Ch11: Airway Management Flashcards
What is part of the upper airway?
nose
nasal air passage
nasopharynx
mouth
oropharynx
pharynx
epiglottis
glottis
larynx
What is part of the lower airway?
trachea
bronchus
bronchioles
Adaptation of nasopharynx
has cilia that produce mucus to get rid of DDM
How does epiglottis prevent food from getting into trachea?
When you swallow, the larynx elevates and epiglottis covers glottis to prevent food from going into trachea
What cartilage, ligaments and components are part of the larynx?
Epiglottis
Glottis (vocal cords)
Hyoid bone
thyrohyoid ligament
thyroid cartilage
cricothyroid membrane
cricoid cartilage (1st ring of trachea)
Function of vocal cords
speech production
contain defense reflexes that close to prevent food from entering lower airway
How long is the trachea?
4 - 5 inches (10 - 12 cm)
What are bronchi supported by?
cartillage
What are bronchioles made of?
Smooth muscle
that can contract or dilate based on stimuli
which pleura lines the lungs?
visceral
what is the mediastinum and what does it contain
area between the lungs.
heart
trachea
major bronchi
esophagus
great vessels
nerves
which pleura lines the inside of the thoracic cavity?
parietal
what controls the contraction of the diaphragm?
phrenic nerve
what is residual volume
the volume of air that remains in the lungs after maximum expiration
what is the tidal volume of a healthy male?
500 mL
what is alveolar ventilation and how do you calculate it?
the volume of air that reaches the alveoli; calculate it by subtracting tidal volume by dead space
what is minute volume and how do you calculate it?
the volume of air moved through the lung in one minute; calculated by multiplying tidal volume with respiration rate
what is partial pressure? what are they for O2 and CO2 in the alveoli?
amount of gas dissolved in a fluid (mmHg)
PaO2 = 104 mmHg
PaCO2 = 40 mmHg
what is dead space in the lungs?
volume of ventilated air that does not partake in GE
what conditions may interrupt ventilation?
trauma (e.g. flail chest), foreign body airway obstruction,
injury to spinal cord and phrenic nerve
what is a patent airway?
unobstructed & clear
early signs of hypoxia
restlessness, irritability, apprehension, tachycardia, anxiety
late signs of hypoxia
altered mental status, thready pulse, cyanosis
how is ventilation regulated? how do feedback loops play a role
pH feedback loop:
CO2 concentration increase
Cerebrospinal fluid (CSF) and blood pH decreases
Chemoreceptors detect change and stimulate medulla to increase RR
Remove CO2 more efficiently
where are chemoreceptors located and how do they differ?
central chemoreceptors - medulla - respond to slight CO2 increases and CSF pH decreases
peripheral chemoreceptors - carotid arteries, aortic arch - respond to decreases in O2 level and low blood pH
The brainstem is made up of the midbrain, pons and medulla. How does the pons influence ventilation?
Can increase or decrease RR
Influence depth of respirations
Internal factors affecting ventilation
infection
allergies
swelling because of infections or allergies
trauma to brain or spinal cord
medications that depress CNS
muscular dystrophy
unresponsiveness, tongue obstruction
External factors affecting ventilation
trauma that physically and directly affects ventilation (e.g. puncture to chest, mandible fracture)
foreign body airway obstruction (FBOA)
Internal factors affecting respiration
hypoglycemia
conditions that decrease lung SA (e.g. emphysema)
conditions that cause fluid build-up in alveoli (e.g. drowning, pneumonia)
nonfunctional alveoli causing intrapulmonary shunting
infection
External factors affecting respiration
Altitude (partial pressure of oxygen decreases)
Closed environments where O2 conc decreases
CO and other toxic gases
Causes of circulatory compromise
Hemothorax (blood in pleural space)
Pneumothorax (closed, open and tension)
Hemopneumothorax
Cardiovasc conditions like heart failure, cardiac tamponade (fluid/blood in pericardial space around heart muscle that puts pressure on it)
Blood loss
Anemia
Hypovolemic shock (loss of LARGE blood volume so heart can’t pump it around the body
Vasodilatory shock (blood vessels are too dilated so bp is hard to maintain
intrapulmonary shunting
when deoxygenated blood passes by nonfunctional alveoli, so no GE occurs and blood remains deoxygenated as it returns to the heart
Signs of adequate breathing
normal rate (12-20 breaths/min for adults)
regular insp and exp rhythm
equal and clear breathing sounds on both sides
equal and regular chest rise and fall
adequate depth (tidal volume)
normal SpO2 reading
94%+
name aerosol-generating procedures (always wear PPE for AGPs and suctioning!!)
