airway management

Airway Management

Yohanes WH George,SpAn

Topics for Discussion

Airway Maintenance Objectives Airway A&P 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 Mgmt & Ventilations Risks to the Paramedic

Objectives of Airway Management & Ventilation

Primary Objective: Ensure optimal ventilation

Deliver oxygen to the bloodEliminate carbon dioxide (C02) from the body

Definitions What is Airway Management? How does it differ from spontaneous,

manual or assisted Ventilations?

Objectives of Airway Management & Ventilation

Why is this so important? Brain death occurs rapidly; Other tissue

follows EMS providers can reduce additional

injury/disease EMS providers often neglect BLS airway

& ventilation skills

Airway Anatomy Review

Anatomy of the Upper AirwayAnatomy of the Lower AirwayLung Capacities/VolumesPediatric Airway Differences

Anatomy of the Upper Airway

Functions: Warm, Filter, HumidifyNasopharynx

formed by union of facial bones nasal floor towards ear not eye lined with mucous membranes and cilia tissues are delicate and vascular


Oropharynx Teeth Tongue

Lg muscle attached at mandible and hyoid bonesMost common airway obstruction

PalateRoof of mouthSeparates oro- & nasopharynxAnterior=hard palate; Posterior=soft palate


Oropharynx Adenoids

lymph tissue - filters bacteriacommonly infected

EpiglottisPrevents aspirationDirects air vs. other

Vallecula“pocket” formed by the base of tongue &

epiglottis


Sinuses cavities formed by

cranial bones act as tributaries

for fluid to & from eustachian tubes & tear ducts

trap bacteria, commonly infected


Larynx attached to hyoid bone

hyoid: horseshoe shaped bone (cartilage)hyoid supports trachea

thyroid cartilagefirst tracheal cartilage - shield shapedcartilage anterior but smooth muscle posterior“Adam’s Apple”Glottic opening directly behind


Larynx (cont) Glottic opening

narrowest part of adult tracheadependent on muscle tonecontains vocal bands

• white bands of cartilage• produce voice

Arytenoid cartilageposterior attachment of vocal bands


Larynx (cont) Cricoid ring

first tracheal ringcompletely cartilaginouscompression occludes esophagus

• Sellick maneuver

Cricothyroid membranemembrane between cricoid & thyroid cartilagesite for surgical and needle airway placement


Larynx (cont) associated & adjacent structures

thyroid gland• below cricoid cartilage• lies across trachea and up both sides

carotid arteries• branches across and lie closely alongside trachea

jugular veins• branch across and lie close to trachea


Pediatric vs Adult Upper Airway Larger tongue in comparison to size of

mouth Floppy epiglottis Delicate teeth and gums Larynx is more superior Funnel shaped larynx due to undeveloped

cricoid cartilage Narrowest point at cricoid ring before 10 yoa


From: CPEM, TRIPP, 1998

Anatomy of the Lower Airway

Function exchange O2 and CO2

Location From the glottic opening to pulmonary

capillary membrane


Trachea Bifurcates at carina Right and Left mainstem bronchi Right mainstem bronchi has less angle Lined with mucous cells & Beta 2 receptors

Bronchi Branch into secondary & tertiary bronchi

that branch into bronchioles


Bronchioles Branch into alveolar ducts that end at

alveolar sacsAlveoli

“Balloon-like” clusters Site of gas exchange Lined with surfactant

increases surface tension eases expansion surfactant or alveoli not inflated atelectasis


Lungs Right lung = 3 lobes; Left lung = 2 lobes Parenchymal tissue Membranous outer lining called pleura

visceral and parietalpleural space

Specific lung capacities


Occlusion of the bronchiole Smooth muscle Foreign body (not shown) Inflammation

Lung Volumes & Capacities

Total lung capacity (TLC) in a typical adult male is 6 liters Much of inspired air does not enter

alveoli

Tidal Volume (VT) volume of gas inhaled/exhaled during a

single ventilatory cycle Usually 5-7 cc/kg (typically 500 cc)


