Pediatric Respiratory Emergencies

1. Pediatric Respiratory Emergencies Emergency Medicine Rounds October 3, 2003 Dr. Edward Les

2. Overview • Croup • Bronchiolitis • Status asthmaticus • others

3. Case 1 • 3 year old girl brought to ED with a 2-day history of worsening cough and wheezing • Her mother has been giving her nebulized ventolin treatments every 4 hours for the past day without much improvement • In the ED her temp is 38.5, RR is 50, O2 sat 94% • On exam: moderate increased work of breathing, decreased aeration throughout and diffuse wheezes

4. Case 2 • A 6-year-old girl comes to the ED with respiratory distress. • Known asthmatic, wheezing for 4 days • no response to ventolin MDI as often as q2h at home • She is diaphoretic, RR 60, O2 sat 88% on RA • Able to speak in short sentences b/w breaths • You immediately provide supplemental O2 and 3 back-to-back Ventolin nebs, as well as oral ‘roids; 30 minutes later: no improvement

5. Status asthmaticus Definition: • Any patient not responding to initial doses of nebulized bronchodilating agents Helfaer et al; Textbook of pediatric intensive care, 3rd ed. 1996.

6. Epidemiology of asthma • Clearly on the rise • Unclear why • 10% of kids in U.S. have asthma • Annual hospitalization rates doubled b/w 1980-1993 for 1-4 year-olds • Asthma death rates double for 5-14 year age group

7. Risk Factors for Potentially Fatal Asthma Medical factors • Previous attack with: • Severe, unexpected, rapid deterioration • Respiratory failure • Seizure or loss of consciousness • Attacks precipitated by food Ethnic factors • Nonwhite children (African American, Hispanic, other) Psychosocial factors • Denial or failure to perceive severity of illness • Associated depression or other psychiatric disorder • Noncompliance • Dysfunctional family unit • Inner-city residents

8. But… • As many as 1/3 of children who die from asthma have only had mild preceding asthma • Australian study of 51 pediatric deaths • Only 39% had potentially preventable elements Robertson et al, Pediatric Pulmonol 1992;13:95-100

9. Clinical presentation & assessment • Signs and sx: common knowledge • Measure pulse ox • Clinical asthma scores • Research tool • PFT’s • Do in kids > 5-6 years old • PEF (% of best): based on 3 attempts

10. PEF predicted (%) <30 30-50 50-80 >80 Exacerbation severity Possibly life-threatening Severe Moderate Mild PEF as predictor of asthma severity

11. Treatment guidelines • O2 if needed • 2 agonists: salbutamol • Anticholinergics: ipratropium • Steroids • Magnesium • Heli-ox • (Intubation)

12. Salbutamol Method of delivery? • nebulization • <10 kg: 1.25 mg in NS • 10-20 kg: 2.5 mg in NS • > 20 kg: 5 mg in NS • Single dose/re-evaluate vs q 20 min X3 vs continuous • O2 flow rate important • 10-12 LPM in order to deliver particles in 1-3 mcm range

13. Salbutamol Method of delivery? • MDI with spacer • Australian approach • < 6 years: 6 puffs • > 6 years: 12 puffs • Same frequency as for nebs • Equivalent (or better) efficacy

14. Salbutamol Method of delivery? • IV: patients unresponsive to treatment with continuous ventolin • 10 mcg/kg over 10 minutes, then 0.2-5 mcg/kg/min • Need supplemental K+

15. Anticholinergics: ipratropium When? • Immediately in moderate to severe asthma • Reduces duration and amount of treatment before discharge • Most severely ill kids benefit most Schuh et al, J Pediatr 1995;126:639-645 • 250-500 mcg with salbutamol q20min x 3

16. ‘roids For everybody in E.D.? • NAEPP: to any patient that doesn’t respond completely to one inhaled  agonist treatment, even if the patient has a mild exacerbation

17. ‘roids Route of administration PO and IV: equal efficacy • Usually po • IV when can’t tolerate po or very sick • Methylpredisone 0.5-1 mg/kg q6h, or • Hydrocortisone 2-4 mg/kg q6h • 1-2 mg/kg/day prednisone • 0.15-0.3 mg/kg/day dexamethasone

