GUIDELINES ON MANAGEMENT OF ADULT ASTHMA

 

 

A CONSENSUS STATEMENT OF THE MALAYSIAN THORACIC SOCIETY

 


 

Outline

 

 



ForewordAsthma morbidity and mortality is on the increase in a number of developed countries. Our country, which is rapidly becoming industrialized, is also probably similarly saddled, especially with increased morbidity. It is therefore timely that a guideline on the management of asthma be produced for use of Malaysian doctors. These guidelines will hopefully provide well accepted and well recognized methods for the management of asthma to doctors who see and treat patients with asthma in their practice. The committee which set up to draw these guidelines consisted of chest physicians with many years of experience in managing the asthmatic patients. They have also extensively studied guidelines previously established by other groups on asthma management and modified several aspects to suit the local situation.

 

It is the sincerest hope of the Malaysian Thoracic Society that these guidelines will benefit both Malaysian doctors and their patients who suffer from asthma.

 

Thank you.

Dr. I. Kuppusamy 
President, 
Malaysian Thoracic Society

 


Acknowledgements 
We would like to express our gratitude to the following companies who have contributed to the successful production of these guidelines:

 

Astra Pharmaceutical (M) Sdn Bhd 
Boehringer Ingelheim Division, Diethelm Malaysia Sdn Bhd 
GlaxoWellcome (Malaysia) Sdn Bhd 
3M Pharmaceuticals, 3M Malaysia Sdn Bhd

 

We would also like to express our gratitude to Puan Norhayati Bakri for her help in the preparation of these guidelines.


 

Preface 

Asthma is a common disease which affects both adults and children. It continues to cause significant mortality and potentially preventable with proper management. Clinicians managing asthma need to keep abreast with the current concept of the disease and its management so that optimal care can be provided. While this may be possible for some, many may not be able to do so because of the constrain of time due to the nature of their work or practice and the difficulty to get access to reading materials. There are guidelines published by a number of societies/countries which are available but some recommendations concerning certain aspects of the management may not be suitable for local patients. Realising these various factors the Malaysian Thoracic Society has initiated the efforts to produce the guidelines on the management of asthma in adults. I am greatly honored to be given the task to gather a group of dedicated and highly knowledgeable people who have spent their invaluable time and experience to produce these guidelines. I would like to express my gratitude and thanks to these members who have patiently worked together until the completion of the guidelines. They include Dr. Aziah Ahmad Mahayuddin, Dr. Hooi Lai Ngor, Dr. I Kuppusamy, Associate Professor C.K. Liam, Dr. George Simon, Associate Professor Dr. A. Wahab Sufarlan, Dr. Wong Wing Kin and Associate Professor Dr. Ismail Yaacob. Without their help I dont't think we could have successfully produced theses guidelines. I am also thankful to members of the Malaysian Thoracic Society who have given their constructive views or comments on the guidelines.

 

We are also indebted to Astra Pharmaceutical (Malaysia) Sdn Bhd, Boehringer Ingelheim Div. Diethelm Malaysia Sdn Bhd, Glaxo Wellcome (Malaysia) Sdn Bhd and 3M Malaysia Sdn Bhd for their generosity in financially supporting this project. My special thanks also goes to Ms Norhayati Bakri for typing the manuscript.

The completion of these guidelines does not mean the end of our efforts to disseminate information on proper asthma care but rather the beginning of more efforts towards achieving an overall better informed and competent clinicians who are to manage asthma effectively. Obviously more seminars, workshop and round table discussions are needed to achieve this goal and MTS will definitely have a big role play in this respect.

 

With your support I am sure we can do it. 

