Download CBT621: Infectious Disease

CBT425-EMT11: Respiratory
Emergencies
© 2011 Seattle / King County EMS
Introduction
• Patients with lung & heart diseases
frequently call 9-1-1 due to breathing
difficulty
• This course reviews common disorders that
can cause respiratory emergencies &
prehospital management of these
conditions
© 2011 Seattle / King County EMS
Objectives
1. Identify the anatomic structures of the respiratory
system
2. Demonstrate an understanding of the physiology of the
respiratory system and its relationship to BLS treatment
3. Identify signs and symptoms of respiratory emergencies
4. Identify treatment of respiratory emergencies
5. Distinguish between normal and abnormal breath sounds
6. Identify correct technique for auscultation of breath
sounds
7. Identify correct BVM technique and suctioning technique
© 2011 Seattle / King County EMS
Terms
chronic obstructive pulmonary disease (COPD) - A category
of diseases characterized by a slow process of dilation and
disruption of pulmonary alveoli.
dyspnea - A term for shortness of breath or breathing difficulty.
embolus - A blood clot or other substance that has formed in a
blood vessel or the heart, that breaks off and travels to another
blood vessel, where it may cause blockage.
flail chest - A condition in which three or more ribs are fractured
in two or more places such that a section of the chest wall is
detached from the rest of the chest wall.
© 2011 Seattle / King County EMS
Terms, continued
gag reflex - A protective contraction of the muscles of the throat
caused especially by stimulation of the pharynx that prevents
food and liquids from entering the airway.
hypoxia - A condition in which the body's cells and tissue do not
have enough oxygen.
pleuritic chest pain - A sharp, stabbing pain in the chest that is
worsened by a deep breath; often caused by inflammation or
irritation of the pleura.
pneumothorax - Condition where air enters the pleural space
and is trapped during expiration. It can occur without trauma
as in a spontaneous pneumothorax.
© 2011 Seattle / King County EMS
Terms, continued
pulmonary edema - A buildup of fluid in the lungs, usually as a
result of congestive heart failure.
rales - Crackling, rattling breath sounds signaling fluid in the air
spaces of the lungs.
rhonchi - Coarse breath sounds heard in patients with mucus in
the airways.
stridor - A harsh, high-pitched inspiratory sound often heard in
acute laryngeal (upper airway) obstruction.
© 2011 Seattle / King County EMS
Terms continued
tension pneumothorax - A life-threatening condition in which
air enters the pleural space and the pressure inside the lung
cavity progressively increases and compresses the lung. It may
displace the mediastinum and other structures toward the
opposite side.
traumatic asphyxia - Condition characterized by distended neck
veins, cyanosis in face and neck and bleeding in the sclera of
the eye that is caused by severe compression of the chest.
wheeze - A high-pitched, whistling breath sound,
characteristically heard on expiration in patients with asthma or
COPD.
© 2011 Seattle / King County EMS
New Terms
hypoxic drive - A condition in which the body's stimulus for
taking a breath is low oxygen. Occurs in people with COPD.
metabolism - The process by which food molecules are broken
down to provide material and energy for cellular function.
pH (potential of hydrogen) - A measure of the acidity or alkalinity
of a solution, numerically equal to 7 for neutral solutions,
increasing with increasing alkalinity and decreasing with
increasing acidity. The pH scale ranges from 0 to 14. Numbers
from 7 and below represent increasing acidity.
© 2011 Seattle / King County EMS
New Terms continued
perfusion - The movement of blood through an organ
or tissue in order to supply nutrients and oxygen.
tidal volume – The volume of gas that is moved with
each breath which is normally 500 ml in an adult.
ventilation – The rate at which gas enters or leaves
the lungs. Generally it is described in terms of good
or poor ventilation. Bluish or dusky skin can indicate
poor ventilation.
