NZ has one of highest rates of childhood asthma in developed world

leading acuse of sleep disturbance, missed school and hospital admissions in children

1/4 children have some form of asthma or asthma symptoms

Maori/pacific > pakeha

• asthma symptoms resolve by adulthood in 50-75%

• no difference in QoL from children without asthma if accurate diagnosis and managmeent

  • caveat

    • poor management

    • incorrect diagnosis

    • under/over-prescription of medicine

• Maori 28.5%

  • less likely to receive corticosteorids compared to euro

• Pacific 25.2%

• European children 20.7%

Diagnosis

clinical

symptoms

recurrent and episodic symptoms of:

• wheezing

• cough

• difficulty breathing

• chest tightness

other factos:

• personal history of atopy

• family history of asthma or atopy

• widespread wheeze on auscultation

• improvement in symptoms / lung function with treatment

Wheezing

• most familiar and useful sign

  • one of large number of nosises

“ high-pitched musical or whistling sound coming from the chest”

• Acute, severe episodes most often triggered by viral illensses

• interval symptoms

  • symptoms between severe episodes

  • triggered by:

    • exercise

    • cold

    • damp air

    • exposure to pets

    • emotion/laughter

• may be worse at night or in early morning

Differential

• inhaled FB

• laryngeal abnormal

• ocngenital airway narrowing

• chronic aspiration

• bronchiectasis

• cystic fibrosis

• primary/acquired immune deficiiency syndromes

clues something other than asthma:

• sudden onset

• abnormal voice/cry

• continuous daily wheeze

• wheeze persistent since infancy

• Failure to thrive

• digital clubbing

• chronic moist or wet sounding cough

• persistent diarrhoea

• recurrent skin or other infections

Asthma cough

• common symptom

• unlikely in cough without wheeze that due to asthma

• “cough-varient asthma” shouldn’t be used

• often dry

• occurs in response to trigger

• chronic cough > 6/52

  • CXR

• trials of:

  • asthma

  • reflux

  • hayfever

  • not appropriate in children unless specific features suggesting underlying cause

lung function testing

• not easy in children

• spirometry >5yo in 2ary care

• bronchodilator response

  • clinically/symptoms

  • >12% PEFR 20 min after 6 puffs of salbutamol

• Regular PEFR monitoring generally considered inaccurate in children

• FEV1 more reproducible measure

Probability of asthma

High probabliity

• typical hsitory and exam

• no features of alternate diagnosis

• cxr/spiro not necessary

• response to treatment assessed 2-3 months

• no repsond: d/w paediatrician

Intermediate probability

• wheeze

• do not fit clinical picture

• no signs to suggest alterante diagnosis

• first step =

  • wat

  • review 1mo

• alternate =

  • trial resonse to treatment

• symptoms may resolve

• postiive response to trial of bronchodilator increase likelihood

Low likelihood

• features suggest alternate diagnosis

• diagnostic trialling with asthma unlikely to be beneficial in this group

Long term management

step wise

Aim of treatment:

1. minimise/eliminate symptoms

2. maximise lung function

3. prevent exacerbations

4. adjust medications to lowest efefctive dose

5. minimiise adverse effects of treatment

6. rovide enough information and support to favilitate self managmenet

7. SABA alone

8. ICS

   1. add at low dose

      1. 1 puff bd fluticasone 50mcg

      2. 1 puff bd beclomethasone/budesondie 100mcg

   2. increase to moderate dose

      1. 2 puffs bd

9. Add LABA

   1. if \<5 then refer paediatrician

   2. max dose = 50mcg salmeterol bd or 12mcg eformoterol bd

   3. need to be using ICS

10. High dose ICS + LABA and/add oral medication

    1. consider referral

    2. under 12; 200mcg fluticasone bd

11. Frequent or continuous oral steroids

    1. referral

12. children with frequent interval symtoms start step 2

13. assessed after 2-3 mo or earlier

14. lowest step that achieves level of control

\< 5yo

• won’t benefit from ICS

• Montelukast can be effective

using ≥ 2 canisters per month or 10-12 puffs/day = marker of poorly controlled asthma

@ risk of potentially life threatening asthma

choice of inhaler

• ≤ 4 require MDI via spacer and mask

• >7 may prefer dry powder

  • turbulaher

  • accuhaler

    • technique is difficult

taper ICS 25-50% at 3 month intervals

children with food allergy are at increased risk of life-threatening anaphylaxis if also have asthma

Adults

Diagnosis:

• single PEFR little diagnostic value

• PEFR variability >15% highly specific for asthma

Management

• corticosteroids have flat dose response curve

  • Fluticaonse - most won’t need above 500mcg fluticasone or 800-1000mcg beclomethasone or budesonide

• initiate coritcostroeids @ fluticasone 200mcg/day

• ICS

  • reduce symptoms

  • imrpove lung function

  • slow rate of decline

  • reduce hostpial admissions and mortality

• LABA

  • moderate-severe

    • improve day and night syptoms control

    • improve lung function

    • reduce exacerabtion

• Ipratropium

  • improves clinical outomes when used early in acute asthma

adverse effects from ICS

• cataracts

• decrease BMD

• glaucoma

• bruising

• @ > 1000mcg/day beclomethasone

Asthma control test

1. during past 4 weeks; how often did your asthma prevent you from getting as much work doen @ work, school/home?

2. During past month; how often have you had shortness of breath?

   1. ≥ 1/day

   2. once/day

   3. 3-6 / week

   4. 1-2/wk

   5. not at all

3. During past month, how often did your asthma symptoms wake you up at night or earlier than usual in the morning

   1. ≥4/week

   2. 2-3/week

   3. once/week

   4. one-twice

   5. not at all

4. during past month how often have you used your reliever

   1. ≥ 3/day

   2. 1-2 time/day

   3. 2-3/week

   4. once/week

   5. not at all

5. how would you rate your control during past month

25 = control

20-24 on target

\<20 - off target

also: \< 1 course of steroid last 12mo or no admission = marker of good control

Management of acute asthma

Moderate

• spo2 ≥ 92%

• able to talk

• PEFR ≥ 50%

• \<5yo

  • hr ≤140/min

  • rr ≤ 40/min

• >5yo

  • hr ≤125

  • rr ≤ 30/min

Management

• salbutamol 6 puffs

• prednisolone 1-2mg/kg

Severe

• spo2 \<92%

• too breathless to talk

• obvious accessory neck muscle use

• PEFR 33-50%

• \<5yo

  • hr > 140

  • rr > 40

• > 5yo

  • hr >125

  • rr >30

managmeent

• o2 via facemask

• salbutamol 5 puffs via spacer or nebulised salbutamol 2.5-5mg

• prednisolone 1-2mg/kg

Life threatening

• spo2 \<92 + any:

  • poor resp effort

  • exhaustion

  • agititaiton

  • altered consciousness

  • cyanosis

  • silent chest

  • PEFR \<33% best or predicted

management

• call ambulance

• o2

• nebulised salbutamol 5mg + ipratropium 0.25mg

• Prednisolone 1-2mg/kg or hydrocortisone 4mg/kg

• extreme: consider IM adrenaline at anaphylaxis dose

• continuous salbutamol nebulisers