18. ‘roids Inhaled steroids for status asthmaticus? • Cochrane meta-analysis of six RCT’s suggests benefit Edmonds et al, in The Cochrane Library (Issue 2), 2001 • But… • Compared inhaled to placebo, not to parenteral steroids • No children with severe asthma enrolled • PO or IV steroids remain avenue of choice

19. ‘roids alert Children with acute asthma and recent exposure to chickenpox should not receive steroids, unless they are considered immune • Even a single course of corticosteroids can increase the risk for fatal varicella Kasper et al, Pediatr Infect Dis J,1990;9: 729-32

20. Magnesium Good evidence for efficacy in children Ciarallo, et al, Arch Pediatr Adolesc Med, 2000;154:979-983 • 30 patients in RDBPC trial • Tx group: 40mg/kg IV Mg over 20 minutes to children with moderate-severe asthma refractory to nebulization therapy • 50% of tx group discharged home • 100% of placebo group admitted (P = 0.002) Rowe, Ann Emerg Med, 2000;36(3):181-90 • Systematic review of literature: 7 trials (5 adult, 2 pediatric) • Beneficial for patients who present with severe acute asthma

21. Magnesium ? Causes relaxation of smooth muscle by inhibiting calcium uptake • Dose: 30-75 mg/kg IV over 20 minutes • Max dose 2 g • Safe and well tolerated • Occasional nausea, flushing, weakness

22. Heli-ox Not used much in ED • Theoretical advantage: reduces turbulent flow • Prospective randomized double-blind crossover study in in 11 severe non-intubated pediatric asthmatics failed to show benefit Carter et al, Chest 1996;109:1256-61 • Use limited by patients’ O2 requirement

23. Intubation/mechanical ventilation Avoid if at all possible: high morbidity/mortality • RSI: which sedative? • Ketamine with atropine • Ventilation principles • Low rate, long exp times, controlled pressure, permissive hypercarbia

24. Case 1 (cont) • After appropriate treatment she is much improved with RR 30 and O2 sat 98% on RA, with minimal residual wheezing. • What are criteria for discharge home? • What therapy will you prescribe?

25. Asthma: disposition from the ED Asthma flow sheets very helpful • Patients should be observed for 30-60 minutes post-ventolin for symptom recurrence • Most require at least 2 hours ED care • Steroids kick in @ 4-6 hours

26. Asthma: disposition Consider hospitalization more strongly if: • Prior hx of sudden, severe exacerbation • Prior intubation or ICU admission •  2 hospitalizations in last year •  3 ED visits in past year •  2 MDI’s used in a month • Current steroid use or recent wean from steroids • Medical or psychiatric comorbidity • Poor perceiver of symptoms (adolescents) • Substance abuse • Low socioeconomic status Baren JM in Emergency Asthma, 1999

27. Asthma: disposition NAEPP guidelines for discharge • PEF has returned to 70% of predicted • Exacerbation symptoms minimal or absent • Observed 30-60 minutes after last tx • Medications prescribed • PO steroids, ventolin, inhaled steroids • OP care can be established with a few days Use asthma clinic!

28. Case 3 • 4 month old girl brought to ED in February: wheezing of 2 days duration • cough, rhinorrhea and fever to 37.8 C • poor feeding last 24 hours • wheezing is worsening • born at 31 weeks gestation; required mechanical ventilation for 4 days after her birth • On exam • alert, RR 56 with mild retractions, O2 sat 94% RA • Diffuse wheezes bilaterally, scattered creps

29. CXR

30. Management options? • Supportive care  • O2, fluids, suctioning, saline nose drops • Ventolin  • Shuang huang lian • Racemic epinephrine  • Ribavirin  • Steroids  • Vitamin A 

31. Management options? • Supportive care  • O2, fluids, suctioning, saline nose drops • Ventolin ? • Shuang huang lian • Racemic epinephrine ? • Ribavirin  • Steroids ? • Vitamin A 

32. Bronchiolitis • Primarily b/w 0 and 24 months • Peak 2-8 months • Infects almost all children • May be predictive of future asthma if hospitalized • 1% of all hospitalizations of children in 1st year of life • $300 million per year in U.S. • Mostly seasonal • 60-90% RSV • Extremely contagious • Affects terminal bronchioles in young children • Symptoms peak around day 5

