airway Flashcards
DAS guidelines exubation steps
Plan
prepare
Perform
Post extubation care
what to consider if extubation ready
CNS - GCS >8, no encephalopathy CVS - stability, low norad Resp - adequate O2 (FiO2 0.4), initiate resp effort - spont breathing test - manage secretions - good cough - cuff leak
Has underlying pathology been resolved
No plans to return to OT
Rapid shallow breathing index
RR/Vt (L)
Concern if >105
major risk factors for post-extubation stridor
Prolonged ventilation
Female gender
Under-sedation (i.e. insufficiently deep; too awake)
Difficult intubation (multiple attempts)
Self-extubation
High BMI (over 26.5)
Ratio of tube size to laryngeal size in excess of 45%
High cuff pressure
High SAPS II score (i.e. severe illness)
Medical patient (i.e. it was not an elective perioperative intubation)
POssible causes of suctioning feed from trache
Simple feed intolerance with regurgitation
Impaired swallowing of oral contents
failure of the tracheostomy cuff to maintain a sealed airway (i.e. cuff is failing to maintain pressure, or the whole tracheostomy has migrated out of the stoma and there is nothing in the trachea)
Tracheo-oesophageal fistula.
techniques for percutaneous tracheostomy
- Classical Ciaglia (multiple dilators)
- Ciaglia Blue Rhino
- Griggs forceps technique
- Fantoni technique (translaryngeal) - access trachea and then pass guidewire up through the mouth
Surgical trache - adv and disadv
Ad -
Gold standard for difficult anatomy
Better control of bleeding
Fewer intraoperative complications
Disadvantages - More postprocedural complications - Higher incidence of tracheal stenosis - Higher incidence of stomal infections Expensive; requires the operating theatre to be fully staffed Takes longer to organise Exposes patients to risk of transfer
Perc trache - adv and disadv
Adv - Less postprocedural complications such as accidental decannulation, bleeding and wound infection. (Dulguerov et al, 1999) Less bleeding risk (smaller hole) Lower incidence of tracheal stenosis Lower incidence of tracheal infection Johnson-Obaseki et al (2016) The cosmetic effect is better No transfer, thus no risks of transfer Cheaper Faster (10-15 minutes) More easily available in the ICU
Disadv -
Inadequate backup for major complications or difficult anatomy.
Much of the technique is essentially blind.
Diathermy is not available in ICU
Cardiothoracic surgical support is lacking
Bronchoscopy is required for safety
The bronchoscope may get damaged
Disposable percutaneous kits cost more than a bedside surgical tracheostomy
There is a greater risk of death and cardiac arrest. (Dulguerov et al, 1999)
Some intraoperative complications are unique to percutenous technique (eg. knotted guide wire)
Advantages of tracheostomy
Improved patient comfort
- Decreased sedation requirement
- Enhanced ability to communicate
- Improved positioning and mobility
Avoidance of orotracheal tube-related complications
- Less vocal cord damage
- Less risk of laryngeal stenosis
- Better recovery of voice quality
- Less damage to the tongue and lips
Improved mechanics of ventilation
- Lower resistance to air flow
- Decreased work of breathing
- Decreased apparatus dead space
- Improved respiratory function parameters:
- More rapid weaning from mechanical ventilation
Advantages in airway care and secretion control
- Lower incidence of tube obstruction
- Better oral hygiene
- Better clearance of secretions by suctioning
- Lower incidence of VAP
Advantages for upper airway function
- Better preservation of swallowing
- Earlier oral feeding
- Preservation of “glottic competence”
- Decreased aspiration risk
Pragmatic advantages
- Less skilled insertion
- Less skilled care
- Deferral of end-of-life decisions to a better time
Disadvantages of tracheostomy
Disadvantages related to safety and complications
- The complications of the percutaneous and surgical tracheostomy procedure
- Potential for dislodgement
- Humidification is inadequate
- Passive humidifiers increase the work of breathing
- Blockage with secretions
Disadvantages related to care for the artifical airway
- Complication of emergency airway management
- Skilled care is still required
Ethical implications
- Failure to wean despite tracheostomy is still possible
- There is no mortality benefit from tracheostomy
Lung mechanic criteria for extubation
Adequate oxygenation: FiO2 40%
PEEP less than 8 cmH2O
Satisfactory tidal volume: VT > 5ml/kg
Satisfactory vital capacity: VC > 10ml/kg
Satisfactory MIP: less than 20-25 cmH2O (i.e pressure trigger)
Satisfactory RSBI: an fR/VT less than 105 breaths.min-1L-1
Basic preconditions to consider extubation
Resolution of the condition which had required the intubation and ventilation
Patient-directed mode of ventilation (eg. PSV)
Haemodynamic stability (the patient is unlikely to need massive fluid resuscitation in the near future, and their cardiac function is satisfactory to endure the increased demand from hard-working respiratory muscles)
Adequate muscle strength
Airway protection assessment before extubation
Good cough reflex on tracheal suctioning
Good gag reflex on oropharyngeal suctioning
Adequate neurological performance (obeying commands, or at whatever cognitive baseline previously permitted spontaneous breathing)
Gas exchange criteria before extubation
Adequate oxygenation: SpO2 over 90% on FiO2 under 40%
Normal acid base status (pH >7.25), i.e. no significant respiratory acidosis
General things to consider before extubation
basic preconditions
airway protection
gas exchange
lung mechanics
Management of post extubation stridor
Methylpred - 20mg q4H for 4 doses Adrenaline nebs Extubation on to NIV Extubation on to heliox Extubation in the operating theatre with ENT on standby
Things to consider before a difficult extubation:
Perform a cuff leak test.
