airway mx 2014 levitandelayed sequence intubation (dsi) weingart sd. j emerg med 2010. pmid:...

Airway management

Gabriel Blecher

Richard Levitan

1: Weingart SD, Levitan RM. Preoxygenation and prevention of desaturation during emergency airway management. Ann Emerg Med. 2012 Mar;59(3):165-75.e1. doi: 10.1016/j.annemergmed.2011.10.002. Epub 2011 Nov 3. Review. PubMed PMID: 22050948. !2: Levitan RM, Kelly JJ, Kinkle WC, Fasano C. Light intensity of curved laryngoscope blades in Philadelphia emergency departments. Ann Emerg Med. 2007 Sep;50(3):253-7. Epub 2007 Jun 22. PubMed PMID: 17588707. !3: Levitan RM, Chudnofsky C, Sapre N. Emergency airway management in a morbidly obese, noncooperative, rapidly deteriorating patient. Am J Emerg Med. 2006 Nov;24(7):894-6. PubMed PMID: 17098124. !4: Levitan RM, Pisaturo JT, Kinkle WC, Butler K, Everett WW. Stylet bend angles and tracheal tube passage using a straight-to-cuff shape. Acad Emerg Med. 2006 Dec;13(12):1255-8. Epub 2006 Nov 1. PubMed PMID: 17079788. !5: Levitan RM, Kinkle WC, Levin WJ, Everett WW. Laryngeal view during laryngoscopy: a randomized trial comparing cricoid pressure, backward-upward-rightward pressure, and bimanual laryngoscopy. Ann Emerg Med. 2006 Jun;47(6):548-55. Epub 2006 Mar 14. PubMed PMID: 16713784.

Richard Levitan

6: Collins JS, Lemmens HJ, Brodsky JB, Brock-Utne JG, Levitan RM. Laryngoscopy and morbid obesity: a comparison of the "sniff" and "ramped" positions. Obes Surg. 2004 Oct;14(9):1171-5. PubMed PMID: 15527629. !!7: Levitan RM, Everett WW, Ochroch EA. Limitations of difficult airway prediction in patients intubated in the emergency department. Ann Emerg Med. 2004 Oct;44(4):307-13. PubMed PMID: 15459613. !!8: Levitan RM, Mechem CC, Ochroch EA, Shofer FS, Hollander JE. Head-elevated laryngoscopy position: improving laryngeal exposure during laryngoscopy by increasing head elevation. Ann Emerg Med. 2003 Mar;41(3):322-30. PubMed PMID: 12605198. !!9: Levitan RM, Mickler T, Hollander JE. Bimanual laryngoscopy: a videographic study of external laryngeal manipulation by novice intubators. Ann Emerg Med. 2002 Jul;40(1):30-7. PubMed PMID: 12085070.

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Prior Preparation Prevents Piss Poor Performance

Pre-oxygenation: why?

Preoxygenation goals

1. Bring SpO2 close to 100% 2. Denitrogenate lungs 3. Denitrogenate + maximally oxygenate

bloodstream

Preoxygenation

How long? • 3 minutes How? • Reservoir facemask with max flow rate (beyond

15L/min) OR • BVM with 1-way inhalation and exhalation ports

with 2-hand technique (E-C grip)

Bad lungs?

• If SpO2 <93-95% after 3min preox: SHUNT • eg consolidation, atelectasis, interstitial/alveolar

fluid Rx? • NIV or PEEP valve on BVM

Fighting NIV mask?

• Consider “DSI” - i.e. procedural sedation using !!

ketamine !!

• See http://academiclifeinem.com/paucis-verbis-delayed-sequence-intubation/

Delayed Sequence Intubation (DSI) Weingart SD. J Emerg Med 2010. PMID: 20378297

Weingart SD, Levitan RM. Ann Emerg Med 2012. PMID: 20378297 EMCrit Podcast 40—Delayed Sequence Intubation (DSI)

Sehdev RS, et al. Emerg Med Australas 2006 PMID: 16454773 Bourgoin A, et al. Crit Care Med 2003 PMID: 12626974

General Concepts • DSI is procedural sedation/dissociation where the procedure is preoxygenation • Breaks up the sequence of RSI to preoxygenate prior to paralysis—prolongs safe

apnea duration and decreases risk of gastric insufflation or aspiration • Maintains patient’s spontaneous respirations and reflexes

Candidates for DSI • Agitated due to EtOH, head injury, or psychosis, but with normal lungs • Agitated, but with lungs capable of being oxygenated on non-rebreather (NRB)

mask: hypoxic due to COPD, pneumonia, ARDS • Agitated, but require NIV to preoxygenate • Unobtainable or unacceptable vital signs due to any of the above • Need to perform a procedure that the patient is not tolerating prior to intubation

