Transcript Respiratory Emergencies

Respiratory Emergencies
A Comprehensive Look
Respiratory system
• Provided for the passage of O2 to enter
• Necessary for energy production and for
• CO2 to exit
• Waste product of body’s metabolism.
Upper airway
• Mouth and nose to larynx
• Nasopharynx: Tonsils, uvula
• Oropharynx: Tongue
• Uvula
composed of connective tissue containing a
number of racemose glands, and some
muscular fibers
Lower Airway
• Below the larynx to the alveoli
Pharynx
• Muscular tube
• Extends vertically from back of the soft
palate to superior aspect of the esophagus
• Allows air to flow in and out of the
respiratory tract and food to pass into the
digestive tract
Larynx
• Joins the pharynx with the trachea
• Consists of the thyroid and cricoid
cartilage, glottic opening, vocal cords,
cricothyroid membrane.
Trachea:
• 10 to 12 centimeter long tube that connects the
larynx to the two mainstem bronchi.
• Lined with respiratory epithelium containing cilia
and mucous producing cells.
• Mucous traps particles that the upper airway did
not filter.
• Cilia move the trapped particles up into the
mouth where it is expelled or swallowed.
Bronchi:
• At the carina bifurcates into the right a left mainstem bronchi.
Alveoli
• Bronchioles divide into the alveolar ducts and terminates into the
alveoli
• Comprise the key functional unit of the respiratory system
• Contain an alveolar membrane that is only 2 cells thick
• Most CO2 and O2 exchange takes place
• Become thinner as they expand
• Surface area totals more than 20 square meters, enough to cover
half a tennis court
• The hollow structure resists collapse due to the presence of a
surfactant, a chemical that decreases their surface tension and
makes it easier for them to expand.
Atelectasis
• Aveolar collapse
Lung Parenchyma
• Parenchyma: Principal or essential parts
of an organ
• Organized into the lobes
• Right lung has three lobes where as the
left lung has only two as it shares thoracic
space with the heart.
Pleura
• Membranous connective tissue that covers
the lungs
• Visceral: Envelopes the lungs and does
not contain nerve tissue
• Parietal: Lines the Thoracic cavity and
contains nerve fibers
RESPIRATION AND VENTILATION
• Ventilation: The mechanical process that moves air into
and out of the lungs
• Pulmonary or external respiration: Alveoli
• Cellular or internal respiration occurs in the peripheral
capillaries It is the exchange of respiratory gases
between the RBCs and various body tissues
• Cellular respiration in the peripheral tissue produces CO2
which is picked up by the blood in the capillaries and
transports it as bicarbonate ions through the venous
system to the lungs.
RESPIRATORY CYCLE
• Nothing within the lung parenchyma makes it contract or
expand
• Ventilation depends upon changes of pressure within the
thoracic cavity
• Begins when the lungs have achieved a normal
expiration and the pressure inside the thoracic cavity is
equal to the atmospheric pressure
• Respiratory centers in the brain communicate with the
diaphragm by way of the phrenic nerve, signaling it to
contract. This initiates the respiratory cycle
Then……….
• Thorax increases; pressure within decreases;
•
becomes lower than atmospheric pressure; with
the negative pressure, air rushes in; the alveoli
inflate with the lungs, becoming thinner allowing
oxygen and CO2 to diffuse across their
membranes.
When the pressure in the thoracic cavity is
again that of the atmospheric pressure, the
alveoli are maximally inflated.
• Pulmonary expansion stimulates microscopic
stretch receptors in the bronchi and bronchioles
that signal the respiratory center by way of the
vegus nerve to inhibit respiration and the influx
of air stops.
At the end of respiration:
• Respiratory muscles relax
• Size of the chest cavity decreases
• Elastic lungs recoil forcing air out of the lungs
(expiration)
• Expiration is passive
• Respiration is active process using energy
Use of Accessory muscles:
• Strap muscles of the neck, and abdominal
muscles to augment efforts to expand the
thoracic cavity
Pulmonary Circulation
• During each cardiac cycle, the heart
pumps just as much blood to the lungs as
it does to the peripheral tissues.
