Upper airway obstruction in pediatric patient s from anesthesiologist vew

1. Upper airway obstruction in pediatric patientsfrom anesthesiologist vew Prof. Mirjana Shosholcheva University clinic of surgery “St. NaumOhridski” Medical faculty-Skopje, Macedonia

2. Disclosures • No financial disclosures • No conflict of interest

3. Key points Causes of airway obstruction in children Signs of airway obstruction Airway obstruction with foreign body Airway obstruction during emergence from anaesthesia Management of laryngospasm Securing the airway in a child with airway obstruction

4. Upper airway obstruction accounts for up to 15% pediatric emergency* The major causes are: Viral croup (80%)** Epiglotitis (5%) Foreign body aspiration Failure to manage the airway is the leading cause of preventable pediatric deaths Epidemiology and mortality Infants and children decompensate more quickly compared to adults • *Loftis L. Emergent evaluation of acute upper airway obstruction in children. • Reprint from Up to date www.uptodate.com • ** Manno M. Pediatric respiratory emergencies: Upper airway obstruction and infections. In: Marx J, ed. • Rosen's Emergency Medicine: Concepts and Clinical Practice . 7th ed. Philadelphia, Pa: Mosby Elsevier; • 2009:chap 166

5. Important causes of airway obstruction in children Laryngospasm after tracheal extubation –major of UAO after surgery Life-threatening emergency • Depressed • conscious level Congenital anomalies • Post-extubation laryngospasm • Anaphylactoid • reactions Rapidly progressive Airway obstruction Infections • Thermal injury Airway foreign body Trauma • *Morton NS. Large airway obstruction in children: causes, assessment • and management. Update Anaesthesia 2004; 18 (article 13):1

6. Signs of airway obstruction in children conscious patient unconscious or sedated patient • marked respiratory distress • altered voice • dysphagia • the hand-to-the-throat choking sign • stridor, facial swelling • prominence of neck veins • absence of air entry into the chest • tachycardia • inability to ventilate with • a bag-valve mask • asphyxia progresses to cyanosis • bradycardia • hypotension • irreversible cardiovascular collapse Obstructive noise or stridoris specific for UAO

7. Mild upper airway obstruction child recovering from anaesthesia tonsillar hypertrophy and obstructive sleep apnea Signs of partial upper airway obstruction include biphasic snoring and mild desaturation Severe, non-complete, progressive airway obstruction increased work of breathing respiratory failure Hypoxemia cardiac arrest Children with severe croup, tracheitis, epiglottitis, airway burns Specifics regarding signs of airway obstruction in children Trauma, depending on its severity and location, may produce immediate or progressive obstruction

8. Signs of increased work of breathing Tachypnea Paradoxical respiration “See-saw” pattern of breathing (dyssynchrony between rib cage and abdomen) • Suprasternal, intercostal, and subcostal retraction along with an increased use of accessory muscles of respiration • auto CPAP • Position: Infants may assume an opisthotonic position; the "tripod" or sniffing position is seen in the older child

9. Stridor Inspiratory stridor Expiratory stridor airway compromise at the supraglotic or laryngeal level intrathoracic obstruction The magnitude or severity of stridor does not correlate with the severity of obstruction

10. Signs of ineffective breathing and respiratory failure: Cyanosis Altered consciousness Bradypnea, apneic spelss Silent chest in spite of vigorous effort Post-extubation laryngospasm, angiooedema and anaphylactoid reactions Compleet airway obstruction Choking,absent breath sounds and aphonia This rapidly progresses to cyanosis, bardycardia and cardiac arrest

11. Airway obstruction with foreign body Foreign-body aspiration is a relatively frequent accident and a leading cause of accidental death in children under 5 years of age Diagnosis of foreign body aspiration should be suspected in children who do not respond to appropriate intervention Laryngeal impaction is life-threatening (large or sharperdged foreign bodies may lodge in the larynx) Most foreign bodies pass the vocal cords and lodge in the lower airways (bronchi -80%) Symptoms can mimic other diseases such as croup or asthma

12. Airway obstruction with foreign body • Nasal foreign bodies • unilateral rhinorrhea and stinking breath • Oropharyngeal foreign bodies: • mouth breathing • Children with a history of choking and subsequentsymptoms must be referred to immediate bronchoscopy! What about the child who has stridor and wheezing? • The causes of stridor and wheezing in older infants and children include • foreign bodies in the airway and in the esophagus • and combination of infectious causes