(e.g. NGT placement prior to intubation of GI bleeder) Ketamine • Dose: 1 mg/kg IV push (may need to re-dose 0.5 mg/kg to maintain dissociation) • Pros: 30 sec onset, achieves dissociative state, maintains spontaneous

respirations and airway reflexes, maintains hemodynamic stability • Cons: May increase intracranial pressure in patients with high MAP, may cause

laryngospasm, use with caution in patients with CAD, HTN, or tachycardia Equipment & Troubleshooting • Respiratory therapist • Nasal cannula (NC) • Non-rebreather (NRB) mask • Bag valve mask (BVM) with PEEP valve • 2 O2 flow meters (NRB or BVM, NC) • Ventilator with NIV settings • Non-vented mask with straps for CPAP • ETCO2 monitor Pearls: DSI ≠ NIV • Preoxygenation may be achieved with NC, NRB mask, OR NIV, depending on the

patient’s needs • If your patient is not agitated, NIV may be sufficient without the need for

sedation/dissociation • Intubation may be avoided if adequate dissociation and oxygenation is attained

Positioning

• Preoxygenation: NOT FLAT! !Why? • atelectasis • regurgitation/aspiration risk

Apneic oxygenation

Mechanism: • 250mL/min of O2 moves from alveoli into

bloodstream • Only 8-29mL/min of CO2 moves into alveoli • —> subatmospheric pressure in alveoli • mass flow of gas from pharynx to alveoli

Apneic oxygenation: how

• Nasal cannulae set to >15L/min • Need clear path from nose —> pharynx:

• Consider nasopharyngeal airways • Head elevation • Jaw thrust • Chin lift • Ear to sternal notch position

Digression: procedural sedation

• Do you use supplemental O2 or no?

Effect of supplemental O2

Procedural sedation

• Nasal cannulae on but not flowing • Monitor SpO2 and ETCO2

Hypoventilation due to oversedation?

O.O.P.S: • Oxygen on: NC + NRB • Pull mandible forward • Sit patient up

Back to the programme….

Ventilation before laryngoscopy?

• Severe metabolic acidosis • Raised ICP • PaCO2 increases by 8-16 mmHg in first min of

apnea then 3 mmHg/min How? • Slow: 1-2 sec/breath • Low volume: one hand squeezing bag (6-7mL/

kg) • Low rate: 6-8/min

Laryngoscopy

“Epiglottoscopy”

• Finding the epiglottis is key • Proceed slowly down tongue • Fluids, blood, saliva pool in hypopharynx: use

suction!

“Bimanual laryngoscopy”

• Manipulation of thyroid cartilage to improve view • NOT B.U.R.P or cricoid pressure • Once view optimized, assistant can maintain

pressure

Positioning: EAM to sternal notch

Tube shape

• Too much tube curvature: • tip catches on anterior tracheal rings • limited maneuverability within hypopharynx • obstructs view of target

• Solution: straight-to-cuff shape; angle <35°

Tube shape

Tube delivery issues

1. Can’t get tube to glottis

Tips

• Use right corner of mouth • Insert tube behind maxilla • Come from below: avoid line of sight • Use bougie for epiglottis-only view

2. Tube won’t pass

2. Tube won’t thread off bougie

Video laryngoscopes

2 blade styles: • hyperangulated shape: Glidescope • Macintosh shape: eg C-MAC, Glidescope direct

blade

Glidescope: common issues

• Great view - can’t intubate! • Poor view with blood/secretions

Solutions

• Use GlideRite stylet (70°) • Must have glottis in top half of screen: often

need to back up scope • Insert tube in midline, direct vision until can’t see

tip • Hold tube at end, not as a pencil • After passing through cords, pop stylet up • Any resistance: turn tube clockwise • Remove stylet (towards feet) before passing

tube

Questions?

References

• Gerstein NS, Carey MC, Braude DA, Tawil I, Petersen TR, Deriy L, et al. Efficacy of facemask ventilation techniques in novice providers. Journal of Clinical Anesthesia. 2013 May;25(3):193–7

• Collins JS, Lemmens HJM, Brodsky JB, Brock-Utne JG, Levitan RM. Laryngoscopy and morbid obesity: a comparison of the "sniff" and “ramped” positions. Obes Surg. 2004 Oct;14(9):1171–5

• Weingart SD, Levitan RM. Preoxygenation and prevention of desaturation during emergency airway management. Ann Emerg Med. 2012 Mar;59(3):165–75.e1

• Ramachandran SK, Cosnowski A, Shanks A, Turner CR. Apneic oxygenation during prolonged laryngoscopy in obese patients: a randomized, controlled trial of nasal oxygen administration. Journal of Clinical Anesthesia. Elsevier; 2010 May;22(3):164–8.

• Fu ES, M.D., Downs, John B,M.D., F.C.C.P., Schweiger, John W,M.D., F.C.C.P., Miguel RV, M.D., Smith, Robert A,PhD., R.R.T. Supplemental Oxygen Impairs Detection of Hypoventilation by Pulse Oximetry*. Chest 2004 11;126(5):1552-1558.