Download Airway Management

Airway Management
Part 1
Prof. M.H. MUMTAZ
Topics for Discussion
Airway Maintenance Objectives
 Airway Anatomy & Physiology Review
 Causes of Respiratory Difficulty & Distress
 Assessing Respiratory Function
 Methods of Airway Management
 Methods of Ventilatory Management
 Common Out-of-Hospital Equipment Utilized
 Advanced Methods of Airway Management and
Ventilation
 Risks to the Paramedic

Objectives of Airway Management &
Ventilation

Primary Objective:
 Ensure
optimal ventilation
 Deliver
oxygen to blood
 Eliminate carbon dioxide (C02) from body

Definitions
is airway management?
 How does it differ from spontaneous, manual
or assisted ventilations?
 What
Objectives of Airway Management &
Ventilation

Why is this so important?
 Brain
death occurs rapidly; other tissue follows
 EMS providers can reduce additional
injury/disease by good airway, ventilation
techniques
 EMS providers often neglect BLS airway,
ventilation skills
Airway Anatomy Review
Upper Airway Anatomy
 Lower Airway Anatomy
 Lung Capacities/Volumes
 Pediatric Airway Differences

Anatomy
of the
Upper
Airway
Upper Airway Anatomy
Functions: warm, filter, humidify air
 Nasal cavity and nasopharynx

 Formed
by union of facial bones
 Nasal floor towards ear not eye
 Lined with mucous membranes, cilia
 Tissues are delicate, vascular
 Adenoids
 Lymph
tissue - filters bacteria
 Commonly infected
Upper Airway Anatomy

Oral cavity and oropharynx
 Teeth
 Tongue
 Attached
at mandible, hyoid bone
 Most common airway obstruction cause
 Palate
 Roof
of mouth
 Separates oropharynx and nasopharynx
 Anterior= hard palate; Posterior= soft palate
Upper Airway Anatomy

Oral cavity and oropharynx
 Tonsils
 Lymph
tissue - filters bacteria
 Commonly infected
 Epiglottis
 Leaf-like
structure
 Closes during swallowing
 Prevents aspiration
 Vallecula
 “Pocket”
formed by base of tongue, epiglottis
Upper Airway Anatomy
Upper Airway Anatomy

Sinuses



cavities formed by
cranial bones
act as tributaries for
fluid to, from
eustachian tubes,
tear ducts
trap bacteria,
commonly infected
Upper Airway Anatomy

Larynx
 Attached
to hyoid bone
 Horseshoe
shaped bone
 Supports trachea
 Thyroid
cartilage
 Largest
laryngeal cartilage
 Shield-shaped
 Cartilage anteriorly, smooth muscle posteriorly
 “Adam’s Apple”
 Glottic opening directly behind
Upper Airway Anatomy

Larynx
 Glottic
opening
 Adult
airway’s narrowest point
 Dependent on muscle tone
 Contains vocal bands
 Arytenoid
 Posterior
cartilage
attachment of vocal bands
Upper Airway Anatomy

Larynx
 Cricoid
ring
 First
tracheal ring
 Completely cartilaginous
 Compression (Sellick maneuver) occludes
esophagus
 Cricothyroid
 Membrane
membrane
between cricoid, thyroid cartilages
 Site for surgical, needle airway placement
Upper Airway Anatomy

Larynx and Trachea
 Associated
 Thyroid


arteries
branch across, lie closely alongside trachea
 Jugular

gland
below cricoid cartilage
lies across trachea, up both sides
 Carotid

Structures
veins
branch across and lie close to trachea
Upper Airway Anatomy
Upper Airway Anatomy

Pediatric vs Adult Upper Airway
 Larger
tongue in comparison to size of mouth
 Floppy epiglottis
 Delicate teeth, gums
 More superior larynx
 Funnel shaped larynx due to undeveloped
cricoid cartilage
 Narrowest point at cricoid ring before ~8
years old
Upper Airway Anatomy
From: CPEM, TRIPP, 1998
Upper Airway Anatomy
Glottic Opening
Lower Airway Anatomy

Function
 Exchange

O2 , CO2 with blood
Location
 From
glottic opening to alveolar-capillary
membrane
Lower Airway Anatomy

Trachea
 Bifurcates
(divides) at carina
 Right, left mainstem bronchi
 Right mainstem bronchus shorter, straighter
 Lined with mucous cells, beta-2 receptors
Lower Airway Anatomy

