Pediatric Respiratory Emergencies

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Pediatric Respiratory Emergencies

• Moritz Haager
• Dr. David Johnson
• May 09, 2002

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Case

• 8 mo male w/ 2/7 Hx of URTI Sx and progressively
  labored breathing
• Presents w/ tachypnea, indrawing, lethargy, ill
  looking child
• 380 / 200 / 60 / 88-90 on RA
• Decd AE and diffuse wheeze bilat., creamy d/c
  from eyes
• ABG 7.38 / 38 / 51 / 22/ -2
• WBC 14.6
• CXR peri-bronchial cuffing in RLL

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Whats your DDx for wheeze?

• Bronchiolitis
• Pneumonia
• Asthma
• Foreign body aspiration
• CHF
• CF
• Pertussis
• Anatomic abnormalities

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Whats your approach to bronchiolitis?

• ABCs
• Oxygen
• ?Bronchodilators (which one?)
• ?Steroids
• ?Antibiotics
• Supportive care
• Monitor for complications

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Bronchiolitis

• Common contagious LRTI of infants young
  children (0-24 mo)
• Usually viral and self-limited illness
• RSV (60-90)
• Para-influenza, adenovirus, rhinovirus, influenza
• Affects terminal bronchioles ? necrosis of
  ciliated cells ? inflammation w/ cellular debris
  mucous plugging ? wheezing and incd WOB
• Seasonal epidemics (winter months)
• Usually no long-term sequelae but may pre-dispose
  to (or uncover) asthma

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Are bronchodilators useful?

• Controversial point in literature
• Meta-analysis looking at 15 RCTs (mostly
  salbutamol) concluded moderate short-term benefit
  from bronchodilator therapy, but no effect on
  admission rate or oximetry
• Kellner et al. 1996. Arch Ped Adol Med. 150
  1166-72
• Cochrane systematic review of 394 kids in 8
  trials showed 54 improved clinically vs.. 25 of
  placebo
• Concluded modest short-term symptomatic benefit
  need more studies to better elucidate utility
• Kellner et al. 2002. Coch Data Sys Rev. (1)

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Salbutamol or Epinephrine?

• 4 RCTs show epinephrine (racemic or L-epi) as
  appearing to be superior to salbutamol
• All found significant symptomatic improvement,
  and two found decd admission rate or shortened
  hospital stay no adverse effects noted
• Only 2 were in ED setting
• Reijonen et al. 1995. Arch. Ped. Adol. Med. 149
  686-92
• Menon et al. 1995. J. Ped. 126 1004-007
• Sanchez et al. 1993. J. Ped. 122 145-51
• Bertrand et al. 2001. Ped. Pulmonolgy. 31 284-8
• Hartling and Klassen in process of preparing a
  Cochrane review
• Epi appears superior based on current evidence

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What about Atrovent?

• Double-blind placebo-controlled RCT of 69 infants
  6wks 24 mo w/ acute bronchiolitis
• Randomized to either salbutamol ipratropium or
  salbutamol placebo
• No sig difference in admission rate, RR, WOB,
  wheezing, or O2 sats
• No additional benefit when given in addition to
  salbutamol.
• Schuh et al. 1992. Pediatrics. 90 920-23

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Is there a role for Steroids?

• 3 RCTs all fail to show benefit
• Roosevelt et al. 1990. Lancet. 348 292-95
• Van Woensel et al. 1997. Thorax. 52 634-47
• Klassen et al. 1997. J. Ped. 130 191-196.
• 3 more recent studies support this and also fail
  to show any long-term benefit in reducing risk of
  post-bronchiolitis wheezing or asthma
• Van Woensel et al. 2000. Ped. Pulmonology. 30
  92-6
• Wong et al. 2000. Euro. Resp. J. 15 388-94
• Cade et al. 2000. Arch. Dis. Child. 82 126-30
• Literature does not support use in bronchiolitis
• Patel et al are preparing a Cochrane review

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Does this Kid need Antibiotics?

