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					ASTHMA IN
PAEDIATRICS
…3am phone call…
            ASTHMA

 Reversible bronchoconstriction

 Smooth muscle contraction

 Increase mucus secretion
Asthma
    Morbidity/Mortality
 0.9/100,000 deaths for children aged 5-19 (very few <5yrs)

 Peak mortality age is 15-24 yrs
    Victorian study of asthma deaths
         44% had been admitted in the year prior to death
    Sudden and unexpected death occurred in 63% of all cases,
     with collapse and death within minutes from onset of attack,
     often without time for any intervention.
    If an acute care facility is reached, patient usually survives
    In ~60% some preventable factors including inadequate
     treatment, poor compliance, not recognising severity of attack
     and delay in seeking help could be identified.

 Risk Factors for mortality include:
    Chronic severe asthma
    Past ICU admission
    Poor compliance
    Psychosocial disturbance
    Recent hospitalisation
                     HISTORY
THIS EPISODE:
 Duration & nature of symptoms
    Wheeze
    Cough
    Chest tightness/Breathlessness

 Treatments used (relievers/puffers)

PREVIOUS EPISODES:
 History of asthma symptoms & frequency of brochodilator use

 Severity & pattern
    Infrequent episodic, frequent episodic, persistent
    Interval symptoms:
        Sleep disturbance
        Early morning symptoms
        Exercise induced cough or wheeze
                      History

 Worsening symptoms in pollen season

 Pattern & course of previous acute episodes (admission/ICU)

 Trigger factors
    URTIs
    Allergy
    Passive smoking

 History of allergic disease (e.g. atopic eczema/allergic rhinitis)

 Family history of allergic disease
             EXAMINATION
VITAL:
 ** General appearance/mental state
 * * Work of breathing
    Respiratory rate
    Accessory muscle use/recession
    Prolonged expiratory phase
    Hyperinflation

HELPFUL:
 Initial SaO2 in air
 Heart rate
 Ability to talk

LESS RELIABLE
 Wheeze intensity
 Pulsus paradoxus
 Peak expiratory flow rates are not reliable
              INVESTIGATIONS
 Chest x-ray: Generally not required. Consider if:
    Concerns of complications
           Atelecastsis
           Pneumothorax
           Pneumomedistinum
           Pneuonnia
     Signs:
         Fever > 38.5oC
         Focal examination findings (rales/decreased air entry)
         Extreme tachypnea or tachycardia
     Lack of response to asthma therapy to look for other process
      that may mimic asthma  vascular ring; foreign body
      aspiration
            INVESTIGATIONS
Cap/arterial blood gases:
 Children in respiratory distress with normal or elevated pCO2 are
  at risk of imminent respiratory failure.

 HOWEVER….

 Arterial blood gas (& spirometry) rarely required in children
    Distressing and can cause a child with respiratory compromise
     to deteriorate further
    Child's clinical state is more important in guiding therapy
DIFFERENTIAL DIAGNOSIS

   Cystic Fibrosis
   Primary Ciliary Dyskinesia
   Chronic bronchitis
   Structural abnormality
   Vocal cord dysfunction
   Foreign body
   Cardiac failure
   Hyperventilation-anxiety
   Exertional dyspnoea
   Aspiration
                Asthma - mild
Assessment:
   * Normal mental state
   * Subtle or no accessory muscle use/recession
   SaO2 > 95% in air.
   Able to talk normally

Management:
   Salbutamol by MDI/spacer (dose) - once and review after 20 mins.
      Salbutamol dose: 6 puffs if < 6 years old, 12 puffs if >6 years old
      Good response - discharge on B2-agonist as needed.
      Poor response - treat as moderate.
   Consider oral prednisolone (1 mg/kg daily for 1-3 days)
   Ensure device / technique appropriate
   Written advice on what to do if symptoms worsen
   Follow up
            Asthma - moderate
ASSESMENT
 * Normal mental state
 * Some accessory muscle use/recession
 SaO2 92-95% in air
    May be reduced in absence of significant airway obstruction by
     factors such as atelectasis & mucous plugging
 Tachycardia
 Some limitation of ability to talk