Bronchi
 Branch
into secondary, tertiary bronchi that
branch into bronchioles

Bronchioles
 No
cartilage in walls
 Small smooth muscle tubes
 Branch into alveolar ducts that end at alveolar
sacs
Lower Airway Anatomy

Alveoli
 “Balloon-like”
clusters
 Site of gas exchange
 Lined with surfactant
surface tension  eases expansion
  surfactant  atelectasis (focal collapse of
alveoli0
 Decreases
Lower Airway Anatomy

Lungs
 Right
lung = 3 lobes; Left lung = 2 lobes
 Parenchymal tissue
 Pleura
 Visceral
 Parietal
 Pleural
space
Lower Airway Anatomy
Lower Airway Anatomy

Occlusion of
bronchioles




Smooth muscle
contraction
(bronchospasm
Mucus plugs
Inflammatory edema
Foreign bodies
Lung Volumes/Capacities
Typical adult male total lung capacity = 6
liters
 Tidal Volume (VT)

 Gas
volume inhaled or exhaled during single
ventilatory cycle
 Usually 5-7 cc/kg (typically 500 cc)
Lung Volumes/Capacities

Dead Space Air (VD)
 Air
unavailable for gas exchange
Lung Volumes/Capacities

Dead Space Air (VD)
 Anatomic
dead space (~150cc)
 Trachea
 Bronchi
 Physiologic
dead space
 Shunting
 Pathological
 Formed
dead space
by factors like disease or obstruction
 Examples: COPD
Lung Volumes/Capacities

Alveolar Air (alveolar volume) [VA]
 Air
reaching alveoli for gas exchange
 Usually 350 cc
Lung Volumes/Capacities

Minute Volume [Vmin](minute ventilation)
 Amount
of gas moved in, out of respiratory
tract per minute
 Tidal volume X RR

Alveolar Minute Volume
 Amount
of gas moved in, out of alveoli per
minute
 (tidal volume - dead space volume) X RR
Lung Volumes/Capacities

Functional Reserve Capacity (FRC)
 After
optimal inspiration, amount of air that
can be forced from lungs in single exhalation
Lung Volumes/Capacities

Inspiratory Reserve Volume (IRV)
 Amount
of gas that can be inspired in
addition to tidal volume

Expiratory Reserve Volume (ERV)
 Amount
of gas that can be expired after
passive (relaxed) expiration
Lung Volumes/Capacities
Ventilation

Movement of air in, out of lungs

Control via:
 Respiratory
center in medulla
 Apneustic, pneumotaxic centers in pons
Ventilation

Inspiration
Stimulus from respiratory center of brain (medulla)
 Transmitted via phrenic nerve to diaphragm, spinal
cord/intercostal nerves to intercostal muscles
 Diaphragm contracts, flattens
 Intercostal muscles contract; ribs move up and out
 Air spaces in lungs stretch, increase in size
  intrapulmonic pressure (pressure gradient)
 Air flows into airways, alveoli inflate until pressure
equalizes

Ventilation

Expiration
Stretch receptors in lungs signal respiratory center
via vagus nerve to inhibit inspiration (Hering-Breuer
reflex)
 Natural elasticity of lungs pulls diaphragm, chest wall
to resting position
 Pulmonary air spaces decrease in size
 Intrapulmonary pressure rises
 Air flows out until pressure equalizes

Ventilation
Ventilation
Ventilation

Respiratory Drive
 Chemoreceptors
in medulla
 Stimulated  PaCO2 or  pH
 PaCO2 is normal neuroregulatory control of
ventilations

Hypoxic Drive
 Chemoreceptors
in aortic arch, carotid bodies
 Stimulated by  PaO2
 Back-up regulatory control
Ventilation

Other stimulants or depressants
 Body
temp: fever; hypothermia
 Drugs/meds: increase or decrease
 Pain: increases, but occasionally decreases
 Emotion: increases
 Acidosis: increases
 Sleep: decreases
Gas Measurements

Total Pressure
 Combined
pressure of all atmospheric gases
 760 mm Hg (torr) at sea level

