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THE EGYPTIAN SOCIETY OF PEDIATRIC ALLERGY AND IMMUNOLOGY

 

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               This booklet is distributed (free of charge) during ESPAI's congresses and scientific meetings.

Asthma Therapy         

Goals of Therapy = Disease Control

- Full participation in physical activity.

- Good school attendance.

- Uninterrupted sleep.

 

Basic lines of therapy include:-

1. Patient education for allergen avoidance.

2. Bronchodilators (Adjuvant therapy).

3.Anti-inflammatory therapy (cornerstone of therapy)

Acute Asthma

Clinical classification of acute asthma exacerbations

Data

Mild

Moderate

Severe

Respiratory failure

Breathlessness

- While walking

- While walking

- Difficult feeding in infants

- At rest

- Infants stop feeding

 

Talking

Sentences

Phrases

Words

 

Alertness

Agitated

(may be)

Agitated (usually)

Agitated (usually)

Drowsy

Respiratory rate

Increased

Increased

>30/min

 

Suprasternal retraction

Not

Commonly

Usually

Paradoxical thoraco-abdominal movements

Wheeze

- Moderate

- End expiratory

- Loud

-Throughout expiration

-Usually loud

- Inspiratory & expiratory

Absent

Pulse

<100/min

100-120/min

>120/min

Bradycardia

Pulsus  paradoxus

Absent (<10 mmHg)

May be present

(10-25 mmHg)

May be present

(20-40 mmHg)

Absence suggests respiratory muscle fatigue

Peak  expiratory flow rate (PEFR)

>80%

50-80%

<50%

 

 

Management of acute asthma exacerbation at hospital:

I. Mild to moderate exacerbations:

1.     Inhaled short acting b2-agonist by metered dose inhaler (MDI) or nebulizer up to 3 doses at 20 min. intervals then every 60 min. for 1-3 hours e.g. salbutamol (5 mg/ml solution for nebulizer). Dose: 0.15 mg/Kg i.e. 0.03 ml/Kg (max. 5 mg i.e. 1 ml) to be diluted in 2 ml normal saline. Nebulization with O2 at 6 L/min. is preferred.

       For children =6 yr of age:-

       b2 agonist by MDI or nebulizer ± ipratropium bromide 250-500 µg at 20 min intervals for 3 doses then every 2-4 hours if needed.

2.     O2 therapy at 2-3 L/min.

3.     Oral systemic corticosteroids: only if there is no response or if the patient recently took oral steroids (before the attack). Prednisone may be used (1-2 mg/Kg/day in a decreasing dose over 5-7 days).

Note: Do not rush into systemic corticosteroids in mild to moderate exacerbations unless indicated.

4. Theophylline indications:-

a)    Patients who have been receiving maintenance theophylline treatment.

b)    Patients  unable  to  tolerate  maximal  treatment  with inhaled b2  agonists.

c)    Patients with severe airway obstruction.

Dose:   20 mg/Kg/day orally in 4 divided doses or 5 mg/Kg  IV over 20 min followed by constant infusion as follows:-

0.5 mg / Kg / hr -------------------->    1-6 months of age

1  mg  / Kg / hr --------------------->    6-12 months

1.2 mg - 1.5 mg/Kg/hr ------------>    1-9 years

0.9 mg / Kg / hr -------------------->    =10 years

Theophylline level should be monitored. Peak serum concentration should not exceed 10 µg/ml.

After 3 hours of emergency room treatment (provided there is no deterioration), assessment should be repeated:

-    If still the patient has moderate attack: admit to hospital.

-    If good response sustained for one hour after the last treatment (PEFR = 70%), discharge home and  continue on inhaled or oral b2 agonist if necessary and continue the course of oral systemic corticosteroid (if started at hospital). Afterwards, start the long term management according to stage and severity of illness.

 

II. Acute severe asthma:

1.  Inhaled high-dose b2-agonist and anticholinergic by nebulization every 20 minutes or continually for one hour in a dose of 0.5 mg/Kg/hour (0.1 ml/Kg/hr).

2.  Oxygen therapy.

3.  Systemic steroids: Methyl prednisolone (Solu-Medrol) is preferable to hydrocortisone due to lower side effects.

4.  Theophylline: I.V.

* If poor response Admit to ICU:

1-  Baseline  investigations: chest X-ray - urine volume - arterial blood gases.

2-  Oxygen therapy.

3-  Inhaled b2 agonist.

4-  Intravenous theophylline: 0.7 mg/Kg/hr (as drip).

5-  Intravenous fluid therapy: 2/3 maintenance.

6-  Intravenous corticosteroids: hydrocortisone (15-20 mg/Kg/ day in 4 divided doses) or methyl prednisolone in a dose of 1-2 mg/Kg/24 hr for the first 48 hr followed by 1-2 mg/Kg/24 hr (maximum 60 mg) in 2 divided doses until the PEFR is 70% of the personal best or predicted.

 

If no improvement within 6-12 hours ---------> consider intubation and mechanical ventilation.

Note:- Because b2-agonists may produce hypokalemia, potassium should be added to the I.V. fluids after the patient voids.

 

III. Impending or actual respiratory arrest

- Admit to ICU.

- Intubation and mechanical ventilation with 100% O2.

- Nebulized b2-agonists and anticholinergics.

- I.V. corticosteroids.

