BLOCK 6: AIRWAY MANAGEMENT Flashcards
how long can brain cells survive without oxygen before permanent damage occurs
6 minutes
the upper airway includes all structures above ___
the glottis
what is the glottis
space between the vocal cords
what is the first and largest anatomic structure to manipulate when managing patient’s airway
tongue
if the tongue is not managed during airway what does it tend to do
fall back into the posterior pharynx
2 things the uvula does
prevents food we eat from going up your nose and triggers gag reflex when stimulated
what is the muscular tube that extends from nose and mouth to the esophagus and trachea
pharynx
the pharynx starts and ends where
starts: nose and mouth
ends: esophagus and trachea
what composes the pharynx (3 in order from top to bottom)
nasopharynx, oropharynx, laryngopharynx
where does the lower airway start and end
starts: glottis
ends: pulmonary capillary membrane
what marks where the upper airway ends and lower airway begins
larynx
shield-shaped structure palpable on the anterior neck
thyroid cartilage
superior part of the thyroid cartilage that forms a V shape
thyroid notch
what is laryngeal prominence also known as
Adam’s apple
where is the laryngeal prominence
immediately inferior to the thyroid notch
where is the thyroid cartilage located
directly anterior to glottic opening and vocal cords
what does the cricoid cartilage form
the lowest portion of the larynx
what is special about the cricoid cartilage
only circumferential ring of the trachea
which structure is more prominent in males?
which structure is more prominent in females?
laryngeal prominence in males
the cricoid ring in females
where are cricothyrotomies performed
the cricothyroid membrane
what is the narrowest protion of the adult airway
glottis
what is the leaf-shaped cartilaginous structure
epiglottis
what closes over the trachea during swallowing
epiglottis
what 3 things must be visualized before inserting ET tube
epiglottis, glottis, and vocal cords
physical act of moving air into and out of the lungs
ventilation
process of loading oxygen molecules onto hemoglobin molecules in the bloodstream
oxygenation
exchange of oxygen and carbon dioxide in the alveoli and tissues of the body
respiration
what is the active part of ventilation?
what is the passive part of ventilation?
active: inhalation
passive: exhalation
what is external respiration also called
pulmonary respiration
what is internal respiration also called
cellular respiration
what is external respiration
exchanging oxygen and carbon dioxide between alveoli and blood in pulmonary capillaries
what is internal respiration
exchanging of oxygen and carbon dioxide between systemic circulation and cells of the body
what type of problem is an overdose on CNS depressors
ventilation problem
what type of problem is a person trapped in a place devoid of oxygen
oxygenation problem
circulation of blood within an organ or tissue in adequate amounts to meet the current needs of the cells
perfusion
what is a dangerous condition in which the tissues and cells do not receive enough oxygen
hypoxia
early signs of hypoxia (5)
restlessness, irritability, apprehension, tachycardia, anxiety
late signs of hypoxia (3)
change in mental status, weak/thready pulse, cyanosis
how to assess cyanosis in dark skinned patients
mucous membranes (lips, gums, inner eyelids, and nailbeds)
what is dyspnea
shortness of breath
how does gas exchange occur
simple diffusion
what is a failure to match ventilation and perfusion called
V/Q mismatch
what contributes to most abnormalities in oxygen and carbon dioxide exchange
V/Q mismatch
what is normal resting minute ventilation
6L/min
what is normal resting alveolar volume
4L/min
what is normal pulmonary artery blood flow
5L/min
what is the ratio of ventilation to perfusion
4:5L/min or 0.8L/min
the ventilation-to-perfusion ratio is highest where? lowest where?