Partial Pressure
 Pressure
exerted by each gas in a mixture
Gas Measurements

Partial Pressures
 Atmospheric
 Nitrogen
597.0 torr (78.62%); Oxygen 159.0 torr
(20.84%); Carbon Dioxide 0.3 torr (0.04%); Water
3.7 torr (0.5%)
 Alveolar
 Nitrogen
569.0 torr (74.9%); Oxygen 104.0 torr
(13.7%); CO2 40.0 torr (5.2%); Water 47.0 torr
(6.2%)
Respiration
Ventilation vs. Respiration
 Exchange of gases between living
organism, environment
 External Respiration

 Exchange

between lungs, blood cells
Internal Respiration
 Exchange
between blood cells, tissues
Respiration

How are O2, CO2 transported?
 Diffusion
 Movement
of gases along a concentration gradient
 Gases dissolve in water, pass through alveolar
membrane from areas of higher concentration to
areas of lower concentration
 FiO2
%
oxygen in inspired air expressed as a decimal
 FiO2 of room air = 0.21
Respiration

Blood Oxygen Content
 dissolved
O2 crosses capillary membrane,
binds to Hgb of RBC
 Transport = O2 bound to hemoglobin (97%)
or dissolved in plasma
 O2 Saturation
%
of hemoglobin saturated with oxygen (usually
carries >96% of total)
 O2 content divided by O2 carrying capacity
Respiration

Oxygen saturation affected by:
 Low
Hgb (anemia, hemorrhage)
 Inadequate oxygen availability at alveoli
 Poor diffusion across pulmonary membrane
(pneumonia, pulmonary edema, COPD)
 Ventilation/Perfusion (V/Q) mismatch
 Blood
moves past collapsed alveoli (shunting)
 Alveoli intact but blood flow impaired
Respiration

Blood Carbon Dioxide Content
 Byproduct
of work (cellular respiration)
 Transported as bicarbonate (HCO3 ion)
  20-30% bound to hemoglobin
 Pressure gradient causes CO2 diffusion into
alveoli from blood
 Increased level = hypercarbia
Respiration
Inspired Air: PO2 160 & PCO2 0.3
Alveoli PO2 100 & PCO2 40
PO2 40 & PCO2 46 - Pulmonary circulation - PO2 100 & PCO2 40
Deoxygenated
Heart
Oxygenated
PO2 40 & PCO2 46 - Systemic circulation - PO2 100 & PCO2 40
Tissue cell PO2 <40 & PCO2 >46
Diagnostic Testing
Pulse Oximetry
 Peak Expiratory Flow Testing
 Pulmonary Function Testing
 End-Tidal CO2 Monitoring
 Laboratory Testing of Blood

 Arterial
 Venous
Causes of Hypoxemia
Lower partial pressure of atmospheric O2
 Inadequate hemoglobin level in blood
 Hemoglobin bound by other gas (CO)
  pulmonary alveolar membrane distance
 Reduced surface area for gas exchange
 Decreased mechanical effort

Causes of Airway/Ventilatory Compromise

Airway Obstruction
 Tongue
 Foreign
body obstruction
 Anaphylaxis/angioedema
 Upper airway burn
 Maxillofacial/laryngeal/trachebronchial trauma
 Epiglottitis
 Croup
Obstruction

Tongue
 Most
common cause
 Snoring respirations
 Corrected by positioning
Foreign Body
Partial or Full
 Symptoms include

 Choking
 Gagging
 Stridor
 Dyspnea
 Aphonia
 Dysphonia
Laryngeal Spasm
Spasmatic closure of vocal cords
 Frequently caused by

 Overly
aggressive technique during intubation
 Immediately upon extubation
Laryngeal Edema

Causes
 Angioedema
 Anaphylaxis
 Upper
airway burns
 Epiglottitis
 Croup
 Trauma
Aspiration

Significantly increases mortality
 Obstructs
Airway
 Destroys bronchial tissue
 Introduces pathogens
 Decreases ability to ventilate
 Frequently occult
Obstructive Airway Disease

Obstructive airway disease
 Asthma
 Emphysema
 Chronic
Bronchitis
Gas Exchange Surface

Pulmonary edema



Left-sided heart failure
Toxic inhalation
Near drowning
Pneumonia
 Pulmonary embolism

Blood clots
 Amniotic fluid
 Fat embolism

Causes of Airway/Ventilatory Compromise

Thoracic Bellows
 Chest
 Fib
trauma
fractures
 Flail chest
 Pneumothorax
 Hemothorax
 Sucking chest wound
 Diaphragmatic hernia
Causes of Airway/Ventilatory Compromise