© 2011 Seattle / King County EMS
Respiratory Structures
• Airway protection & oxygen administration
are perhaps the most important BLS skills
you have
• Important to know structures of respiratory
system
• Understand basic physiology affected by BLS
treatment
Learning Activity for Functions of Respiratory Structures
http://www.emsonline.net/resp2011/functions.asp
© 2011 Seattle / King County EMS
PHYSIOLOGY
© 2011 Seattle / King County EMS
Metabolism Produces Carbon Dioxide
• Process by which body breaks
down or "burns" stored fuel to
create energy
• Cells use oxygen to transform
stored glucose into energy
• Think of glucose as "fuel" &
oxygen as "match" that
releases energy
• Byproduct of metabolism is
carbon dioxide (CO2)
© 2011 Seattle / King County EMS
Metabolism
• Carbon dioxide produced by cells & carried
by circulatory system to lungs where it is
expired
• If respirations impaired
• Carbon dioxide builds up in blood
• Excess carbon dioxide combines with water in
blood to produce acid
© 2011 Seattle / King County EMS
pH
• Acidity in solution such as blood measured by
potential of Hydrogen
• Body must maintain relatively narrow pH
range (neither too acidic nor too basic)
• Respiratory system helps maintain balanced
acid level or pH in blood
© 2011 Seattle / King County EMS
The pH Balancing Act
• Respiratory system – mirror
for other changes that happen
in the body
• Blood pH becomes too low
(acidic)
• Respiratory system will
attempt to fix by making lungs
breathe more deeply & rapidly
• Excreting more carbon
dioxide
• Homeostasis – body attempts
to maintain balance
© 2011 Seattle / King County EMS
Hypercarbia
• Excessive carbon dioxide
in the body
• Results in acidosis as
carbon dioxide causes
chemical reaction
producing carbonic acid
• Hypercarbia can occur
through:
• Metabolic processes that
form acids
• Muscle exertion
• Shivering
© 2011 Seattle / King County EMS
• Occurs through
decreased elimination of
carbon dioxide, for
example with:
• Airway obstruction
• Inability to exhale fully
(e.g., asthma or
emphysema)
• Depressed respiratory
drive (e.g., overdose of
sedative drugs)
Hypoxic Drive
• Amount of carbon dioxide in blood is primary
stimulus for breathing
• Secondary stimulus is hypoxia
• Decrease in oxygen
• Occurs in small percentage of COPD patients
• Expirations so inefficient their bodies become
accustomed to higher than normal levels of
carbon dioxide
• Decrease in oxygen, rather than increase in
carbon dioxide, provides primary stimulus for
taking breath
© 2011 Seattle / King County EMS
Respiratory Drive
• Act of breathing – autonomic & involuntary
function controlled by centers in brain
sensitive to blood levels of oxygen & carbon
dioxide
• Body’s response to increased carbon dioxide
in blood is to "blow off” carbon dioxide by
increasing rate & depth of respirations
© 2011 Seattle / King County EMS
Metabolic Problems
• Metabolic imbalances affect chemistry of
body affecting pH & other measures of body
chemistry
• Not a respiratory problem, respiratory system
often tries to compensate by changing depth
and/or rate of respirations
© 2011 Seattle / King County EMS
Metabolic Problems
Ketoacidosis – inefficient metabolism of sugars in a diabetic
causes body to turn to other fuel sources for energy (fat &
muscle)
• Byproducts – acids called ketoacids
• Presence of ketoacids & related compounds in blood will cause
lower pH
• Respiratory system responds by increasing depth and/or rate of
respirations
Aspirin overdose – an acid (the chemical name is acetylsalicylic
acid)
• Taken in large quantities, person becomes acidotic
• Body compensates by increasing depth and/or rate of respirations
© 2011 Seattle / King County EMS
Metabolic Problems
Fever increases metabolic rate, causing production of more
carbon dioxide which leads to more acid in blood
• Tissue perfusion fails (as it can in sepsis)
• Excess metabolic acids accumulate causing metabolic acidosis
with a low pH
• Body responds by increasing depth and/or rate of respirations
Hyperventilating breathing deeply & rapidly
• Efficient way of ridding body of carbon dioxide which in turn may
alter the body’s equilibrium
• Causes alkalosis (meaning very "basic")
• Symptoms of respiratory alkalosis may include faintness & tingling
in the extremities
© 2011 Seattle / King County EMS
CLINICAL
SYNDROMES
© 2011 Seattle / King County EMS
Airway Obstruction
• EMS providers should intervene if choking victim has
signs of severe airway obstruction
– Poor air exchange or increased breathing difficulty
(indicated by silent cough) cyanosis or inability to speak or
breathe
• Mild obstruction & victim coughing forcefully
– Do not interfere with efforts to relieve obstruction
– Attempt to relieve obstruction only if it becomes severe
• Use a finger sweep only if you can see solid material
obstructing airway of unresponsive patient
© 2011 Seattle / King County EMS
Asthma
• Chronic, inflammatory disease of airways
• Asthma attacks induced by different factors:
–
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Allergens
Infections
Exercise
Smoke
• During asthma attack:
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Muscles around bronchioles tighten
Lining of inside bronchioles swells
Inside of bronchioles fills with thick mucous
Severely restricts expiration of air from lungs
© 2011 Seattle / King County EMS
Asthma
• Asthma attack – muscles
around airways tighten, making
airway openings narrower so
less air can flow through
• Inflammation increases and
airways become more swollen
and narrow
• Cells in airways also produce
more mucus than normal
–Extra mucus also narrows
the airways.