highest: apex of the lung
lowest: base of the lung
what is the most common airway obstruction in an unresponsive patient and what are the two indicators
tongue - improper head/neck position and snoring respirations
what two neuromuscular disorders can affect the ability of the CNS to control breathing
muscular dystrophy and poliomyelitis
how does muscular dystrophy affect the CNS’s ability to control breathing
degeneration of muscle and its contractility as well as curvature of the spine
how does poliomyelitis affect the CNS’s ability to control breathing
affects the nerves that regulate ventilation and result in paralysis
what three conditions are bronchoconstriction associated with
allergic reactions, asthma, and COPD
intrinsic factors that cause airway obstruction (3)
infection, allergic reactions, unresponsiveness
extrinsic reactions that cause airway obstruction (2)
trauma and foreign body airway obstruction
what is respiratory splinting
purposely breathing shallow to alleviate pain caused by injury such as flail chest
hypoventilation
CO2 production exceeds body’s ability to eliminate it or CO2 elimination is depressed and can’t keep up with normal metabolism
hyperventilation
CO2 elimination exceeds carbon dioxide production
if the pH of blood is too high, what happens to the patient’s breathing and why
shallow/slow breaths in attempt to retain carbon dioxide
if the pH of blood is too low, what happens to the patient’s breathing and why
hyperventilation to expel more carbon dioxide
what two examples can cause hyperventilation/pH acidity
hyperglycemic ketoacidosis and aspirin OD
decrease in minute volume leads to ____
hypercapnia
increase in minute volume leads to ____
hypocapnia
what is hypercapnia
buildup of CO2 in the blood
what is hypocapnia
decrease of CO2 in the blood
how does hypoventilation affect minute volume
goes down
how does hypoventilation affect CO2 elimination
goes down
how does hypoventilation affect CO2 levels
goes up (hypercapnia)
how does hyperventilation affect minute volume
goes up
how does hyperventilation affect CO2 elimination
goes up
how does hyperventilation affect CO2 levels
goes down (hypocapnia)
what two things have key roles in the process of respiration
atmospheric pressure and partial pressure of oxygen
what happens to percentage of oxygen, partial pressure, and total atmospheric pressure at higher altitudes
oxygen - stays the same
partial pressure - decreases
total atmospheric pressure - decreases
what is PaO2
partial pressure of oxygen
what makes it difficult to breathe at high altitudes
low PaO2
carbon monoxide has a ___x higher affinity for hemoglobin than oxygen
250
what is intrapulmonary shunting
blood entering the lungs from the right side of the heart bypasses the alveoli and returns to the left side of the heart in an unoxygenated state
what does fluid accumulation in the alveoli lead to
anaerobic respiration and increase in lactic acid accumulation
what is anemia
deficiency of red blood cells
hemorrhagic vs vasodilatory shock
hemorrhagic: decrease in blood volume caused by internal/external bleeding
vasodilatory: increase in size of blood vessels causing decrease in BP and blood flow
what is the fastest way the body can eliminate excess H+ ions
creating water and carbon dioxide
four main clinical presentations of acid-base disorders
respiratory acidosis and alkalosis
metabolic acidosis and alkalosis
side effect of positive pressure ventilation in patients
decreased cardiac output and preload, increased afterload, and hypotension
what draws air into the chest cavity
negative-pressure ventilation
normal adult resp rate
12-20
normal child resp rate
12-37
normal infant (1month-1year) resp rate
30-53
what is a clear indicator of a depressed or absent gag reflex
pooling of secretions in patient’s mouth
what is the gag reflex
spastic pharyngeal and esophageal reflex triggered by stimulating the uvula or posterior pharynx
low oxygen level in arterial blood
hypoxemia
deficiency of oxygen at the tissue and cellular levels
hypoxia
lack of oxygen that results in tissue and cellular death
anoxia
difference between hypoxemia and hypoxia treatment
hypoxemia can be reverse by administering supplemental oxygen and hypoxia require more aggressive oxygenation and ventilatory support
what is adventitious breath sounds
abnormal
what is the upright sniffing position
patient is sitting up with head moved forward until the earlobes are on the same vertical plane as the manubrium of the sternum
what is the tripod position
patient is sitting up and leaning forward with elbows bent
proper airway management order (4)
opening airway
clearing airway
assessing breathing
providing appropriate interventions
what is orthopnea
positional dyspnea
what is breathing retractions
skin pulling between and around the ribs during inhalation
what muscles are used during accessory muscle use breathing
sternocleidomastoid muscles, pectoralis major muscles, abdominal muscles
what are staccato speech patterns
one or two word dyspnea
what is paradoxical motion and what does it indicate
