Airway Management - FINAL

8/6/2019 Airway Management - FINAL

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Airway ManagementAirway Managementin the ICUin the ICU


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Objectives Recognise signs of threatened airway

Describe techniques of establishing airway

and for mask ventilation

Explain proper applications of airwayadjuncts

Describe preparation for endotracheal

intubation and difficult intubation

Describe alternative methods


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Global AssessmentGlobal Assessment

Assess underlying need for airway control Duration of intubation

- Nasal intubation less advantageous for potentially prolonged ventilator

requirements

Permanent support

- Underlying advanced intrinsic lung or neuromuscular disease Temporary support

Anesthesia

Presence of reversible intrinsic lung or neuromuscular disease

Protection of the airway due to depressed mental status

Presence of reversible upper airway pathology

Patient care needs (e.g., transport, CT scan, etc.)

Significant comorbidities

Aspiration potential or increased respiratory secretions

Hemodynamic issues such as cardiac disease or sepsis

Renal or liver failure


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Pathophysiology of the respiratoryfailure

Hypoxic respiratory failure

- In case of hypoxic respiratory failure, differentnoninvasive oxygen delivery devices can be used.

- The severity of hypoxia and presence or absence of

underlying disease (such as COPD) will dictate the

device of choice.

Hypercapnic respiratory failure

- The noninvasive device of choice for hypercapnic

respiratory failure is BIPAP.


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Oxygenation Respiratory rate and use of accessory muscles

- Is the patient in respiratory distress?

Amount of supplemental oxygen

- What is the patients oxygen demand?

Airway Anatomy

- Will this patient be difficult to intubate?

Patency

- Is there a reversible anatomical cause of respiratory failure

as opposed to intrinsic lung dysfunction?


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Oxygen Delivery DevicesOxygen Delivery Devices(In order of degree of support)

Nasal Cannula 4% increase in FiO2 for each 1 L of flow (e.g., 4 L flow = 37% or 6 L flow

= 45%)

Face tent At most delivers 40% at 10-15 L flow

Ventimask Small amount of rebreathing

8 L flow = 40%, 15 L flow = 60%

Nonrebreather mask Attached reservoir bag allows 100% oxygen to enter mask withinlet/outlet ports to allow exhalation to escape - does not guarantee

100% delivery.


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Degree of Respiratory DistressDegree of Respiratory Distress

Respiratory pattern Accessory muscle use is an indication of distress.

Rate > 30 can indicate need for more support by noninvasive positive

pressure or intubation

Need for artificial airway

Tongue and epiglottis fall back against posterior pharyngeal wall Nasopharyngeal airway better tolerated

Pulse oximetry

O2 saturation less than 92% on 60 - 100% oxygen can suggest the need

for intubation based on whether there is anything immediately reversible

which could improve ventilation.

Arterial blood gas

pH < 7.3 can indicate need for more support by noninvasive positive

pressure or intubation.


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Temporizing MeasuresTemporizing Measures

Naloxone for narcotic overdose 40 mcg every minute up to 200 mcg with:

- 45 minutes to one hour duration of action

0.4 - 2 mg of naloxone is indicated in patients with respiratory arrest and

history suggestive of narcotic overdose

- There is a potential for pulmonary edema, so large dose is reserved

for known overdose and respiratory arrest

Caution in patients with history of narcotic dependence

Naloxone drip can be titrated starting at half the bolus dose used to

obtain an effect

- Manufacturer recommended 2 mg in 500 ml of normal saline or D5gives 0.004 mg/ml concentration


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Temporizing MeasuresTemporizing Measures (cont'd)

Flumazenil for benzodiazepine overdose 0.2 mg every minute up to 1 mg

Caution in patients with history of benzodiazepine or alcohol dependence

Caution in patients with history of seizure disorder as it will decrease the

seizure threshold

Artificial airway for upper airway obstruction in patientswith oversedation May be necessary in patients with sleep apnea despite judicious sedation

100% oxygen and maintenance of spontaneous

ventilation in patients with pneumothorax Washout of nitrogen may decrease size of pneumothorax

Positive pressure may cause conversion to tension pneumothorax


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Airway Anatomy Suggesting DifficultAirway Anatomy Suggesting Difficult

IntubationIntubation

Length of upper incisors and overriding maxillary teeth

Interincisor (between front teeth) distance < 3 cm (two finger tips)

Thyromental distance < 7 cm

tip of mandible to hyoid bone (three finger breaths)

Neck extension < 35 degrees

Sternomental distance < 12.5 cm

With the head fully extended and mouth closed

Narrow palate (less than three finger breaths)

Mallampati score class III or IV

Stiff joint syndrome About one third of diabetics characterized by short stature, joint rigidity, and tight waxy skin

Positive prayer sign with an inability to oppose fingers

No sign is foolproof to indicate intubation difficulty

Erden V, et al. Brit J Anesth. 2003;91:159-160.

