Endotracheal Intubation in the ICU

David Oxman, MDJuly 12, 2013

Objectives

• Discuss Airway Assessment– Assessing for difficult bag mask ventilation– Assessing for difficult intubation– Specific conditions of critically-ill.

• Discuss 4 Ps of Pre-intubation: – Preparation– Pre-oxygenation– Positioning– Planning.

Objectives

• Discuss obtaining intubating conditions– induction–paralytics

• Discuss Direct Laryngoscopy and tube placement

• Post-intubation care• Overview Rescue Devices

Why Intubate

• Indications for endotracheal intubation1. inadequate oxygenation or ventilation2. airway protection in a patient with altered

mental status3. expectation 1 or 2 will develop soon!!

• Contraindications1. Laryngeal Trauma2. Obstructed Airway

Who should intubate in the ICU?

Chest, December 2012

Why Intensivists Should Intubate

• It’s the A in ABC.• Competent to perform vast majority

of intubations. • Will be expected in many settings.• Complications mostly not related to

airway itself.

Airway Assessment

• Can be more challenging in critically ill.• Must avoid the “cannot intubate, cannot

ventilate” scenario.• Must assess

1) Risk for difficult mask ventilation2) Risk for difficult intubation

Bag Mask Ventilation

• Crucial airway management skill.• Takes practice to perform correctly. • Gives time for well-planned approach to

definitive airway management.• 3 keys:–Patent airway–Good mask seal–Proper ventilation

Bag Mask Ventilation: Opening Airway

Head Tilt and Chin Lift Jaw Thrust

• One hand applies downward pressure to forehead and index and middle finger of the second hand lift at chin.

• Lifts tongue from posterior pharynx

• For unstable cervical spine• Place heels of hands on parieto-occipital area • Grasp angles of mandible with fingers, and displace jaw anteriorly.

Adjuncts for Opening Airway

• Need to size properly• Avoid pushing tongue into posterior pharynx. • Start with curve of OPA inverted and rotate 180 degrees as tip reaches posterior pharynx. • Avoid in awake patient aspiration risk

Bag Mask VentilationOne-handed technique Two-handed techniques

Three facial landmarks that must be covered by mask:1. Bridge of the nose2. Two malar eminences3. Mandibular alveolar ridge

Small tidal volumesSqueeze steadily – don’t force air too quickly10-12 breaths/minuteAssess for rise and of fall chest

Airway Assessment:Difficult Bag Mask Ventilation

• Incidence approx 5%• MOANS• M ask seal: cant approximate mask• O besity: redundant tissues impede

airflow• A ge >55: loss of elasticity tissues• N o teeth: mask doesn’t sit

properly• S tiff (lungs/body): need increased

pressure

Airway Assessment:Identification Difficult Intubation

• Incidence difficult intubation varies. • No clear definition. Approximately 5%• Corresponds to glottic view• Can’t intubate/can’t ventilate = 1 in 10,000• Strongly associated with adverse outcomes

– Airway trauma– Aspiration– Hypoxemia/Anoxic brain injury– Hypotension– Cardiac arrest and death

Assessing the Airway:Identification Difficult Intubation

LEMON

–L ook–E valuate 3-3-2 –M allampati–O bstruction/Obesity–N eck mobility

Assessment for Difficult Intubation“Look”

• External – Facial trauma– Unusual anatomy

• Internal– Foreign body– Obstructing mass

• Sensitive but not specific

Assessment for Difficult Intubation:Evaluate: 3-3-2 Rule

Mouth opening Tip of mentum to hyoid bone Thyromental distance

Access to airwayand obtaining glottic

view

Can tongue be deflected to accomdate laryngoscope

Predicts location larynx to base of the tongue. If larynx highangles difficult

Assessment for Difficult Intubation: Mallampati Score

• Validated but not as solitary predictor.

• Relates amount of mouth opening to size of tongue.

• Provides estimate of space for oral intubation by direct laryngoscopy.

• Class I or II : easy laryngoscopy

• Class III difficult • Class IV: extreme

difficulty. (10%failure).

Assessment for Difficult Intubation:Obesity

• Redundant tissue in upper airway may obscure glottis.

• Controversial about how often difficult airway.• Proper positioning key.

Assessment for Difficult Intubation:Neck Mobility

• Decreased cervical spine mobility compromises sniffing position.

• Impairs alignment of axises and glottic view• Degenerative or rheumatoid arththritis• Cervical immobilzation• Test: extending neck/touching chest

Additional Considerations in Critically Ill

• Complications intubation higher than ICU (20-40%.)– Limited physiologic reserve– Pre-existing hypoxemia or hemodynamic instability.– Inability to properly assess airway.

• Special Considerations in ICI: Three Hs: – Hypoxemia– H+ – Hemodynamics (hypotension/pulmonary hypertension)

Steps for Endotracheal Intubation

1. The 4Ps:– Preparation– Pre-oxygenation– Positioning– Premedication

2. Achieving Intubating Conditions: Laryngoscopy/Intubation

3. Post-intubation Care

Preparation

• Airway assessment– Signs of difficult bag mask ventilation– Signs of difficult intubation

• Assembling necessary equipment and medications.