Thoracic Bellows
 Pleural
effusion
 Spinal cord trauma
 Morbid obesity (Pickwickian Syndrome)
 Neurological/neuromuscular disease
 Poliomyelitis
 Myasthenia
gravis
 Muscular dystrophy
 Gullian-Barre syndrome
Causes of Airway/Ventilatory Compromise

Control System
 Head
trauma
 Cerebrovascular accident
 Depressant drug toxicity
 Narcotics
 Sedative-Hypnotics
 Ethanol
Assessment of Airway/Ventilatory
Compromise
Respiratory Distress/Dyspnea =
Possible Life Threat
 Assess/Manage Simultaneously
 Priorities

 Airway
 Breathing
 Circulation
 Disability
Assessment of Airway/Ventilatory
Compromise

Airway
 Listen
to patient talk/breathe
 Noisy breathing = Obstructed breathing
 But, all obstructed breathing is not noisy
 Adventitious sounds
 Snoring
= Tongue
 Stridor = “Tight” Upper Airway
Assessment of Airway/Ventilatory
Compromise

Breathing
 Look
 Symmetry
of Chest Expansion
 Signs of Increased Effort
 Skin Color
 Listen
 Mouth
and Nose
 Lung Fields
 Feel
 Mouth
and Nose
 Symmetry of Expansion
Assessment of Airway/Ventilatory
Compromise

Breathing
 Tachypnea
 Bradypnea
 Signs
of distress
 Nasal
flaring
 Tracheal tugging
 Retractions
 Accessory muscle use
 Tripod positioning
 Cyanosis
Assessment of Airway/Ventilatory
Compromise

Circulation
 Don’t
let respiratory failure distract you!!!
 Tachycardia = Early hypoxia in adults
 Bradycardia = Early hypoxia in infants,
children; Late hypoxia in adults
Assessment of Airway/Ventilatory
Compromise

Disability
 Restlessness,
anxiety, combativeness =
hypoxia until proven otherwise
 Drowsiness, lethargy = hypercarbia until
proven otherwise
 When the fighting stops, a patient isn’t
always getting better
Assessment of Airway/Ventilatory
Compromise

Focused Exam
 Respiratory
Patterns
 Cheyne-Stokes
= diffuse cerebral cortex injury
 Kussmaul = acidosis
 Biot’s (cluster) = increased ICP; pons, upper
medulla injury
 Central Neurogenic Hyperventilation = increased
ICP; mid-brain injury
 Agonal = brain anoxia
Assessment of Airway/Ventilatory
Compromise

Focused Exam
 Neck
 Trachea
mid-line?
 Jugular vein distension?
 Subcutaneous emphysema?
 Accessory muscle use?/hypertrophy?
Assessment of Airway/Ventilatory
Compromise

Focused Exam
 Chest
 Barrel
chest?
 Deformity, discoloration, asymmetry?
 Flail segment, paradoxical movement?
 Adventitious breath sounds?
 Third heart sound?
 Subcutaneous emphysema?
 Fremitus?
 Dullness, hyperresonance to percussion?
Assessment of Airway/Ventilatory
Compromise

Focused Exam
 Extremities
 Edema?
 Nail
bed color?
 Clubbing?
Assessment of Airway/Ventilatory
Compromise

Mechanical Ventilation
 Increased
resistance
 Changing compliance
Assessment of Airway/Ventilatory
Compromise

Pulsus Paradoxus
 Systolic
BP drops > 10 mm Hg w/inspiration
 May detect change in pulse quality
 COPD, asthma, pericardial tamponade
Assessment of Airway/Ventilatory
Compromise

History
 Onset
gradual or sudden?
 What makes it worse, better?
 How long?
 Cough? Productive? Of what?
 Pain? What kind?
 Fever?
Assessment of Airway/Ventilatory
Compromise

Past History





Hypertension, AMI, diabetes
Chronic cough, smoking, recurrent “colds”
Allergies, acute/seasonal SOB
Lower extremity trauma, recent surgery,
immobilization
Interventions



Past admission? Ever admitted to ICU?
Medications? Frequency of prn medication use?
Ever intubated before?
BLS Airway/Ventilation Methods

