Respiratory EmergenciesRespiratory Emergencies

A Comprehensive LookA Comprehensive Look

Respiratory system Respiratory system

• Provided for the passage of O2 to Provided for the passage of O2 to enterenter

• Necessary for energy production and Necessary for energy production and for for

• CO2 to exit CO2 to exit

• Waste product of body’s metabolism.Waste product of body’s metabolism.

Upper airway Upper airway

• Mouth and nose to larynxMouth and nose to larynx

• Nasopharynx: Tonsils, uvulaNasopharynx: Tonsils, uvula

• Oropharynx: TongueOropharynx: Tongue

• UvulaUvula

composed of connective tissue composed of connective tissue containing a number of racemose containing a number of racemose glands, and some muscular fibersglands, and some muscular fibers

Lower AirwayLower Airway

• Below the larynx to the alveoliBelow the larynx to the alveoli

PharynxPharynx

• Muscular tubeMuscular tube

• Extends vertically from back of the Extends vertically from back of the soft palate to superior aspect of the soft palate to superior aspect of the esophagusesophagus

• Allows air to flow in and out of the Allows air to flow in and out of the respiratory tract and food to pass into respiratory tract and food to pass into the digestive tractthe digestive tract

LarynxLarynx

• Joins the pharynx with the tracheaJoins the pharynx with the trachea

• Consists of the thyroid and cricoid Consists of the thyroid and cricoid cartilage, glottic opening, vocal cartilage, glottic opening, vocal cords, cricothyroid membrane.cords, cricothyroid membrane.

Trachea: Trachea:

• 10 to 12 centimeter long tube that connects 10 to 12 centimeter long tube that connects the larynx to the two mainstem bronchi. the larynx to the two mainstem bronchi.

• Lined with respiratory epithelium containing Lined with respiratory epithelium containing cilia and mucous producing cells. cilia and mucous producing cells.

• Mucous traps particles that the upper airway Mucous traps particles that the upper airway did not filter.did not filter.

• Cilia move the trapped particles up into the Cilia move the trapped particles up into the mouth where it is expelled or swallowed.mouth where it is expelled or swallowed.

Bronchi: Bronchi: • At the carina bifurcates into the right a left mainstem At the carina bifurcates into the right a left mainstem

bronchi.bronchi.AlveoliAlveoli• Bronchioles divide into the alveolar ducts and terminates Bronchioles divide into the alveolar ducts and terminates

into the alveoliinto the alveoli• Comprise the key functional unit of the respiratory systemComprise the key functional unit of the respiratory system• Contain an alveolar membrane that is only 2 cells thickContain an alveolar membrane that is only 2 cells thick• Most CO2 and O2 exchange takes placeMost CO2 and O2 exchange takes place• Become thinner as they expandBecome thinner as they expand• Surface area totals more than 20 square meters, enough to Surface area totals more than 20 square meters, enough to

cover half a tennis courtcover half a tennis court• The hollow structure resists collapse due to the presence of The hollow structure resists collapse due to the presence of

a surfactant, a chemical that decreases their surface tension a surfactant, a chemical that decreases their surface tension and makes it easier for them to expand.and makes it easier for them to expand.

Atelectasis Atelectasis • Aveolar collapseAveolar collapseLung ParenchymaLung Parenchyma• Parenchyma: Principal or essential Parenchyma: Principal or essential

parts of an organparts of an organ• Organized into the lobesOrganized into the lobes• Right lung has three lobes where as the Right lung has three lobes where as the

left lung has only two as it shares left lung has only two as it shares thoracic space with the heart.thoracic space with the heart.

PleuraPleura

• Membranous connective tissue that Membranous connective tissue that covers the lungscovers the lungs

• Visceral: Envelopes the lungs and Visceral: Envelopes the lungs and does not contain nerve tissuedoes not contain nerve tissue

• Parietal: Lines the Thoracic cavity Parietal: Lines the Thoracic cavity and contains nerve fibersand contains nerve fibers

RESPIRATION AND VENTILATIONRESPIRATION AND VENTILATION• Ventilation: The mechanical process that moves Ventilation: The mechanical process that moves

air into and out of the lungsair into and out of the lungs• Pulmonary or external respiration: AlveoliPulmonary or external respiration: Alveoli• Cellular or internal respiration occurs in the Cellular or internal respiration occurs in the

peripheral capillaries It is the exchange of peripheral capillaries It is the exchange of respiratory gases between the RBCs and various respiratory gases between the RBCs and various body tissuesbody tissues

• Cellular respiration in the peripheral tissue Cellular respiration in the peripheral tissue produces CO2 which is picked up by the blood in produces CO2 which is picked up by the blood in the capillaries and transports it as bicarbonate ions the capillaries and transports it as bicarbonate ions through the venous system to the lungs.through the venous system to the lungs.