13. Management of airway obstruction with foreign body *if the child can cough and verbalized it is placed in the position of comfort and oxygen is given IV line placement and other interventions which may agitate the child in this case are avoided X-ray evaluation for localization can be performed urgently in stable children The presence of asphyxia indicates the need for immediate resuscitation and securing the airway • *Schmidt H., ManegoldBC. Foreign body aspiration in children. SurgEndosc 2000; 14:644-8

14. “Circulus viciosus” BLS maneuvers (Heimlich, Guidel ) Most patients can be discharged within 24 h Magill forceps or suction direct laryngoscopy flexible bronchoscopy Complications 1. Mild oedema of the respiratory mucosa 2. Tracheobronchitis 3. granulation tissue short course of corticosteroids Repeat bronchoscopy rigid bronchoscopy

15. Child is in respiratory distress! inhalational induction with 100% oxygen and sevoflurane After loosing the consciousness. i.v. cannula TIVA with propofol and fentanyl gentle assistance with inhalational technique cords are sprayed with local anaesthetic rigid bronchoscope with a ventilating side arm is inserted, facilitated by laryngoscopy higher FiO2 The foreign body is withdrawn by a forceps through the bronchoscope Dexamethadone Laryngeal edema might be worsening after multiple insertions of the rigid bronchoscope, and post-procedure reintubation might be required

16. Securing the airway in a child with airway obstruction – General considerations Laryngoscopy and intubation volatile anaesthetics Sevoflurane might be choice, but its use has some controversy, because lower potency of sevoflurane may not permit intubation The Jackson-Rees modification of Ayer,s “T piece” circuit - CPAP Attempts to assist ventilation against complete obstruction are usually futile! Alveolar ventilation in these children is severely compromised. Uptake of volatile agents is very slow and induction of anaesthesiamay take more than 15 min

17. Any attempt at “asynchronous” assistance leads to complete obstruction, especially in large foreign bodies “Synchronized” assistance (analogous to triggered ventilation) is very helpful to maintain oxygenation

18. As the depth of anaesthesia increases, the child may be gradually lowered to the supine position flexible fiberoptic bronchoscopy intubation is difficult or impossible If the condition of the child deteriorates, cricothyrotomy and ventilation through a T piece circuit can be considered Jet ventilation is not appropriate as it may lead to barotrauma

19. The safest option is emergent tracheostomy under musk anaesthesia for most children who cannot be intubated in one or two attempts

20. Controversy associated with heliox therapy in UAO • Heliox has been used in several conditions: postextubation laryngeal edema, tracheal stenosis or extrinsic compression, status asthmaticusand angioedema • To be effective, the helium–oxygen ratio must be at least 70:30 • Although the work of breathing and dyspnea improves to some degree with the use of heliox, the mechanical obstruction is still in place • The use of heliox in patients with severe UAO should only beused to provide temporary support pending definitive diagnosis and management

21. Algorithm for management of upper airway obstruction

22. Infective causes of airway obstruction acute clinical syndrome of hoarse voice, barking cough and stridor Radiological presentation of subglottic oedemain viral croup (left) compared with a normal trachea (right) Endoscopic view of subglottic oedema in viral croup There is some controversy regarding treatment with epinephrine Usually affects children from 6 months to 4 years of age, with a peak incidence at 2 years of age

23. Epiglotitis Schematic (left) and endoscopic view (right) of epiglottitis. Lateral neck radiographs of a normal child (left) and a child with epiglottitis with the typical thumb sign (right). Conversely, epinephrine is not effective in the treatment of epiglottitis and may be deleterious. Controversy! To look or not to look

24. Airway burns Heat produces an immediate injury to the airway mucosa edema Suspect for inhalation injury Exposure in an enclosed space Decreased level of consciousness, confusion Soot in mouth, nares Carbonaceous sputum Swelling, ulceration of oral mucosa or tongue Dyspnoea Increased work of breathing Hoarseness Oxygen saturations <94% in air Caboxyhaemoglobin >5% on co-oximetry Stridor, wheeze, crepitations

25. Effect of deep face burns on airway maintenance are: Airway obstruction by intraoral and laryngeal edema Anatomic distortion by face and neck edema, which increases the difficulty of endotracheal intubation Oral edema decreasing clearance of intraoral secretion Impaired protection of the airway from aspiration Maintaining an adequate airway! • Maintain airway patency • Protect against aspiration • Pulmonary toilet to decrease mucous plugging and infection risks • Need for positive-pressure When in doubt, it is safer to intubate!

