip of ETT through glottic opening
Placement of nasogastric tube into oesophagus under direct vision
Placement of throat pack
Removal of foreign body
Venturi mask - what is it and “sizes”?
High flow 02 therapy device
Allows for entrenchment of air to dilute O2
White/blue = 4 L/min, 24% Yellow = 8 L/min, 28% Green = 8 L/min, 35% Pink = 8L/min, 40%
Uses of OPA/Guedel airway?
Prevents tongue from flopping back and obstructing airway
Prevents biting on ET tube when awakening
Use of Ambubag?
Provides positive pressure manual ventilation
Bag self-inflating with air, but O2 can be added
Patient can still breathe spontaneously
Blades of the laryngoscope?
Straight = miller/magill (inserted into oropharyx beyond epiglottis)
Curved = macintosh (sits in the vallecula)
ETT tube types:
Normal
RAE (facial surgery, ENT)
Armoured/reinforced - neurosurgery
ETT tube colouring?
Blue: high volume, low pressure, normal/L lumen
Yellow/Red: low volume, high pressure, small lumen, stiff
