Respiratory Emergencies Flashcards
If a patient is breathing fairly adequately, how should you manage their airway? In other words, what’s the first line of airway management?
give supplemental osygen with nasal cannula or a mask and reposition the patient to maximize air exchange
If the patient’s breathing is labored, but their airway is still intact, what’s the next step you can take beyond cannula or mask?
consider assisting their breathing with CPAP or BiPAP
How do CPAP and BiPAP differ?
CPAP is continuous positive airway pressure and bipap will have positive pressure during inspiration and then let up on the pressure during expiration
If you have to intubate someone, how can you assist oxygenation prior to doing so?
Using a bag-valve mask
What are four examples of trauma injuries that often require airway management?
facial traumas
neck injuries
flail check
burns
What are some illnesses leading to hypoxia requiring airway management?
pulmonary edema COPD aspiration infeciton drugs allergid reactions - anaphylaxis and angioedema
What is one class of drug that is particularly bad for causing angioedema - even years after stopping the drug?
ACE inhibitors
What are some mechanical reasons to manage an airwa?
- comrpession of the airway by infection
2. partial or complete obstruction secondary to foreign body or infections like epiglotitis or trachiitis
What are 4 signs that someone isn’t protecting their airways?
decreased LOC (GCS less than 8)
absence of protective reflexes (gag or cough)
apnea
hypoventilation leading to hypercapnia and hypoxia
What are 3 primary reasons not to intubate?
- patient is protecting their airway adequately
- oxygenation can occur by other less invasive means
- DNI
Where do you place an endotracheal tube? How do you know if it’s gone too far?
You want it to go down the trachea to above the carina.
if you pushed too far, it will go down the right main bronchus so you will only hear breath sounds on the right and not the left - just pull back a bit
When should you switch to the back-up plan?
if you fail intubation a second time
What are the “back-ups” to intubation?
combitube
king airway
laryngeal mask airway (LMA)
How does a combitube work?
same concept - there’s a distal cuff that will obstruct the esophagus and a proximal cuff that obstructs the mouth so the only place the air can go is down the trachea
Describe a king airway?
same concept as a combitube, but the actually tube used is less complex. cuffs are inflated afterward
Describe a laryngeal mask airway. Who uses it?
there’s a leaf-like thing that covers over the esophagus. you can do a blind insertion - doesn’t need to go past the vocal chords. Anesthesiologists like this.
If all else fails, what can you do?
cricothyroidotomy
Describe someone who is a potentially difficult intubation?
short neck prominent upper incisors receding mandible limited jaw opening limited cervical spine mobility
(an ape)
What is rapid sequential intubation?
basically a list of drugs you should use in intubation
What is the depolarizing neuromuscular blocker?
succinylcholine
Describe succinylcholine’s mechanism of action
it’s an ultrashort-acting skeletal muscle relaxant that combines with cholinergic receptors at the motor endplate to produce flaccid paralysis - binds even more firmly to the receptor than acetylcholine
How is succinylcholine broken down?
rapidly by pseudocholinesterases into succinylmonocholine
How can you see the depolarizing action at the muscle’s motor endplate?
clinically visible muscle fasiculations
How long does it take for succinylcholine to take effect? How long does it last?
takes effect in 30-60 seconds, so optimal intubating ocnditions occur at 60-90 seconds
paralysis usually lasts 8-12 minutes
What might make the paralysis longer than 12 minutes for sucicnylcholine?
inherited or acquired pseudocholinesterase deficiency
What are the sid eeffects of succinylcholine/
bradycardia (treat with atropine)
increased pressures (gastric, cranial, and ocular)
hyperkalemia and related effects
fever
What’s the mnemonic for succinylcholine “appearance”
eyes like a mole, moist as a slug (salivation, lacrimation, urination and defacation), weak as a kitten
What are the two nondepolarizing neuromusclar blockers?
vecuronium
rocuronium
How does vecuronium work? Onset? Duration?
