GPAC: Guidelines and Protocols Advisory Committee

Diagnosis and Management of Asthma

Effective Date: July 1, 2003

Summary | Flow Sheet | Patient Guide | Full Guideline in PDF

Recommendations and Topics

Scope

Standard of Care

1. Diagnosis of asthma

2. Patient education and environmental control

3. Control of asthma

4. Initiating pharmacological treatment

5. Managing chronic asthma

Rationale

References

Sponsors

Scope

This guideline is based on the Canadian Asthma Consensus Report (1999)¹ and the Asthma Guidelines update 2001². It applies to patients age six and older.

Asthma is a syndrome that is characterized by paroxysmal or persistent symptoms such as breathlessness, chest tightness, wheezing, sputum production and cough. It is associated with variable airflow limitation and airway hyperresponsiveness in response to endogenous and exogenous stimuli. Inflammation and its resultant effects on airway structure are considered to be the main mechanisms leading to the development and persistence of asthma.

Standard of care

The literature recommends the following standards for the diagnosis and management of asthma:

• Smoking cessation in the home and workplace is a cornerstone of asthma management
• Confirm diagnosis and assess severity by objective measures of airflow obstruction
• Consider relevant contributing factors (e.g. dust, pet allergens, ß-blocker eye drops, reflux esophageal disease, occupational exposure) in light of the person's history.
• Initiate patient/family education, focusing on environmental control and self-management
• Prescribe medication required to achieve control
• Achieve acceptable asthma control
• Develop an action plan in consultation with patient
• Once control is achieved, reduce medications to the minimum dose required to maintain control

Twice a year:

• Review asthma symptoms and degree of control
• Review medication needs and side effects
• Review action plan with patient
• Measure growth in children

RECOMMENDATION 1: Diagnosis of asthma

When asthma is suspected from symptoms and clinical presentation, and other disorders have been considered and ruled out, confirm the diagnosis by objective measures of variable airflow obstruction and assess severity. In most cases, the following criteria would suffice as objective evidence of variable airflow obstruction:

• Spirometry: A 12-15 % or greater improvement in forced expiratory volume (FEV₁ ) ( and >180 ml in adults) from the baseline 15 minutes after use of an inhaled short acting beta 2 agonist; or 20% or greater "spontaneous variability" in spirometry values.
• Serial measures of peak expiratory flow (PEF): A >20% change after administration of a bronchodilator; a 20% change in values over time.

In rare cases the following tests may be used to help in the diagnosis of asthma:

• Methacholine challenge
• Exercise challenge
• Steroid trial: appropriate doses of inhaled steroids for 4-6 weeks or oral steroids for 10-14 days (adult) resulting in >20% improvement in FEV₁.

RECOMMENDATION 2: Patient education and environmental control

Patients should receive adequate education and support so they understand their responsibility for control of asthma. Education on environmental control, particularly avoidance of relevant allergens and respiratory irritants, is essential to achieve adequate control. Patients may be supported with:

• A written action plan
• Practical information regarding avoidance of allergens and respiratory irritants
• Identification of an asthma support team
• Education regarding proper use of medications and technique of administration
• Education regarding what constitutes 'control'
• Self-monitoring using either measurement of PEF or symptom monitoring
• Diaries
• A patient registry
• Referral to an asthma education program if available

See Asthma Guide for Patients and web resources for environmental control material, examples of action plans and other patient education tools.

RECOMMENDATION 3: Control of asthma

Control of airway hyperresponsiveness is the key to success. Most people with asthma should have minimal to no impact on their quality of life.

Review diary, action plan and inhaler technique.

Criteria indicating adequate control:

• Daytime symptoms less than four days/week
• Night-time symptoms less than one night/week
• Normal physical activity
• Mild infrequent exacerbations
• No absenteeism due to asthma
• Fewer than four doses of beta-agonist needed per week apart from 1 dose/day before exercise
• FEV₁ or PEF 90% of personal best or greater
• Diurnal variability in PEF less than 10% to 15%
• No need for emergent/urgent physician visits for asthma

RECOMMENDATION 4: Initiating pharmacological treatment

• If symptoms are infrequent and expiratory flows are normal, an inhaled short acting beta 2 agonist should be used as needed.
• If a rescue beta 2 agonist is needed more than 3 times per week or if lung function is abnormal, an initial inhaled glucocorticosteroid equivalent to 400-1000 mcg/day (child: 200-1000 mcg) of beclomethasone dipropionate is the preferred next step.
• If symptoms are severe and/or expiratory flows are <60% predicted value, oral steroids may be part of the initial management plan.
• In selected cases, the use of long-acting inhaled beta-agonists is helpful, as is the use of combined inhaled long-acting beta agonists and corticosteroids.