opposite of normal chest movements (inward movement of chest segment during inhalation and outward movement of chest segment during exhalation) indicating flail chest
what is pulsus paradoxus and what does it indicate
drop in systolic BP of more than 10, change in pulse quality, or disappearing of pulse during inhalation indicating decompensating COPD, pericardial tamponade, or other increase in intrathoracic pressure
what is sneezing caused by
irritation of the nasal cavity
what is hiccupping
sudden inhalation caused by spasmodic contraction of the diaphragm cut short by closure of the glottis
what creates breath sounds
air moving through the tracheobronchial tree
what type of respiratory pattern is gradual increasing rate and depth of respirations followed by gradual decrease of respirations with intermittent periods of apnea and what is it associated with
Cheyne-Stokes respirations
brainstem injury
what type of respiratory pattern is deep, rapid respirations and what is it associated with
Kussmaul respirations
diabetic ketoacidosis
what type of respiratory pattern is irregular pattern, rate, and depth of breathing with intermittent periods of apnea and what is it associated with
Biot (ataxic) respirations
intracranial pressure
what type of respiratory pattern is prolonged, gasping inhalation followed by extremely short, ineffective exhalation and what is it associated with
Apneustic respirations
increased intracranial pressure
what type of respiratory pattern is slow, shallow, irregular or occasional gasping breaths and what is it associated with
agonal gasps
cerebral anoxia (shortly after heart has stopped but brain is still sending signals to the muscles)
what type of respiratory pattern is tachypneic hyperpnea (rapid, deep respirations) and what is it associated with
central neurogenic hyperventilation
increased intracranial pressure or direct brain injury
what is the inspiratory/expiratory ratio
1:2 (expiration time is twice as long as inspiration)
the I/E in patients with lower airway obstruction or asthma may be what ratio
1:4 or 1:5
what is the I/E ratio in patients with tachypnea
1:1
wheezing is what pitch and represents what
continuous high-pitched
constricted lower airway (asthma)
rhonchi is what pitch and represents what
continuous low-pitched
mucus or fluid in larger lower airways (pulmonary edema)
what is crackles and represents what
also known as rales
discontinuous
airflow causes mucus or fluid into the smaller lower airways
what is stridor and represents what
high-pitched during inspiration
foreign body aspiration, infection, swelling or trauma immediately above the glottic opening
what causes pleural friction rub
inflammation causing pleurae to thicken, allowing visceral and parietal pleurae to rub together
what does a pulse oximeter measure
percentage of saturated hemoglobin in arterial blood and patient’s pulse
when auscultating breath sounds emergently, where do you auscultate
bilaterally at the third or fourth intercostal space in the midaxillary line
normal oxygenated patient should have what SpO2 level
greater than 95%
less than 95% SpO2 in nonsmoker suggests what
hypoxemia
SpO2 less than 90% accompanied with respiratory distress signals a need for what
aggressive oxygen therapy
hemoglobin loaded with oxygen
oxygemoglobin
hemoglobin from which oxygen has been released to the cells
reduced hemoglobin
compound formed by oxidation of iron on the hemoglobin
methemoglobin
hemoglobin loaded with carbon monoxide
carboxyhemoglobin
peak expiratory flow rate in healthy adults
350-750mL
what is used to evaluate bronchoconstriction and with what tool
peak rate of forceful exhalation with peak expiratory flowmeter
what ABG measurements are used to evaluate patient’s acid-base status and what is the normal range of both
pH and Hco3-
pH: 7.35-7.45
Hco3-: 21-28mEq/L
what ABG measurement is used to evaluate patient’s effectiveness of ventilation and what is the normal range
PaCO2
35-45mm Hg
what ABG measurements are used to evaluate patient’s oxygenation and what is the normal range of both
PaO2 and SaO2
PaO2: 80-100mm Hg
SaO2: above 95%
what is the “smoke of metabolism”
carbon dioxide
how many ATP does aerobic metabolism create from each glucose molecule
38
how many ATP does anaerobic metabolism create from each glucose molecule
2
what is the recommended method of monitoring placement of advanced airway device
capnography
what reading approximates the arterial PaCO2 level and by how close
ETCO2 level is usually 2-5mmHg lower than arterial PaCO2 levels
what happens to CO2 levels after ROSC
abrupt and sustained increase
colorimetric carbon dioxide detector function
treated paper turns from purple to yellow during exhalation signifying presence of carbon dioxide
Phase 1 (A-B) of capnography waveform
respiratory baseline
initial stage of exhalation (dead space gas free of CO2)
Phase II (B-C)
expiratory upslope
alveolar gas mixes with dead space gas
Phase III (C-D)
alveolar plateau
all alveolar ga, max CO2 level
Phase IV (D-E)
inspiratory downstroke
displaces CO2 causing waveform to return to base level