CPR
Endotracheal intubation
Nebulizer treatments (small machine that turns liquid medicine into a mist that can be easily inhaled)
CPAP (pressurizes air for positive pressure ventilation)
Signs of inadequate breathing (also in Ch10)
abnormal RR
irregular rhythm
abnormal breath sounds
use of accessory muscles
unequal or inadequate chest expansion
retractions
pale, cyanotic, clammy skin
labored breathing, agonal gasps
tripod, sniffing position
two to three word dyspnea
Cheyne-Stokes respirations (rapid breaths followed by long periods of apnea)
Ataxic respirations (bc of serious head injuries –> irregular, ineffective respirations that may or may not have an identifiable pattern)
Kussmaul respirations (bc of metabolic disorder or acidosis –> deep, rapid respirations)
What does Pulse Oximetry measure
percentage of hemoglobin molecules that bound to O2 in blood to assess oxygenation; good indication of how much O2 is getting to tissues
Two Indications of Respiration
1) Mental status (LOC, orientation, changes in status)
2) Skin condition
- pallor (pale skin & mucous membranes)
- cyanosis first around fingertips and then mucous membranes and around lips
- mottling (blotches of different colors because of anaerobic resp)
what do you have to be careful about pulse oximetry?
time delay of 1 minute that shows any decline in conditions later than they actually happen
how to use a pulse oximetry
1) put it on patient’s finger
2) palpate other hand’s radial artery to see it correlates with LED display on PO
what factors may cause inaccurate pulse oximetry readings
dark, metallic nail polish
dirty fingers
hypovolemia
severe vasoconstriction
anemia
CO poisoning (pulse oximetry can’t distinguish O2 and CO binding to hemoglobin hence CO poisoned patients will show normal SpO2 values)
How to position an unconscious patient from prone into supine position
2 people needed:
one person secures head
the other straightens the legs
coordinate and log roll the patient onto his/her back: one person secures head and neck with both hands, the other puts one hand on the shoulder and the other on the hip
you can assess airway now!
what is end-tidal CO2
maximum concentration of O2 at the end of an exhalation
what devices measure end-tidal CO2
capnometry = provides digital numeric (normal range is 33-45 mmHg)
capnography = provides results in the form of graph or real-time image
4 phases of a normal capnographic waveform
I. Respiratory baseline - INITIAL stage of exhalation where all the dead space gas is exhaled (which is why graph is flat)
II. Expiratory upslope - alveolar gas mixes with dead space gas = rapid rise in CO2 mmHg
III. Alveolar plateau - all alveolar gas with high CO2 mmHg (graph is flat but at a high pressure)
IV. Inspiratory downstroke - fresh gas enters lungs and displaces CO2
What maneuver to use to clear an obstructed airway in a patient with a suspected spine injury
jaw thrust maneuver
What maneuver to use to clear an obstructed airway in a patient with no suspected spine injury
head tilt–chin lift maneuver
How to do head tilt–chin lift maneuver
one hand on forehead pushing down
two/three fingers under jaw pushing up
note: mouth should be slightly open
How to do jaw thrust maneuver
two fingers on each side of the angular part of jaw (right under the ear) *palms facing up
thumbs downwards across the cheek and chin to help direct lower jaw
lift mandible forwards & upwards
result: mouth should be slightly open and jaw jutting forward
patients with what kind of medical histories or conditions should not receive a head lift–jaw thrust maneuver?
with rheumatoid arthritis or down syndrome, as they are predisposed to cervical spine instability
how do you open the patient’s mouth if it’s still closed after an airway maneuver
cross-finger technique (think of snapping thumb with first finger:
thumb pushes up
first finger pushes down
so they end up being crossed (kind of like sarangheyoo)
why isn’t chest wall movement (rise and fall) the best indicator of patent airways?
a patient’s chest and abdomen may be rising and falling as they are frantically trying to breathe even though the airway is completely obstructed
why is suctioning important?
you need to keep the airway clear for ventilation support. if aspirations (foreign substances like vomit) in the airways enter the lungs, mortality increases significantly
how do you know if a patient needs suctioning?
wet, gurgling sound - they have fluids in airways
what is a suction catheter?
hollow, rigid cylindrical device that removes fluids from airways
what type of catheter is used for infants and children
tonsil-tip catheter
what kind of catheters are used for patients with a stoma?