RECOMMENDATION 5: Managing chronic asthma

• Educate patients to actively manage their illness
• Identify and eliminate barriers to effective control
• In your office create:
• a registry of patients with asthma
• an automated recall system
• flowcharts and checklists
• Review care/education offered to patient/family periodically
• Review of asthma symptoms, medication needs, delivery device technique and action plan
• Annual flu vaccine

See the attached sample Personal Action Plan and Guide for patients

Rationale

Asthma is one of the most frequent medical diagnoses among hospitalized children and elderly patients in BC. Despite an increasing understanding of its pathogenesis, asthma remains a major cause of emergency care requirements, missed school, considerable morbidity, disability, and occasional mortality at all ages. The most important contributing factors for inadequate management may include:^3-5

• Delayed diagnosis and insufficient patient education (including airflow measurements)
• Underassessment of the severity of the disease
• Undertreatment with anti-inflammatory agents
• Over-reliance on inhaled beta-agonists
• Failure to consider co-morbid medical conditions e.g. rhinosinusitis, gastro-esophageal reflux disease (GERD), cystic fibrosis (CF), depression, or social conditions e.g. family discord, life stresses as contributors

Medical care delivery can be improved by addressing these factors.

During the 1980s, increased death and hospital admission rates were reported in many countries including Canada. These rates have subsequently declined during the 1990s.^3,6The true burden of asthma in Canada is hard to quantify because the rates of death (400 to 500 per year) and hospital admissions (78,400 per year) underestimate the disability and lost quality of life experienced by the 8% of Canadians who have this disease.⁶

In British Columbia, there were 58 deaths from asthma in 2001.⁷ From 1994 to 1998 there has been a decrease in the number of cases of asthma patients admitted to hospital and admission days from 6,773 to 4,877 and 26,490 to 17,746 respectively. A review of MSP billings indicates about 350,000 visits coded with a diagnosis of asthma are assigned to about 125,000 patients each year.

Early detection, appropriate treatment, and consistent application of guidelines for education, self-management and follow-up would lead to reduced morbidity and mortality and, possibly, reduction of costs associated with the treatment of asthma.

References

1. Boulet LP, Becker A, Berube D, Beveridge R, Ernst P. Canadian Asthma Consensus Report, 1999. Canadian Asthma Consensus Group. CMAJ 1999;161(11 Suppl):S1-61.
2. Asthma guidelines update 2001. Can Resp J 2001;8:1A-48A.
3. Weiss KB, Gergen PJ, Wagener DK. Breathing better or wheezing worse? The changing epidemiology of asthma morbidity and mortality. Annual Rev Public Health 1993;14:491-513.
4. Richman E. Asthma diagnosis and management: New severity classifications and therapy alternatives. Clinician Reviews [serial online] 1997;7(8):76-78, 83-84, 86-90, 96-97, 101-102, 107-109, 112.
5. Weinberger M. Asthma management: Guidelines for the primary care physician. 1997. Medscape Respiratory Care.
6. Respiratory Disease in Canada. Canadian Institute for Health Information. Health Canada. Sept 2001. Ottawa.
7. British Columbia, Vital Statistics, 2001.

Sponsors

This guideline was developed by the Guidelines and Protocols Advisory Committee. It was approved by the British Columbia Medical Association and adopted by the Medical Services Commission.

Funding for this guideline was provided in full or part through the Primary Health Care Transition Fund.

Revised Date: April 1, 2007

This guideline is based on scientific evidence current as of the effective date.

Disclaimer

The Clinical Practice Guidelines (the "Guidelines") have been developed by the Guidelines and Protocols Advisory Committee on behalf of the Medical Services Commission. The Guidelines are intended to give an understanding of a clinical problem, and outline one or more preferred approaches to the investigation and management of the problem. The Guidelines are not intended as a substitute for the advice or professional judgment of a health care professional, nor are they intended to be the only approach to the management of clinical problems.

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