what happens to waveform during hypoventilation
high waveforms, prolonged alveolar plateau, and longer-than-normal intervals between waveforms
what happens to waveform during hyperventilation
small waveforms, short alveolar plateau, shorter-than-normal intervals between waveforms
what is “shark fin” waveform
caused by bronchospasms
gradual upsloping phase II (B-C)
how is rebreathing CO2 shown on waveform
waveforms elevate and never return to the baseline at the end of the inspiratory downstroke phase IV (D-E)
cause of too high CO2 in apneic with a pulse patient
positive-pressure ventilation is too slow
cause of too low CO2 in apneic with a pulse patient
positive-pressure ventilation is too fast
cause of too high CO2 in apneic and pulseless patient
positive-pressure ventilation is too slow or could indicate ROSC
cause of too low CO2 in apneic and pulseless patient
misplaced ET tube, prolonged arrest, inadequate chest compressions, positive-pressure ventilation is too fast
preferred technique for opening the airway of a patient without cervical spine trauma
head tilt-chin lift maneuver
assessing breathing in an unresponsive patient should take no longer than ____
10 seconds
preferred technique for opening the airway of a patient with suspected cervical spine trauma
jaw-thrust maneuver
which maneuver to use on a jaw-fracture and why
jaw-thrust to keep tongue away from back of throat
preferred technique for opening a patient’s airway for suctioning or inserting an airway
tongue-jaw lift maneuver
mechanical or vacuum-powered suction units should be capable of at least ___ mm Hg with ___ seconds
300, 4
tonsil-tip catheter and what they are good options for
large diameter and rigid
suctioning oropharynx in adults, kids, and infants
large volumes of fluid rapidly
all names for rigid pharyngeal suction tips
tonsil-tip, Yankauer, DuCanto
whistle-tip catheters and what they are good options for
smaller diameter, soft nonrigid catheters
suctioning oropharynx/nasopharynx, down an ET tube, or stomas
all names for nonrigid plastic catheters
French or whistle-tip catheters
be careful not to stimulate the back of the throat especially in young children/infants because
can induce a vagal response and cause bradycardia
how to measure for proper sized catheter
from corner of the mouth to the earlobe or angle of the jaw
apply suction in a ___ motion
circular
an oropharyngeal (oral) airway is designed to do what
hold the tongue away from the posterior pharyngeal wall
rough airway insertion can do what
injure the hard palate and cause oral bleeding
nasopharyngeal (nasal) airway size range
12Fr-36Fr
contraindication to nasopharyngeal airways
facial or skull fractures, can enter the cranial vault through the hole caused by the fracture
in adults, sudden foreign body airway obstruction usually occurs ____
in children, it usually occurs ____
during a meal
while eating or playing with small toys
typical foreign body obstruction patient
middle-aged or older
wears dentures
consumed alcohol or has a condition (stroke) that decreases airway reflexes
dysphonia
difficulty speaking
aphonia
inability to speak
what is a laryngeal spasm and what is it usually caused by
spasmodic closure of the vocal cords, completely occluding the airway
usually caused by trauma during overly aggressive intubation attempt
what is laryngeal edema and what is it usually caused by
causes glottic opening to become extremely narrow or totally closed
usually caused by epiglottitis, anaphylaxis, inhalation injury (burns to upper airway)
most effective means of dislodging mild airway obstruction
forceful cough
what is lung compliance
ability of alveoli to expand when air is drawn or pushed into the lungs during ventilation
what is poor lung compliance characterized by
increased resistance during ventilation attempts
at what oxygen level in the air can side effects start to occur
19%
Heimlich maneuver aka ___
abdominal thrust maneuver
what to do instead of Heimlich in patients with advanced stages of pregnancy or morbid obesity
chest thrusts
what is a direct laryngoscopy and what do you use to remove the foreign body from the upper airway
visualization of the airway with a laryngoscope
Magill forceps
what can giving a patient who does not need oxygen cause
oxidative stress and hyperoxic injury
most common oxygen cylinder class and amount in field
D cylinder - 350L of oxygen
most common oxygen cylinder class and amount stored on the ambulance
M cylinder - 3,000L of oxygen
when to replace oxygen cylinder with new one (safe residual pressure)
200psi or lower
formula for determining duration of flow for oxygen cylinder
(tank pressure PSI - 200PSI) x (cylinder constant/flow rate in L/min) = duration of flow in minutes
do not subject oxygen cylinders to temperatures greater than ___ degrees (F/C)
125F / 50C
have the oxygen cylinder hydrostatically tested every ____
10 years
pressure of gas in a full oxygen cylinder
2,000psi
what is a therapy regulator
reduces high pressure of gas in oxygen cylinder to a safe range of about 50psi
