Presentation on theme: "Endotracheal Intubation in the ICU David Oxman, MD July 12, 2013."— Presentation transcript:
Endotracheal Intubation in the ICU David Oxman, MD July 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 intubation 1.inadequate oxygenation or ventilation 2.airway protection in a patient with altered mental status 3.expectation 1 or 2 will develop soon!! Contraindications 1.Laryngeal Trauma 2.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 ventilation 2)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 Ventilation One-handed technique Two-handed techniques Three facial landmarks that must be covered by mask: 1.Bridge of the nose 2.Two malar eminences 3.Mandibular alveolar ridge Small tidal volumes Squeeze steadily – don’t force air too quickly 10-12 breaths/minute Assess 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 airway and obtaining glottic view Can tongue be deflected to accomdate laryngoscope Predicts location larynx to base of the tongue. If larynx high angles 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)
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 (V E = 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
Direct Laryngoscopy Opening 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