Dead Space Air (VD) Air remaining in air passageways,

unavailable for gas exchange (usually 150 cc)

Anatomic dead spacetracheabronchi

Physiologic dead spaceformed by factors like disease or obstructionExamples: COPD & atelectasis


Minute Volume [Vmin](minute ventilation) amount of gas moved in and out of

respiratory tract per minute (tidal volume - dead space volume) X RR

Functional Reserve Capacity (FRC) after optimal inspiration, the optimum

amount of air that can be forced from the lungs in a single exhalation


Alveolar Air (alveolar volume) [VA] Air reaching alveoli for gas exchange Usually 350 cc

Inspiratory Reserve (IRV) Amount of gas that can be inspired in

addition to tidal volumeExpiratory Reserve (ERV)

Amount of gas that can be expired after a passive (relaxed) expiration

VentilationDefined as movement of air into & out of lungs Inspiration

stimulus from respiratory center of brain (medulla) transmitted via phrenic nerve to diaphragm diaphragm flattens during contraction intercostal muscles contract ribs elevate and expand results in intrapulmonic pressure (pressure

gradient) results in air being drawn into lungs & alveoli inflated

Ventilation

Expiration Stretch receptors in lungs signal

respiratory center via vagus nerve to inhibit inspiration

Hering-Breuer Reflex Natural elasticity of lungs passively

expires air (in non-diseased lung)Control via Pons

Apneustic & Pneumotaxic centers

Ventilation

Chemoreceptors Carotid bodies & Aortic arch Stimulated by PaO2, PaCO2 or pH

PaCO2 considered normal neuroregulatory control of ventilations

Hypoxic Drive default regulatory control Senses changes in Pa02

Ventilation

Other stimulations or depressants to ventilatory drive body temp: w/ fever & w/hypothermia drugs/meds: increase or decrease pain: increases but occasionally decreases emotion: increases acidosis: increases sleep: decreases

Ventilation

Measurement of Gases

Total Pressure combined pressure of all atmospheric

gases 760 mm Hg or torr at sea level

Partial Pressure Pressure exerted by each gas of a mixture 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%)

Measurement of Gases

Partial Pressures 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. RespirationExchange of gases between a living

organism and its environmentExternal Respiration

exchange between lungs & blood cellsInternal Respiration

exchange between blood cells & tissues

Respiration

How are O2 and CO2 transported? Diffusion

definitiongases dissolved in water and pass through

alveolar membrane

FiO2

% of oxygen in inspired air (e.g. FiO2 = 0.95)

Respiration

Oxygen Content of Blood dissolved O2 crosses pulm cap membrane

and 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 pulm membrane

(pneumonia, pulm edema, COPD) Ventilation/Perfusion (V/Q) mismatch

blood moves past collapsed alveoli (shunting)

alveoli intact but blood flow impaired

Respiration

Carbon Dioxide content of blood 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

Alveoli PO2 100 & PCO2 40

PO2 40 & PCO2 46 - Pulmonary circulation - PO2 100 & PCO2 40

Heart

PO2 40 & PCO2 46 - Systemic circulation - PO2 100 & PCO2 40

Tissue cell PO2 <40 & PCO2 >46

Inspired Air: PO2 160 & PCO2 0.3

OxygenatedDeoxygenated

Diagnostic Testing

Pulse OximetryPeak Expiratory Flow TestingPulmonary Function TestingEnd-Tidal CO2 MonitoringLaboratory Testing of Blood

Arterial Venous

Causes of Hypoxemia

Environment lower partial pressure of atmospheric O2

Transport inadequate hemoglobin level in blood hemoglobin bound by other gas

Medical pulm alveolar membrane distance

pneumonia, pulmonary edema, COPD

Causes of Hypoxemia

Traumatic Reduced surface area for gas exchange

pneumothorax, hemothorax, atelectasis

Decreased mechanical effortpain, traumatic asphyxiation,

hypoventilationsucking chest wound, obstruction

Pathologic Causes of Airway and/or Ventilatory Compromise

Obstruction of the Airway Tongue

most commonsnoringreposition airway

Foreign Bodypartial or completechoking, gagging, stridor, aphonia,

dysphonia


Laryngeal Spasm or Edema Spasmotic closure of vocal cords stimulation with intact gag reflex edema results in narrowed airway epiglottitis, anaphylaxis Treatment

calmingventilationmuscle relaxants


Fractured Larynx decreased airway size laryngeal edema increased ventilatory effort

