SPECIAL ISSUES IN INTUBATION lecture - shah

SPECIAL ISSUES IN INTUBATION lecture - shah

Transcript

1. SPECIAL ISSUES IN INTUBATION/ EXTUBATION Usman ali shah, md
2. Outline • Background • Physiology • Anatomy • Cuffed vs Uncuffed ETTs • Syndromes • Planning • Equipment • Questions
3. Physiology • High metabolic rate • 7-9 mL O2/kg/min • Increased MV/FRC ratio • Closing capacity higher in infants • High chest wall compliance, low lung compliance • Infant is an obligate nasal breather • Epiglottis more cephalad • Hagen-Poiseuille’s Law: R = (8ln)/П r4
4. Pediatric Airway • Large head, short neck, large tongue, narrow nasal passages, larynx more cephalad (C4) and anterior, epiglottis long and stiff, trachea short, occiput • More mobile laryngeal structures aid in DL
5. Cuffed ETTs • Eckenhoff 1951 • Based on cadaveric dissections by Bayeux in 1897 • Narrowest portion of the upper airway – level of the cricoid cartilage • “funnel morphing into cylinder”
6. Cuffed ETTs • Litman et al 2003 • 99 children under 14 y/o • Larynx in sedated, unparalyzed children undergoing MRI • More cylindric than funnel-shaped • Narrowest portion at VC • Cricoid lumen is elliptical (greater AP diameter) • Dalal et al 2008, 2009 • 128 children under 13 • Bronchoscope imaging in anesthetized and paralyzed children
7. Cuffed ETTs • Weiss and Dullenkopf, 2009 • 2246 children in 24 centers • Current problems with cuffed ETTs – oversized external diameters, inadequately designed cuffs, cuff overinflation • New cuffed ETT with polurethane cuff • Reliably sealed airway < 20 cm H20 • Decreased exchanges • No increase in post-extubation stridor
8. Syndromes – Cranial Vault • Craniosynostoses • ~0.6 per 1000 births • Normal newborn brain allows for rapid growth of brain via unfused sutures and open fontanelles; premature closure results in craniosynostosis • Nonsyndromic (most common ~50% affects only saggital) vs syndromic (~20% of cases) • Hypoplastic midface can lead to challenging mask fit
9. Craniosynostosis
10. Syndromes – Cranial Vault Apert’s – craniosynostosis, midface hypoplasia, syndactyly
11. Syndromes - Craniovertebral • Klippel-Feil • Varying combinations of fusion of cervical vertebrae; neck is short, may also be atlantooccipital fusion • Associated with fetal alcohol syndrome, Goldenhar’s (hemifacial microsomia), and anomalies of the extremities • Challenging laryngoscopy/intubation
12. Syndromes - Face Cleft lip/palate Among most common congenital anomalies, ~1/800 25% of cleft lip b/l, and 85% associated with palate Alone, syndrome (>300), sequence (Pierre-Robin) Difficulty with laryngoscopy not uncommon; Grade 3/4 view as high as 4-7%. Difficulty predicted by b/l clefts and retrognathia Can be associated with Pierre- Robin, Treacher-Collins, Goldenhar
13. Syndromes - Face • Pierre Robin Sequence • Retrognathia, glossoptosis, airway obstruction (as many as ¼ will need surgical intervention) • Small mandible results from fixed fetal position in utero that inhibits mandibular growth
14. PRS • Management options: prone/lateral positioning, tongue-lip suture, mandibular distraction, tracheostomy
15. Syndromes - Face • Treacher-Collins • Aka mandibulofacial dysostosis • Autosomal Dominant, variable penetrance • Mandibular and midface hypoplasia, ear deformities, hearing loss, cleft palate in 1/3 • Airway obstruction
16. Down’s • ~1 per 600 – 800 live births • Hypotonia may affect patency of their upper airway • Obstruction <- relatively large tongue, short neck, and crowded midface and laryngomalacia • Worsened by sedatives and inhalation induction • Increased incidence of subglottic stenosis • Ligamentous laxity of the atlantoaxial joint -> C1/2 subluxation and SCI
17. Evaluation of the Airway • Preop airway exam – mouth opening, dentition, cervical mobility, tongue, retrognathia, micrognathia • Predictors of difficult intubation – mandibular hypoplasia, limited mouth opening, facial asymmetry including ear, stridor, history of OSA Deal with it
21. Spontaneous Breathing • Maintain spontaneous ventilation during inhalation induction • Assessment of depth of anesthesia
22. Equipment - Ventilation • Cushion-seal face masks • Dead space – 50 – 80 cc • Midface hypoplasia – dental rolls between gingiva and buccal mucosa
24. Equipment - intubation • BURP (Apply your fingers to the thyroid or cricoid cartilage. Apply backward pressure and push the cartilage toward the chin. Move it to the patient's right.) • Bimanual laryngoscopy • Wide Flange • Flagg • Wis-hipple • Robertshaw