RESPIRATORY CYCLERESPIRATORY CYCLE• Nothing within the lung parenchyma makes it Nothing within the lung parenchyma makes it

contract or expandcontract or expand• Ventilation depends upon changes of pressure within Ventilation depends upon changes of pressure within

the thoracic cavitythe thoracic cavity• Begins when the lungs have achieved a normal Begins when the lungs have achieved a normal

expiration and the pressure inside the thoracic cavity expiration and the pressure inside the thoracic cavity is equal to the atmospheric pressureis equal to the atmospheric pressure

• Respiratory centers in the brain communicate with Respiratory centers in the brain communicate with the diaphragm by way of the phrenic nerve, signaling the diaphragm by way of the phrenic nerve, signaling it to contract. This initiates the respiratory cycleit to contract. This initiates the respiratory cycle

Then……….Then……….

• Thorax increases; pressure within Thorax increases; pressure within decreases; becomes lower than atmospheric decreases; becomes lower than atmospheric pressure; with the negative pressure, air pressure; with the negative pressure, air rushes in; the alveoli inflate with the lungs, rushes in; the alveoli inflate with the lungs, becoming thinner allowing oxygen and CO2 becoming thinner allowing oxygen and CO2 to diffuse across their membranes.to diffuse across their membranes.

• When the pressure in the thoracic cavity is When the pressure in the thoracic cavity is again that of the atmospheric pressure, the again that of the atmospheric pressure, the alveoli are maximally inflated.alveoli are maximally inflated.

• Pulmonary expansion stimulates Pulmonary expansion stimulates microscopic stretch receptors in the bronchi microscopic stretch receptors in the bronchi and bronchioles that signal the respiratory and bronchioles that signal the respiratory center by way of the vegus nerve to inhibit center by way of the vegus nerve to inhibit respiration and the influx of air stops.respiration and the influx of air stops.

At the end of respiration:At the end of respiration:• Respiratory muscles relaxRespiratory muscles relax• Size of the chest cavity decreasesSize of the chest cavity decreases• Elastic lungs recoil forcing air out of the Elastic lungs recoil forcing air out of the

lungs (expiration)lungs (expiration)

• Expiration is passiveExpiration is passive

• Respiration is active process using Respiration is active process using energyenergy

Use of Accessory muscles: Use of Accessory muscles:

• Strap muscles of the neck, and Strap muscles of the neck, and abdominal muscles to augment abdominal muscles to augment efforts to expand the thoracic cavity efforts to expand the thoracic cavity

Pulmonary CirculationPulmonary Circulation

• During each cardiac cycle, the heart During each cardiac cycle, the heart pumps just as much blood to the lungs pumps just as much blood to the lungs as it does to the peripheral tissues.as it does to the peripheral tissues.

• Bronchial arteries that branch from the Bronchial arteries that branch from the aorta supply most of their blood.aorta supply most of their blood.

• Bronchial veins return blood from the Bronchial veins return blood from the lungs to the superior vena cava.lungs to the superior vena cava.

• Hypoventilation: Reduction in Hypoventilation: Reduction in breathing rate and depthbreathing rate and depth

• Pneumothorax: Air or gas in the Pneumothorax: Air or gas in the pleural cavitypleural cavity

• Hemothorax: Accumulation of blood Hemothorax: Accumulation of blood or fluid containing blood in the or fluid containing blood in the pleural cavitypleural cavity

• Pulmonary embolism: Blood clot that Pulmonary embolism: Blood clot that travels to the pulmonary circulation travels to the pulmonary circulation and hinders oxygenation of bloodand hinders oxygenation of blood

Hypoxic DriveHypoxic Drive• The body constantly monitors the PaO2 and The body constantly monitors the PaO2 and

the pH.the pH.• COPDCOPD• Chronically elevated PaCO2Chronically elevated PaCO2• Body no longer uses PaCO2 levels to stimulate Body no longer uses PaCO2 levels to stimulate

breathingbreathing• Hypoxic drive increases respiratory stimulation Hypoxic drive increases respiratory stimulation

when PaO2 level falls and inhibits respiratory when PaO2 level falls and inhibits respiratory stimulation when PaO2 levels increase.stimulation when PaO2 levels increase.