French/whistle-tip catheter (they are non-rigid)
how do you suction a patient’s airway?
- turn on the assembled suction unit, make sure it can reach up to 300 mmHg pressure
- measure catheter from the corner of the mouth to the angle of jaw
- turn patient’s head sideways (UNLESS SUSPECTED OF SPINAL INJURY) and use cross finger technique to open mouth
- insert catheter to measured depth and apply suction; remove it from the mouth in a circular motion
contraindications for oropharyngeal airway (OPA)
conscious patient
any patient with gag reflex
if a patient gags while you try to insert an oropharyngeal airway (OPA), what should you do?
prepare to log roll and suction the patient should vomiting occur
how do you insert an oral airway?
- select proper size of airway by measuring from corner of mouth to ear lobe
- insert the airway first curving upwards towards the roof of the mouth to prevent pushing the tongue further into the pharynx
- when it is partially inserted, rotate by 180° and push until the airway rests on the patient’s mouth and teeth
how do you insert an oral airway with 90° rotation?
- select proper size of airway by measuring from corner of mouth to ear lobe.
- use a tongue depressor to hold down the tongue white inserting airway sideways (so it curves sideways instead of up against the hard palate)
- rotate the airway 90° and remove tongue depressor. gently push until airway rests on the patient’s teeth/mouth
when do you use a nasopharyngeal airway?
when a patient has an intact gag reflex
contraindications for using a nasal airway
bleeding through nose
history of fractured nasal bone
how do you insert a nasal airway?
- select the correct size airway by measuring from nostril to ear lobe
- coat with water-soluble lubricant
- insert into the RIGHT nostril (usually bigger and straighter), curving downwards to follow the nasal air passage
- gently push the airway until inserted and let it rest on the nostril
For what kind of patient is the recovery position used to maintain clear airways?
unconscious, breathing spontaneously on their own, not injured
How to put a patient in recovery position
Log roll patient to their side
Extend patient’s lower arm and put upper arm under cheek
Bend upper leg
what is the importance of the recovery position?
it prevents aspirations into the lungs
maintains clear airways
what colors are oxygen cylinders?
green, white or chrome
what are older vs newer oxygen cylinders made from?
newer = lightweight aluminium
so older ones are heavier
what does the date stamp on an oxygen cylinder mean?
the last time it was tested
what cylinder sizes are often portable in an ambulance?
D (350 L)
Jumbo D (500 L)
E (625 L)
what is the pin-indexing system (aka PISS) on portable cylinders?
system corresponding to the pins on portable cylinders that help providers connect the right regulator to the right cylinder (and avoid connecting CO2 regulator to O2 cylinder for example)
what is the safety system for large gas cylinders?
American Standard Safety System (ASSS!); they use threaded gas outlet valves, the size of thread depends on cylinder
how do pressure regulators work?
the intial pressure of gas inside a cylinder is typically 200 psi. pressure regulators reduce the pressure to 40-70 psi, appropriate for patient use.
what are flowmeters?
They measure the volume of gas flowing out of the gas cylinder.
what are the two types of flowmeters?
pressure-compensated: they have a ball that rises with different levels of gas flow. has to be attached vertically otherwise affected by gravity
Bourdon-gauge: not affected by gravity but outdated and replaced by newer ones that have dials/knobs that set the flow
How do you set up an oxygen cylinder to be used?
1) “crack” the cylinder by slowly opening the valve counterclockwise using a tank key, and then closing it. helps get dirt and debris out of the way
2) align port and specific pins (rmb PISS) of the pressure regulator/flowmeter with the holes in the valve stem
3) secure and tighten the regulator/flowmeter by rotating the screw
4) put on the oxygen connective tubing to the flowmeter nipple
5) set flow rate to appropriate level (based off the equipment you’re using)
How do you turn off the gas cylinder?