Aspiration increased mortality destroys bronchiolar tissue increased risk of infection increases pulm alveolar membrane distance

Assessment & Recognition of Airway & Ventilatory Compromise

Respiratory Difficulty & Distress Upper or lower obstruction Inadequate ventilation rate or depth Impaired ventilatory muscles Impaired ventilatory stimulation system


Dyspnea (rate, regularity or effort) May be result of or result in hypoxia hypoxia

lack of oxygen availablelack of oxygen to tissuesanoxia = total absence


Visual Assessment Position

tripodorthopnea

Rise & Fall of chest Audible gasping,

stridor, or wheezes Obvious pulm

edema (fulminant)

Visual Assessment Skin color Flaring of nares Pursed lips Retractions Accessory Muscle Use Altered Mental Status Inadequate Rate or

depth of ventilations


Auscultation Air movement at mouth and nose Tracheal sounds Vesicular lung sounds

Palpation Air movement at mouth and nose chest wall

paradoxical motionretractions


Mechanical Ventilation increased resistance or changing

compliance with ventilationsPulsus Paradoxus

Systolic BP drops > 10 mm Hg w/inspirationmay detect change in pulse qualitycommon in COPD, asthma, pericardial

tamponade


History Onset

sudden vs gradualKnown cause?

DurationConstantRecurrent

Provocation/Palliation


ExacerbationAssociated Signs/Symptoms

Cough, chest pain, feverInterventions

past evals/admits meds ever intubated before?


Respiratory Patterns Cheyne-Stokes

brain stem

Kussmaulacidosis

Biot’sincreased ICP

Respiratory Patterns Central Neurogenic

Hyperventilationincreased ICP

Agonalbrain anoxia


Inadequate Ventilation body cannot compensate for increased

oxygen demand or maintain balance Causes

infectiontraumabrainstem injurytoxic inhalationrenal failure

Airway & Ventilation Methods: BLS

Supplemental Oxygen increased FiO2 increases available

oxygen objective is to maximize hemoglobin

saturation


Oxygen source compressed gas liquid oxygen

RegulatorsHumidifier

Delivery Devices nasal cannula partial rebreather

mask non-rebreather

mask venturi mask small volume

nebulizer


Airway Maneuvers Head-tilt/Chin-lift Jaw thrust Sellick’s maneuver

Other Types tracheostomy with

tube tracheostomy with

stoma

Airway Devices Oropharyngeal

airway Nasopharyngeal

airway


Mouth to MouthMouth to NoseMouth to MaskOne person BVMTwo person BVMThree person BVMFlow restricted

powered ventilatorTransport ventilator

One Person BVM difficult to master mask seal often

inadequate may result in

inadequate tidal vol gastric distention

risk ventilate only until

see chest rise


Two person BVM most efficient

method Useful in C-spine inj improved mask seal

and tidal volume

Three person BVM less utilized used when difficulty

with mask seal crowded


Flow-restricted, powered ventilator Cardiac sphincter opens at 30 cm H2O high volume/high conc not recommended for children,

noncompliant or poor tidal volume oxygen delivered on inspiratory effort may cause barotrauma


Automatic transport ventilators Not like a “real” ventilator Usually only controls Volume and rate Useful during prolonged ventilation times Not useful in obstructed airway or

increased airway resistance Frees personnel Can not detect changes


Pediatric considerations mask seal force may obstruct airway best if used with jaw thrust BVM sizes: neonate & infant=450 ml + Children > 8 yoa require adult BVM just enough volume to see chest rise