33. Bronchiolitis:predictors of severe disease • Ill or toxic appearing • SaO2 < 95% • Gestational age < 34 weeks • RR > 70 breaths per minute • Atelectasis on CXR • Age less than 3 months Single best objective predictor: infant’s SaO2 while feeding Shaw et al, Am J Dis Child, 1991;145:151-55

34. Salbutamol in bronchiolitis Many studies • 1996 meta-analysis by Kellner et al in Arch Pediatr Adolesc Med 150:1166-72 suggested benefit • Multiple conflicting reports since • Despite that: used widely

35. Racemic epinephrine in bronchiolitis Again, many studies • Generally more positive than salbutamol studies Sanchez et al, J Pediatr 1993;122:145-51 Reijonen et al, Arch Pediatr Adolesc Med 1995;149:686-92 Menon et al, J Pediatr 1995;126:1004-1007 Certainly safe Dose: 0.25 – 0.5 mL neb in NS L-isomer alone may be more effective

36. Steroids in bronchiolitis • Theoretically sound • Recent Sick Kids study • 1st study based in the ED • DBRPC trial involving 70 kids under 2 yrs • Dexamethasone group had hospitalization rate less than ½ of placebo group Schuh et al, J Pediatr 2002;140(1) • Recent meta-analysis also suggested statistical improvement with dexamethasone Garrison, Pediatrics 2000;105(4):E44 Overall, however, the bulk of individual studies have not shown benefit

37. Prevention of bronchiolitis • Palivizumab (Synergis®) • Monoclonal antibody • effective • $$$$$ • Given only to high risk infants • CLD • prems

38. Bronchiolitis – indications for admission • Age – generally if less than 1-2 months • Apnea • Oxygen requirement • Poor feeding • If received racemic epi in ED? • seems logical criteria given this is a med you can’t prescribe for home management! • Underlying condition e.g. • Prematurity • Congenital heart disease

39. Case 4 • A 2 year old boy arrives at triage at 1 a.m with his Dad • You’re awakened by….. • He’s brought back to obs • Sat is 90%, moderate retractions, very hoarse voice, continued noisy breathing • Dad gives you xray taken one hour ago at walk-in clinic

41. Croup – acute laryngotracheobronchitis • Stridor, barky cough, hoarseness • 6 months to 6 years of age • Often preceding URTI • Typically worse at night • Severe cases have biphasic stidor • Diagnosis is clinical

42. croup

43. Croup - treatment • Humidification • Often occurs on way to hospital • Corticosteroids • PO equivalent to IM • Dose 0.6 mg/kg (0.15 mg/kg may be adequate) • Nebulized budesonide also effective; may be additive • Racemic epinephrine • Need to observe in ED 2-3 hours post admin: potential rebound mucosal edema

44. Case 5

45. Epiglottitis • RARE now with Hib gone • Pneumococcus, Staph, Strep now more common as cause • 3 – 7 years of age • Rapid onset • Medical emergency • Don’t bug the kid but don’t let him out of your sight • Call anesthesia; intubate in OR

46. Case 6 3 year old with progressive stridor, fever, meningismus • Diagnosis?

47. Retropharyngeal abscess • 1-6 years • Retropharyngeal LN’s gone after this • GAS, anaerobes, S. aureus • Need good film for diagnosis • Neck extended in inspiration • Width of prevertebral soft tissue > ½ C3 vertebral body • Loss of cervical lordosis • IV abx, ENT consult

48. Case 7 • 4 year old fully immunized girl • Febrile, croupy cough, drooling, stridor • Looks unwell, but no acute distress • Coryza and sore throat for one day • No rashes; no choking episodes • You give racemic epi… no response • You order lateral neck XR… no FB, no steeple sign, epiglottis normal, upper airway has irregular margins

49. Bacterial tracheitis Uncommon • Can mimic croup quite closely; may be a complication of croup • sicker, high fever, gradual onset of illness • S. aureus usual cause • “Shaggy trachea” on XR secondary to pseudomembrane formation • Admit to ICU for iv antibiotics and observation “not all croup is viral croup”

50. Case 8 • 15-month-old girl • Acute onset wheeze and cough 2 hours ago • Previously well • Has past hx bronchiolitis; sib has asthma • On exam • afebrile, sat 95% RA, RR 44, AE sl decreased on left, wheeze L>R