26. TRAUMATIC LESIONS Damage from endotracheal intubation and tracheotomy Even the dictum that ‘cuffed endotracheal tubes should not be used in children under the age of 8 years’ can no longer be maintained since the development of high-volume, low-pressure cuffs* Endotracheal tube complications • incorrect size, traumatic or multiple intubations • up and down movements of the endotracheal tube • inadequateanalgesia and sedation, whereby the infants struggle while intubated *Newth CJL, Rachman B, Patel N, Hammer J. The use of cuffed versus uncuffed endotracheal tubes in pediatric intensive care. J Pediatr2004; in press

27. Cuff vsUncuffed Endotracheal Tube Controversial issue • Traditionally, uncuffed ETT recommended in children < 8 yrs old to avoid post-extubation stridor and subglottic stenosis • Arguments against cuffed ETT: smaller size increases airway resistance, increase work of breathing, poorly designed for pediatric patients, need to keep cuff pressure < 25 cm H2O • Arguments against uncuffed ETT: more tube changes for long-term intubation, leak of anesthetic agent into environment, require more fresh gas flow > 2L/min, higher risk for aspiration -

28. Concluding Recommendations - • For “short” cases when ETT size >4.0, choice of cuff vsuncuffedprobably does not matter • Cuffed ETT preferable in cases of: • high risk of aspiration (ie. Bowel obstruction), • low lung compliance (ie. ARDS, pneumoperitoneum, CO2 insufflation of the thorax, CABG), • precise control of ventilation and pCO2 (ie. increased intracranial pressure, single ventricle physiology) Golden, S. “Cuffed vs. Uncuffed Endotracheal tubes in children: A review” Society for Pediatric Anesthesia. Winter 2005 edition.

29. Laryngeal Mask Airway – WHEN? Supraglottic airway device • Flexible bronchoscopy, radiotherapy, radiologic procedures, urologic, orthopedic, ENT and ophthalmologic cases are most common pediatric indications for LMA • Useful in difficult airway situations, and as a conduit of drug administration (ie. Surfactant) • Different types of LMAs: Classic LMA, Flexible LMA, ProSeal LMA, Intubating LMA • Disadvantages: Laryngospasm, aspiration

30. Airway obstruction during emergence from anaesthesia Postoperative laryngospasm - life-threatening complication aspiration, airwayobstruction Tracheal extubation awake deep anesthesia Concern:light plane of anesthesia! local irritation by blood or saliva light planes of anaesthesia Child undisturbed - in the lateral recovery position Hypoventilation Hypoxemia Hypercarbia Cardiac dysrhythmias Cardiac arrest

31. Emergence and extubation: A systemic approach Can this patient be extubated while deeply anesthetized? Yes No • Difficult musk ventilation • Difficult intubation • Residual NMB present • Full stomach • No rezidual NMB • Easy musk ventilation • Easily intubated • Not at increased risk for • regurgitation/aspiration • - Normothermic Can this patient be extubated immediately following surgery and emergence from general anesthesia?

32. Can this patient be extubated immediately following surgery and emergence from general anesthesia? Yes No • - Hypoxic (O2 saturation < 90 mmHg) • - Excessively hyperbaric(Pa CO2 >50mm Hg • - Hypothermic (< 34 C) • - NMB present • Awake • Following commands • Breathing spontaneuosly • Wheel oxigenated • Not excessively hyperbaric • (PaCo2  50 mmHg • Fully recovered from MR • Sustained head lift • Strong hand grip • Strong tongue protrusion

33. Partial laryngospasm complete laryngospasm inspiratory stridor absence of air movement Tracheal tug and paradoxical (“see-saw”) movement of the abdomen Increased airway problems • childrenwith a history of a recent upper respiratory tract infection • former premature infants • children with chronic, obstructive sleep apnea

34. Managamentof laryngospasm jaw thrust maneuver, neck extension and mouth opening mild biphasic snoring-noisy breathing placing the child in the “safe” position oxygen by face mask positive pressure with a bag and face mask maybe required along with a naso-pharyngeal airway If necessary a dose of succinylcholine followed by tracheal re-intubation (in children older than 2 years!!!)