1) Close valve at the top with tank key
2) remove tubing
3) Set flowmeter to 0
*make sure pressure gauge says 0
Hazards of Supplemental Oxygen
1) Combustion
2) O2 toxicity
3 oxygen-delivery devices
1) non-rebreathing masks with reservoir
2) bag-mask device with reservoir
3) nasal cannula (the tube that goes into nostrils)
When do you use a nonrebreathing mask?
In emergency cases where patient is significantly hypoxemic and needs O2 asap, but they don’t need help with breathing
What flowrate do you set for a non-rebreathing mask
10-15 L/min
make sure the bag stays inflated. if it deflates during inhalation, increase flowrate
How much oxygen is delivered by a non-rebreathing mask (in %)?
90%
How does a non-rebreathing mask have such a high oxygen delivery rate?
The reservoir bag it is connected to contains the oxygen and is connected to mask by a one way valve (so CO2 cannot get in). Flapper valve ports on the mask let out CO2 in exhaled breath through a one-way valve. So, the patient doesn’t inhale the exhaled CO2.
Why can using a nasal cannula irritate cause dryness or irritate mucous membranes of the nose?
It continuously delivers dry O2 through the nostrils. (e.g. non-rebreathing masks only allow oxygen in when the patient inhales)
*consider humidification for longer transports!
What flowrate do you set for a nasal cannula?
no more than 6 L/min
what is the oxygen delivery rate of nasal cannula?
24 - 44%
in what situations will a nasal cannula be of no help?
if patient has nasal obstruction
patient breathes through mouth
how is a partial rebreathing mask different to a non-rebreathing mask?
partial rebreathing masks have a two-way valve between the mask and reservoir bag instead of the one-way valve in non-rebreathing masks.
this allows patients to breathe some of the exhaled CO2 back in, especially in cases where low PaCO2 after hyperventilation is a concern.
when are Venturi masks used?
mostly used in the hospital setting for a patient with a low/moderate O2 need. Its advantage is the fine adjustment of oxygen delivery.
what is the oxygen delivery rate of Venturi masks?
24 - 40%
what is an oxygen humidifier?
It is a bottle of sterile water that is attached to the flowmeter nipple. The oxygen tubing connects to the humidifier
what is the risk of oxygen humidifiers?
aerosolization increase risk of transmission of disease
A patient cannot breathe on their own. Which ventilation technique do you use?
Artificial ventilation - bag mask device with 100% oxygen delivery
What are the 2 treatment options for respiratory distress/failure?
1) assisted ventilation
2) CPAP
How many bag mask device pumps should you give an apneic adult with a pulse?
1 every 6 seconds
How many bag mask device pumps should you give an infant/child with a pulse?
1 every 2-3 seconds
Risks of positive pressure ventilation
Reduce blood return to heart, decrease cardiac output
Gastric distention (air forced into stomach) that can cause vomiting and aspirations
What is the flow rate for a bag mask device?
15 L/min
total volume of an adult bag mask device
1200 - 1600 mL
total volume of a child bag mask device
500 - 700 mL
total volume of an infant bag mask device
150 - 240 mL
how do you perform one-rescuer bag mask ventilation?
1) head tilt-chin lift or jaw thrust maneuver (based on spinal cord injury)
2) suction airway if needed. insert a oropharyngeal/nasopharyngeal airway to maintain patent airway
3) put bag mask over patient’s nose and mouth and secure with the E-C hand position:
C - with first finger and thumb to hold down the mask
E - with the other 3 fingers to lift up the jaw
4) squeeze the bag mask until adequate chest rise and fall (once every 6 secs for adults and once every 2-3 secs for infants/children)
how do you perform a two-rescuer bag mask ventilation?
1) head tilt-chin lift or jaw thrust maneuver
2) suction if needed. insert oropharyngeal/nasopharyngeal airway
3) secure bag mask on patient’s nose & mouth. one provider holds down mask with both hands, while the other squeezes the bag mask with two hands
4) squeeze the bag until adequate chest rise & fall (1 per 6 secs for adults and 1 per 2-3 secs for infants/children)
Signs of adequate ventilation
adequate chest rise and fall
ventilations at the appropriate rate
HR back to normal range
Skin color is normal (pink)
O2 saturation increases
Signs of inadequate ventilation
no chest rise/fall
ventilation at an inappropriate rate
heightened HR
cyanotic, mottled skin
O2 sat low
what is an automatic transport ventilator (ATV)?
ventilator attached to a control box that can adjust different factors like tidal volume and respiratory rate
How to estimate tidal volume for ATVs?