Squeeze - Release - Release


Stoma patients expose stoma pocket mask BVM

Seal around stoma siteseal mouth and nose if air leak is evident


Airway Obstruction Techniques Positioning OPA/NPA Heimlich maneuver Finger sweep with caution Chest Thrusts Chest thrust and back blows for infants Suctioning Direct laryngoscopy


Suctioning Manual or Powered devices Suction catheters

rigidsoft

Tracheobronchial suctioninglubricate catheter3-5 cc sterile water or salineinsert catheter until resistance is felt


Gastric Distention Common when ventilating without

intubation pressure on diaphragm resistance to BVM ventilation increase time of BVM ventilation

Airway Management: Part 2

EMS Professions

Temple College

Airway & Ventilation Methods: ALS

Gastric Tubes nasogastric

caution with esophageal disease or facial traumatolerated by awake patients but is uncomfortablepatient can speakinterferes with BVM seal

orogastricusually used in unresponsive patientslarger tube may be usedsafe in facial trauma


Nasogastric Tube Insertion Select size (french) Measure length

nose to ear to xiphoid

Lubricate end of tubewater soluble

Maintain aseptic technique Position patient sitting up if possible


Nasogastric Tube Insertion (cont) Insert into nare towards base Advance gradually but steadily to

measured length Have patient swallow Assess placement & secure

Instill air & ausculateaspirate gastric contents

May connect to low vacuum (80-100 mm Hg)


Orogastric Tube Insertion Select size (french) Measure length Lubricate end of tube Maintain aseptic technique Position patient (usually supine) Insert into mouth Advance gradually but steadily


Orogastric Tube Insertion (cont) Assess placement & secure

instill air or aspirate

Evacuate contents as needed


Endotracheal Intubation Tube into the trachea to provide

ventilations using BVM or ventilator Sized based upon inside diameter in

mm Lengths increase with increased ID

cm markings along length

Cuffed vs Uncuffed


Endotracheal Intubation Indications

present or impending respiratory failureapneaunable to protect own airway

Advantagessecures airwayroute for a few medicationsoptimizes ventilation and oxygenation


These are NOT Indications Because I can intubate Because they are unresponsive Because I can’t show up at the hospital

without it


Complications of endotracheal intubation Bleeding or dental injury Laryngeal edema Laryngospasm Vocal cord injury Barotrauma Hypoxia Aspiration Dislodged tube or esophageal intubation Right or Left mainstem intubation


Techniques of Insertion Orotracheal Intubation by direct

laryngoscopy Blind Nasotracheal Intubation Digital Intubation Retrograde Intubation Transillumination techniques


Orotracheal Intubation by direct laryngoscopy Position & Ventilate patient Monitor patient

ECGPulse oximeter

Assess patient’s airway for difficulty Assemble & check equipment (suction) Hyperventilate patient (30-120 sec)


Orotracheal Intubation by direct laryngoscopy (cont) Position patient Open mouth & insert laryngoscope blade Attempt to sweep tongue (straight blade) Identify anatomical landmarks Advance laryngoscope blade

Vallecula for curved (Miller) bladeUnder epiglottis for straight (Miller) blade


Orotracheal Intubation by direct laryngoscopy (cont) Elevate epiglottis Directly with straight (miller) blade Indirectly with curved (macintosh) blade Visualize the vocal cords & glottic

opening Enter the mouth with the tube from

corner of mouth


Orotracheal Intubation by direct laryngoscopy (cont) Advance into glottic opening approx.

1/2 inch past vocal cords Continue to hold tube & note location Inflate cuff until firm (approx 10 cc) Ventilate & Auscultate

epigastriumleft and right chest


Orotracheal Intubation by direct laryngoscopy (cont) Secure tube Reassess Ventilation Effectiveness

auscultationclinical signsend-tidal CO2Esophageal detection device


Equipment Laryngoscope Handle

(lighted) & Blades Stylet Syringe Magills Lubricant Suction BVM BAAM (BNI)