 

Long Term Management of Chronic Cases

Long term management depends on the ability to characterize asthma into specific stages:-

 

 

Initial assessment before treatment

Children less than

6 yr of age

Children more than

6 yr of age

Step I

(Mild intermittent)

• symptoms =2

   times/week

• Night symptoms

  =2 times/month

• PEFR =80%

No daily medications needed

inbetween attacks

Step 2

(Mild persistent)

• symptoms >2

  times/week.

• Night symptoms

  >2  times/month

• PEFR = 80%

Daily use of cromolyn Na by nebulizer

[20 mg/amp: 1/2-1 amp/12 hr]

or MDI [1 mg/puff: 1-2 puffs 2-3 times/day]

or low-dose inhaled corticosteroid

(Only if the former is not effective]

Step 3

(Moderate persistent)

• Daily symptoms

• Night symptoms

  >1 time a week

• PEFR = 60-80%

Daily inhaled cortico­steroid (medium dose) with spacer ± long acting theophylline (20 mg/Kg/day in 2 daily divided doses)

Daily inhaled cortico­steroid (medium dose) ± long acting inhaled b2- agonist             (e.g. salmeterol) especially for night symptoms or long acting theophylline

Step 4

(Severe  persistent)

• continuous symptoms

  with limited physical

  activity

• Frequent night

  symptoms

• PEFR = 60%

Daily high-dose inhaled cortico­steroids with spacer and if needed add systemic cortico­steroids 2 mg/Kg/day with attempts to reduce to lowest daily or alternate-day dose

Daily high-dose inhaled cortico­steroids and long acting inhaled b2-agonist and cortico­steroid orally with attempts to reduce the dose

 

Quick relief (rescue) therapy at any of the previous steps:

Children < 6 yr of age

Children = 6 yr of age

Inhaled short-acting

b2-agonist by nebulizer or spacer

Inhaled short-acting

b2-agonist by MDI

Or

Oral b2-agonist e.g. Salbutamol

0.15 mg/Kg/day in 3 divided doses

if inhalation therapy cannot be maintained

Note: If not relieved refer to previous section on acute asthma management.

Aids for inhalation therapy

 

- Nebulization

Any age

- Metered dose inhaler

= 7 years

- Metered dose inhaler + Aerochamber

> 3 years

- Metered dose inhaler + mask

> 6 months

- Inhalation of dry powder

> 5 years

Notes:

1-  â Step down :

     Review treatment every 1-6 months. If control is sustained for at least 3 months, a gradual stepwise reduction in treatment is possible.

2-  á Step up :

     If control is not maintained after reviewing the patient's compliance and environmental control.

3-  The severity of the acute attack has no relation to the disease grade i.e. patients with intermittent asthma may develop severe life threatening attacks.

4-  Antibiotics are used only if there is evidence of upper or lower respiratory tract infection.

5-  Bacterial vaccines are of no proven efficacy.

6-     Expectorants and mucolytics are not advisable during bronchospasm. They may be needed after complete bronchodilatation.

7-     Antihistamines may be needed if there is associated nasal or skin allergy.

8-     Some new adjuvant lines of treatment can be considered in mild to moderate cases like leukotriene antagonists e.g. Montelukast.

9-     Reassurance of the child and parents and discussing the prognosis with them are important.

10-  Patients are to be educated how to use inhalation therapy and should be convinced that it is the safest and preferred line of therapy.

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 Normal Peak Expiratory Flow Rates

(From Sly RM: Pediatric Allergy. New Hyde Park, NY, Medical Examination Publishing Company, 1985)

Recommendations for 1ry Prevention of Asthma

(1) Non specific measures:

- Breast feeding for 2 years.

- No exposure to tobacco smoke.

- Non traumatic delivery.

- Reduce air pollution.

(2) Allergen avoidance: e.g.

- No solid foods during the first 6 months (delay weaning).

- Eggs and fish after 12 months.

- Consider maternal elimination diet during breast feeding.

- Avoid day care centers during infancy (risk of infection).

Avoidance of Provocative Agents

(1) Viral infections:

-    Avoid contact with infected subjects.

-    Non specific immunopotentiation via breast feeding, proper nutritional support.... etc.

(2) Environmental control:

-    House dust mite control.

-    Animal allergens control (pet avoidance)

-    Cockroach allergens control.

-    Avoid indoor irritants as tobacco smoke, insecticides, volatile agents and any strong odours.

 

Examples of Available Medications
Used in Asthma

I.     Short acting b2-agonists e.g.

 - Salbutamol 

- Terbutaline

 - Fenoterol

II.   Long acting b2-agonists e.g.

- Salmeterol inhaler (25 mg/puff):
1-2 puffs/12 hours.

 - Formoterol

III.  Anti-cholinergics:  

- Ipratropium bromide by MDI or nebulization.

IV.  Combinations e.g.

- Salbutamol + Beclomethasone DP

- Fenoterol + Ipratropium bromide

- Salbutamol + Ipratropium bromide

- Salmeterol + Fluticasone

V.   Slow release theophyllin e.g.

- Available as tablets or capsules.

- Dose: 15-20 mg/Kg/day in 2 divided doses.

VI.  Na cromoglycate or Nedocromil Na

VII. Inhaled corticosteroides e.g.

 - Beclomethasone DP:
 50 & 100 µg/puff.

 - Budesonide: 200 µg/puff.

 - Fluticasone: 50 & 125 µg/puff.

 - Triamcinolone acetonide: 100µg/puff.

VIII. Anti-leukotrienes:

- Montelukast

- Zafirlukast

IX.  Anti-histamines e.g.

- Promethazine HCl

- Loratidine

- Fexofenadine

- Mequitazine

- Terfenadine

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