BMZ Zainudin, MD, MRCP, FCCP, AM  
Chairman of the Committee on Asthma Management Guidelines  
Malaysian Thoracic Society  
March 1996

 

 

 

List Of Participants 
Participants :

 

  • Chairman  A Proffesor Dr BMZ Zainudin - Department of Medicine Universiti Kebangsaan Malaysia Kuala Lumpur
  • Dr A M Aziah - Institute of Respiratory Medicine  Hospital Kuala Lumpur
  • Dr L N Hooi - Chest Unit  Penang Hospital
  • A Professor Dr A W Sufarlan - Department of Medicine  Universiti Kebangsaan Malaysia  Kuala Lumpur
  • A Professor Dr Ismail Yaacob - Department of Medicine  Universiti Sains Malaysia  Kubang Kerian 
  • Dr I Kuppusamy - Institute of Respiratory Medicine  Hospital Kuala Lumpur
  • Dr George Simon - Chest Unit  Hospital Alor Setar
  • A Professor Dr C K Liam - Department of Medicine  Hospital University  Kuala Lumpur
  • Dr W K Wong - Pantai Medical Centre  Kuala Lumpur

 

Introduction

Asthma is a common disease with unacceptably high morbidity and mortality. Many deaths and morbidity have been associated with inadequate treatment, underuse of objective measurement of severity and inadequate supervision. Realising the need to improve the management of asthma among doctors in Malaysia, the Malaysian Thoracic Society initiated efforts to produce and publish this consensus statement on the management of asthma. Since consensus on management of asthma in children was initiated at about the same time by the Academy of medicine of Malaysia, this statement by the Malaysian Thoracic Society only covers management of asthma in adults.

 

We realise that several asthma management guidelines for example those by the British Thoracic Society, those from Australia and New Zealand and the International consensus are already available. However, local factors such as our health care delivery system, diverse socio-cultural background and level of education which are unique to our country need to be addressed. This prompted us to produce these local guidelines.

We regard the publication of guidelines on asthma management as one of the strategies to improve the overall management of asthma in the country. It should complement other programmes such as lectures, workshops, meetings and periodic publications. We hope these guidelines will serve as a useful reference for doctors although we also appreciate that views may differ in certain aspects of management. In certain circumstances, modification in management may have to be carried out.

Although there is no evidence to date that asthma management guidelines reduce asthma mortality, it is not unreasonable to expect that proper management will result morbidity and consequently mortality too.

To ensure a spread of opinions the working party was selected among doctors working in government hospitals, academic institutions and private hospital.


 

Concept Of Asthma

Asthma is a chronic inflammatory condition of the airways the cause of which is not completely understood. The inflammation is characterised by oedema, infiltration with inflammatory cells especially eosinophils, hypertrophy of glands and smooth muscle and damaged epithelium. The inflammation results in the state of hyperresponsiveness where airways narrow easily in response to a wide range of stimuli.7 This may result in coughing, wheezing, chest tightness and shortness of breath, which are often worse at night. These are the symptoms of an attack. The airway narrowing is usually reversible but in some patients with chronic asthma the inflammation may lead to irreversible airways obstruction.8 In general the more severe the asthma the more frequent and severe are the attacks. Sometimes an acute attack can be fatal.

 


 

Management Of Chronic Asthma 

 

Aims of management 
The aims of management are:

  1. to recognise asthma
  2. to abolish symptoms
  3. to restore normal or best possible long term airway function
  4. to reduce morbidity and prevent mortality

 

Approach to management 

In order to achieve those aims the approach to management should include:


  1. Education of patient and family
  2. Avoidance of precipitating factors
  3. Use of the lowest effective dose of convenient medications minimising short and long term side effects
  4. Assessment of severity and response to treatment.

 

Education of patient and family

This is an important but often neglected aspect in the management of asthma. It is essential in ensuring the patient's cooperation and compliance with therapy. As far as possible patients and their families should be encouraged and trained to actively participate in the management of their own asthma. Patient education should include the following information:


  1. Nature of asthma
  2. Preventive measures/avoidance of triggers
  3. Drugs used and their side-effects
  4. Proper use of inhaled drugs
  5. Proper use of peak flow meter
  6. Knowledge of the difference between relieving and preventive medications
  7. Recognition of features of worsening asthma (increase in bronchodilator requirement, development of nocturnal symptoms, reducing peak flow rates).
  8. Self management plan for selected, motivated patients or parents. (Appendix 1)
  9. The danger of non prescribed self medication including certain traditional medicines.