• Bronchial arteries that branch from the
aorta supply most of their blood.
• Bronchial veins return blood from the
lungs to the superior vena cava.
• Hypoventilation: Reduction in breathing
rate and depth
• Pneumothorax: Air or gas in the pleural
cavity
• Hemothorax: Accumulation of blood or
fluid containing blood in the pleural cavity
• Pulmonary embolism: Blood clot that
travels to the pulmonary circulation and
hinders oxygenation of blood
Hypoxic Drive
• The body constantly monitors the PaO2 and the
pH.
• COPD
• Chronically elevated PaCO2
• Body no longer uses PaCO2 levels to stimulate
breathing
• Hypoxic drive increases respiratory stimulation
when PaO2 level falls and inhibits respiratory
stimulation when PaO2 levels increase.
• Hypoxemia: Decreases partial pressure of
oxygen in the blood
• Respiratory Acidosis: Retention of CO2
can result from impaired ventilation due to
problems occurring in either the lungs or
in the respiratory center of the brain.
• Respiratory Alkalosis results from
increased respiration and excessive
elimination of CO2.
MEASURES OF RESPIRATORY FUNCTION
• Respiratory rate:
• Adults
12
to
20
• Children
18
to
24
• Infants
40
to
60
Eupnea: Normal Respiration
• Fever
Increases
• Emotion
Increases
• Pain
Increases
• Hypoxia
Increases
• Acidosis
Increases
• Stimulant Drugs
Increases
• Depressant Drugs
Decreases
• Sleep
Decreases
Total Lung Capacity
• Total amount of air contained in the lung at the end of the maximal
respiration
• 6L
Tidal Volume
• Average volume of gas inhaled or exhaled in one respiratory cycle
• 500 mL (5 to 7 cc/kg)
Dead Space Volume
The amount of gas in the tidal volume that remains in the air
passageways unavailable for gas exchange.
• Anatomic dead space includes the trachea and bronchi
• Physiologic dead space from COPD, obstruction or atelactesis
• 150 ml
Minute Volume
• Amount of gas moved in and out of the
respiratory tract in one minute
• Vmin = VT x Respiratory Rate
• Alveolar Minute Volume
• Amount of gas that reaches the alveoli for
gas exchange in one minute
• VA-min = (VT – VD) X Respiratory rate
RESPIRATORY PROBLEMS
• Dyspnea: An abnormality of breathing
rate, pattern, or effort
• Hypoxia: Oxygen deficiency
• Anoxia: The absence or near-absence of
oxygen
Modified forms of respiration
• Coughing: forceful exhalation of a large volume of air form the
lungs, expelling foreign materials from the lungs
• Sneezing: Sudden forceful exhalation from the nose. Nasal
irritation
• Hiccoughing: Sudden inspiration; caused by spasmodic contraction
of the diaphragm with spasmodic closure of the glottis. No
physiologic purpose. Occasionally been associated with MI on the
inferior (diaphragmatic) surface of the heart
• Sighing: Slow, deep, involuntary inspiration followed by a
prolonged expiration; hyperventilates the lungs and reexpands
atlectatic alveoli; occurs once a minute
• Grunting: Forceful expiration; occurs against a partially closed
epiglottis; usually an indication of respiratory distress.
Accessory Respiratory Muscles:
• Intercostal
• Suprasternal
• Supraclavicular
• Subcostal retractions
• Abdominal muscles
• In Infants
• Nasal flaring
• Grunting
• COPD
Purse their lips
Pulsus Paradoxus
Comparison of blood pressure between that of
inspiration and that of exhalation
• A drop in blood pressure greater than 10 torr
• Drop in blood pressure during inspiration
• Drop is due to increased pressure in the thoracic
cavity that impairs the inability of the
• ventricles to fill.