• Hypoxemia: Decreases partial Hypoxemia: Decreases partial pressure of oxygen in the bloodpressure of oxygen in the blood

• Respiratory Acidosis: Retention of Respiratory Acidosis: Retention of CO2 can result from impaired CO2 can result from impaired ventilation due to problems occurring ventilation due to problems occurring in either the lungs or in the in either the lungs or in the respiratory center of the brain.respiratory center of the brain.

• Respiratory Alkalosis results from Respiratory Alkalosis results from increased respiration and excessive increased respiration and excessive elimination of CO2.elimination of CO2.

MEASURES OF RESPIRATORY FUNCTIONMEASURES OF RESPIRATORY FUNCTION• Respiratory rate:Respiratory rate:• AdultsAdults 12 12 to to 2020• ChildrenChildren 1818 toto 2424• InfantsInfants 4040 toto 6060Eupnea: Normal RespirationEupnea: Normal Respiration• FeverFever IncreasesIncreases• EmotionEmotion IncreasesIncreases• PainPain IncreasesIncreases• HypoxiaHypoxia IncreasesIncreases• AcidosisAcidosis IncreasesIncreases• Stimulant DrugsStimulant Drugs IncreasesIncreases• Depressant DrugsDepressant Drugs DecreasesDecreases• SleepSleep DecreasesDecreases

Total Lung CapacityTotal Lung Capacity• Total amount of air contained in the lung at the end of the Total amount of air contained in the lung at the end of the

maximal respirationmaximal respiration• 6L6LTidal VolumeTidal Volume• Average volume of gas inhaled or exhaled in one respiratory Average volume of gas inhaled or exhaled in one respiratory

cyclecycle• 500 mL (5 to 7 cc/kg)500 mL (5 to 7 cc/kg)Dead Space VolumeDead Space VolumeThe amount of gas in the tidal volume that remains in the airThe amount of gas in the tidal volume that remains in the airpassageways unavailable for gas exchange.passageways unavailable for gas exchange.• Anatomic dead space includes the trachea and bronchiAnatomic dead space includes the trachea and bronchi• Physiologic dead space from COPD, obstruction or atelactesisPhysiologic dead space from COPD, obstruction or atelactesis• 150 ml150 ml

Minute VolumeMinute Volume

• Amount of gas moved in and out of the Amount of gas moved in and out of the respiratory tract in one minuterespiratory tract in one minute

• Vmin = VT x Respiratory RateVmin = VT x Respiratory Rate

• Alveolar Minute VolumeAlveolar Minute Volume

• Amount of gas that reaches the alveoli Amount of gas that reaches the alveoli for gas exchange in one minutefor gas exchange in one minute

• VA-min = (VT – VD) X Respiratory rateVA-min = (VT – VD) X Respiratory rate

RESPIRATORY PROBLEMSRESPIRATORY PROBLEMS

• Dyspnea: An abnormality of Dyspnea: An abnormality of breathing rate, pattern, or effortbreathing rate, pattern, or effort

• Hypoxia: Oxygen deficiencyHypoxia: Oxygen deficiency

• Anoxia: The absence or near-Anoxia: The absence or near-absence of oxygenabsence of oxygen

Modified forms of respirationModified forms of respiration• Coughing: forceful exhalation of a large volume of air form Coughing: forceful exhalation of a large volume of air form

the lungs, expelling foreign materials from the lungsthe lungs, expelling foreign materials from the lungs• Sneezing: Sudden forceful exhalation from the nose. Nasal Sneezing: Sudden forceful exhalation from the nose. Nasal

irritationirritation• Hiccoughing: Sudden inspiration; caused by spasmodic Hiccoughing: Sudden inspiration; caused by spasmodic

contraction of the diaphragm with spasmodic closure of the contraction of the diaphragm with spasmodic closure of the glottis. No physiologic purpose. Occasionally been glottis. No physiologic purpose. Occasionally been associated with MI on the inferior (diaphragmatic) surface of associated with MI on the inferior (diaphragmatic) surface of the heartthe heart

• Sighing: Slow, deep, involuntary inspiration followed by a Sighing: Slow, deep, involuntary inspiration followed by a prolonged expiration; hyperventilates the lungs and prolonged expiration; hyperventilates the lungs and reexpands atlectatic alveoli; occurs once a minutereexpands atlectatic alveoli; occurs once a minute

• Grunting: Forceful expiration; occurs against a partially Grunting: Forceful expiration; occurs against a partially closed epiglottis; usually an indication of respiratory closed epiglottis; usually an indication of respiratory distress.distress.