Supplemental Oxygen
 Increased
FiO2 increases available oxygen
 Objective = Maximize hemoglobin saturation
Oxygen Equipment
 Oxygen
source
 Compressed
 Tank
gas
size
D
400L
 E 660L
 M 3450 L
 Liquid
oxygen
Oxygen Equipment
 Regulators
 High
Pressure
 Cylinder
 Low
to cylinder
Pressure
 Cylinder
 Humidifier
to patient
Delivery Devices
Nasal cannula
 Simple face mask
 Partial rebreather mask
 Non-rebreather mask
 Venturi mask
 Small volume nebulizer

Nasal Cannula
Optimal delivery 40% at 6 LPM
 Indication

 Low
FiO2
 Long term therapy

Contraindications
 Apnea
 Mouth
breathing
 Need for High FiO2
Venturi Mask

Specific O2 Concentrations
 24%
 28%
 35%
 40%
Simple Face Mask
Range 40-60% at 10 LPM
 Volumes greater that 10 LPM does not
increase O2 delivery
 Indications

 Moderate

FiO2
Contraindications
 Apnea
 Need
for High FiO2
Non-Rebreather Mask
Range 80-95% at 15 LPM
 Indications

 Delivery

of high FiO2
Contraindications
 Apnea
 Poor
respiratory effort
Partial Rebreather
Range 40 – 60%
 Indications

 Moderate

FiO2
Contraindications
 Apnea
 Need
for High FiO2
BLS Airway/Ventilation Methods

Airway Maneuvers




Other Types



Head-tilt/Chin-lift
Jaw thrust
Sellick’s maneuver
Tracheostomy with tube
Tracheostomy with stoma
Airway Devices


Oropharyngeal airway
Nasopharyngeal airway
BLS Airway/Ventilation Methods








Mouth-to-Mouth
Mouth-to-Nose
Mouth-to-Mask
One-person BVM
Two-person BVM
Three-person BVM
Flow-restricted, gas powered ventilator
Transport ventilator
BLS Airway/Ventilation Methods
Mouth to Mouth
 Mouth to Nose
 Mouth to Mask

BLS Airway/Ventilation Methods

One-Person BVM
Difficult to master
 Mask seal often inadequate
 May result in inadequate tidal volume
 Gastric distention risk
 Ventilate only until see chest rise

BLS Airway/Ventilation Methods

Two-person BVM




Most efficient method
Useful in C-spine injury
improved mask seal, tidal volume
Three-person BVM



Less utilized
Used when difficulty with mask seal
Crowded
BLS Airway/Ventilation Methods

Flow-restricted, gas-powered ventilator
 Cardiac
sphincter opens at 30 cm H2O
 High volume/high concentration
 Not recommended for children, poor
pulmonary compliance, or poor tidal volume
 Oxygen delivered on inspiratory effort
 May cause barotrauma
BLS Airway/Ventilation Methods

Automatic transport ventilators
 Not
like “real” ventilator
 Usually only controls volume, rate
 Useful during prolonged ventilation times
 Not useful in obstructed airway, increased
airway resistance
 Frees personnel
 Cannot respond to changes in airway
resistance, lung compliance
BLS Airway/Ventilation Methods

Pediatric considerations
 Mask
seal force may obstruct airway
 Best if used with jaw thrust
 BVM sizes: neonate, infant=450 ml +
 Children > 8 y.o. require adult BVM
 Just enough volume to see chest rise
 Squeeze - Release - Release
BLS Airway/Ventilation Methods

Stoma patients
 Expose
stoma
 Pocket mask
 BVM
 Seal
around stoma site
 Seal mouth, nose if air leak is evident
BLS Airway/Ventilation Methods

Airway obstruction techniques
 Positioning
 Finger
sweep with caution
 Suctioning
 Oral airway/nasal airway (tongue)
 Heimlich maneuver
 Chest thrusts
 Chest thrust/back blows for infants
 Direct laryngoscopy
BLS Airway/Ventilation Methods

Suctioning
 Manual
or powered devices
 Suction catheters
 Rigid
 Soft
BLS Airway/Ventilation Methods

Gastric Distention
 Common
when ventilating without intubation
 Complications
 Pressure
on diaphragm
 Resistance to BVM ventilation
 Vomiting, aspiration
 Increase
BVM ventilation time