Selection Typical Adult ET

Tube SizesMale - 8.0, 8.5Female - 7.0, 7.5, 8.0

BladeMac - 3 or 4Miller - 3

Tube DepthUsually 20 - 22 cm at

the teeth

Equipment Review

From AHA PALS


Pediatric Equipment Differences Uncuffed tube < 8

yoa Miller blade

preferred Tube Size

Premie: 2.0, 2.5Newborn: 3.0, 3.51 year: 4Then: (age/4)+4

Pediatric Differences Anatomic

Differences Depth (cm)

Tube ID x 312 + (age/2)easily dislodged

Intubation vs BVM


Patient Positioning Goal

Align the 3 planes of view, so that

The vocal cords are most visible

T - trachea P - Pharynx O - Oropharynx

From AHA PALS


Assessing the Possibility of Difficulty in Intubation

Difficulty


What effect would the angle of the mandible have on intubation difficulty?


Curved (Macintosh) Blade Visualize anatomy Insert from right

to left Lift upward and

away Blade in vallecula Lift epiglottis

indirectly

From AHA ACLS


Straight (Miller) Blade Visualize anatomy Insert from right to

left moving tongue away

Lift upward and away Blade past vallecula

and over epiglottis Lift epiglottis directly

From AHA ACLS

Tube Positioning

From TRIPP, CPEM


Blind Nasotracheal Intubation Position & Oxygenate patient Monitor patient

ECG MonitorPulse oximeter

Assess for BNI difficulty or contraindication Assemble & check equipment

Lubricate end of tube; Do not warmAttach BAAM (if available)


Blind Nasotracheal Intubation (cont) Position patient (preferably sitting upright) Insert tube into largest nare Advance slowly but steadily Listen for sound of whistle via BAAM Advance tube Inflate cuff & Assess placement Secure & Reassess


Digital Intubation Blind technique Variable probability of success Using middle fingers to locate epiglottis Lift epiglottis Slide lubricated tube along side fingers Assess tube placement & depth as with

orotracheal intubation


Digital Intubation

From AMLS, NAEMT


Surgical Cricothyrotomy Indications

absolute need for a definitive airway AND• unable to perform ETT due for structural or anatomic

reasons, AND• risk of not intubating is > than surgical airway risk

OR

absolute need for a definitive airway AND• unable to clear an upper airway obstruction, AND• multiple unsuccessful attempts at ETT, AND• other methods of ventilation do not allow for effective

ventilation and respiration


Surgical Cricothyrotomy Contraindications (relative)

No real demonstrated indicationRisks > benefitsAge < 8 years (some say 10)evidence of fx larynx or cricoid cartilageevidence of tracheal transection


Surgical Cricothyrotomy Tips

Know your anatomyShort incision, avoid inferior tracheaIncise, Do not sawWork quickly. Have a planBe prepared with a backup plan


Needle Cricothyrotomy & Transtracheal Jet Ventilation Indications

Same as surgical cricothyrotomy along withContraindication for surgical cricothyrotomy

ContraindicationsNone when demonstrated needcaution with tracheal transection


Jet Ventilation Usually requires high-

pressure equipment Ventilate 1 sec then

allow 3-5 sec pause Hypercarbia likely Temporary: 20-30

mins High risk for

barotrauma

Airway & Ventilation Methods: BLS & ALS

Alternative Airways Multi-Lumen Devices (CombiTube, PTLA) Laryngeal Mask Airway (LMA) Esophageal Obturator Airways (EOA,

EGTA) Lighted Stylets


Pharyngeal Tracheal Lumen Airway

(PTLA)

From AMLS, NAEMT


No. 1

100 ml

No. 1100 ml

Combitube®

From AMLS, NAEMT


Combitube® Indications Contraindications

HeightGag reflexIngestion of corrosive or volatile substancesHx of esophageal disease


Laryngeal Mask Airway (LMA) Use in OR Gaining use in out-

of-hospital Not useful with

high airway pressure

Not a replacement for ETT

Multiple models & sizes


Esophageal Obturator Airway & Esophageal Gastric Tube Airway Used less frequently today Increased complication rate Significant contraindications Better alternative airways are now

available

Esophageal Gastric Tube Airway (EGTA)

From AHA ACLS


Lighted Stylette Not yet widespread use expensive Another method of visual feedback re.