Accessory Respiratory Muscles:Accessory Respiratory Muscles:• IntercostalIntercostal• SuprasternalSuprasternal• SupraclavicularSupraclavicular• Subcostal retractionsSubcostal retractions• Abdominal musclesAbdominal muscles• In InfantsIn Infants• Nasal flaringNasal flaring• GruntingGrunting

• COPDCOPD

Purse their lipsPurse their lips

Pulsus ParadoxusPulsus Paradoxus

Comparison of blood pressure between that ofComparison of blood pressure between that of

inspiration and that of exhalationinspiration and that of exhalation

• A drop in blood pressure greater than 10 torrA drop in blood pressure greater than 10 torr

• Drop in blood pressure during inspirationDrop in blood pressure during inspiration

• Drop is due to increased pressure in the Drop is due to increased pressure in the thoracic cavity that impairs the inability of thoracic cavity that impairs the inability of the the

• ventricles to fill.ventricles to fill.

ABNORMAL RESPIRATORY PATTERNSABNORMAL RESPIRATORY PATTERNSKusssmaul’s RespirationsKusssmaul’s Respirations• Deep, slow or rapid, gasping breathing, Deep, slow or rapid, gasping breathing, • Commonly found in diabetic ketoacidosisCommonly found in diabetic ketoacidosisCheyne-Stokes RespirationsCheyne-Stokes Respirations• Progressively deeper, faster breathing alternating Progressively deeper, faster breathing alternating

gradually with shallow, slower breathing.gradually with shallow, slower breathing.• Indicates brain-stem injuryIndicates brain-stem injuryBiot’s RespirationsBiot’s Respirations• Irregular pattern of rate and depth with sudden, Irregular pattern of rate and depth with sudden,

periodic episodes of apneaperiodic episodes of apnea• Indicates increased intracranial pressureIndicates increased intracranial pressure

Central Neurogenic hyperventilationCentral Neurogenic hyperventilation

• Deep, rapid respirationsDeep, rapid respirations

• Indicates increased intracranial Indicates increased intracranial pressurepressure

Agonal RespirationsAgonal Respirations

• Shallow, slow, or infrequent Shallow, slow, or infrequent breathingbreathing

• Indicates brain anoxiaIndicates brain anoxia

• Rales: Fine, bubbling sound; on Rales: Fine, bubbling sound; on inspiration; fluid in smaller bronchiolesinspiration; fluid in smaller bronchioles

• Rhonchi; Course, rattling noise on Rhonchi; Course, rattling noise on inspiration; associated with inflammation, inspiration; associated with inflammation, mucous or fluid in the bronchiolesmucous or fluid in the bronchioles

• Stridor: Harsh, high-pitched heard on Stridor: Harsh, high-pitched heard on inhalation; laryngeal edema or constrictioninhalation; laryngeal edema or constriction

• Snoring: Partial obstruction of the upper Snoring: Partial obstruction of the upper airway by the tongueairway by the tongue

• Gurgling: Accumulation of blood, vomitus, Gurgling: Accumulation of blood, vomitus, or other secretions in the upper airwayor other secretions in the upper airway

Tension PnuemothoraxTension Pnuemothorax• Any tear in the lung parenchyma can cause a Any tear in the lung parenchyma can cause a

pneumothorax. pneumothorax. • Tension: Large pneumothorax that affects other Tension: Large pneumothorax that affects other

structures in the cheststructures in the chest• Progressively worsening compliance when baggingProgressively worsening compliance when bagging• Diminished unilateral breath soundsDiminished unilateral breath sounds• Hypoxia with hypotensionHypoxia with hypotension• Distended neck veinsDistended neck veins• Marked increase in pressure can prevent ventricles Marked increase in pressure can prevent ventricles

from adequately filling decreasing cardiac outputfrom adequately filling decreasing cardiac output• Tracheal deviationTracheal deviation