MANAGEMENT
 O2 if saturation is < 92%
 Salbutamol by MDI/spacer - 1 dose every 20 ms for 1 hour ;
  review 10-20 min after 3rd dose ?admission vs discharge
 Prednisolone (1 mg/kg daily for 3 days)
            Asthma - severe
ASSESSMENT
 *Agitated/distressed
 * Moderate-marked accessory muscle use/recession
 SaO2 < 92% in air
 Tachycardia
 Marked limitation of ability to talk

MANAGEMENT
 Oxygen
 Salbutamol by MDI/spacer- 1 dose (dose) every 20 minutes for 1
  hour. Review on-going requirements 10-20 min after 3rd dose
    If improving reduce frequency
    If no change continue 20 minutely
    If deteriorating at any stage treat as critical
 Oral prednisolone (1 mg/kg daily)
    If vomiting give i.v. methylprednisolone
 Ipratropium (Atrovent) by MDI/spacer
    (20mcg/puff: 4 puffs if < 6 years old, 8 puffs if >6 years old
            Asthma - critical
ASSESSMENT
 * Confused/drowsy
 * Maximal accessory muscle use/recession. Exhaustion
 SaO2 < 90% in air
 Marked tachycardia
 Unable to talk

MANAGEMENT
 Oxygen
 Continuous neb salbutamol
 Nebulised ipratropium 250 mcg 3 times in 1st hr only (20
  minutely, added to salbutamol)
 Methylprednisolone 1 mg/kg i.v. 6-hourly.
 Aminophylline: If deteriorating or child is very sick
    Loading dose: 10 mg/kg i.v. (max 500 mg) over 60 min
    Unless markedly improved, follow with continuous infusion or 6
     hourly dosing
            Asthma - critical

 Magnesium sulphate:
    50% Mg Sulphate - 0.1ml/kg (50mg/kg) over 20 mins, then
     0.06ml/kg/hr (30mg/kg/hour) by infusion
    Aim to keep serum Mg between 1.5 and 2.5mmol/L

 IV Salbutamol:
    5 mcg/kg/min for 1hr as a load, followed by 1-2 mcg/kg/min.
    Beware toxicity: tachycardia, tachypnoea, metabolic acidosis.
        Lactate commonly high

 Aminophylline, magnesium & salbutamol must be given via
  separate IV lines.

 Intensive care admission for respiratory support (facemask CPAP,
  BiPAP, or intubation/IPPV) may be needed.
             Glucocorticoids
 SYSTEMIC
    Pred/methylpred – 1mg/kg
    Decrease airway inflammation & secretions
    Relative CI: Hypersensitivity reactions; Varicella infections;
     HSV keratitis (balance severity of bronchospasm vs risk)

 INHALED (e.g: Pulmicort)
    No role in paediatric acute asthma exacerbation!
    Neither in addition to, or instead of, systemic glucocorticoids
Magnesium Sulphate
  Inexpensive

  Minimal side effects

  Readily available

  Useful in severe asthma that fails to respond to conventional
   therapy of salbutamol & corticosteroids
                    ??Other
 ANTIBIOTICS
    No benefit in acute asthma exacerbations
    May be necessary if co-existing infections
     (pneumonia/sinusitis)

 CHEST PHYSIOTHERAPY
    No benefit
    May subject child to unnecessary stress
ASTHMA - CLASIFICATION
  Infrequent episodic (70-75%)
     attacks > 6 weeks apart
     no symptoms between attacks
     normal examination and lung function between attacks
     often seasonal (winter months)

     By 10yo 40% will have stopped wheezing altogether, may
      have persistent bronchial hyperreactivity
     Majority have little if no symptoms in adults life. A small
      number may have more troublesome symptoms as adults.
     Usually normal interval PFTs
ASTHMA - CLASIFICATION
  Frequent episodic: (20-25%)
     Attacks < 6 weeks apart
     No interval symptoms
     Often seasonal (winter months)
     Usually starts prior to age 3
     Initially viral URTIs are trigger
     By age 6/7 exercise, allergens, weather
     20-30% will have an abnormal FEV1 during childhood, but only
      about 15% in adulthood
ASTHMA – CLASIFICATION
  Persistent asthma (5-10%)
     25% wheeze prior to 6/12
     Often worst between 8-14 yrs
     Usually persistently abnormal PFTs
     5% will become totally wheeze free in adult life, 15% trivial,
      >50% have very frequent or persistent asthma
     Small proportion will develop irreversible airways obstruction in
      adulthood
           PREVENTERS
 Consider preventive treatment if:
    There are frequent acute episodes or
    Chronic symptoms
       More than one disturbed night per week
       Difficulty participating in physical activities
       Or bronchodilator use on more than one day per week
Steroids
  Fluticasone (Flixotide): Recommended starting dose is 200 ug/day
   in 2 divided doses

