AIRWAYAIRWAY

UNC Emergency Medicine

Medical Student Lecture Series

Created: Benjamin Leacock 6/21/08

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ObjectivesObjectives

• Brief anatomy review• Indications for airway support• Passive oxygen assistance• Non-invasive mechanical ventilation• Intubation• Difficult Airway• Mechanical ventilation• Pediatric considerations

THIS IS INTERACTIVE SO SPEAK UP

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AnatomyAnatomy

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AnatomyAnatomy

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What are the indications for intubation?

What are some of the situations when you have seen someone intubated?

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Airway SupportAirway Support• Intubation

» Airway protection • GCS < 8, • Can not handle secretions, • Airway edema (burns, angioedema)

» Ventilation

» Oxygenation

» High metabolic demand from work of breathing• Sepsis

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What are the types of passive oxygenation support? (Tubes on your face)

How much O2 do they deliver?

What are the limitations?

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Passive Oxygen SupportPassive Oxygen Support• NC

»    2 L 29%        

»    4 L 37%        

»    6 L 45%

• Venti Mask» 4-10L 24-50%

• Non-Rebreather – Reservoir bag» 15L 60%

LIMITATION: You are not ventilating the patient, or protecting their airway.

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What is non-invasive ventilation?

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Non-Invasive VentilationNon-Invasive Ventilation• CPAP

» Continuous pressure

» Settings: Typically 5-10 cm H2O

• BIPAP» Inspiratory and expiratory levels

» Settings: IPAP set at 10, EPAP set at 3 cm H2O

With either setting remember that you are increasing intrathorasic pressure, thus decreasing cardiac output.

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What conditions qualify for non-invasive ventilation?

What are the contraindications?

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Non-Invasive VentilationNon-Invasive Ventilation• Conditions

» Pulmonary Edema

» COPD

» Asthma – (Questionable efficacy)

» Pneumonia – (Questionable efficacy)

• Contraindications» Uncooperative patient

» Obtunded patient

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Bag-Mask-VentilationBag-Mask-Ventilation

How should you hold the BMV?

(Note: BMV is not part RSI)

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BMVBMV

Airway AdjunctsAirway Adjuncts

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How do you size and position oral and nasal airways?

Airway AdjunctsAirway Adjuncts

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Size by looking at angle of jaw

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IntubationIntubation

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IntubationIntubation

What is RSI?

Why do we use RSI?

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Intubation - RSIIntubation - RSI• RSI is administration of a potent induction agent followed

immediately by a rapidly acting neuromuscular blocking agent to induce unconsciousness and motor paralysis for tracheal intubation

• RSI increases success rates of intubation

• RSI decreases aspiration

• Limits sympathetic discharge and limits ICP increase.

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IntubationIntubation

What are the basic steps of RSI?

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Intubation - RSIIntubation - RSI1. Preparation

2. Pre-oxygenation

3. Positioning

4. Pre-induction

5. Induction

6. Paralysis

7. Tube

8. Confirmation

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IntubationIntubation

What equipment do you need to set up?

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Intubation - RSIIntubation - RSI• Preparation:

» Ambu bag

» Suction

» Blades – check lights

» Tubes – check cuff

» Stylette

» Syringe – 10 cc

» Capnography

• Patient » Needs IV, O2, Monitor

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IntubationIntubation

How do you position the adult patient?

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Intubation - RSIIntubation - RSI• Position:

» Place the pt in the “sniff position”

» In the adult this means ramping the head up

» Align the ear with the sternal notch

» Maintain cricoid pressure.

• For c-spine precautions:» You can not move the head

» An assistant holds the head in position while the front of the collar is removed.

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IntubationIntubation

Why do we pre-oxygenate?

How do we do it? How do we not do it?

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Intubation – Pre-OxygenationIntubation – Pre-Oxygenation• We preoxygenate to prevent hypoxia during the apnea that

will follow.» 100% for 2 min of normal breathing will permit 8 minutes of

apnea in the healthy adult.

• This should be done passively if possible» The reason is that bagging the patient will always put air in

the stomach – thus increasing the chance of aspiration.

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IntubationIntubation

What are the common pre-induction agents?