Competes for cholinergic receptors are motor endplate initiating flaccid paralysis
onset in about 2 minutes - so you have to wait
duraiton of action 25-40 minutes (but complete recovery takes 45-60)
How is vecuronium metabolized and how does this affect recovery time?
metabolized by the liver and the kidneys
renal failure doesn’t significantly affect recovery time, but liver failure can double it
Why is rocuronium better than vecuronium?
it’s unique among the non-depolarizing neuromuscular blocking agents because it’s onset of action is almost as quick as that of succinylcholine - onset is within 15-20 seconds with complete paralysis at 45-60 seconds
What’s the duration fo action for rocuronium?
25-60 minutes
True or false: vecuronium does not cause hypotension or tachycardia.
true
What makes the ideal sedative for intubation purposes?
very rapid onset (within 20-30 seconds)
relatively short half-life
What’s an example of a barbiturate used for sedation in intubation?
thiopental
What’s the onset for thipental?
peak concentrations in the brain achieved within 30 seconds
What is the main side effect of thiopental (and other barbs)?
hypotension
What does ketamine do?
disrupts conduction between the thalamocortical access - induces a disassociative state in which the patient is unaware of any sensory or painful stimuli
When do we usually use ketamine?
sedation and analgesia for children unergoing lacceration repairs, fracture relocations or other painful procedures
What is the onset and duration for ketamine?
optimal intubating at 30 seconds with peaking at 60-90 seconds. effect lasts for 5 to 10 minutes
What are some other useful qualities of ketamine?
it’s mildly sympathomimeti, so it’s useful in trauma for hypotensive state and for bronchodilation in asthmatics
What are the main side effects of ketamine?
- bad trips - hallucinations, irrational behavior
- hypertension
- increased upper airway secretions - they drool
How do you treat the bad trips on ketamine?
co-administration of benzodiazepines
What benzo do we use for intubation?
midazolam - a short-acting CNS depressant that also causes a lack of recall
Whats the onset for midazolam?
2-2.5 minutes
What’s the side effect for midazolam?
may produce a slight drop in mean arterial pressure
What are the two non-receptor, rapid acting sedative hypnotics?
propofol
etomidate
How does propofol work?
it’s extremely lipophylic, so it will infiltrate itself directly into the lipid bilayer of the nerve’s cell membrane and disrupt nerve conduction.
When it propofol’s onset of action?
within on circulation time between the heart and brain, so 10-20 seconds with peak effect between 20-40
How long is the duration?
8 minutes or less - great for short procedures like cardioversion
What are the side effects of propofol?
apnea
potential cardiovascular depressant - transient hypotension is common
What are the other helpful effects of propofol?
anti-convulsants (used in status)
profound anti-emetic
can lower intracranial pressure
in general: useful in brief procedures
What is etomidate an dexample of?
an imidazole - rapid acting hypnotic unrelated to all others
Etomidate onset of action? Duration?
20-30 seconds
lasts 20 minutes
Why is etomidate ideal for hypovolemic patients or those in hemorrhagic shock?
it doesn’t produce cardiovascular depression
What are the side-effects for etomidate?
vomiting and myoclonus
What’s an example of a typical RSI protocol?
-3.00 Preoxygenate, IV lines, monitor, oximetry, equipment including that for emergency surgical airway control
-0.55 Etomidate
-0.45 Succinylcholine
0.00 Intubation
+0.30 Assess tube placement
+8.0 Check patient’s temperature (because of succinylcholine)
What does the I SOAP ME mnemonic tell you for intubation prep?
I - IV S - suction O - oxygen (at 15 l/m) A - airways - get your tube and backups P - pharmacology M - monitors E - examine patient
What do we usually pretreat patients with before RSI. It’s optional….
lidocaine to blunt the ICP/cough/bronchospasm
fentanyl to blunt ICP and for sedation/analgesia
THEN WAIT FOR EFFECT
What is the gold standard for confirming tube placement?
visualization of tube through cords
can also check breath sounds in both axillae and not over stomach, correct PaCO2 with detector or bulb suction