 

 

Avoidance of precipitating factors
The following factors may precipitate asthmatic attacks:


  1. Beta blockers - contraindicated in all asthmatics
  2. Aspirin and nonsteroidal anti-inflammatory drugs - if known to precipitate asthma, these drugs should be avoided.
  3. Allergens, e.g. house dust mites, domestic pets, pollen should be avoided whenever possible.
  4. Occupation - should be considered as a possible precipitating factor
  5. Smoking - active or passive.
  6. Day to day triggers - such as exercise and cold air. It is preferable to adjust treatment if avoidance imposes inappropriate restrictions on lifestyle.
  7. Atmospheric pollution.
  8. Food - if known to trigger asthma, should be avoided.

 

 

Drug treatment 
There are 2 major groups of drugs to treat asthma:

  1. Bronchodilator drugs - to relieve bronchospasm and improve symptoms.
  2. Anti inflammatory drugs - to treat the airway inflammation and bronchial hyperresponsiveness, the underlying cause of asthma, i.e. to prevent attacks.

  1. Bronchodilators
    These drugs treat symptoms of asthma. They should be used as required rather than regularly. When asthma is severe and difficult to control, bronchodilators may be taken on regular basis. There are 3 main groups of bronchodilators:
    1. Beta2 agonists
    2. Anticholinergics
    3. Methylxanthines

    a. Beta2 agonists

    These drugs are the most effective bronchodilators available. They are safe drugs with few side effects when taken by inhalation. The therapeutic effect is felt within a few minutes of inhalation. The main side effects are tremors and tachycardia. Oral slow release preparations and inhaled long acting beta2 agonists such as Salmeterol /bambuterol are useful for nocturnal asthma.
    Examples:

    Inhaled beta2 agonist:
      salbutamol (Ventolin, Respolin)
    terbutaline (Bricanyl)
    fenoterol (Berotec) 
    salmeterol (Serevent) - long acting
    Oral long acting beta2 agonist:
      salbutamol (Volmax)
    terbutaline (Bricanyl durules)
    bambuterol (Bambec)
    Oral short acting beta2 agonist:
      salbutamol
    terbutaline etc.

    b. Anticholinergic drugs

    Inhaled anticholinergics have lower onset but longer duration of action. They have very few side effects.
    Examples: Ipratropium bromide (Atrovent)

c.Methylxanthines 


These drugs are available in oral and parenteral forms. Their usefulness is limited by very variable metabolism and a narrow therapeutic window. Sustained release preparations may be useful in nocturnal asthma.9 
Examples: Nuelin SR, Theodur, Euphylline

Note: Inhaled beta2 agonists are the bronchodilator of choice. As far as possible, avoid using oral beta2 agonists or xanthines as first line bronchodilator drugs.


  1. Anti-Inflammatory Drug

    As asthma is a chronic inflammatory condition, anti-inflammatory drugs should be a logical treatment for most patients except for those with mildest asthma. Reducing the inflammatory will decrease bronchial hyperresponsiveness. The types of anti-inflammatory drugs include:

    i. Corticosteroids

    Steroids are the main prophylactic drugs in adult asthmatics. They should be taken by inhalation and the dosage should be kept to a minimum to reduce side effects (usually local side effects).10 Oral steroids maybe required for severe chronic asthma. 
    Examples: Beclomethasone dipropionate (Becotide, Becloforte, Beclomet, Aldecin, Respocort) Budesonide (Pulmicort)

    ii. Sodium cromoglycate (Intal)

    This drug is very safe with no significant side effects. It is given by inhalation (power Spinhaler or metered dose inhaler). It is of greatest benefit in young, atopic patients.11

 

Other treatments 
Anti-histamines including ketotifen have been proven to be of limited efficacy in many clinical trials in asthma.12-14 Hyposensitisation is of limited value in the management of asthma.15

 

Drug Deliver
The inhaled route is preferred for beta2 agonists and steroids as it produces the same benefit with fewer side-effects as compared to the oral route. The pressurised metered dose inhaler (MDI) is suitable for most patients as long as the inhalation technique is correct.

 

For patients with poor coordination, alternative methods for durg inhalation include: 
spacer devices, dry powder devices and breath-actuated pressurised MDI.16-21

Although oral treatment is convenient for most patients, the dose required is higher and therefore side effects are more common.22-23


 

Approach To Drug Therapy - "Stepwise Approach"

Treatment should be carried out in a stepwise manner. Patients should be started on treatment at the step most appropriate for the initial severity of their condition. Treatment would then be changed (stepped-up or stepped-down) according to their progress.

