Airway part I Flashcards
Airway evaluation
If airway is:
- Critical- do immediate intervention
- OK or mildly compromised- no real hurry
- Moderately compromised- consider intervention, but must also monitor very closely
Airway management
Least invasive to most
Cont’d observation, O2, pulse oximeter, ECG
Pt re-positioning, airway devices, jaw thrust
LMA, other devices
Endotracheal intubation
Tracheotomy or cricothyrotomy
How to assess pt airway
Quick observation: resp effort/apnea, air moving, cyanosis, retraction, dyspnea, air hunger, resp. rate, obtunded, M-S weakness Acute obstruction (blood, vomitus, secretions, foreign body, trauma); or hx of chronic airway or pulm condition (pt normally impaired) Auscultation: wheeze, rales, rhonchi, stridor, air movement
What does the lemon law stand for?
Look externally Examine (3-3-2) Mallampati grade Obstruction (Obesity) Neck mobility
Air hunger
Dyspnea with great discomfort
Retrognathia
Jaw is behind
Nearly impossible to do standard intubation
3-3-2 rule
Assess oral opening- 3 fingers
Measure the mandible- 3 fingers
Position of larynx- 2 fingers
Assessing the oral opening
Should be able to accommodate 3 fingers
Measuring the mandible
Should be able to fit 3 fingers between the mentum and the hyoid bone
Assessing the position of the larynx
Should get 2 fingers between the thyroid cartilage and the mandible
Do not extend head all the way when using this rule
Mallampati classification
Ranges from classes I-IV
Class I is most patent, IV is most obstructed
III- only top part of uvula is seen
Class I- can see hard palate, soft palate, uvula, pillar
What are causes of obstruction?
Obstruction can result from both external compression or internal blockage (foreign body, tumor, etc.)
Stridor
A high-pitched, harsh sound occurring during inspiration
It is a sign of upper airway obstruction
May be caused by laryngospasm, epiglottitis, foreign body, aspiration, airway trauma
Neck mobility
Not every pt will come in with neck brace, must ask pt about neck
Intubation requires neck extension
Airway management caveats
First, do no harm
Get help and monitor pt
Continue to observe during tx efforts
Less invasive is safest- don’t over-treat
Pt directives and informed consent: DNI or DNR should be followed
If algorithms or pathways are available, follow them, but-
1st branch of algorithm tree is more impt: obstructed airway (crisis) or lung problem
3 big indications for E-T intubation
Pt’s inability to maintain and protect patent (open, unobstructed) airway
Failure/insufficiency of oxygenation or ventilation
Anticipated need that is based on clinical course or tx requirements- airway, pulmonary, cardiac, neurologic, sepsis/shock, pending surgery with general anesthesia
Who are the airway experts?
Anesthesiologists EMTs Intensivists/pulmonologists ICU/CCU/ER staff Resp therapists
Why to defer to the airway experts
They have more experience with, and are better at:
- The airway evaluation
- Use of less invasive devices (nasal/oral airways)
- LMA devices, laryngoscopes
- Have access to expensive non-standard equipment
- Better able to recognize/anticipate complications
Where does airway obstruction most commonly occur?
Above epiglottis, at oropharynx; the tongue and/or soft palate touch posterior pharyngeal wall which occludes airway (as in sleep apnea)
Why jaw thrust works
What airway devices are available?
Ambu bag and mask Oral airways Nasal airways LMAs Oral tubes (combitube, King device) E-T tubes Crico-thyrotomy devices Tracheotomy
Nasal airway
Also called “nasal trumpet” due to shape
Made of latex or silastic; different sizes
Should always be lubricated before insertion (and warm)
Many pts have deviated septum- don’t force
LMA
Used a lot in anesthesia, more comfortable than NG tube
Doesn’t seal off airway- don’t use in conscious pts
Intubating LMA
ET tube is specifically designed to fit through LMA
Designed to not only assist with achieving an airway, but also to facilitate intubation
LMA can be removed over the ET tube once it is placed properly
BVM
Purpose- To provide positive-pressure ventilation for non-intubated ventilation
Device has one-way valve to prevent rebreathing and port to add oxygen flow
Various mask sizes
May be difficult, requires expertise
Use the least pressure needed for given pt (to prevent gastric insufflation)
BVM ventilation difficulties
Mask fit
Mask seal- more problematic for obese pt, or those with facial hair
-Lube can help with seal
Airway patency- may need airway assist devices
Gastric insufflation- common if high pressures used for mask ventilation
Frequently requires 2 ppl
What does JAWS stand for?