placement in trachea


Pharmacologic Assisted Intubation (“RSI”) Sedation

Reduce anxietyInduce amnesiaDepress gag reflex & spontaneous breathingUsed for

• induction• anxious or agitated patient

Contraindications• hypersensitivity• hypotension


Pharmacologic Assisted Intubation (“RSI”)

Common Medications for Sedation/InductionBenzodiazepines (diazepam, midazolam)Narcotics (fentanyl) Anesthesia Induction Agents

• etomidate• ketamine• propofol (Diprivan®)


Pharmacologic Assisted Intubation (“RSI”) Neuromuscular Blockade

Induces temporary skeletal muscle paralysisIndications

• When Intubation is required in a patient who– is awake,– has a gag reflex, or– is agitated or combative


Pharmacologic Assisted Intubation (“RSI”) Neuromuscular Blockade

Contraindications• Most are Specific to the medication• inability to ventilate patient once paralysis is induced

Advantages• enables to provider to intubate patients who otherwise

would be difficult or impossible to intubate• minimizes patient resistance to intubation• reduces risk of laryngospasm


Pharmacologic Assisted Intubation (“RSI”) Mechanism of Action for NMB agent

acts at the neuromuscular junction where ACh normally allows nerve impulse transmission

binds to nicotinic receptor sites at skeletal muscledepolarizes or does not depolarize specific to medblocks further action by ACh at receptor sitestherefore, blocks further depolarization resulting

in muscular paralysis


Pharmacologic Assisted Intubation (“RSI”) Disadvantages & Potential Complications

Does not provide sedation or amnesiaProvider unable to intubate or ventilate after

NMBAspiration during procedureDifficult to detect motor seizure activitySide effects and adverse effects of specific

meds


Pharmacologic Assisted Intubation (“RSI”) Common Used NMB Agents

Depolarizing NMB agents• succinylcholine (Anectine®)

Non-depolarizing NMB agents• vecuronium (Norcuron®)• rocuronium (Zemuron®)• pancuronium (Pavulon®)


Pharmacologic Assisted Intubation (“RSI”) Summarized Procedure

Prep all equipment and medications while ventilating patient

Hyperventilate Administer induction/sedation agents &

pretreatment meds (e.g. lidocaine or atropine)Administer NMB agentSellick maneuverIntubate per usualContinue NMB and sedation/analgesia prn


Examples ofSecondary Tube Placement

Confirmation Devices(From AMLS, NAEMT)

From AMLS, NAEMT


Needle Thoracostomy (chest decompression) Indications

Positive sx/sx of tension pneumothoraxCardiac arrest with PEA or Asystole when

the possibility of trauma and/or tension pneumo exist

ContraindicationsAbsence of indications


Tension Pneumothorax Sx/Sx

severe respiratory distress or absent lung sounds (unilateral

usually) resistance to manual ventilationCardiovascular collapse (shock)asymmetric chest expansionanxiety, restlessness or cyanosis (late)JVD or tracheal deviation (late)


Needle Thoracostomy Prep equipment Locate landmarks: 2nd intercostal space

at midclavicular line one-way valve


Chest Escharotomy Indications

In the presence of severe edema to the soft tissue of the thorax as with circumferential burns:

• inability to maintain adequate tidal volume even with PPV

• inability to obtain adequate chest expansion with PPV

Rarely needed


Chest Escharotomy Considerations

must rule out the possibility of upper airway obstruction

ProcedureIntubate if not already donePrep site and equipmentVertical incision to anterior axillary lineHorizontal incision only if necessaryCover and protect

Airway & Ventilation: Risks & Protective Measures

BSI Gloves Face & eye shields Respirator if concern for airborne disease Be prepared for

coughingspittingvomitingbiting

Airway & Ventilation Methods

Saturday’s class Practice using the

equipmentorotracheal intubationnasotracheal

intubationgastric tube insertionsurgical airwaysneedle thoracostomycombituberetrograde intubation

airway management

Documents

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upper airway

airway management

bladevisualize

airway management

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