© 2011 Seattle / King County EMS
• Patients often describe history
of asthma
• Have prescription for
metered-dose inhaler
• BLS treatment considerations
include:
– Calming the patient
– Airway management
– Oxygen therapy
– Assisting with a prescribed
inhaler
COPD
• Chronic obstructive pulmonary disease
(COPD)
• Category of diseases that includes:
– Asthma
– Emphysema
– Chronic bronchitis
• Slow process of dilation & disruption of
airways & alveoli
• Includes several related irreversible
conditions that limit ability to exhale
© 2011 Seattle / King County EMS
© 2011 Seattle / King County EMS
COPD
• Patients present with
shortness of breath, fever and
increased sputum production
– Medical history can include:
– Upper-respiratory infection
– Chronic bronchitis
– Emphysema
– History of smoking
– Working in hazardous
environment (e.g., coal
smoke, asbestos)
Common medications include:
• Prednisone
• Proventil
• Ventolin
• Atrovent
• Azmacort
BLS treatment for a COPD patient with respiratory
distress should include high flow oxygen .
© 2011 Seattle / King County EMS
Emphysema
• Very small airways that join alveoli are damaged &
walls lose elasticity
• Chronic irritation of small airways causes
inflammation & swelling – reducing diameter of air
passages
• Irritation causes bronchospasms & further decreases
the lumen
• On inspiration, expansion of lungs holds airways
open
• On exhalation, lungs relax & airways narrow,
trapping air
© 2011 Seattle / King County EMS
Chronic Bronchitis
• Characterized by structural changes in
airways of the lungs
• Enlargement of mucous glands – cause
coughing & production of sputum
• Causes shortness of breath
• Often accompanied by infection, mucus
production & coughing
© 2011 Seattle / King County EMS
Congestive Heart Failure
• During acute
exacerbation patient will
present:
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–
–
Sitting up
Short of breath
Diaphoretic
Pale
Cyanotic in color
• Breath sounds can
include rales or wheezes
© 2011 Seattle / King County EMS
• Medical history can
include:
– Increased salt ingestion
– Respiratory infection
– Non-compliance with
medications
– Angina
– Symptoms of acute
coronary syndrome
Congestive Heart Failure
• Result of too much fluid in lungs
making it difficult to get air in—as
opposed to COPD patient who has
trouble getting air out
• Occurs when ventricles weakened
by myocardial infarction,
underlying coronary artery disease,
hypertension or valve disease
• Impairs heart’s ability to contract
& empty during systole
– Blood backs up in lungs &
tissues of body
• Increased pressure in left
ventricle transmitted to lung
capillaries
– Fluid forced into alveoli
– Interrupts gas exchange &
results in shortness of breath
• Increased pressure in right
ventricle causes fluid to back up
into body’s tissues
– Leading primarily to swelling in
lower extremities
• Do not suffer from purely leftor purely right-ventricle heart
failure
– Rather present with
combination of symptoms
© 2011 Seattle / King County EMS
CHF Symptoms
© 2011 Seattle / King County EMS
Congestive Heart Failure
• Common medications include:
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ACE inhibitors
Furosemide (Lasix)
HCTZ (hydrochlorthiazide)
Beta-blockers
Angiotensin II receptor blockers
Digoxin (Lanoxin)
• Medications can help differentiate this
patient's symptoms from those of someone
with COPD
© 2011 Seattle / King County EMS
Congestive Heart Failure
When treating CHF:
• Seat the patient upright
• Administer high flow oxygen
• Consider positive pressure ventilation with a
BVM if the patient is experiencing severe
respiratory difficulty
© 2011 Seattle / King County EMS
Inhalation Injuries
• Breathing of chemicals, smoke or other substances
• Common chief complaints include:
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Shortness of breath