 

Step 1 
This treatment is for patients with MILD EPISODIC ASTHMA, characterised by normal or near normal lung function, infrequent symptoms and no nocturnal symptoms (Table 1).

A beta2 agonist by inhalation should be used on an as needed basis. If not well controlled, i.e. requiring usage of beta2 agonist more than once a day, advance to Step 2.

 

Step 2 
This treatment is for MODERATE ASTHMA characterised by abnormal lung function (PEF 60-80% predicted), frequent symptoms requiring beta2 agonist more than once daily or with night symptoms.

Addition of an inhaled anti-inflammatory agent is required. Low dose inhaled corticosteroids are the drugs of choice (e.g. beclomethasone or budesonide 200-800 mcg daily). Twice daily dosing is preferred to improve compliance. Sodium cromoglycate may also be effective in some patients.

 

Step 3 
This step is for SEVERE CHRONIC ASTHMA, i.e. patients with persistent symptoms (especially nocturnal symptoms), a continuing need for inhaled bronchodilators and peak flow of less than 60% predicted or best.

High dose of inhaled steroid should be used (beclomethasone or budesonide 800-2000 mcg daily) whilst inhaled beta2 agonist should be taken on an as required basis. It may be necessary to add one or more of the following:

  1. Regular beta2 agonists - oral beta2 agonists (preferably long acting) or inhaled long acting beta2 agonist or nebulised beta2 agonists.
  2. Inhaled ipratropium bromide (Atrovent) 40mcg 3-4 times a day.
  3. Sustained release theophylline. Whenever possible blood levels should be monitored.

Alternatively, whenever there are problems with high doses of inhaled steroids, these drugs may be added to Step 2 medications.

 

Step 4 
This step is for VERY SEVERE ASTHMA characterised by persistent symptoms not controlled by the above measures. Oral steroids should be added and the dose kept to the lowest possible that achieves control.

 

Step down 
Patients should be reviewed regularly. When the patient's condition has been stable for 3-6 months, drug therapy may be stepped down gradually. The monitoring of symptoms and peak flow rate should be continued during drug reduction.

 


 

Management Of Chronic Asthma In Adults 
See Chart 1 

Rescue Course Of Steroid Tablets 


"Rescue" courses of oral steroids may be needed to control exacerbations of asthma at any step. Indications may include:

  1. symptoms and peak expiratory flow (PEF) get progressively worse day by day.
  2. PEF falls below 60% of patient's best.
  3. sleep is disturbed by asthma.
  4. morning symptoms persist until midday.
  5. there is a diminishing response to inhaled bronchodilators.
  6. emergency treatment with nebulised or injected bronchodilators is required.

Method: 
Give 30-60 mg of prednisolone immediately. The dose should be tapered down and stopped within 7-14 days. 
 

 

Assessment Of Severity And Response To Treatment 
Assessment should be done as follows:

  1. Clinical assessment. This should include patient's symptoms, sleep disturbances, effort tolerance, disturbance of daily activities and the frequency of bronchodilator drug and/or rescue courses of steroid used.
  2. Measuring peak expiratory flow (PEF). This can either be measured by Wright peak flow meter or mini-Wright peak flow meter. Mini-Wright peak flow meters are affordable for many patients.

 

PEF Measurements

  1. During periods of well-being

    This allows measurement of patient's best PEF value which will provide the target for the doctor and the patient to aim for. Twice daily measurements (morning and evening) before any inhaled bronchodilator treatment will determine the diurnal variability of airway calibre. This is calculated as the range divided by the highest value and expressed as a percentage.

    PEF (max) - PEF (min)     x     100 = _____________% 
            PEF (max) 

    PEF variability of less than 20% is regarded as mild, between 20-30% is moderate and more than 30% is severe. A good control of asthma means PEF variability is maintained at less than 10%.
  2. During symptomatic episodes

During an attack of asthma PEF fairly accurately measures the degree of bronchospasm. A PEF of less than 50% of normal or best suggests a severe attach and a PEF of less than 33% suggests a very severe and life threatening attack. When the best PEF value is not known, a single reading of less of 200 l/min usually indicates a severe attack.