25. Bougie
26. Optical Stylet • Shikani – distally malleable, insufflation port • Storz Bonfils – nonmalleable • 2.5 ETT
27. Rigid Fiberoptic/Video Laryngoscopy • Bullard – 1st indirect laryngoscope, pediatric and adult size, 0.64cm
28. Rigid Fiberoptic/Video Laryngoscopy • Airtraq – channel for ETT, 4 sizes (+nasal and DLT), disposable, portable, inexpensive • Storz video – Miller 0 and 1, Miller 3, Mac 2 • Truphatek EVO2 • Glidescope – 0,1,2,2.5
29. Fiberoptic Bronchoscope • Gold Standard • Ultrathin bronchoscopes can load 2.5 ETT (Olympus LF-P with diameter of 2.2mm) • Not all have channels for suctioning/insufflation • May have limited tip movement
33. Ultrasound • Dalesio et al, 2014 • Ultrasound used to visualize anatomy in awake 3 y/o • Visualize left VC paresis in awake 10 month old • Direct periglottic steroid injection through cricothyroid membrane in 20 month old under GA for laryngotracheomalacia, confirmed via rigid bronch
34. Ultrasound • Fiadjoe, 2014 • 14 month old female with PFO, ecrodactyly, blindness • DL x 2 poor view, while waiting for video laryngoscope, used ultrasound to visualize VC • Operator performed jaw thrust with one hand, ETT with the other
35. Take Home Points • Cuffed ETTs are being considered more for use in pediatric anesthesia, owing to recent studies • There is no accepted pediatric difficult airway algorithm, though proposed algorithms often mirror the ASA Difficult Airway Algorithm • Few or no prospective studies demonstrate the superiority of certain equipment or techniques over others, though there are many case reports detailing their use
37. References • Smith’s Anesthesia for Infants and Children, 8th Edition. Davis et al • Perioperative Management of Pediatric Patients with Craniosynostosis. JL Koh, H Gries - Anesthesiology clinics, 2007 - Elsevier • Anaesthetic considerations in Klippel-Feil syndrome. M Naguib, H Farag, AEW Ibrahim - Canadian Anaesthetists' Society, 1986 – Springer • Airway Management in Cleft Lip and Palate Surgery. DJ Hatch - British journal of anaesthesia, 1996 - British Jrnl Anaesthesia • Prediction of difficult airway in school-aged patients with microtia. Uezono S, Holzman RS, Goto T et al. Paediatr Anaesth 2001; 11: 409–413. • Proposal for the management of the unexpected difficult pediatric airway. M Weiss, T Engelhardt - Pediatric Anesthesia, 2010 - Wiley Online Library • Monitored anesthesia care with a combination of ketamine and dexmedetomidine during magnetic resonance imaging in three children with trisomy 21 and obstructive sleep apnea. N Luscri, JD Tobias - Pediatric Anesthesia, 2006 - Wiley Online Library • Some Anatomic Considerations of the Infant Larynx Influencing Endotracheal Anesthesia. JE ECKENHOFF - Anesthesiology, 1951 - journals.lww.com • Developmental Changes of Laryngeal Dimensions in Unparalyzed, Sedated Children. RS Litman et al. Anesthesiology, 2003 - journals.lww.com
38. References • Upper airway dimensions in children using rigid video-bronchoscopy and a computer software: description of a measurement technique. PG Dalal, D Murray, A Feng, D Molter… - Pediatric …, 2008 - Wiley Online Library • Prospective randomized controlled multi-centre trial of cuffed or uncuffed endotracheal tubes in small children. M Weiss, A Dullenkopf, et al - British journal of Anaesthesia, 2009 - British Jrnl Anaesthesia • The efficacy of the “BURP” maneuver during difficult laryngoscopy. O Takahata, M Kubota, K Mamiya, Y Akama… - Anesthesia & Analgesia 1997 - journals.lww.com • Laryngeal View During Laryngoscopy: A Randomized Trial Comparing Cricoid Pressure, Backward-Upward-Rightward Pressure, and Bimanual Laryngoscopy. RM Levitan, WC Kinkle, WJ Levin… - Annals of emergency …, 2006 – Elsevier • Management of the difficult pediatric airway with Shikani Optical Stylet. M Shukry, RD Hanson, JR Koveleskie… - Pediatric Anesthesia 2005 - Wiley Online Library • The Bullard Laryngoscope: A New Indirect Oral Laryngoscope (Pediatric Version). LM Borland, M Casselbrant - Anesthesia & Analgesia, 1990 - journals.lww.com • The Efficacy of the Storz Miller 1 Video Laryngoscope in a Simulated Infant Difficult Intubation. JE Fiadjoe, PA Stricker, RS Hackell et al - Anesthesia & Analgesia, 2009 - journals.lww.com • Ultrasound Use in the Pediatric Airway: The Time Has Come. NM Dalesio, D Kattail et al - A&A Case Reports. 2014 - journals.lww.com • Ultrasound-guided Tracheal Intubation: A Novel Intubation Technique. JE Fiadjoe, P Stricker, H Gurnaney, A Nishisaki… - Anesthesiology, 2012 - journals.lww.com