Transcript Airway 2x

Airway 2:
Infraglotic
and
Difficult Airways
L MH E R R O U N D S
O C TO B E R 2 7 , 2 0 1 5
P R E PA R E D B Y
S H A N E B A R C L AY
Objectives
1. Examine pros and cons of direct versus video laryngoscopy
2. Review the steps on ET Tube intubation.
3. Surgical Airway - Cricothyroidotomy
What is the ‘difficult airway’?
This presentation will not discuss the characteristics of what a ‘difficult
airway’ is per se. This is covered in such areas as ‘up to date’ etc.
In the emergency setting every airway should be considered ‘difficult’
until proven otherwise (i.e. successfully intubated).
Because all airways should be considered difficult, the biggest advantage
you can have is having a PLAN. In particular a back up plan which can
include a rescue airway (LMA, Kingtube) and the ultimate backup plan,
doing a Cricothyrotomy.
Rapid Sequence Intubation (RSI)
RSI is one term used in Emergency Medicine to indicate a technique of
controlling the airway by inducing unresponsiveness (via induction
agents) and muscle relaxation/paralysis (via neuromuscular blocking
agents), then intubating the patient.
There are other ‘modified’ RSI protocols which endeavor to help maintain
oxygenation, prevent respiratory acidosis etc. but these are often at the
expense of increased risk of aspiration.
The biggest ‘risk’ for RSI is that once you have given the paralytic, the
patients life “is in your hands”. You must be able to either intubate or at
the least ventilate the patient.
Review of Indications for Intubation
1. Airway protection and patency
2. Respiratory failure (either hypercapnia and hypoxia), secretion management.
3. Minimize oxygen consumption and increase oxygen delivery (ie sepsis)
4. Unresponsiveness to pain treatment, terminate seizure, prevent secondary
brain injury.
5. Temperature control (serotonin syndrome)
6. Safety and comfort of patient (psychotic patient in transport, procedures etc)
What can make for a ‘difficult airway’?
• Dynamically deteriorating clinical situation, i.e., there is a real “need
for speed”
• Non-cooperative patient
• Respiratory and ventilatory compromise
• Impaired oxygenation
• Full stomach (increased risk of regurgitation, vomiting, aspiration)
• Extremely short safe apnea times
• Secretions, blood, vomitus, and distorted anatomy
Steps for RSI – “9Ps”
1. Plan
2. Preparation (drugs, people, equipment ..)
3. Protect the cervical spine
4. Positioning (sniff and head up)
5. Pre-oxygenate
6. Pre-treatment (optional i.e. atropine, lidocaine, fentanyl)
7. Paralysis and Induction
8. Placement of proof
9. Post intubation management
Roles and persons for RSI
In an ‘ideal’ setting:
1. Airway proceduralist
2. Airway assistant
3. Medication administrator
4. Person to perform crioid pressure if necessary
5. Scribe
The Team Leader may perform one of these roles, but ideally
should be separate and in a ‘stand alone’ role.
Equipment
1. Suction. Place between mattress and bed.
2. Oxygen. Non rebreather (NRBM) or Bag Mask (BVM) with 15 lpm O2.
Can also use nasal cannula during intubation – high flow 10-15 lpm
3. Airway 7.5 ETT for most adults, 7.0 for smaller females. 8.0 for large males or if
possible for asthmatics. Test balloon with 10 cc air with syringe. Leave syringe
attached to ETT.
Stylet, place in ETT. Or Bougie
Blade – Mac 3 or 4 for adults. Same sizing for McGrath Video scope.
Handle – attach blade and make sure light works.
Backup – ALWAYS have an LMA and surgical Cric kit available.
Equipment
4. Pre-oxygenate 15 lmp with NRBV or flow from BVM. If patient not
breathing, ensure BMV vents at 10-12 per minute with appropriate volume.
5. Monitoring equipment.
Cardiac monitor (best if hooked up to defib pads on the Lifepac)
Pulse oximeter
BP cuff
Have EtCO2 on BVM or ready to hook up to ETT.