Hence, in additional to history and physical findings the PEF helps the doctor to decide on the appropriate therapy (besides history and physical findings). As far as possible patients with moderate and severe asthma should regularly measure their PEF twice a day especially when their asthma is worsening or when treatment is altered. Comparison to local normal values should be made24.


 

Specialist Referral 
Referral to a respiratory physician is appropriate when:

  1. there is doubt about the diagnosis
  2. occupational asthma is suspected
  3. management is difficult, e.g. brittle asthma or very severe asthma not successfully controlled
  4. long term treatment with nebulised bronchodilator is needed
  5. asthma is worsening in a pregnant woman
  6. asthma is interfering with patient's lifestyle despite changes in treatment

 

Pregnancy And Asthma

During pregnancy asthma in about one-third of women becomes worse, in one-third better and in one-third remains unchanged. However this cannot be predicted. Achieving good control of asthma is more important in order to prevent adverse effects on both fetus and mother than the theoretical risks of any of the presently used anti-asthma medications. Most drugs used to treat asthma are safe with the exception of alpha adrenergic compounds and epinephrine (both are not usually used to treat asthma in Malaysia). Asthma in pregnancy therefore should be managed as in other patients. Acute exacerbations should be treated aggressively in order to avoid fatal hypoxia and maintain maternal well-being. Treatment should include nebulised beta2-agonists and oxygen, systemic corticosteroids should be instituted when necessary. Patients should also have adequate opportunity to discuss the safety of their medication.

 


Guidelines For The Management Of Acute Asthma In Adults 

The presentation of a patient with acute asthma requires rapid assessment of its severity so that the appropriate treatment can be instituted.

 

Although an acute severe attack of asthma may occasionally develop within a few minutes or hours, it usually occurs against a background of long term poorly controlled asthma or asthma that has been worsening for some days or weeks. The severity of acute asthma attacks is usually underestimated by patients, their relatives and their doctors, mainly because of the failure to make objective measurements.25 Inadequate assessment of such attacks or inappropriate treatment with over-reliance on bronchodilators and underuse of steroids contribute to morbidity and deaths.26-29


 

Aims Of Management 

The aims of management are:

  1. To prevent death
  2. To relieve respiratory distress
  3. To restore the patient's lung function to the best possible level as soon as possible.
  4. To prevent early relapse

 

Assessment 4,30-32 

The severity of the attack should be assessed by:

  1. History taking
  2. Physical examination
  3. PEF measurement

 

Features of moderately severe asthma

  • normal speech
  • pulse rate < 110/min
  • respiratory rate < 25 breaths/min
  • PEF > 50% predicted or best value

Features of acute severe asthma 

The presence of any of the following indicates a severe attack of asthma:

  • too breathless to complete sentences in one breath
  • respiratory rate ³ 25 breaths/min
  • pulse rate ³ 110/min
  • PEF £ 50% predicted or best value

 

Life threatening features 

The presence of any of the following indicates a very severe attack of asthma:

  • central cyanosis
  • feeble respiratory effort
  • silent chest on auscultation
  • bradycardia or hypotension
  • exhaustion
  • confusion or unconsciousness
  • PEF < 33% predicted or best value (or a single reading of <150 l/min of patients who are not able to blow)

Arterial blood gas (ABG) tensions should be measured if a patient has any of the severe or life threatening features.

ABG markers of a very severe, life threatening attach include:

  • a normal (5-6 kPa, or 36-45 mmHg) or high PaCO2
  • severe hypoxaemia: PaO2 < 8kPa (60 mmHg) irrespective of treatment with oxygen
  • a low pH

 

Management Of Acute Asthma In Accident And Emergency Department

 

Initial PEF > 75% (Mild acute asthma) 
Sometimes, patients with mild acute asthma may present at the A&E. This is characterised by an initial PEF of >75% of predicted or best value. In this situation, just given the patient's usual inhaled bronchodilator (e.g. salbutamol, terbutaline or fenoterol) from a metered dose inhaler.