Coughing
Hoarseness
Chest pain due to bronchial irritation
Nausea
• Individuals with decreased respiratory reserve (e.g.,
history of COPD or CHF) are likely to experience an
exacerbation of the disease
© 2011 Seattle / King County EMS
Inhalation Injuries
Patient in respiratory distress:
• Treat immediately with high flow oxygen
• Assist breathing with a BVM if the respiratory
effort is insufficient
– Indicated by a slow rate & poor air exchange
© 2011 Seattle / King County EMS
Pneumonia
• Symptoms include:
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Fever
Chills
Cough (often with yellowish sputum)
Shortness of breath
General discomfort
Fatigue
Loss of appetite
Headache
• Can be chest pain associated with breathing (usually sharp and
stabbing in nature) and worsened by coughing or deep
inspirations
• Other signs sometimes present are rales, clammy skin, upper
abdominal pain & blood-tinged sputum
• Emergency care – may include oxygen therapy.
© 2011 Seattle / King County EMS
Pneumothorax
• Presence of air in pleural
space
• Caused when internal or
external wound allows air
to enter space between
pleural tissues
– Causes collapse of lung
• Cause sharp chest pain
& shortness of breath
– May be able to feel
subcutaneous air & breath
sounds will be diminished
© 2011 Seattle / King County EMS
Pneumothorax
• Treatment of pneumothorax includes highflow oxygen
• Be judicious with use of positive-pressure
ventilation
– Can turn a spontaneous pneumothorax into a lifethreatening tension pneumothorax.
A pneumothorax can cause collapse of the entire
lung. The only symptom may be sudden chest pain.
© 2011 Seattle / King County EMS
Pneumothorax
• Under normal conditions
no air between these
layers of pleura because
sealed together
• Air or blood can enter
space
– Example when hole is
punctured in chest wall by
gunshot or stab wound
© 2011 Seattle / King County EMS
• Can occur spontaneously
– Rupture due to disease or
localized weakness of the
lung lining
– Result of trauma
– Forceful coughing
• Chest injury and prior
history of pneumothorax
possible medical histories
• COPD – risk factor
Tension Pneumothorax
• Progressively worsening
pneumothorax – begins to
impinge on function of lungs &
circulatory system
• Caused when lung injury acts
like one-way valve that allows
free air to move into pleural
space
– Prevents free exit of that air
• Pressure builds inside pleural
space & compresses lungs &
other organs
© 2011 Seattle / King County EMS
Early signs of a tension
pneumothorax include:
• Increased dyspnea
• Cyanosis
• Signs of shock
• Distended neck veins
• Shift in PMI (Point of
maximum intensity, where
heart is loudest through
auscultation)
• Tracheal displacement
• Tracheal deviation
Pulmonary Embolism
• Particle such as blood clot, fat embolus,
amniotic fluid embolus or air bubble gets
loose in blood stream
• Travels to the lungs
• Embolus lodges in major branch of
pulmonary artery
• Circulation through large portion of lung is
interrupted
• Blood not able to reach alveoli & it cannot be
oxygenated
© 2011 Seattle / King County EMS
Pulmonary Embolism
• Causes include:
– Immobility of the lower
extremities
– Prolonged bed rest
– Recent surgery
• Signs of PE:
– Sudden-onset of:
– Shortness of breath
– Tachypnea
– Chest pain worsened by
breathing
– Coughing up blood
© 2011 Seattle / King County EMS
• Pulmonary embolism –
life-threatening condition
– Treated with high flow
oxygen
– Rapid transport
• Move patient gently to
avoid dislodging additional
emboli
PATIENT CARE
© 2011 Seattle / King County EMS
Assessment of Respiratory Status
• Assess rate & depth of respirations
• Normal rate is between 12 & 20 respirations
per minute for adult
• Depth of respirations more subjective &
varies from shallow, normal, labored or
gasping
• Together rate & depth will tell whether tidal
volume is adequate.