  Side effects:
     Oral candidiasis
     Pharyngitis
     Hoarse voice
     Marked adrenal suppression said to occur with doses >1500ug
      per day (750 ug of fluticasone)
     Growth – effect on growth is said to occur mainly in the first
      year of treatment, with gradual catch up , and no significant
      effect on adult height
     No effect seen on bone mineral density with long term inhaled
      corticosteroids
Long acting
bronchodilators
  LABA: Salmeterol (Serevent)
Combination
LABA and ICS

   Seretide
   Symbicort
LEUKTORIENE RECEPTOR ANTAGONISTS


  Singulair; available as a chewable tablet

  Mild persistent asthma

  Not as effective as ICS though ?role as steroid sparing agent

  Role in allergic rhinitis & nasal polyps

  No role in acute asthma exacerbation
DISCHARGE
 Each child should have a written action plan

 Observe inhaler technique before discharge




 Advise parents to return if the patients condition deteriorate or if
  there is no significant improvement within 48 hours
CRITERIA FOR ADMISSION

 (1) Salbutamol more of then 2-3 hours

 (2) Not improved after administration of systemic glucosteroids

 (3) Oxygen requirement

 Other considerations:
  A history of rapid progression of severity in past exacerbations
  Poor adherence with outpatient medication regimen
  Inadequate access to medical care
  Poor social support at home
TRICKY QUESTIONS

Question 1

 If a child has infrequent episodic asthma
  associated with viral respiratory
  infections, would inhaled corticosteroids
  decrease the frequency and severity of
  the exacerbations?
 Answer: No!

 Benefits are well established for use of maintenance
  ICS in persistent asthma
    Well documented in adults and children that low
     dose maintenance ICS reduces the number of
     asthma exacerbations by ~45%
    NEJM2000: 343:1054

 In children with infrequent episodic asthma,
  maintenance ICS does not reduce the frequency or
  severity of viral respiratory infection induced
  exacerbations of asthma
Question 2

 If a child is not on an inhaled
  corticosteroid, would commencing them
  at the start of a viral respiratory infection
  reduce the risk or severity of an
  exacerbation of asthma?
 No!

 High dose ICS at the commencement of a viral
  respiratory infection does not reduce the need
  for intervention with oral corticosteroids or
  hospitalisation in asthma exacerbation
QUESTION 3

 If a child with frequent interval symptoms
  is put on ICS will the frequency and
  severity of viral respiratory infection
  associated exacerbations be reduced?
 Yes!

 Use of inhaled corticosteroids in a child
  with frequent interval symptoms will
  reduce the frequency and severity of viral
  respiratory infection associated
  exacerbations in addition to the beneficial
  effect on interval symptoms
Question 4

 If a child is on inhaled corticosteroids
  would increasing the dose during a viral
  respiratory infection decrease the risk or
  severity of exacerbation?
 No!

 The available evidence shows no
  reduction in risk or severity of
  exacerbations with a doubled dose of
  inhaled corticosteroids during a viral
  respiratory infection.
 QUESTION 5

 Do oral corticosteroids given with viral respiratory
  infections (or at the onset of an exacerbation)
  reduce the risk or severity of an exacerbation?
 Yes!

 Administration of oral corticosteroids at
  home early in a viral respiratory infection
  induced exacerbation of asthma is
  effective in reducing the severity/risk of
  the exacerbation.
Asthma - Resources

  You:
    http://www.rch.org.au/clinicalguide/cpg.cfm?
     doc_id=5251
  Parents:
    http://www.rch.org.au/kidsinfo/factsheets.cfm
     ?doc_id=3714
    http://www.nationalasthma.org.au/
Thank-you

				
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