ABNORMAL RESPIRATORY PATTERNS
Kusssmaul’s Respirations
• Deep, slow or rapid, gasping breathing,
• Commonly found in diabetic ketoacidosis
Cheyne-Stokes Respirations
• Progressively deeper, faster breathing alternating
gradually with shallow, slower breathing.
• Indicates brain-stem injury
Biot’s Respirations
• Irregular pattern of rate and depth with sudden, periodic
episodes of apnea
• Indicates increased intracranial pressure
Central Neurogenic hyperventilation
• Deep, rapid respirations
• Indicates increased intracranial pressure
Agonal Respirations
• Shallow, slow, or infrequent breathing
• Indicates brain anoxia
• Rales: Fine, bubbling sound; on inspiration;
•
•
•
•
fluid in smaller bronchioles
Rhonchi; Course, rattling noise on inspiration;
associated with inflammation, mucous or fluid in
the bronchioles
Stridor: Harsh, high-pitched heard on
inhalation; laryngeal edema or constriction
Snoring: Partial obstruction of the upper airway
by the tongue
Gurgling: Accumulation of blood, vomitus, or
other secretions in the upper airway
Tension Pnuemothorax
• Any tear in the lung parenchyma can cause a
pneumothorax.
• Tension: Large pneumothorax that affects other
structures in the chest
• Progressively worsening compliance when bagging
• Diminished unilateral breath sounds
• Hypoxia with hypotension
• Distended neck veins
• Marked increase in pressure can prevent ventricles from
adequately filling decreasing cardiac output
• Tracheal deviation
Tachypnea/Bradypnea
• Respiratory effort: How hard a patient
has to work to breathe
• Orthopnea: Difficulty breathing while
lying supine
Hypothermia
• Combines the mechanisms of convection,
radiation, and evaporation
• Accounts for a large proportion of the body’s
heat loss
• Heat is transferred to from the lungs to inspired
air by convection and radiation
• Evaporation in the lungs humidifies the inspired
air.
• During expiration, warm humidified air is
released into the environment, creating heat loss
Respiratory Shock
• Respiratory system is not able to bring
oxygen into the alveoli and remove CO2
• Blood leaves the pulmonary circulation
without adequate oxygen and with an
excess of
• CO2
• The cells become hypoxic while the
bloodstream becomes acidic
RESPIRATORY CONTROL
• Respiratory centers within the brainstem control
respiration
• Inspiration and expiration occur automatically and are
triggered by impulses generated in the respiratory center
of the medulla oblongata during normal respiration
• The medullary respiratory system contains
chemoreceptors that respond to changes in the CO2 and
pH levels in the CSF
• CO2 rapidly diffuses across the blood-brain barrier in to
the CSF while H+ and bicarbonate ions do not.
Two Respiratory Centers in the Pons
Apneustic
• Located in the lower pons
• Acts as a shut-off switch to inspiration
• If non-functional, prolonged inspiration interrupted by occasional expiration
Pneumotaxic Center
• Located in the upper pons
• Moderates the activity of the apneustic center and provide fine tuning
Medulla Oblongata
• CO2 receptors
Internal Carotid Arteries
• CO2, O2 and B/P receptors
Aorta
• CO2, O2 and B/P receptors
Lungs
• Stretch receptors
Pons
• Modifies rate and depth of breathing
Medulla Oblongata
• Sets basic rate and depth of breathing
Nasal Canulae
• 4 to 6 liters per minute
• 22 to 44% oxygen
Non-rebreather
• 10 to 15 liters per minute
• 80 to 100% oxygen
• Inhaler: Bronchodilator
• Inhaler: Stimulation of the Sympathetic
Nervous System
• One metered dose
• Inhaler
purse lips around inhaler
depress inhaler as patient inhales
deeply
Patient hold their breath for a few
seconds
• Inhaler: Breathing difficulties with history
of COPD/Asthma
• Inhaler
The patient is not responsive enough
The maximum dose has been taken