6. Medications. Have induction and paralytics drawn up.
‘Quick Review’ of Induction Agents
• Ketamine 1.5-2 mg/kg IBW
• Fentanyl 2-10 mcg/kg TBW
• Midazolam 0.1-0.3 mg/kg TBW
• Propofol 1-2.5 mg/kg IBW + (0.4 x TBW) (others simply
use 1.5 mg/kg x TBW as the general guide)
‘Quick Review’ of Induction Agents
Ketamine
• Dose: 1.5 – 2 mg/kg IV (4 – 5 mg/kg IM)
• Onset: 60-90 sec
• Duration: 10-20 min
• Use: any RSI, especially if hemodynamically unstable (OK in TBI, does
not increase ICP despite traditional dogma) or if reactive airways disease
(causes bronchodilation)
• Drawbacks: increased secretions, caution in cardiovascular disease
(hypertension, tachycardia), laryngospasm (rare)
‘Quick Review’ of Induction Agents
Propofol
• Propofol 1-2.5 mg/kg IBW + (0.4 x TBW) (others simply use 1.52.5 mg/kg x TBW as the general guide)
• Onset: 15-45 seconds
• Duration: 5 – 10 minutes
• Use: Hemodynamically stable patients, reactive airways disease,
status epilepticus
• Drawbacks: hypotension, myocardial depression, reduced cerebral
perfusion, pain on injection, variable response, very short acting
‘Quick Review’ of Induction Agents
Midazolam
• Dose: 0.3mg/kg IV TBW
• Onset: 60-90 sec
• Duration: 15-30 min
• Use: not usually recommended for RSI anymore, some practitioners use
low doses of midazolam and fentanyl for RSI of shocked patients.
• Drawbacks: respiratory depression, apnea, hypotension, paradoxical
agitation, slow onset, variable response
‘Quick Review’ of Induction Agents
Fentanyl
• Dose IV 2-10 mcg/kg TBW
• Onset: <60 seconds (maximal at ~5 min)
• Duration: dose dependent (30 minutes for 1-2 mcg/kg, 6h for 100 mcg/kg)
• Use: may be used in a low dose as a sympatholytic premedication (e.g. TBI, SAH,
vascular emergencies); may be used in a ’modified’ RSI approach in low doses or
titrated to effect in cardiogenic shock and other hemodynamically unstable
conditions
• Drawbacks: respiratory depression, apnea, hypotension, slow onset, nausea and
vomiting, muscular rigidity in high induction doses, bradycardia, tissue
saturation at high doses or if given rapidly.
‘Quick Review’ of Neuromuscular
Blocking Agents
• Succinylcholine 1-2 mg/kg TBW
• Rocuronium 0.6-1.2 mg/kg IBW
‘Quick Review’ of Neuromuscular
Blocking Agents
Succinylcholine
• Dose: 1.5 mg/kg IV (2 mg/kg IV if myasthenia gravis) and 4 mg/kg IM (in extremis)
• Onset: 45-60 seconds
• Duration: 6-10 minutes
• Use: widely used unless contraindicated; ideal if need to extubate rapidly following
an elective procedure or to assess neurology in an intubated patient
• Drawbacks: numerous contra-indications (hyperkalemia, malignant hyperthermia,
>5d after burns/ crush injury/ neuromuscular disorder), bradycardia (esp after repeat
doses), hyperkalemia, fasciculations, elevated intra-ocular pressure(?), will not wear
off fast enough to prevent harm in ‘Can’t intubate, can’t ventilate’ (CICV) situations
‘Quick Review’ of Neuromuscular
Blocking Agents
Rocuronium
• Dose: 1.2 mg/kg IV IBW
• Onset: 60 seconds
• Use: can be used for any RSI unless contra-indication or require rapid
recovery for extubation after elective procedure or neurological
assessment; ensures persistent ideal conditions in CICV situation (i.e.
immobile patient for cricothyroidotomy) Drawbacks: allergy (Rare)
RSI Steps
1. Check neck for potential cric, have cric kit and LMA available
2. Positioning – sniffing position, ideally head up
3. Preoxygenation – 100% NRB 15 lpm x 3 minutes or flow via BVM
4. Attach in line EtCO2 monitor to BVM
5. Pick ET tube. Check balloon with 10 cc air, leave syringe attached.
Place stylet or have bougie handy.
6. ‘Lube the tube’ – put small amount of sterile lube jelly on ETT tip
7. Choice of laryngoscope. Check bulb working.
8. Suction – turn on, place handle under right shoulder of patient or
under pillow.
RSI Steps
9. Have epinephrine push dose on hand – 5-10 mcg/kg IV
10. Induction agents – Ketamine 1.5 mg/kg or
Propofol 1.5 – 2.0 mg/kg (or Midazolam 0.3 mg/kg TBW)
11. Neuromuscular blocking agents – Succinylcholine 1-2 mg/kg TBW
12. Cricoid pressure – BURP
13. Intubate – place ETT 23 cm to lips for males, 21 cm to lips for
females. Inflate balloon.