Prayer Sign


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Mallampati ScoreMallampati Score

Class I: Uvula/tonsillar pillars visible

Class II: Tip of uvula/pillars hidden by tongue

Class III: Only soft palate visible

Class IV: Only hard palate visible

Den Herder, et al. Laryngoscope. 2005;115(4):735-739.


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ComorbiditiesComorbidities

Potential for aspiration requires rapid sequence intubation withcricoid pressure

Clear liquids < 4 hours

Particulate or solids < 6hours

Potential for hypotension

Cardiac dysfunction, hypovolemia, and sepsis May need to consider awake intubation with topical anesthesia

(aerosolized lidocaine) as sedation may precipitate hemodynamic

compromise and even arrest.

Organ failure

Renal and hepatic failure will limit medication used.

Potential for preexisting pulmonary edema and airway bleeding from

manipulation


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Induction AgentsInduction Agents

Sodium Thiopental 3 - 5 mg/kg IV

Profound hypotension in patients with hypovolemia, histamine release, arteritis

Dose should be decreased in both renal and hepatic failure.

Propofol 2 - 3 mg/kg IV

Hypotension, especially in patients with systolic heart dysfunction, bradycardia,and even heart block

Unlikely to have prolonged effect in organ failure

Ketamine 1 - 4 mg/kg IV, 5 - 10 mg/kg IM

Stimulates sympathetic nervous system

Requires atropine due to stimulated salivation and midazolam for potential ofdysphoria

Avoid in patients with loss of autoregulation and closed head injury


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Neuromuscular BlockersNeuromuscular Blockers

Succinylcholine 1 - 2 mg/kg IV, 4 mg/kg IM

Avoid in patients with malignant hyperthermia, > 24 hours out from burn or

trauma injury, upper motor neuron injury, and preexisting hyperkalemia

Rocuronium

0.6 - 1.2 mg/kg, highest dose required for rapid sequence Hemodynamically stable, 10% renal elimination

Vecuronium 0.1 mg/kg

Hemodynamically stable, 10% renal elimination

Cisatricurium 0.2 mg/kg

Mild histamine release, Hoffman degradation, not prolonged in renal or

hepatic failure


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Rapid Sequence IntubationRapid Sequence Intubation

Preoxygenate for three to five minutes prior to induction Wash out nitrogen to avoid premature desaturation during intubation.

Cricoid pressure should be applied from prior to induction until

confirmation of appropriate placement.

Succinylcholine 1 - 2 mg/kg IV will achieve intubationconditions in 30 seconds; Rocuronium 1.2 mg/kg IV will

achieve intubation conditions in 45 seconds.

Other muscle relaxants do not produce intubation conditions in less than

60 seconds.

Avoid mask ventilation after induction. Potentially can inflate stomach

Use only if necessary to ensure appropriate oxygenation during

prolonged intubation.


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Y BAG PEOPLEY BAG PEOPLE (Reference #6)


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Cricoid PressureCricoid Pressure

Cricoid is circumferential

cartilage

Pressure obstructsesophagus to prevent

escape of gastric

contents

Maintains airway patency

Koziol C, et al. AORN. 2000;72(6):1018-1030.


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SniffingPositionSniffingPosition

Align oral, pharyngeal, and laryngeal axes to

bring epiglottis and vocal cords into view.

Hirsch N, et al. Anesthesiology. 2000;93(5):1366.


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Mask VentilationMask Ventilation

Mask ventilation crucial,especially in patients who are

difficult to intubate

Sniffing position with tight

mask fit optimal

May require two hands


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Oral/Nasal AirwaysOral/Nasal Airways


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Laryngoscope Blades and EndotrachealLaryngoscope Blades and Endotracheal

TubesTubes

Miller blade: End of blade should be under epiglottis

Mac blade: End of blade should be placed in front of epiglottis in valecula

ETT for Fastrach LMA

Pediatric uncuffed ETT

ETT for blind nasal

Standard ETT


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Graded Views on IntubationGraded Views on Intubation

Grade 1: Full glottis visible

Grade 2: Only posterior commissure

Grade 3: Only epiglottis

Grade 4: No glottis structures are visible

Yarnamoto K, et al. Anesthesiology. 1997;86(2):316.