• Not routinely indicated, but
• One study shows 86 of kids w/ bronchiolitis
  have concomitant OM
• 5-10 have M. pneumoniae or Chlamydia
  co-infection
• Consider Tx in kids with
• OM and high fever
• Atypical features
• More ill than expected
• CXR evidence of pneumonia (other than
  atelectasis)
• This child received IV amoxicillin for ill
  appearance

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Your student suggests Ribavirin

• Synthetic nucleotide anologue w/ virostatic
  properties
• Expensive, possibly teratogenic, can cause
  bronchospasm
• Controversial, but mounting evidence it does not
  work
• At least 3 RCTs fail to show benefit
• Everard et al. 2001. Resp. Med. 95 275-80
• Guerguerin et al. 1999. Am. J. Resp. Crit. Care
  Med. 160 829-34
• Moler et al. 1996. J. Ped. 128 422-28
• Cochrane review of 378 infants lt 6mo in 10 trials
  suggests possible decrease in length of stay, but
  studies lack sufficient power.
• Randolph and Wang. 2002. Coch Data Sys Rev. Issue
  1
• Bottom line not indicated in ED

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Other Treatments for Bronchiolitis

• Shuang huang lian
• 1 RCT shows decd duration of Sx
• Heliox
• One RCT in PICU showing benefit
• Surfactant
• Case reports in PICU setting
• ECMO
• Case reports of benefit in premies or unstable
  pts refractory to conventional Tx
• Prevention
• RSVIG
• Palivizumab

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What complication can arise?

• Hypoxemia / respiratory failure
• Apnea (esp. in lt6 mo)
• Hypercarbia
• Pneumonia (viral or bacterial)
• Concomitant OM
• Long-term ? Asthma some studies suggest incd
  risk esp. in kids w/ incd IgE
• Mortality lt 1, and usually occurs in children w/
  underlying heart dz, lung dz, or prematurity.

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Are there any predictors of MM?

• Predictors of severe disease
• GA lt 34 wks
• SpO2 lt 95
• RR gt70
• Age lt 3 mo
• Ill or toxic appearance
• Atelectasis on CXR
• Presence or absence of all 6 has PPV of 81 and
  NPV of 88 for severe course
• Shaw et al. 1991. Am. J. Dis. Child. 145 151-55

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Who needs intubation?

• 2-7 of hospitalized infants end up requiring
  intubation for resp. failure
• Indications for intubation
• Severe resp. distress
• Apnea
• Hypoxia or hypercapnea
• Lethargy
• Poor perfusion
• Metabolic acidosis
• Wright et al. 2002. Emerg Med Clin NA. 20 93-113

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Case

• 3 yo female presents w/ 3/7 Hx of coryza, fever,
  and a harsh cough
• Today started making noise with every breath and
  hoarse voice which is worse at night
• O/E 386 / 120 / 35 / 96 RA
• Inspiratory stridor

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Whats your DDx for stridor?

• Epiglottitis
• Bacterial tracheitis
• Retro-pharyngeal abscess
• Croup
• Uvulitis
• Foreign body obstruction
• Hemangioma
• Neoplasm

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Whats your approach to Croup?

• ABCs
• Oxygen
• ?Humidification
• ?Epinephrine
• ?Steroids
• ?Intubation

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Croup

• Laryngotracheobronchitis, viral croup
• Common URTI and cause of stridor in infants and
  children 6 mo 6 yo
• Viral infection ? inflammation of subglottic area
  ? stridor (can be biphasic in severe cases) ?
  potentially hypoxia and death (rare)
• Biphasic peaks in fall and winter
• Etiology
• Parainfluenza 1 3 (gt65) gt RSV gt Parainfluenza
  2 gt Influenza A gt M. pneumoniae gt Influenza B

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Humidification does it work?

• Long-standing first-line Tx at home
• Anecdotal evidence
• studies to date fail to show objective benefit
  from mist therapy, one of which was an RCT of 16
  pts receiving either RA or humidified air
• Bourchier et al. 1984. Aust. Pediatr. J.
  20289-91
• Reports of Pseudomonas contamination and
  hyper-sensitivity reactions
• We need a larger RCT to clear this up
• Cochrane review by Moore and Little in progress

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Epinephrine

• a- effects decd bronchial secretions edema
• b- effects bronchodilation, tachycardia
• Most studies on racemic epinephrine but at least
  one double-blind RCT suggests equivalence to
  L-epi
• Waisman et al. 1992d. Pediatrics. 89 302-06
• 0.5 ml 2.25 racemic epinephrine 5 ml 11000
  L-epinephrine
• L-epi more available and less expensive

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Does Epi work in Croup?