35.  Of particular concern have been the instances of life-threatening malignant hyperpyrexia and reports of rare, but often fatal, hyperkalaemic cardiac arrests in young boys with undiagnosed muscular dystrophy. As a result of these reports, in 1994, the US Food and Drug Administration (FDA) recommended that ‘the use of succinylcholine in children should be reserved for emergency intubation and instances where immediate securing of the airway is necessary, e.g. laryngospasm, difficult airway, full stomach, or for i.m. use when a suitable vein is inaccessible’.Since the publication of this recommendation, the use of succinylcholine in routine anaesthesia in children has been declined.

36. RISK OF CARDIAC ARREST FROM HYPERKALEMIC RHABDOMYOLYSIS This syndrome often presents as peaked T-waves and sudden cardiac arrest within minutes after the administration of the drug in healthy appearing children (usually, but not exclusively, males, and most frequently 8 years of age or younger). There have also been reports in adolescents.

37. Recent concerns about the elective use of succinylcholine in pediatric patients have focused on the occasional reports of hyperkalemic cardiac arrest, particularly in children with undiagnosed Duchenne muscular dystrophy. The incidence of Duchenne muscular dystrophy is only 1 in 3000 to 8000 male children. The revised labeling continues to permit the use of succinylcholine for emergency control of the airway and treatment of laryngospasm.Succinylcholine is the only neuromuscular blocking agent currently available that has been demonstrated to be effective after intramuscular (IM) administration when emergency control of the airway is required and there is no IV access. In this circumstance, the dosage must be increased to 4 to 5 mg/kg IM. Atropine is administered simultaneously. Following IM succinylcholine, onset of neuromuscular blockade takes approximately 2 to 5 minutes; the response in patients who are hypotensive or hypovolemic is unpredictable. 

38. In the Proposed Approachto the management of laryngospasmfirst of all is to think of: • Airway irritation/obstruction • Blood/secretions • Light anaesthesia • Regurgitation

39. The main aim is to rapidly oxygenate child! • 100% oxygen (warm, humidified, • oxygen enriched air mixture in neonates) • Visualize and clear pharynx/airway • Jaw thrust with bilateral digital pressure behind • temporomandibularjoint, oral/nasal airway • Deepen anaesthesia with propofol (20% induction dose) Succinylcholine 0.5 mg/kg to relieve laryngospasm (1.0-1.5 mg/kg i.v. or 4.0 mg/kg i.m. for intubation Be aware of use in children < 2 years old!!! • Intubate and ventilate

40. Airway obstruction in the postoperative period post-intubation croup Laryngeal edema - in neonates and infants= inspiratory stridor within 6 h of extubation (Subglottic edema of 1 mm in neonates can reduce the laryngeal lumen by 35%) - Supraglottic oedema - Retroarytenoidal oedema - Subglottic oedema Associated risk factors tight fitting tube trauma at intubation duration of intubation >1 h coughing on the tube change of head and neck position during surgery

41. Management of laryngeal edema warm, humidified, oxygen enriched air mixture nebulized epinephrine 1:1000 (0.5 ml kg−1 up to 5 ml) • dexamethasone 0.25 mg kg−1 followed • by 0.1 mg kg−1 six hourly for 24 h reintubation with a smaller tube in severe cases

42. Conclusion ● Upper airway obstruction (UAO) is a life-threatening emergency that requires prompt diagnosis and treatment ● Severe UAO can be surprisingly asymptomatic at rest if it develops gradually. Sudden clinical deterioration is unpredictable ● Patients with possible UAO must never be sedated until the airway is secured. Minimal sedation may precipitate acute respiratory failure ●Achievement of airway patency in total airway obstruction and reestablishment of ventillatory airflow is the first and foremost goal of the anaesthesiologists

43. Conclusion ● Critical care physicians must be aware that pharmacologic interventions (epinephrine, steroids, and heliox) provide temporary support but cannot significantly improve mechanical UAO ●Bronchoscopy constitutes the most accurate diagnostic tool and frequently provides the best way to correct UAO ●Cricothyroidotomy is the surgical intervention of choice to reestablish airflow when medical interventions have failed

44. Conclusion If the anaesthesiologist is competent in the full range of airway access procedures and when appropriately management is performed, the possibility of incidence and consequences of acute airway obstruction in children will be very low

45. Thank you