• Developing an airway management plan– Back-up plan– Back-up to back-up plan

Preparation Equipment

• S uction• T ools (laryngoscope, blade, extra batteries)• O xygen• P ostioning/plan• M onitors (pulse ox, BP, capnography)• A mbu bag, airway devices• I ntravenous access• D rugs (premeds, induction, NMB)

Preparation:Preoxygenation

• Establishment of oxygen reservoir– Replace nitrogenous mixture of room air– FRC = 30ml/kg– Preferable time = 5 minutes

• Bag mask ventilation not needed if good preoxygenation.

• Preoxygenation often challenging in ICU– NIPPV– Elevating head of bed

Preoxygenation: Apnea Time (VE= 0)

- Time from 90% to 0% MUCH shorter than time from 100% to 90%.

- Obese and critically-ill desaturate quicker.

Preparation:Pretreatment

Drugs to mitigate adverse effects of intubation

•L idocaine (reactive airways or elevated ICP)•O pioids ( blunts sympathetic response and

increased BP)•A tropine ( bradycardia – mainly kids)•D efasiculating Agents (low dose competitive neuromuscular blocker in elevated ICP)

Preparation:Head Positioning

Supine

Head Elevated

Head Elevated and Neck Extending = Sniffing Position

Positioning: RAMP

• In supine patient access to airway obstructed.

• With patient propped in RAMP position, access to airway improved.

• Imaginary horizontal line from external auditory meatus to the sternal notch

Preparation:The Need for a Plan

Main Airway Algorithm

Achieving Intubation Conditions

• Many ICU patients need very little or no drugs.– Crash airway– Patient relaxed and unresponsive, similar to

conditions with rapid sequence intubation (RSI).

• May not want to stop spontaneous breathing.

Induction Agents

• Purpose: Blunt sympathetic responses, provide amnesia and improve intubating conditions.– Rapid Sequence Intubation: simultaneous

administration of sedative and a neuromuscular blocking.

– ICU patients with crash airway or pseudo-crash airway often need very little induction drug or none at all.

Induction Agents

• Midazolam: (dosage 0.1-0.3 mg/kg; time to effect >15 minutes; hypotension)

• Etomidate: (rapid onset; no hypotension; no analgesia; concerns with sepsis unjustified)

• Propofol: 1.5 to 3 mg/kg; rapid onset; hypotension; no analgesia.

• Ketamine: sedation and analgesia; no hypotension; bronchodilator effect; respiratory drive preserved; good for “awake look.”

• Thiopental: rapid onset; no analgesia; myocardial depressant; severe hypotension

Neuromuscular Blockade

• Rapid Sequence Intubation– Goal: quickly obtain intubating conditions and

quickly secure airway.– Avoid BMV and minimize risk of aspiration.– NMB standard of care in ED

Neuromuscular Blockade

• Succinylcholine– Onset 45-60 seconds; duration 6-10 minutes– 1-1.5 mg/kg– Contraindications: hx of malignant hyperthermia,

neuromuscular disease with denervation (MD, stroke > 72 hours, burns >72 hours) rhabdomyolysis, hyperkalemia.

• Non-depolarizing neuromuscular blockers– Rocuronium 0.8 -1.2mg/kg: fast onset, longer duration

than succinylocholine; can be reversed– Cisatricurium (Nimbex): not for RSI as slow onset– Vercuronium

Laryngoscopes

Macintosh Blade Miller Blade

Laryngoscopy Technique

Direct LaryngoscopyOpening Mouth and Inserting Blade

Opening Mouth with Scissors Technique

Inserting Laryngoscope

Macintosh Blade in Vallecula Miller Blade Under Epiglottis

Laryngoscopy is a predictable sequence of progressively visualized structures

“Epiglottoscopy”

• Blade inserted with laryngoscope handle pointed at the patient’s feet.

• Tongue and jaw are distracted downward to insert the blade.

• Minimal force required

• Tip of blade gets around base of tongue, permitting change in angle of lifting and better mechanical advantage.

• Epiglottis edge lifted off pharyngeal wall. (Epiglottis often camouflaged against mucosa of posterior pharynx).

• With full insertion of curved blade into vallecula the angle of lifting changes to ~40 degrees from the horizontal.

• Now the lifting force can be increased as needed.

• Tip position (not force) is the main determinant of glottic exposure.

Lifting the Scope

Yes No

Laryngoscopy: Optimizing Glottic View

Cormack-Lehane Scoring of Glottic View

Cricoid Pressure

Sellick maneuver or BURP

Avoid regurgutation of gastric contents

Imaging studies undermine theory

May worsen glottic view

Optimizing Glottic View:Bimanual Laryngoscopy

1) Drives tip of blade into proper position optimizing mechanics of indirect epiglottis elevation. 2) Moves larynx downward into line of sight.

Inserting Endotracheal Tube

Yes, good

No, bad

Inserting Endotracheal Tube

Proof of Placement• Unrecognized esophageal

intubation devastating.• Clinical indicators alone

cannot be relied upon.• Capnography gold standard.• Beware

– Esophageal intubation may give transient color change. Need >5 breaths.

– Cardiac arrest patients can give false negative color change. (Other methods = syringe test)

Rescue Strategies

• Return to spontaneous breathing• Videolaryngoscopy

• Extraglottic devices

• Bougie• Cricothyroidotomy (open vs. percutaneous)

A

Parting Thoughts

• Airway Management/Intubation in intensivists’ domain of practice.

• Getting competent requires dedication• Procedures for intubation at Jeff– Never without attending– Anesthesia supervision if not available