Observe for 60 minutes. If the patient is stable and PEF is still >75%, discharge.

Before discharge:

  • review adequacy of usual treatment and step up if necessary according to guidelines for treatment of chronic persistent asthma
  • ensure patient has enough supply of medications
  • check inhaler technique and correct if faulty
  • advise patient to return immediately if asthma worsens.
  • make sure patient has a clinic follow-up appointment

P/S: Patients should be considered for admission if social situations such as staying alone, lack of transport for emergency visit to hospital, etc.

 

Initial PEF < 75% 
Patients who present to the A&E with more severe degrees of acute asthma characterised by an initial PEF < 75% predicted or best value, should be managed as follows:

 

  1. Immediate Treatment With :

    1. High concentration oxygen (>40%) in cases with initial PEF <50% at presentation.
    2. High doses of inhaled beta2 agonist (salbutamol 5mg or terbutaline 5mg or fenoterol 5mg) via nebuliser driven by oxygen. If compressed air nebuliser is used, administration of supplemental oxygen when indicated should be continued.

      Alternatively, beta2 agonist may be given by multiple actuations of a pressurised aerosol inhaler into a large spacer device (2-5mg, i.e. 20-50 puffs, five puffs at a time).

      Consider adding anticholinergic (e.g. ipratropium bromide 0.5mg) to nebulised beta2 agonist for patients with acute severe asthma.
    3. Prednisolone tablets 30-60mg. Very ill patients should be given intravenous hydrocortisone 200mg stat.

      NB. Sedatives should not be prescribed. 
      Antibiotics are indicated only if there is evidence of a bacterial infection.
      Do a chest x-ray if pneumothorax or pneumonia is suspected or features of acute severe or life threatening asthma are present.

        If life threatening features are present:

    1. Intravenous aminophylline 250mg slowly over 20 minutes or intravenous terbutaline or salbutamol 250mcg over 10 minutes.(Bolus aminophylline should not be given to patients already taking oral theophylline).

      *    Patients with features of life threatening asthma require admission preferably to the intensive care unit (ICU) and should be accompanied by a doctor.

      Effects Of Treatment
      The effects of treatment are monitored by:‚Äč
  • the patient's assessment of symptoms
  • physical examination
  • repeat measurement of PEF 15-30 minutes after starting treatment

Good response to initial treatment 
Such patient should

 

  • be free of wheezing and dyspnoea
  • have a clear chest on auscultation
  • have a postbronchodilator PEF which is >75% of predicted or best value.

Incomplete response to initial treatment
Such a patient has

  • persistent wheezing or dyspnoea
  • rhonchi on chest auscultation
  • a postbronchodilator PEF which is 50-75% of predicted or best value.

Poor response to initial treatment
Such a patient has

  • persistent, marked wheezing or breathlessness
  • diffuse rhonchi on chest auscultation and other signs of acute severe asthma
  • a postbronchodilator PEF <50% of predicted or best value.

The subsequent management of patients with an initial <75% predicted or best value is summarised in Table 2.

  1. Subsequent Management In The Ward Or ICU

    Continue - oxygen at 40%
    • intravenous hydrocortisone 200mg 6-hourly or prednisolone 30-60mg daily
    • nebulised beta2-agonist 4-hourly; this can subsequently be changed to metered dose inhaler (It may be necessary to give nebulised beta2-agonist more frequently, up to every 15-30 minutes and to add ipratropium bromide 0.5mg to nebulised beta2-agonist and repeat 6-hourly if patient is not improving.)

 

        If patient is still not improving, also give

    • aminophylline infusion (0.5-0.9mg/kg/hour); monitor blood levels (where facility is available) if aminophylline infusion is continued for more than 24 hours.
    • terbutaline or salbutamol infusion as an alternative to aminophylline, at 3-20mcg/min after an initial intravenous bolus dose of 250mcg over 10 minutes.

 

  1. Monitoring The Effects Of Treatment

 

    • Repeat measurement of PEF 15-30 minutes after starting treatment.
    • Maintain arterial oxygen saturation above 92% (if facility for pulse oximetry is available)

 

 

 

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