When should you consider them?

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Intubation – Pre-InductionIntubation – Pre-InductionLOAD

» Lidocaine: 1.5 mg/kg – limits bronchospasm in reactive airways and limits ICP response.

» Opioid: Fentanyl 3ug/kg – limits sympathetic response, used in CAD, ICH, ICP or aortic dissection.

» Atropine: 0.02 mg/kg in kids under 10 to prevent bradycardia.

» Defasciculation: 10% of the planed defasiculationg dose to mitigate succ induced elevated ICP.

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IntubationIntubation

Common inductions agents?

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Intubation - InductionIntubation - Induction• Etomidate – Most often used.

» Hemodynamically stable,

» No ICP increase

» Myoclonus is common

• Propofol – Quick on, quick off» No ICP increase

» Can cause hypotension

• Ketamine – » Sympathometic – may be useful in asthma.

» May increase ICP.

• Many additional agents: Benzos, barbiturates

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IntubationIntubation

The two basic classes of paralytics?

What are the contraindications?

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Intubation - ParalyticsIntubation - Paralytics• Depolarizing - Succinylcholine

» Basically two Ach molecules (so it can cause bradycardia)

» Works within 60 sec, lasts 6-10 min (resp may occur within 7 min)

» Contrainducations many related to K.• Hyperkalemia• Burns, Crush, Stroke, cord injury, intra abdominal sepsis. For

all of these must have condition > 5 days

• Non-Depolarizing – Rocuronium and vecuronium » Rocuronium is agent of choice when succinylcholine is

contraindicated. Give 1mg/kg which works within 60 sec and lasts 50 minutes

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IntubationIntubation

What is the difference between a Mac and Miller blades?

Typical tube sizes in adults?

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Intubation – Tubes + BladesIntubation – Tubes + Blades

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IntubationIntubation

What are the basic steps once you are ready to intubate?

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Intubation - StepsIntubation - Steps1. Scope in left hand.

2. Scissor teeth open with right hand.

3. Place blade in right of mouth and sweep tongue to left.

4. Insert blade deeper

5. Lift up and away

6. With R hand manipulate head and/or cricoid for the best view

7. Pass tube

DO NOT PASS THE TUBE IF YOU CAN NOT VISUALIZE

DO NOT LET GO OF THE TUBE UNTIL SECURE

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Intubation - StepsIntubation - Steps

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IntubationIntubation

How do we confirm the tube?

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Intubation - ConfirmationIntubation - Confirmation• Confirm

» Visualization!

» Capnography – most sensitive

» Listen – stomach, then lungs

» X-ray

» Esophageal Detector

DO NOT LET GO OF TUBE UNTIL IT IS SECURED

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IntubationIntubation

Options for the difficult airway?

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Intubation – Difficult AirwayIntubation – Difficult Airway• Boggie• Glide-Scope – Camera on blade• LMA/ILMA - useful out of hospital but should only be used in ED in

failed airway. Does not protect airway.• Lighted Stylet – Primary or rescue• Combitube – difficult to use if C-spine immobilized, should be

temporary only. Same indications as LMA. • Retrograde Intubation – The cricothyroid membrane is punctured,

wire sent through and retrieved through mouth. • Fiberoptic Intubation – View while you intubate• Transtracheal Jet Ventilation – larger 10g needle inserted through

the cricothyroid. Inferior to cricothyrotomy, only use is in children <10 where a cric is difficult.

• Surgical Airway

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AirwayAirway

How do you perform a surgical airway?

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Surgical AirwaySurgical Airway

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KidsKids

Anatomical differences of kids?

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Intubation – Kid AnatomyIntubation – Kid Anatomy

Don’t forget that kids have big heads

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KidsKids

How do you determine tube size in a kid?

How is positioning of the child different?

Blades?

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Intubation – KidsIntubation – Kids• Tubes

» (Age + 4)/4Width of the nail of the little (5th) finger

» The narrowest part of the child’s airway is subglottic so use a tube without a cuff or a low pressure cuff.

• Blades» In younger kids the epiglottis is large and floppy so use a

Miller blade.

• Positioning» Kids have large heads so they typically do not need to be

“ramped up.”