• 5 prospective double-blind RCTs of epinephrine
  in croup
• 4 demonstrate decreased airway obstruction with
  effect lasting 2 hours
• Kuusela et al. 1988. Acta Paed. Scand. 77 99-104
• Taussig et al. 1978. Am J Dis Child 132 484-87
• Westley et al. 1978. Am J Dis Child 132 484
• Fogel et al. 1982. J. Ped. 101 1028-31
• One failed to show any benefit but unsure of
  length of observation time
• Gardner et al. 1973. Pediatrics 52 52-55
• Epinephrine appears to offer symptomatic benefit

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Does Epi help decrease admission?

• 3 studies totaling 166 pts who got epi
  steroids, observed for 2-3 hrs and then
  discharged w/ arranged f/u in 48 hrs
• 47/50 required no further Tx in one study, while
  the other 2 were able to D/C 55 and 51 of pts
  w/ only 1 recurrence of resp. distress in pts who
  otherwise would have been admitted
• Kelly et al. 1992. Am J Emerg 10 181-83
• Ledwith et al. 1995. Ann Emerg Med 25 331-37
• Prendergast et al. 1994. Am J Emerg Med. 12
  613-16

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How much epi can we safely give?

• Studies give 0.05 ml/kg or 0.25-0.5 ml a of
  2.25 RE soln dont often quote frequency
• Locally known to give 0.5 ml q2h O/N
• Case report of MI in pediatric pt following
  multiple doses of RE via neb
• Developed short run of VT, and mild transient CP
• Abnormal ECG and elevated CK-MB
• Structurally normal heart as per echo angio but
  small infarct seen by nuclear stress scan
• Butte et al. 1999. Pediatrics 104 e9
• Suggests we should be more cautious

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Steroids

• Postulated to work by anti-inflammatory effect to
  decrease edema, but exact mechanism uncertain
• Onset of effect usually quoted as being 6 hrs,
  but some have observed effect as early as 2 hrs

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Are Steroids useful in Croup?

• One meta-analysis comprising 1286 pts in 10 RCTs
  and 2 RCTs quoted as strong evidence
  demonstrating faster clinical improvement, decd
  likelihood of intubation, and shorter admissions.
  Also suggests better effect w/ higher doses.
• Kairys et al. 1989. Pediatrics. 83 683-93
• Super et al. 1989. J Ped. 115 323-29
• Kuusela and Vesikari. 1988. Acta Paed Scand.
  77 99-104
• More recent meta-analysis of 24 RCTs ( incl. 15
  new studies) demonstrates symptomatic
  improvement, fewer interventions, and shorter
  hospital stays in steroid-treated children w/ NNT
  of 5-7, but did not show decd risk of intubation
• Ausejo et al. 1999. BMJ. 319 595-600
• Cochrane review concluded CS are effective in
  relieving the Sx of croup and decreasing need for
  co-interventions, and length of stay in hospital
• Ausejo et al. 2002. Coch Data Sys Rev Issue1

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What steroid, what route, what dose?

• IM Dexamethasone was shown to be superior to
  budesonide in one RCT
• Johnson et al. 1998. N Engl J med. 339 498-503
• Dexamethasone can be given IM or PO no
  head-to-head comparison studies
• Dose more controversial
• Kairys et al incd benefit w/ doses gt 0.3 mg/kg
• Another double-blind RCT of 120 children
  concluded a dose of 0.15 mg/kg just as effective
• Geelhoed and Macdonald. 1995. Ped Pulmonolgy. 20
  362-68
• No studies have shown any safety concerns or
  adverse effects with dexamethasone even at doses
  up to 0.6 mg/kg
• Current recommendation is Dex 0.6 mg/kg PO
• Ausejo et al. 1999. BMJ. 319 595-600

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Does giving steroids early in the ED affect
disposition or Outcome?

• At least 4 RCTs, all suggesting improved
  clinical status with early steroids
• 1 study only had 80 power to detect 67
  difference in admission rate
• Johnson et al. 1996. Arch Ped Adol Med 150
  349-55
• 2 suggest decreased admission rate
• Johnson et al. 1998. N Engl J Med. 339 498-503
• Klassen et al. 1994. N Engl J Med. 331 285-89
• 1 study suggest no sig benefit from nebulized
  budesonide in addition to PO dex
• Klassen et al. 1998. JAMA 279 1629-32
• Steroids early appear to be helpful

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Who do you admit?