14. Confirm – watch for chest rise, listen to chest, check EtCO2
15. Order CXR to confirm ETT depth
16. Post intubation medications – Fentanyl or morphine infusion.
+/- sedation
RSI Steps
17. Ventilator settings. (may vary depending on clinical scenario)
Mode: AC
FiO2 100%
RR 14
Tidal Volume 6-8 cc/kg IBW
PEEP? 5 or as needed.
18. ABG after 10-15 minutes. Consult ARDSnet chart.
Cricothyrotomy
This is your final back up. You should know how to do one!
Although there are various techniques for doing ‘crics’ the one being
advocated most recently is the ‘bougie assisted Cricothyrotomy’.
In Lady Minto Hospital we have the ‘needle cric’ set which use an ‘over
the needle’ technique.
The bougie assist technique has been shown to be vastly quicker (average
60 seconds vs 90-120 seconds) and more accurate than the needle cric.
Cricothyrotomy
Cricothyrotomy
Landmarks for the cricothyroid membrane:
Feel for the laryngeal prominence. The cricothyroid membrane
will be approximately one fingerbreadth below this.
Alternatively, place four fingers longitudinally across the neck
with the 5th finger on the sternal notch. The cricothyroid
membrane ‘should’ be right below your index finger.
Cric “landmarks schmanmarks”
Acad Emerg Med 2015 August
Be Ready to Extend the Incision Beyond Landmarks When Performing a Cric!
Compared with ultrasound, three classic landmark techniques were inaccurate for
identification of the cricothyroid membrane.
While there are a number of landmark techniques for identification of the
cricothyroid membrane, their accuracy is unknown. This study compared three
techniques (general palpation, four-finger, and neck crease) to each other and to
ultrasound (the reference standard).
Each of 50 adult emergency department patients awaiting further care was
assessed by a convenience sample of three emergency physicians who were
randomly assigned to one of the three techniques. An expert then used ultrasound to
identify the cricothyroid membrane in each patient. Compared to ultrasound, the
general palpation, neck crease, and four-finger techniques were accurate 62%, 50%,
and 46% of the time, respectively.
Cricothyrotomy
Knife-finger-bougie approach
Equipment
• scalpel blade (e.g. size 10)(some authors prefer an 11)
• artery forceps - optional
• bougie
• size 6.00 or 6.5 ETT (or tracheostomy tube)
Once decision made to proceed with Emergency Surgical Airway (ESA) extend neck in
supine position to make anatomy more accessible by palpation (aka the ‘laryngeal
handshake’) +/- ultrasound (if time and available); note that airway has priority over
suspected c-spine injury
Stabilise the thyroid cartilage with the non-dominant hand
Dominant hand holds scalpel and rests on the patients sternum for stability and support
Cricothyrotomy
Make a 4 cm vertical incision through skin over cricothyroid membrane (in the
midline). You may need to extend from mandible to sternum if not palpable anatomy.
(step may not be necessary if easily palpable anatomy – can go straight to the
horizontal incision)
Once skin incised, palpate cricothyroid membrane position and blunt dissect with
fingers (some prefer forceps) through subcutaneous tissue until the membrane is
readily identifiable. Ignore bleeding until airway is secure (ETT placement usually has
a tamponade effect)
Cricothyrotomy
Make a 1 cm horizontal incision through lower edge of membrane, (cricothyroid
vessels lie in the superior segment). Drag scalpel blade from one side to the other
then turn knife through 180 degrees and extend to the other side (some prefer to
extend the membrane with forceps). The cricothyroid membrane is bound by a
‘cartilaginous cage’ so resistance will be felt at the margins of the membrane
when the scalpel blade abuts cartilage.
Dilate with gloved little finger and palpate tracheal lumen, ideally identifying the
cartilage of the posterior wall of the trachea/cricoid ring
Pass bougie alongside little finger into trachea
Confirm bougie position with finger, ensuring it passes through membrane
Cricothyrotomy
Bougie usually holds up at carina <10cm from the skin (may feel tracheal rings as
the bougie advances), do not force if it hold up as you may perforate carina
Pass ETT over bougie and intubate trachea. Ensure the ETT balloon is fully deflated
and twist ETT as it passes the skin (hold up here is common). Only advance the ETT
until the balloon is within the airway and no longer visible (if advanced further then
endobronchial intubation is likely).
Ensure ETT is held secure while bougie is removed and ETT is connected to BVM
Confirm ETT placement with ETCO2 (also adjunctive measures: auscultation,
bilateral rise and fall of chest, fogging of tube and subsequent CXR)
Cricothyrotomy
On the web page lmher.com/airway-2
there are two videos demonstrating Cricothyrotomy.