Jaw thrust
Airways (oral/nasal)
Work together
Slow, small squeeze
How to solve the mask leak problem in a BVM
Elevate head, extend neck, leave dentures in
Pull mandible up to mask, don’t push chin down
For facial hair, apply goop
Change mask size, inflate mask cuff, use 2 hands
How to solve the airway failure/obstruction problem in a BVM
Use airways, mandible lift/jaw thrust, decongestants
How to solve the esoph/stomach insufflation, vomiting problem in a BVM
Minimize bag pressure, have suction available
Realize that morbidly obese pt require much higher airway pressure to successfully ventilate
What are the two main problems with BMV?
Insufficient ventilation- not enough airflow in and out of lungs, resulting in rising CO2 and falling O2 saturation (commonly air leak around mask or gastric insufflation)
Airway isn’t protected (lungs not sealed off) from secretions, blood, stomach contents, etc.
CIs and precautions of airway instrumentation
Laryngeal trauma Bleeding Someone more adept is available Anticipated difficult intubation -A failed attempt at intubation almost always makes further attempts more difficult Contraindication to needed meds
Potential intubation complications
Anatomic issues: trauma, tumor, edema, bleeding, difficult anatomy
Physiological issues: Pharmacologic side effects, coughing, vomiting, stress/CV effects
Psychological issues: over or under sedation, pt’s wishes
Ethical: should you intubate- futile care; directives
Complications of intubation attempt
Failed intubation- worsened airway/ventilation
Iatrogenic airway trauma, more difficult intubation
Vomiting with or without aspiration
Respiratory depression from medication
Hypoxia and/or hypercarbia
Hypotension (drugs) hypertension (manipulation)
Cardiac effects- tachycardia, arrhythmia
Trauma (post intubation)- teeth, neck extension, glottis, soft tissue
Intubation/airway tools and equipment
Laryngoscopes (from least to most expensive)
-Direct: MIller and MacIntosh blades
-Fiberoptic
-Video
ET tubes, stylette; bougie; syringe for ETT cuff, mask, LMA
Suction, gloves, lubricant, topical anes. gel
Assorted nasal and oral airways
Ventilation
Always pretest equipment for failure
Age and ET tube sizing
Measured by internal diameter in mm -LBW neonates: 2.5-3.0 mm -Avg neonates: 3.0-3.5 mm Ages 1-15: age in (yrs/4) + 3.5 or 4 mm (uncuffed tube up to age 7-8 yo; then cuffed, bc cricoid is tightest in young children) Adults: -Females: 7-7.5 mm -Males: 7.5-8.5 mm
Direct laryngoscope blade sizes (Miller or MacIntosh)
Size 0 for neonates
Size 1 for infants
Size 2 for children
Size 3 for small adults
Size 4 for large adults
Miller (straight): tip goes underneath epiglottis, is used to lift up tip of epiglottis out of the way
MacIntosh (curved): tip goes in front of epiglottis into vallecula, where it tilts and retracts epiglottis out of the way
Tube cuffs
Smaller pediatric tubes (4.5 or smaller) don’t have cuffs
6.0 or larger do have cuffs
5.0 and 5.5 are available with and without cuffs
Cuffs are filled by syringe attached to pilot tube
Try cuff 1st to make sure it’s not leaking
Mnemonic for tracheal intubation preparation
Suction
Tools for intubation
Oxygen source for preoxygenation and ongoing ventilation
Positioning
Monitors, including ECG, pulse ox, BP, end-tidal CO2, and esophageal detectors
Assistant
IV access
Drugs
Sniffing position
Atlanto-occipital joint is extended, C7 is flexed
Goals of intubation
Try to predict a difficult rel airway based on clinical criteria rather than be surprised by it
Plan for appropriate action in the difficult airway
Initiate appropriate plans of attack with confidence in the can’t ventilate/can’t intubate situation