© 2011 Seattle / King County EMS
Assessment of Respiratory Status
Other signs that indicate adequate oxygen
supply to body’s tissues:
• Level of consciousness
• Breathing effort
• Ability to speak in complete sentences
• Use of accessory muscles
• Skin color
• Breath sounds
• Body position
© 2011 Seattle / King County EMS
Irregular Breathing Patterns
• Caused by specific conditions:
– Example: Cheyne-Stokes respirations
• May be seen in head injuries & stroke
• Characterized by periods of breathing with gradually increasing
& decreasing of tidal volume interspersed with periods of no
breathing
• Ataxic respirations – irregular, ineffective respirations
with no clear pattern
• Agonal respirations – abnormal pattern of breathing
characterized by ineffective, slow inspirations
followed by long pauses
– Often sound like gasps
– Associated with cardiac arrest or severe end-stage shock
© 2011 Seattle / King County EMS
Auscultation of Breath Sounds
Proper technique for auscultating chest using a
stethoscope includes:
• Listen at six locations on the back
• Listen at four locations on the front
• Instruct the patient to take a deep breath through
the mouth then exhale
• Listen to one or two inspiration/expiration cycles per
location
• Avoid listening through clothing
Video demonstration available at
EMS Online:
http://www.emsonline.net/resp2011/
auscultation.asp
© 2011 Seattle / King County EMS
Auscultation of Breath Sounds
• Changing airflow patterns inside lungs
produce normal breath sounds
• Make a "swishing" sound as one breathes in
or out
• Absent breath sounds can indicate apnea,
pneumothorax, hemothorax or lung removal
EMTs must be able to distinguish normal breath
sounds from abnormal breath sounds.
© 2011 Seattle / King County EMS
Airway Management
• Very important skills for EMS provider
• Well versed in the following airway management
techniques:
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Head tilt/chin lift
Jaw thrust
Patient positioning
Airway adjuncts
Suction
Oxygen therapy
Assisted ventilation
Relief of foreign body airway obstruction
© 2011 Seattle / King County EMS
Suction
• Purpose of suction –remove vomit, blood,
excretions & other matter from airway
• Guidelines to use for suctioning:
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Measure tip from corner of mouth to earlobe
Oxygenate patient well (if situation permits)
Insert tip into oral cavity without applying suction
Move suction tip side–to-side
Oxygenate well after suctioning
© 2011 Seattle / King County EMS
Tips for Effective Suctioning
• Measure tip same as for an
oropharyngeal airway—from corner
of mouth to ear lobe or from
center of mouth to angle of jaw
• Insert tip only to base of tongue
• If situation permits (e.g., there is
no significant airway threat), give
at least 30 seconds of oxygen
before suctioning
• Administer oxygen after
suctioning & consider assisting
ventilations with a bag-valve mask
to help provide extra oxygen
• Do not apply suction while
inserting tip – can rob airway of
oxygen.