which flowmeter, the pressure-compensated or the Bourdon-gage flowmeter, is affected by gravity and how do you have to treat it differently
pressure-compensated, must remain in upright position
what usually causes hiccups
swallowed air which leads to spasming of the diaphragm
where to listen for lung sounds
second, fifth, and seventh intercostal space
nonrebreathing mask flow rate and FIO2
12-15L/min, 90%
nasal cannula flow rate and FIO2
1-6LPM, 24-44%
partial rebreathing mask flow rate and FIO2
6-10LPM, 35-60%
tracheal normal breath sounds
inspiratory/expiratory are both loud
bronchial normal breath sounds
inspiratory are shorter than expiratory, both are loud
bronchovesicular normal breath sounds
inspiratory/expiratory are both medium intensity
vesicular normal breath sounds
inspiratory sounds last longer than expiratory sounds, both are faint
two treatment options for patients with severe respiratory distress or failure
positive-pressure ventilation with bas-mask device or CPAP
what can aggressive positive-pressure ventilation do to patient
impair patient’s hemodynamics and push air into stomach
formula for cardiac output
stroke volume x pulse rate
what is gastric distention
air in the stomach
what happens to air movement during PPV
air forced into lungs
what happens to blood movement during PPV
intrathoracic pressure is increased, venous return/preload is impaired, stroke volume and cardiac output are reduced
what happens to airway wall pressure during PPV
more volume is required to have same effects as normal breathing which results in walls being pushed out of their normal anatomic shapes
what happens to esophageal opening pressure during PPV
air is forced into the stomach causing gastric distention resulting in vomiting and aspiration
what happens to overventilation during PPV
forcing volume and rate results in increased intrathoracic pressure, gastric distention, and decreased cardiac output (hypotension)
how much air can patient receive with mouth-to-mask technique
up to 55%
max suctioning time for adults, children, and infants
adult: 15 seconds
child: 10 seconds
infant: 5 seconds
ventilation rate for 12-14 (onset of puberty) and older
1 breath every 6 seconds for 10 breaths/min
ventilation rate for infants/peds up to onset of puberty
1 breath every 2-3 seconds for 20-30 breaths/min
adult bag-mask device reservoir bag volume
1200-1600mL
pediatric bag-mask device reservoir bag volume
500-700mL
infant bag-mask device reservoir bag volume
150-240mL
how much tidal volume to deliver to adult via bag-mask to produce visible chest rise
500-600ml (6-7mL/kg)
deliver each breath with bag-mask over what period of time
1 second
when should you also wear a protective gown when managing airway
significant blood splashing or if the patient is suspected of having infection respiratory infection (SARS, TB, covid)
what technique to use for single rescuer bag-mask ventilation
EC clamp technique
what to do if the patient’s stomach rather than the chest is rising and falling
reposition the head, if spinal injury is present then reposition the jaw
what does the automatic transport ventilator AC mode do
assist/control - controls work of breathing but allows patient to set the respiratory rate
what does the automatic transport ventilator SIMV mode do
synchronized intermittent mandatory ventilation - sets the respiratory rate and volume/pressure delivered and syncs with each patient-initiated breath
what does the automatic transport ventilator pressure support mode do
uses positive pressure to overcome airway resistance to increase patient’s spontaneous breaths (requires patient to be able to initiate breath)
ATV is set based on what and why
the patient’s ideal body weight, not actual body weight because adult lungs do not increase in size or hold more volume due to increased body weight
how much oxygen does ATV consume
5 L/min
what can happen if the ATV’s pressure relief valve fails or if ventilation is too fast/too forceful
barotrauma
atelectasis
alveolar collapse
what about pediatrics makes it more difficult to achieve effective mask-to-face seal compared to adults
flat nasal bridge
length-based resuscitation tape can be used to estimate appropriate size of bag-mask valve for patients up to what weight
75lbs/34kgs
accidentally placing pressure on pediatrics’ eyes while ventilating can do what
stimulate oculocardiac reflex which can decrease HR and BP
contraindications for CPAP
unable to protect airway, hypoventilation, hypotension, pneumothorax, head/facial injury, cardiogenic shock, tracheostomy, GI bleeding, nausea/vomiting, recent GI surgery
what generates PEEP and what is PEEP
patient exhaling against resistance (expiratory positive airway pressure) generates PEEP
PEEP: positive end-expiratory pressure
therapeutic PEEP range
5-10cm H2O
CPAP units can empty a D cylinder in ___ minutes
5-10
CPAP FIO2 level
30-35%
possible effects of CPAP
pneumothorax from barotrauma, increased pressure in chest cavity leading to hypotension, gastric distention
who should get humidified O2
burn patients
how is BPAP different from CPAP
bilevel positive airway pressure - delivers two pressures