• Most pts can be discharged
• Admission for
• Marked distress / ill looking
• Hypoxia
• Dehydration
• Poor Tx response / persistent stridor other Sx
• Other medical co-morbidities (prem, cardiac,
  pulm)
• Young age
• Social far from hospital, questionable f/u,
  scary story, anxious parents

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Who do you intubate?

• Very rare since advent of steroids
• Use ½ size smaller than calculated
• No clear guidelines exercise clinical judgment

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Case

• 13 yo boy w/ known asthma presents w/ runny nose,
  cough, and incd SOB
• O/E 373 / 100 / 22 / 96 RA
• Mild exp wheezes
• PEF 300 compared to usual of 375

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Whats your DDx for wheezing?

• Asthma
• Foreign body
• Bronchiolitis
• CHF
• Anatomic (vascular ring, laryngomalacia..)
• CF
• Pertussis
• Pneumonia

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Asthma

• Most common chronic dz of children
• Rising M M mortality doubled 1977-85
• Chronic inflammatory dz characterized by
  exacerbations remissions, w/ airway obstruction
  partially reversible w/ meds
• Specific triggers
• Goal of ED care is to coordinate w/ existing care
  plan as much as possible

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Whats your approach?

• Initial assessment
• ABCs
• Initial management
• Oxygen, bronchodilators, steroids,
• Identify risk factors and assess Tx response
• Disposition and F/U

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Mortality Risk Factors

• Prior sudden exacerbations
• Prior intubations / ICU stays
• gt2 admissions in past year
• gt3 ED visits in past yr
• Admission or ED visit in past month
• gt2 ventolin inhalers per month

• Currently on, or recent weaning from, steroids
• Poor perception of airflow obstruction
• Co-morbid disease
• Low SE status, urban residence
• Psychiatric dz
• Sensitivity to Alternaria

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Clinical Scoring Systems

• Most common is pulmonary index
• Based on physical exam findings including RR,
  wheezing, I-E ratio, and use of accessory muscles
• None have sufficient validation to be used in
  disposition decisions

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Pulmonary Function Tests

• Formal PFTs are best to measure degree of
  obstruction but not convenient in ED
• PEF commonly used
• correlates w/ FEV1
• Effort-dependant, pt needs to stand
• Compare w/ personal best or standard tables
• PEF pred Severity
• lt30 possibly life-threatening
• lt50 severe
• 50-80 moderate
• gt80 mild

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Pulse Oximetry Oxygen

• No official agreement on normal values
• NAEPEP states anyone lt90 should get O2
• Common practice in the region is lt92
• Acute asthma pts w/ SaO2 lt95 were more likely to
  be admitted and more likely to return to ED if
  discharged
• Geelhoed et al. 1990. J Ped. 117 907-09
• SaO2 lt93 found to be 35 sensitive and 93
  specific fro admission
• Mayefsky and el_Shianway. 1992. Ped Emerg Care
  8 262-4
• Limitations of pulse oximetry
• Decd O2-carrying capacity
• Low perfusion state
• Provides no information on ventilation

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b-agonists

• Salbutamol is 1st line therapy in asthma
• Epinephrine has no benefit over salbutamol
• Klassen et al. 2000. Acad Emerg Med 7 1097-103
• Mechanism of action
• Relax bronchial smooth muscle
• Increase secretion of water from mucous glands
• Increase mucociliary clearance
• Controversies
• Route of administration in ED
• New pure R isomers (levalbuterol)
• Continuous therapy

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MDI or Nebulizer?