© 2011 Seattle / King County EMS
• Apply suction for no more than
15 seconds at a time
• In rare cases, copious vomiting
that threatens airway may require
more suctioning
• In infants & children, suction for
shorter periods of time (e.g., no
more than 5 seconds)
• If there are secretions or emesis
that you cannot easily remove with
suction, position patient, (e.g., by
using log roll) so gravity & a finger
sweep can quickly clear the airway
Assisted Ventilation
• Patients who lack oxygen – must take quick
action to improve depth & rate of
respirations
• Bag-valve mask (BVM) – useful tool for
improving ventilation & acid-base (pH)
balance
• Proper technique for assisting ventilation with
a BVM is as follows:
© 2011 Seattle / King County EMS
Assisted Ventilation
Unconscious breathing
patient:
Non-breathing patient:
• Consider need for an
oropharyngeal airway*
• Do not over-ventilate
• Keep the airway open
• Maintain a good seal
• Apply the Sellick maneuver which
can help reduce airflow into the
stomach
• Deliver a ventilation of 1-second
duration
• Deliver enough volume to make
the chest rise
• 12 ventilations/min
• 8-10 ventilations/min if an
advanced airway is in place
*Follow local protocols
Video demonstration available at
EMS Online:
http://www.emsonline.net/resp2011/
ventilation.asp
© 2011 Seattle / King County EMS
Oxygen Delivery
Amount of oxygen administered patient & method of
administration depend on many factors including
medical history & cause of respiratory problem
Rate
Volume (liters/min) Device
Low Flow
2-6
Nasal cannula or blow
by
High Flow
10 - 15
Non-rebreathing mask
High flow with
ventilation
15 +
Bag-valve mask with
reservoir
Video demonstration available at EMS Online:
http://www.emsonline.net/resp2011/therapy.
asp
© 2011 Seattle / King County EMS
Case Studies
Video Care Study #1
http://www.emsonline.net/resp2011/vcase1.asp
Video Care Study #2
http://www.emsonline.net/resp2011/vcase2.asp
© 2011 Seattle / King County EMS
Summary
Main structures of the respiratory system are:
• Pharynx
• Trachea
• Epiglottis
• Alveoli
• Bronchi
• Bronchioles
• Larynx
• Pleura
• Diaphragm
© 2011 Seattle / King County EMS
Summary
• Respiratory system – important mechanism for
regulating pH in body
– Respiration impaired, carbon dioxide builds up in blood
(hypercarbia) and produces an acid
– BLS providers can help treat this condition by improving
ventilation
• Signs of severe airway obstruction include poor air
exchange and increased breathing difficulty
• Persons with COPD-related emergency may present
with shortness of breath, fever & increased sputum
production
• Signs of congestive heart failure may include an
acute onset of breathing difficulty, diaphoresis &
cyanosis
© 2011 Seattle / King County EMS
Summary
• Pneumothorax can cause sharp chest pain &
shortness of breath
• Signs of pulmonary embolism include a sudden onset
of shortness of breath, tachypnea, chest pain
worsened by breathing & coughing up blood
• Treatment for respiratory emergency can include
high flow oxygen and, in case of decreased
respiratory drive, assisted ventilations
• CHF patients may require positive-pressure
ventilations
© 2011 Seattle / King County EMS
Summary
Proper technique for auscultating the chest includes:
• Listen at six locations on the back
• Listen at four locations on the front
• Move from bottom to top in a medical patient
• Instruct the patient to take a deep breath through
the mouth then exhale
• Listen to one or two inspiration/expiration cycles per
location
• Avoid listening through clothing
© 2011 Seattle / King County EMS
Summary
Guidelines for use of suction include:
• Measure the tip from corner of mouth to
earlobe
• Oxygenate the patient well (if the situation
permits)
• Insert the tip into the oral cavity without
applying suction
• Move the suction tip side to side
• Oxygenate well after suctioning
© 2011 Seattle / King County EMS
Summary
Key points for ventilating an unconscious
breathing patient are:
• Consider oropharyngeal airway
• Do not over-ventilate
• Keep the airway open
• Maintain a good seal
• Apply the Sellick maneuver which can help
reduce airflow into the stomach
© 2011 Seattle / King County EMS
Questions
EMS Online
Guidelines and Standing Orders
http://www.emsonline.net/downloads.asp
Susan Kolwitz
Program Manager
Email support: [email protected]
Dr. Mickey Eisenberg
Medical Director
Ask the Doc: http://www.emsonline.net/doc.asp
© 2011 Seattle / King County EMS