Tachypnea/BradypneaTachypnea/Bradypnea

• Respiratory effort: How hard a Respiratory effort: How hard a patient has to work to breathepatient has to work to breathe

• Orthopnea: Difficulty breathing while Orthopnea: Difficulty breathing while lying supinelying supine

HypothermiaHypothermia• Combines the mechanisms of convection, Combines the mechanisms of convection,

radiation, and evaporationradiation, and evaporation• Accounts for a large proportion of the body’s Accounts for a large proportion of the body’s

heat lossheat loss• Heat is transferred to from the lungs to Heat is transferred to from the lungs to

inspired air by convection and radiationinspired air by convection and radiation• Evaporation in the lungs humidifies the Evaporation in the lungs humidifies the

inspired air.inspired air.• During expiration, warm humidified air is During expiration, warm humidified air is

released into the environment, creating heat released into the environment, creating heat lossloss

Respiratory ShockRespiratory Shock• Respiratory system is not able to bring Respiratory system is not able to bring

oxygen into the alveoli and remove CO2oxygen into the alveoli and remove CO2• Blood leaves the pulmonary circulation Blood leaves the pulmonary circulation

without adequate oxygen and with an without adequate oxygen and with an excess of excess of

• CO2CO2• The cells become hypoxic while the The cells become hypoxic while the

bloodstream becomes acidicbloodstream becomes acidic

RESPIRATORY CONTROLRESPIRATORY CONTROL• Respiratory centers within the brainstem control Respiratory centers within the brainstem control

respirationrespiration• Inspiration and expiration occur automatically and Inspiration and expiration occur automatically and

are triggered by impulses generated in the are triggered by impulses generated in the respiratory center of the medulla oblongata during respiratory center of the medulla oblongata during normal respiration normal respiration

• The medullary respiratory system contains The medullary respiratory system contains chemoreceptors that respond to changes in the CO2 chemoreceptors that respond to changes in the CO2 and pH levels in the CSFand pH levels in the CSF

• CO2 rapidly diffuses across the blood-brain barrier in CO2 rapidly diffuses across the blood-brain barrier in to the CSF while H+ and bicarbonate ions do not.to the CSF while H+ and bicarbonate ions do not.

Two Respiratory Centers in the PonsTwo Respiratory Centers in the PonsApneusticApneustic• Located in the lower ponsLocated in the lower pons• Acts as a shut-off switch to inspirationActs as a shut-off switch to inspiration• If non-functional, prolonged inspiration interrupted by occasional If non-functional, prolonged inspiration interrupted by occasional

expirationexpirationPneumotaxic CenterPneumotaxic Center• Located in the upper ponsLocated in the upper pons• Moderates the activity of the apneustic center and provide fine tuningModerates the activity of the apneustic center and provide fine tuningMedulla OblongataMedulla Oblongata• CO2 receptorsCO2 receptorsInternal Carotid ArteriesInternal Carotid Arteries• CO2, O2 and B/P receptorsCO2, O2 and B/P receptorsAortaAorta• CO2, O2 and B/P receptorsCO2, O2 and B/P receptorsLungsLungs• Stretch receptorsStretch receptors

PonsPons

• Modifies rate and depth of breathingModifies rate and depth of breathing

Medulla OblongataMedulla Oblongata

• Sets basic rate and depth of Sets basic rate and depth of breathingbreathing

Nasal CanulaeNasal Canulae

• 4 to 6 liters per minute4 to 6 liters per minute

• 22 to 44% oxygen22 to 44% oxygen

Non-rebreatherNon-rebreather

• 10 to 15 liters per minute10 to 15 liters per minute

• 80 to 100% oxygen80 to 100% oxygen

• Inhaler: BronchodilatorInhaler: Bronchodilator

• Inhaler: Stimulation of the Inhaler: Stimulation of the Sympathetic Nervous SystemSympathetic Nervous System

• One metered doseOne metered dose

• InhalerInhaler

purse lips around inhalerpurse lips around inhaler

depress inhaler as patient depress inhaler as patient inhales inhales deeplydeeply

Patient hold their breath for a Patient hold their breath for a few secondsfew seconds

• Inhaler: Breathing difficulties with Inhaler: Breathing difficulties with history history of COPD/Asthma of COPD/Asthma

• InhalerInhaler

The patient is not responsive The patient is not responsive enoughenough

The maximum dose has been The maximum dose has been takentaken