• Nebulizers enormously popular in ED
• Cost of nebulizer is 50 greater
• Most people use MDIs at home
• 5 studies show either equivalence, or even
  superiority of MDI over nebulizer
• One double-blind RCT in 5-17 yo subjects showed
  no difference
• Schuh et al. 1999. J Ped. 135 22-27
• Similar study in pts aged 1-4 yo showed decd
  admission rate less wheezing in MDI group
• Leversha et al. 2000. J Ped 136 497-502
• Ploin et al. 2000. Pediatrics. 106 311-17
• MDI makes more sense in ED

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IV Salbutamol

• Few well designed trials
• Cardiotoxicity need to monitor cardiac funxn
  K
• Rationale may get to non-ventilated lung areas
• One double-blind RCT of IV salbutamol in addition
  to continuous nebulized salbutamol showed more
  rapid improvement than control group
• Did not follow cardiac enzymes
• Browne et al. 1997. Lancet. 349 301-305
• Current recommendation is to consider early on in
  severe Tx-refractory cases

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Continuous b-agonist therapy

• Usually administered as 0.5 mg/kg/h , to a
  maximum of 15 mg
• Requires cardiopulmonary monitoring
• some studies (mostly adult) showing improved
  asthma scores, but no difference in PEFs,
  admission rates, or adverse effects
• Besbes-Ouanes et al. 2000. Ann Emerg Med
  36198-203
• Jury still out may consider if tx-refractory

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Levalbuterol

• Salbutamol (albuterol) R S isomers
• R isomer ? bronchodilation
• S isomer ? bronchoconstriction
• Manifests clinically as tolerance after repeated
  use
• Levalbuterol is pure R isomer
• 5x cost of salbutamol
• One double-blind crossover study of 33 kids
  suggests better than or equivalent to salbutamol
  w/ less side effects, but in stable pts (not ED
  setting)
• Gawchik et al. 1999. J Allergy Clin Immunol 103
  615-21
• No head-to-head trials in ED setting
• Not indicated for use at this time needs further
  study

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Anti-Cholinergics

• Ipratropium bromide
• Similar to atropine bromide group prevents
  systemic effect
• Inhibits Ach-mediated bronchoconstriction
• Only useful in addition to b-agonist
• Takes 60-90 min to reach peak effect
• Given as 250 mg x3 doses or 500 mg x2 doses by
  nebulizer over 1 hour repeat q2-4h prn
• One meta-analysis and a Cochrane review show
• Multiple doses (but not single doses) decrease
  admissions in mod - severe exacerbations w/ NNT
  of 12
• No conclusive evidence for use in mild-moderate
  cases
• Plotnick and Ducharme. 1998. BMJ. 317 971-977
• Plotnick and Ducharme. 2002. Coch Data Sys Rev.
  Issue 1
• NAEPP use in severely ill kids, and those not
  responding to high dose b-agonist therapy

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Steroids

• Meta-analysis of 30 RCTs recent Cochrane
  review show
• Early steroids decd admission rates (NNT 8)
• IV PO in efficacy no significant adverse
  effects
• Rowe et al. 1992. Am J Emerg Med. 10 301-310
• Rowe et al 2002. Coch Data Sys Rev. Issue 1
• Speed resolution of obstruction
• Potentiate effects of b-agonists
• Steroids prevent relapse w/ NNT 13, and decrease
  need for b-2 agonists
• Rowe et al 2002. Coch Data Sys Rev. Issue 1
• Indicated for most pts in ED

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Early inhaled steroids?

• Controversial
• One double-blind RCT comparing PO prednisone and
  inhaled budesonide in 185 acute asthma pts d/cd
  from ED suggests equivalence in preventing
  relapse
• FitzGerald et al. 2000. Can Resp J. 7 61-7
• Double-blind RCT of 22 kids treated w/ either
  budesonide or PO prednisolone showed similar
  benefit
• Volovitz et al. 1998. J Allergy Clin Immunol.
  102 605-9
• Another double-blind RCT of 188 pts (no kids)
  found additional benefit of inhaled budesonide in
  addition to PO prednisone in preventing relapse
  in pts discharged from ED
• Rowe et al. 1999. JAMA. 281 2119-26

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Early inhaled steroids?