1. inspiratory positive airway pressure to open lower airways
2. lower expiratory positive airway pressure to help keep lower airways open
how to perform assisted ventilation
match the first 5-10 breaths then slowly adjust the rate
how is invasive gastric decompression performed
inserting gastric tube through mouth or nose into patient’s stomach and removing contents with suction
use caution when inserting NG/OG tubes on which patients and never use NG/OG tubes on which patients
caution: esophageal disease (tumors, varices, strictures)
never: non-patent esophagus
how to confirm proper placement of NG/OG tube
auscultate over epigastrium while injecting 20-30mL of air into the tube and/or observe for gastric contents in tube (no reflux around tube)
what is gastric lavage
cleaning out the stomach’s contents (usually patients who ingested toxins)
laryngectomy
surgical removal of larynx
tracheostomy
surgical opening of trachea
stoma
orifice that connects trachea to outside air
limit suctioning of stoma to ___
10 seconds
how to suction a stoma
inject 3mL of sterile saline through stoma into trachea, tell patient to exhale, insert catheter without providing suction until resistance is felt (no more than 12cm), suction while withdrawing catheter
what adapter size must be on tracheostomy tube to be compatible with ventilatory devices
15/22mm
if a tracheostomy tube becomes dislodged, what can occur
stenosis (narrowing) of the stoma
which dental appliances to leave in and which to remove
leave in place: well-fitted ones maintain facial structure
remove: loose-fitted ones could become an airway obstruction
what obstruction often contain sharp metal ends that can easily lacerate the pharynx or larynx
bridges
facial injuries should increase your index of suspicion for ____
cervical spine injury
do not proceed to advanced airway management too early, do it only for two reasons:
failure to maintain patent airway and/or failure to adequately oxygenate and ventilate
mnemonic to guide assessment of difficult airway
LEMON
Look externally
Evaluate 3-3-2
Mallampati classification
Obstruction
Neck mobility
difficulties for airway just by looking at patient
short, thick necks
morbid obesity
dental conditions like overbite or buck teeth
what is the evaluate 3-3-2 of LEMON
3 - patient’s mouth should open at least 3 fingerbreadths
3 - length of mandible should be at least 3 fingerbreadths long (from tip of chin to hyoid bone)
2 - distance from hyoid bone to thyroid notch should be at least 2 fingerbreadths wide
what is the Mallampati classification
oropharyngeal structures visible in an upright, seated position in full conscious, alert patient who is able to open mouth
what is the Cormack-Lehane classification
classifies views obtained by laryngoscopy based on the structures seen
Class I of Mallampati classification
entire posterior pharynx is fully exposed
Class II of Mallampati classification
posterior pharynx is partially exposed
Class III of Mallampati classification
posterior pharynx cannot be seen; base of uvula is exposed
Class IV of Mallampati classification
no posterior pharyngeal structures can be seen
Class I of Cormack-Lehane classification
full view of epiglottis, arytenoid cartilage, and vocal cords is available
Class II of Cormack-Lehane classification
epiglottis is in full view but only a portion of the glottis or arytenoid cartilage can be seen
Class 2a: partial view of the glottis
Class 2b: arytenoids or posterior part of vocal cords barely visible
Class III of Cormack-Lehane classification
only epiglottis can be seen - glottis nor arytenoid cartilage is visible
Class IV of Cormack-Lehane classification
neither epiglottis nor glottis is visible
ideal position for visualization and intubation
sniffing position - ears aligned with sternal notch
what is endotracheal intubation
ET tube passed through glottic opening and tube is sealed with cuff inflated against tracheal wall
disadvantage of ET intubation
bypasses warming, filtering, and humidifying functions of the upper airway
what is the use of the ET tube’s pilot balloon
indicates whether distal cuff is inflated or deflated after the tube has been inserted
what is the purpose of the ET tube’s Murphy eye
enables ventilation to occur even if the tip becomes occluded by blood, mucus, or tracheal wall
ET tube diameter and length size range
diameter: 2-10mm
length: 12-32cm
what ET sizes are equipped with distal cuff
5-10mm
normal ET tube size for adult female and adult male
female: 7-7.5mm
male: 7.5-8mm
what is the stylet used for
guides the tip of the tube over the arytenoid cartilage and through the vocal cords
how should a stylet be formed and where should it be placed in ET tube
“hockey stick curve”
at least 0.5inch (1cm) back from the end of ET tube
normal ET tube size for pediatrics
2.5-5mm
why are distal cuffs not needed for pediatrics
the cricoid ring (narrowest part of peds airway) forms a seal with the ET tube
good estimates of the diameter of the glottic opening
diameter of nostril or little finger
length-based tape for peds
what is the laryngoscope straight and curved blade called