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Confirmation ofPlacementConfirmation ofPlacement

Direct visualization

Humidity fogging the endotracheal tube

End tidal CO2 which is maintained after > 5 breaths

Low cardiac output results in decreased delivery of CO2

Refill in 5 seconds of self-inflating bulb at the end of the

endotracheal tube

Symmetrical chest wall movement

Bilateral breath soundsMaintenance of oxygenation by pulse oximetry

Absence of epigastric auscultation during ventilation


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Additional ConsiderationsAdditional Considerations

Always have additional personnel and an experiencedprovider as backup available for potential failed

intubation

Always have suction available

Never give a muscle relaxant if difficult mask ventilation

is demonstrated or expected

Awake intubation should be considered in the following: If patient is so hemodynamically unstable that induction drugs cannot be

tolerated (topicalize airway)

If patient has a history or an exam which suggests difficult mask

ventilation and/or direct laryngoscopy


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Alternative MethodsAlternative Methods

Blind nasal intubation

Bleeding may cause problems with subsequent attempts.

Contraindicated in patients with facial trauma due to cribiform plate disruption or

CSF leak

Avoid in immune suppressed (i.e., bone marrow transplant)

Eschmann stylet

Fiber optic bronchoscopic intubation Awake vs. asleep

Laryngeal mask airway

Allows ventilation while bridging to more definitive airway

Light wand

Retrograde intubation Through cricothyrotomy

Surgical tracheostomy

Combitube


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Eschman StyletEschman Stylet

Use especially if Grade IIIview achieved

Direct laryngoscopy isperformed

Place Eschman wheretrachea is anticipated

May feel tracheal ringsagainst stiffness of stylet

Thread 7.0 or 7.5 ETTover stylet with thelaryngoscope still in place


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The Laryngeal Mask Airway (LMA)The Laryngeal Mask Airway (LMA)


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LMA PlacementLMA Placement

Guide the LMA along the

palate

Eventual position should

be underneath the

epiglottis, in front of thetracheal opening, with the

tip in the esophagus

FOB placement through

LMA positions in front oftrachea

Martin S, et al. J Trauma Injury, Infection Crit Care.

1999;47(2):352-357.


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The FastrachThe FastrachTMTM LaryngealLaryngeal

Mask AirwayMask Airway

Reinforced LMA allows for

passage of ETT without

visualization of trachea.

10% failure rate in

experienced hands

20% failure rate in

inexperienced


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The Light WandThe Light Wand

Transillumination of tracheawith light at distal end

Trachea not visualizeddirectly

Should not be used with

tumors, trauma, or foreignbodies of upper airway

Minimal complicationexcept for mucosal bleed

10% failure rate on firstattempt in experiencedhands


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Retrograde IntubationRetrograde Intubation

Puncture of thecricothyroid membrane

with retrograde passage of

a wire to the trachea

Endotracheal tube guidedendoscopically over the

wire through the trachea

Catheter through the

cricothyroid can be usedfor jet ventilation if

necessary.

Wesler N, et al. Acta Anaes Scan. 2004;48(4):412-416.


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CombitubeCombitube (cont'd)

Should be changed to endotracheal tube (ETT) ortracheostomy to prevent progressive airway edema

If in esophagus, take down pharyngeal cuff and attempt direct

laryngoscopy (DL) or fiber optic bronchoscope (FOB)

placement around combitube

Failed exchange attempt can be solved with operative

tracheostomy

Placement of combitube can produce significant airway

trauma Removal prior to DL or FOB should be done with caution after thorough airway

evaluation

Cricoid pressure should be maintained and emergency tracheostomy equipment

available


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TracheostomyTracheostomy

Surgical airway throughthe cervical trachea

Emergent procedure

carries risk of bleedingdue to proximity ofinnominate artery

Can be difficult and timeconsuming in emergent

situations

SharpeM, et al. Laryngoscope. 2003;113(3):530-536.


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ReferencesReferences

1. Caplan RA

, et al. Practice guidelines for management of thedifficult airway.Anesthesiology. 1993;78:597-602.

2. Langeron O, et al. Predictors of difficult mask ventilation.

Anesthesiology. 2000;92:1229-36.

3. Frerk CM, et al. Predicting difficult intubation.Anaesthesia.

1991;46:1005-08.4. Tse JC, et al. Predicting difficult endotracheal intubation in

surgical patients scheduled for general anesthesia.

Anesthesia & Analgesia. 1995;81:254-8.

5. Benumof JL, et al. LMA and the ASA difficult airway

algorithm.Anesthesiology. 1996;84:686-99.

6. Reynolds S, Heffner J. Airway management of the critically

ill patient. Chest. 2005;127:1397-1412.

Airway Management - FINAL

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