• 2 separate Cochrane reviews looking at ICS
• One looked at role of ICS in ED
• 7 trials (2 pediatric) involving 352 pts
• ICS alone can decrease admission rates
• ICS other CS ? non-sig trend towards decd
  admission
• Inconclusive evidence for benefit of adding ICS
• Edmonds et al. 2002. Coch Data Sys Rev. Issue 1
• 2nd review looked at role of ICS after discharge
• 3 trials of 909 pts found non-sig trend towards
  decd relapse in ICS and other CS
• ICS vs. other CS alone no sig differences
  (severe cases excluded)
• Concluded no evidence to support addition or
  substitution of ICS for systemic CS, but may have
  yet undefined role in mild exacerbations
• Edmonds et al. 2002. Coch Data Sys Rev. Issue 1

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Magnesium

• Being re-discovered
• ?MOA counters Ca ions preventing smooth muscle
  contraction
• Can cause N V, weakness, facial flushing.
• Low cost, easy administration, availability
• Good evidence for efficacy in kids
• Dose 25 40 mg/kg IV higher doses appear to
  produce greater improvement

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Magnesium is it useful?

• two RCTs showed improved PFTs, decd admission,
  and no adverse effects with Mg
• Ciarallo et al. 1996. J Ped 129 809-814
• Ciarallo et al. 2000. Arch Ped Adol Med. 154
  979-83
• 2 meta-analyses both agreed current evidence
  supports use of Mg in adults w/ severe asthma
  exacerbations
• Rowe et al. 2000. Ann Emerg Med. 36 181-190.
• Alter et al. 2000. Ann Emerg Med. 36 191-97
• Consider in moderately severely ill pts failing
  to respond to salbutamol

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Who would use Aminophylline?

• Good evidence that it has no benefit over
  salbutamol
• Significant toxicity
• Some suggestion it may be useful in the most
  severe pts in an ICU setting
• Cochrane review
• Found significant improvement in FEV1 but no
  effect on length of stay or need for
  co-interventions
• Incd risk of vomiting (RR 3.69)
• Concluded should be considered in admitted
  Tx-refractory cases of severe asthma
• Mitra et al. 2002. Coch Data Sys Rev. Issue 1
• Not indicated in ED

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Other Tx

• Heliox
• Helium O2 decd density improves air flow
• Often get hypoxia b/c need at least 60 helium
• Cochrane review of 4 RCT's (1 peds) in ED
  concluded no evidence for use in ED
• Rodrigo et al. 2002. Coch Data Sys Rev. Issue 1
• Leukotriene Antagonists
• One abstract describes improved outcome in ED
  setting, but no RCTs
• Silvermanm et al. 1999. Ann Emer Med. 34(suppl)1

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Who gets intubated?

• Last resort
• RSI protocol using ketamine
• Careful to prevent incd intrathoracic pressure ?
  decd venous return ? arrest
• Indications (Rosen)
• Apnea
• PaCO2 gt 42 mm Hg and worsening, or no response to
  Tx
• Signs of impending resp failure

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Any predictors of admission?

• Model for predicting admission
• Age 6 yo or younger
• Male gender
• Requiring O2
• Interval severity of asthma
• Severity of wheeze at initial presentation
• Post-Tx SpO2 (most imp)
• Predictive accuracy of 90, with 86 sensitivity
  and 88 specificity
• Chey et al. 1999. J Clin Epi 52(2) 1157-63

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Case

• 2 yo male w/ fever, cough, vomiting x 2/7
• Looks moderately ill but not lethargic
• O/E 389 / 198 / 60 / 87 RA
• Mild incd WOB, decd AE on RUL
• Normal WBC

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Pneumonia

• Usually in 1st year of life
• Viral causes account for 60-90 (RSV, paraflu)
• 75 of deaths due to bacterial causes
• Bacteriology is age-dependent
• GBS, E. coli, Listeria, Ureaplasma in neonate
• Chlamydia at 3-19 wks
• Strep pneumoniae most common all other age groups
• Mycoplasma pneumoniae usually gt5yo
• Bordetella pertussis usually lt 6mo

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Pneumonia

• Treatment decisions based on
• Age
• Likely pathogen
• Degree of illness
• lt 3mo ? amp gent or amp 3d gen ceph
• gt 3mo
• Inpatients IV cefuroxime or cefotaxime /-
  erythro
• Outpatients macrolide (azithro) or clavulin or
  TMP-SMX must be reassessed in 24 hrs
• If Mycoplasma use macrolide or TMP-SMX

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Who needs admission?

• No CAP score in kids
• Toxic appearance
• Vomiting or dehydration
• Respiratory distress
• Pleural effusion (needs investigation)
• Immunocompromised
• Psycho-social factors
• Age lt 6 mo

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