7 mL/kg x body weight
How does CPAP (continuous positive airway pressure) assist with breathing?
through positive pressure ventilation that opens up alveoli
What is a physiological consequence of all positive pressure ventilation methods (bag mask ventilation, CPAP)?
hypotension, reduced cardiac output
Indications of CPAP
patient is awake and alert
respiratory distress bc of pulmonary edema, COPD
respiratory distress after submersion
rapid breathing
low O2 sats
Contraindications of CPAP
cardiac arrest, respiratory arrest, coma, or any condition requiring immediate intubation
patient can’t speak
unresponsive
has hypotension
pneumothorax, chest thorax
gastrointestinal bleeding, nausea, vomiting
cardiogenic shock
cannot sit upright
How do you put on a CPAP?
1) connect face mask to circuit tubing
2) connect tubing to oxygen cylinder
3) put patient in high Fowler position
4) secure the 2 mask straps over patient’s head
5) adjust the positive end-expiratory pressure (PEEP) according to manufacturer’s instructions
How do you assist ventilation in a patient with a tracheal stoma?
use an infant/child’s mask with bag mask ventilation
seal mouth and nose during inspiration
open during expiration
How do you assist ventilation in a patient with a tracheostomy tube?
use a regular bag mask ventilation method over the tube
cover the mouth and nose during inspiration and open during expiration
What signs indicate mild/partial foreign body airway obstruction?
stridor, wheezing and coughing but patient can still breathe and talk
What signs indicate severe foreign body airway obstruction?
patient cannot breathe or talk, clasping hands around neck, cyanotic
How do you dislodge a foreign object out of a conscious adult or child?
abdominal thrusts until object comes out OR patient goes unconscious
if that doesn’t work, tongue-jaw lift and scan for any visible obstructions. remove the obstructions with gloved finger or suction
if that STILL doesn’t work, begin rapid transport while continuing abdominal thrusts
How do you dislodge a foreign object out of an unconscious adult or child?
chest compressions
tongue-jaw lift to identify and take out any visible
rapid transportation to hospital while continuing chest compressions
4 stages of helping in an ALS procedure
1) Patient Prep
2) Equipment Set-Up
3) Performing the procedure
4) Continuing Care
4 stages of helping in an endotracheal tube intubation
1) Patient prep - preoxygenation with bag mask device + adjunct airway; maintain high nasal cannula on patient during intubation attempt (apneic oxygenation)
2) Equipment setup
3) Performing the procedure - BE MAGIC
4) Continuing care - monitoring SpO2 and RR, end-tidal CO2 level, resistance when ventilating, other signs of poor ventilation or perfusion, dislodgement of ET tube every time patient is moved
BE MAGIC intubation procedure
Bag mask pre-oxygenation
Evaluate for airway difficulties
Manipulate patient (elevate head, into sniffing pos.)
Attempt first-pass intubation
GI use supraGlottic airway if unable to intubate
Continue care + Correct any issues
What is the importance of pre-oxygenation before intubation?
Ensures adequate oxygenation of blood and perfusion to sustain the patient during the intubation attempt
Signs that indicate a complication with intubation
decreasing SpO2 level
absence of end-tidal CO2
increasing resistance when ventilating
other signs associated with poor ventilation and perfusion like skin condition
improper positioning/dislodgement of ET tube
Which of the following organs or tissues can survive the longest?
A. Muscle
B. Liver
C. Kidneys
D. Heart
A. Muscle
At what pressure should a gas cylinder be serviced?
500 psi
consequences of hyperventilation on blood flow
hyperventilation can increase intrathoracic pressure, putting pressure on the vena cava and decreasing the blood flow back to the heart
Which is an example of a mild foreign-body airway obstruction?
a. Cyanosis (blue lips or skin)
b. High-pitched noise while inhaling
c. Inability to speak or cry
d. Wheezing between coughs
d. Wheezing between coughs
*High-pitched noise while inhaling is when there is severe FBAO
What is one technique used to assist in Endotracheal Intubation?
? Selte Maneuver
? Cricothyrotomy
? Vagal Maneuver
? Cricoid Pressure
Cricoid Pressure