Visualise the airway
Scan the airway
Prepare for management of post-extubation stridor
Extubate over an airway exchange catheter
Postpone extubation
Electively convert to tracheostomy
ICU uses of the LMA
As a backup for “can’t intubate, cant ventilate” scenarios
You can intubate though it
You can pass a bronchoscope through it for tracheostomy
You can temporarily ventilate somebody during a procedure
You can use it during an arrest instead of an ETT, if skilled staff are not available
Complications of intubation
Failure of intubation
Oesophageal intubation
Right main bronchus intubation
Broncospasm
Hypoxia
Aspiration
Pneumothorax and tension pneumothorax
Cuff leak
Myocardial ischaemia
Spinal injury
Increased ICP
Increased intraocular pressure
Structural damage:
- lips
- teeth
- tongue
Anatomy relevant to trache
Anterior - skin, subcutaneous tissue, sternothyroid and sternohyoid muscles, and pretracheal fascia.
Sometimes, there is an anterior communicating jugular vein which also travels through this space.
Posteriorly lies the oesophagus.
Posterolaterally, on either side of the oeseophagus lie the recurrent laryngeal nerves
Laterally, on both sides there are the vagus nerves, carotid arteries and the jugular veins, covered by the carotid sheath
Superiorly is the cricoid cartilage and the cricothyroid membrane
Inferiorly lies the isthmus of thyroid and the inferior thyroid veins
Management of acute traumatic upper airway injury
Administer oxygen, to preoxygenate
Administer nebulised adrenaline
Prepare for difficult intubation:
Get the difficult intubation equipment trolley
Contact senior anaesthetic staff and ENT surgeon
Organise drugs for an awake fiberoptic intubation
Generic measures for the management of stridor may apply:
Corticosteroids
Nebulised adrenaline
Helium-oxygen gas mixture
Non-invasive ventilation is contraindicated
Evidence on timing of trache
Cochrane review by Andriolo et al (2015):
n=1977, of which 909 were from TracMan.
There was a statistically significant mortality benefit associated with early tracheostomy (47% vs 53%); the NNT was 11. This mortality benefit was seen at the longest reported follow-up, rather than at 30 days.
The early group had a higher chance of being discharged from the ICU on day 28.
There was no statistically significant effect on the duration of mechanical ventilation.
The early group had decreased duration of sedation.
Data regarding risk of pneumonia could not be subjected to meta-analysis due to heterogeneity.
Steps to prevent hypoxia peri-intubation
try to address underlying respiratory issues and optimise CVS positioning denitrigenation (in obese aim ETO2 >80%) Positive pressure Use rapidly working drugs Anticipate hypoxia and prepare for rapid desat Apnoeic oxygenation Prepare for failure - plan A/B/C
Methods for allowing speech patient with trache
Cuff up, fenestrated tube: Gas flow is via an additional port above the cuff; 4-6L/min flow. The pt. remains ventilated
Cuff down, speaking valve: Gas only exits through the upper airway during exhalation (one way valve)
Cuff down, no speaking valve i.e. gas freely exists via both the tracheostomy and the upper airway
Cuff down, finger occlusion - i.e. the patient blocks the tracheostomy and exhales using the upper airway instead
Sub glottis air insufflation e.g. Pitt tube/Speaking- Tube Gas line with an outlet above the cuff and a thumb port
Electronic larynx
POtential complications of intubation
Failure of intubation
Oesophageal intubation
Right main bronchus intubation
Broncospasm
Hypoxia
Aspiration
Pneumothorax and tension pneumothorax
Cuff leak
Myocardial ischaemia
Spinal injury
Increased intracranial pressure
Increased intraocular pressure
Structural damage:
- lips
- teeth
- tongue