straight: Miller
curved: Macintosh
what population is the straight laryngoscope blade used for and why
infants and small children because the tip directly lifts up the epiglottis
where is the tip of the curved laryngoscope blade placed
vallecula (space between epiglottis and base of the tongue)
blade sizes for laryngoscopes
0-4
blade sizes for children and adults
children: 0, 1, 2
adults: 3(average size), 4 (larger people)
how long to preoxygenate an apneic or hypoventilating patient before intubation
2-3 minutes to as close to 100% as possible
what are the piriform fossae
pockets on both sides of laryngeal inlet
what are the aryepiglottic folds
soft tissue separating larynx from piriform fossae
three axes of the airway
oral, tracheal, pharyngeal
in most supine patients, the sniffing position can be achieved by ____
elevating the occiput 1-2 inches
what side to insert blade into patient’s mouth and why
right side to sweep the tongue to the left side of mouth
what is the critical structure to identify during laryngoscopy
epiglottis
bougie bend at the distal tip
30 degrees
what is the bougie used for
epiglottis-only views to facilitate intubation
when you meet resistance with the bougie, you know that it is where
at the level of the carina
what is the purpose of the bend at the end of the distal tip of the bougie
enables you to feel the tracheal rings
once the ET tube passes through the vocal cords, what do you do with the tube
rotate it to the right and direct the tip downward to follow the trachea
how far to advance the ET tube
until proximal end of the cuff is 0.5 to 0.75inches past the vocal cords
what is the most reliable method of confirming the tube has entered the trachea
visualizing the ET tube passing between the vocal cords
how much air to inflate into the distal cuff
5-10mL
what can overinflating the distal cuff cause
ischemia or necrosis of the tracheal wall which leads to tracheal stenosis (narrowing)
how to determine if the tube migrated after placement
note the depth of the ET tube at patient’s teeth after placement
if copious vomit is being emitted from the ET tube, ___
do NOT remove it
inflate distal cuff, turn tube to the side, and ventilate with bag-mask device
what does breath sounds only on right side of chest indicate and how to correct it
tube was advanced too far and entered the right main stem of bronchus
deflate cuff, slowly retract tube while listening for breath sounds over left side of chest until bilateral breath sounds are present
what is the most reliable method for confirming and monitoring placement of ET tube
waveform capnography
with a firmly secured tube, the tip can move ____
2 inches
if the patient’s head is hyperflexed, what happens to the tube? if the head is hyperextended?
ET tube can be pulled out of the trachea
Et tube could be pushed farther into the trachea and into a main stem bronchus
what is nasotracheal intubation and what is the other term for it
insertion of ET tube into trachea through nose without directly visualizing the vocal cords
“blind” intubation
nasotracheal intubation is only performed on what patients
patients with spontaneous breathing
contraindications of nasotracheal intubation
head trauma, deviated septum, nasal polyps, frequent cocaine use, blood-clotting abnormalities
standard ET tubes should be how much smaller when inserted nasally
1-1.5 mm smaller
how to advance nasotracheal tube
advanced as patient inhales
which nostril for nasotracheal intubation, how to adjust if you have to use other nostril
right nostril, if left nostril must be used, rotate tube 180 degrees
devices used to determine maximum airflow during nasotracheal intubation
humid-vent 1, beck airway airflow monitor (BAAM), stethoscope with head removed
if you see a soft-tissue bulge on either side of the airway after inserting nasopharyngeal tube, what probably happened
the tube has probably been inserted into the piriform fossa
what is the definition of a “failed airway”
failure to maintain adequate ventilation and oxygenation regardless of techniques of airway management being used
tracheobronchial suctioning
passing a suction catheter into the ET tube to remove pulmonary secretions
what can tracheobronchial suctioning cause
cardiac dysrhythmias and cardiac arrest
what to do before tracheobronchial suctioning
preoxygenation and inject 3-5mL of sterile water down ET tube to loosen extremely thick pulmonary secretions
what can happen when extubation is performed on responsive patients
high risk of laryngospasm and upper airway swelling
complications with sedation in airway management are usually what
undersedation and oversedation
examples of benzodiazepine sedative-hypnotics
diazepam (valium) and midazolam (versed)
examples of dissociative anesthetics
ketamine (ketalar)
examples of opioid sedative-analgesics
fentanyl (sublimaze) and alfentanil (alfenta)
examples of non-opioid/nonbarbiturate sedative-hypnotics
etomidate (amidate)
two major classes of sedatives commonly used in airway management and what they do
analgesics: decrease perception of pain