Become informed about some new (and not so new) airway options out there
Meds for ET intubation
Sedation (intubation hurts, triggers cough reflex)
-Propofol, etomidate, ketamine
-Sedative (midazolam) and/or narcotic (fentanyl, morphine)
Muscle relaxants
The two categories of meds either cause resp depression or paralyze the pt; improperly used, will make everything much worse if pt can’t be ventilated
Topical anesthetics: gel for devices, liquid or spray for pt application
Purpose of RSI
Can increase success of ET intubation by using sedation/anesthesia for pt comfort and paralyzing agents to facilitate intubation by giving musculoskeletal relaxation
CIs for RSI
Difficulty or failure with mask ventilation
Inadequate time to prepare (crashing or hypoxic pt)
Known or anticipated difficult intubation
Preparation for RSI
Time to evaluation pt ascertain no emergency
Not likely difficult intubation
No CIs
Gather equipment
Check equipment
Assemble personnel
Prepare meds for administration, monitors, environment, permit
Meds for pretreatment- RSI
O2 (preoxygenation 4-5 min, perhaps other meds)
Meds for after pretreatment- RSI
Induction (sedation); quickly followed by paralysis
Paralysis takes 15-30 secs after infusions
Pretreatment for RSI
Preoxygenate- high flow O2, 4-5 min
Consider:
-Narcotic (fentanyl 1-3 mcg/kg) to blunt stress response
-Atropine (0.01-0.02 mg/kg) to blunt bradycardia, decrease secretions
-Defasciculating dose (0.01 mg/kg vecuronium) to prevent muscle pain from paralytic drug
-IV lidocaine (1.5 mg/kg) blunts increase in HR, BP, and ICP
-midazolam (Versed 0.02 mg/kg) amnestic/anxiolytic
Sedation for RSI
Etomidate (0.3 mg/kg)- CV stability, rapid onset, short duration, may be cerebro-protective
Propofol (2 mg/kg)- rapid onset, short duration, may be cerebro-protective, but drops BP and CO
Ketamine (1-2 mg/kg)- bronchodilator, may increase HR, and BP, has analgesic effects, longer duration, dissociative effects may cause dysphoria
Midazolam is sedative/anxiolytic/amnestic, but not an induction agent (requires big dose-long duration)
Paralysis for RSI
Depolarizing- succinylcholine (2 mg/kg)
-Quickest onset (20-50 secs), shortest duration (8-10 mins); causes fasciculation of muscles and myalgia; may worsen hyperkalemia; may increase intra-ocular pressure; rarely, prolonged duration
Non-depolarizing: rocuronium (1-1.2 mg/kg- a big dose)
-Slower onset (60-75 secs), longer duration (30-50 min), no fasciculation; not best choice for difficult intubation, but good if prolonged paralysis is indicated (status epilepticus, etc)
Effects of sedatives and paralyzing agents for RSI
Removing pt’s protective reflexes for the airway (cord closure, cough)
You are rendering the pt absolutely unable to breathe (apneic)
RSI advantages
Pt comfort- sedated or amnestic Easier intubating conditions If done properly and quickly- minimizes risk of vomiting and aspiration Less airway trauma If done quickly- shorter period of apnea
RSI disadvantages
Polypharmacy
Med side effects
Requires time for implementation
If intubation fails, can lead to catastrophe of can’t ventilate/can’t intubate
Verification of correct ET tube placement
Always auscultate chest and epigastrum
Chest- listen for equal bilat breath sounds; not quality (wheeze, stridor, etc)
Epigastric auscultation: absence of insufflation sound OK; if present, the tube is in esophagus
CXR the gold standard for correct placement
CO2 detection devices handy if available
Factors associated with difficult intubation
Obesity, facial hair, short neck, large tongue
Retrognathia, buck teeth, unstable or fixed neck
Bleeding, secretions, vomiting
Alternatives to ET intubation
BVM
Fiberoptic scopes
Nasotracheal intubation
Cricothyrotomy
