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