sedative-hypnotics: induce sleep and decrease anxiety (do not reduce pain)
benzodiazepines produce what
anterograde amnesia
midazolam vs diazepam
midazolam is 2-4x more potent than diazepam, faster acting, and shorter duration of action
potential side effects of benzodiazepines
respiratory depression and hypotension
what is a benzodiazepine antagonist
Flumazenil (Romazicon)
what is a dissociative anesthetic
produces anesthesia by distorting patient’s perception of sights/sounds and inducing dissociation
what is reemergence phenomenon
occurs during half-life of ketamine when patient is awakening - causes pleasant dreams, vivid nightmares, or delirium
what are opioids
act as CNS depressant and produce insensibility or stupor
how much more potent is fentanyl than morphine
70-150x
alfentanil in comparison to fentanyl
alfentanil is less potent with faster onset of action, shorter duration of action, and eliminated from body quicker
what sedative causes myoclonic muscle movement
Etomidate (Amidate)
how long after receiving IV dose of paralytic will a patient become totally paralyzed
1-2 minutes
how do depolarizing neuromuscular blockers work
competitively bind with ACh receptor sites - causes depolarization of muscle and prevents future signs for depolarization
example of depolarizing neuromuscular blocker
succinylcholine chloride (anectine)
what does succs cuase
fasciculations
succs onset, duration, contraindications, and side effect
onset: 60-90 secs
duration: 5-10mins
contraindications: conditions that can result in hyperkalemia (burns, crush injuries, blunt trauma)
side effects: bradycardia
how do nondepolarizing neuromuscular blockers work
bind to ACh receptor sites, do not cause depolarization of muscle fiber
examples of nondepolarizing neuromuscular blockers
vecuronium, pancuronium, rocuronium
glottic opening in infancy, age 7, and adult
infancy: C1
age 7: C3-4
adult: C4-5
what should be avoided after administering a paralytic agent if possible
bag-mask ventilation
if your choice of paralytic is succs, consider what two medication administrations
defasciculating dose of 10% of normal dose of nondepolarizing paralytic and atropine sulfate to decrease bradycardia risks
ETT size for pediatric patient formula
(age/4) + 4
if patient is hemodynamically unstable (systolic BP less than 90mm Hg) what should be considered over benzos
ketamine or etomidate
two signs of adequate paralysis
apnea and laxity of mandible
what to do with patient who requires ET intubation but cannot be preoxygenated due to mental status
DSI (delayed sequence intubation)
how to perform DSI
administer dissociative dose of ketamine, administer 15LPM via nonrebreathing mask and NC, after maintaining oxygen for 3mins, administer paralytic
what is denitrogenation
replacing alveolar nitrogen with oxygen
what degree to have bed elevated to for RSI
15-30 degrees
what is the single-lumen airway blindly inserted into the esophagus
King LT Airway
main disadvantage of the LMA
does not protect against aspiration and may increase risk of it
what size ET tube can be passed through a size 3 or 4 LMA
6mm
i-gel allows for passage of what size gastric tube
10Fr
iGel size 3 color and weight
yellow
30-60kgs
iGel size 4 color and weight
green
50-90kgs
iGel size 5 color and weight
orange
over 90kgs
where are the superior cricothyroid vessels located
run at transverse angle across upper third of cricothyroid membrane
where are the carotid arteries located
run vertically lateral to the cricothyroid membrane
where does the ET tube or tracheostomy get inserted during cricothyrotomy
subglottic area (below vocal cords) of the trachea
age contraindicated for surgical cricothyrotomy
under 8 years old (use needle cricothyrotomy)
how to make your cut for a surgical cric
vertical 0.5-0.75inches
crics on obese patients run a risk of what
false passage of the tube undermining the subcutaneous tissue
what is subcutaneous emphysema
air infiltrates the subcutaneous (fatty) layers of the skin
characterized by “crackling” sensation when palpated
what to use to cut for cric
number 10 scalpel
what gauge needle for needle cric
12-16 gauge
how to insert needle for needle cric
45 degrees caudally (towards feet)
what is the cylinder constant for D
0.16
what is the cylinder constant for M
1.56
what age range is croup most common in
6 months - 6 years
what time of year is croup more prominent in northern areas
October-March
what two conditions are commonly mistaken for epiglottitis until an abscess is seen
peritonsillar abscess and retropharyngeal abscess
what is diphtheria
bacterium attacks and kills epithelial tissue creating a pseudomembrane
what is aspiration pneumonitis
gastric acid irritates the lung tissue after it is aspirated
what increases risk of aspiration in patients with tube feedings
if they are placed supine immediately after a large feeding
three most chronic obstructive lower airway diseases
emphysema, chronic bronchitis, asthma
how is bronchospasm different from edema
bronchospasm: muscle contracts causing entire tube to narrow
edema: wall of tube swells causing only lumen to narrow
