1. CLINICAL PATHWAY FOR ADULT ASTHMA

2. Clinical Diagnosis of Asthma
Variability:
Episodic breathlessness, wheezing, cough, chest tightness
Precipitation by allergens or non-specific irritants” e.g. smoke, fumes, strong smells or exercise
Nocturnal worsening of symptoms
Positive family history of asthma & atopic disease
Response to appropriate asthma therapy

3. Physical Examination Findings in Asthma
Most usual abnormal PE finding:
Wheezing on auscultation – confirms presence of airflow limitation
PE:
May be normal – because asthma symptoms are variable
Wheezing detected only on forced exhalation
Wheezing may be absent in severe cases due to severely reduced airflow and ventilation but usually with other signs

4. Objective measurements in Asthma diagnosis
Rationale:
Demonstration of reversibility of airflow limitation enhances diagnostic confidence
Patients esp. those with long-standing asthma, frequently have poor recognition of symptoms and poor perception of severity
Physicians may inaccurately assess dyspnea and wheezing

5. Lung Function Measurement in Asthma
Provides an assessment of severity of airflow limitation, its reversibility and variability
Provides confirmation of the diagnosis
Provides complementary information about different aspects of asthma control

6. Spirometry in Asthma Diagnosis of asthma: Spirometry:
Degree of reversibility of FEV1 should be >12% and >200ml from pre-bronchodilator value
Spirometry:
Reproducible but effort-dependent
Pre- & post test lacks sensitivity esp. those on treatment, so repeated testing at different visits is advised
Proper instructions on maneuver must be given

7. PEF measurement in Asthma
Important in both diagnosis and monitoring
Peak flow meters are relatively inexpensive, portable, plastic and ideal for use in home settings for day-to-day objective measurement of airflow limitation
Can underestimate degree of airflow limitation particularly in severe cases

8. PEF measurement in Asthma
Can be helpful to confirm the diagnosis of asthma:
60 L/min (or 20% or more pre-BD PEF) improvement after inhalation of a bronchodilator
A diurnal variation of >20% (with twice daily readings >10%)

9. PEF measurement in Asthma
Can help to improve asthma control esp. in those with poor perception of symptoms:
Self-monitoring using a PEF chart
Can help to identify environmental/occupational causes of asthma symptoms:
PEF daily or several times a day over periods of suspected exposure to risk factors (at home, workplace, during exercise or other activities)

10. Controller Medications
Inhaled glucocorticosteroids
Long-acting inhaled β2-agonists
Systemic glucocorticosteroids
Leukotriene modifiers
Theophylline
Cromones
Long-acting oral β2-agonists
Anti-IgE

11. Reliever Medications Rapid-acting inhaled β2-agonists
Systemic glucocorticosteroids
Anticholinergics
Theophylline
Short-acting oral β2-agonists

12. Asthma Exacerbations
Episodes of progressive worsening of shortness of breath, cough, wheezing or chest tightness or some combination of these symptoms
Characterized by significant decreases in PEF or FEV1 which are more reliable indicators of severity of airflow obstruction than degree of symptoms
May range from mild to life-threatening

13. Severity of Asthma Exacerbations
Mild
Moderate
Severe
Respiratory Arrest Imminent
Breathless
Walking
Talking
At rest
Talks in
Sentences
Phrases
Words
Alertness
May be agitated
Usually agitated
Drowsy or confused
Respiratory rate
Increased
Often >30/min
Accessory muscles & suprasternal contractions
Usually not
Usually
Paradoxical thoraco-abdominal movement
Wheeze
Moderate, often only end-expiratory
Loud
Usually loud
Absence of wheeze
Pulse/min
<100
>120
Bradycardia
Pulsus paradoxus
Absent <10mmHg
May be present 10-25mm Hg
Often present > 25 mm Hg
PEF after initial BD % predicted or % personal best
Over 80%
Approx 60-80%
<60% predicted or personal best (<100/min or response lasts 2 hrs)
PaO2 and/or PaC02
Normal <42 mm Hg
< 42 mm hg
< 60 mm Hg
Possible cyanosis
>42 mm Hg
possible resp failure
Sa02
> 95%
91-95%
<90%

14. Features of Patients at high-risk for asthma-related death
Current use of or recent withdrawal from systemic corticosteroids
Emergency care visit for asthma in the past year
History of near-fatal asthma requiring intubation or mechanical intubation
Not currently using inhaled steroids
Overdependence on rapid acting inhaled β2-agonists, esp. those with more than one canister monthly
Psychiatric disease or psychosocial problems, incl. the use of sedatives
Noncompliance with asthma medication plan

15. Management of Asthma Exacerbations
Treatment of exacerbations depends on:
The patient
Experience of health care professional
Therapies that are the most effective for the particular patient
Availability of medications
Emergency facilities

16. Treatment of Exacerbations
The aims of treatment are to:
Relieve airway obstruction as quickly as possible
Relieve hypoxemia
Restore lung function to normal as early as possible
Plan and avoidance of future relapses
Develop a written action plan in cases of future exacerbations

17. Management of Asthma Exacerbations
Primary therapies for exacerbations:
Repetitive administration of rapid-acting inhaled β2-agonists
Early introduction of systemic glucocorticosteroids
Oxygen supplementation
Closely monitor response to treatment with serial measures of lung function

18. Criteria for Hospitalization
Inadequate response to therapy within 1-2 hours
Persistent PEF <50% after 1 hour of treatment
Presence of risk factors
Prolong symptoms prior to ER consult
Inadequate access to medical care and medications
Difficult home condition
Difficulty in obtaining transport to hospital in event of further deterioration

19. Asthma Exacerbations and Hospitalization
Despite appropriate therapy ~10 to 25% of ER patients with acute asthma will require hospitalization
The response to initial treatment in the ER is a better predictor of the need for hospitalization than is severity on presentation
FEV1 or PEF appears to be more useful in adults for categorizing severity of exacerbation and response to treatment

20. Management of Acute Exacerbations: Hospital Setting
Initial Assessment: History, PE, PEF or FEV1, Sa02
PEF or FEV1 >40% predicted (Mild to Moderate)
Oxygen to achieve Sa02 >90%
Inhaled SABA by nebulizer or MDI with valve holding chamber up to 3 doses in 1st hour
PEF or FEV1 <40% predicted (Severe)
Oxygen to achieve Sa02 >90%
High dose inhaled SABA + Ipratropium by nebulizer or MDI with valve holding chamber every 20 min or continuously for 1 hour
Impending or actual respiratory arrest
Intubation and mechanical ventilation with 100% 02
Nebulized SABA and Ipratropium
Intravenous corticosteroids
Consider adjunct therapies
Repeat Assessment:
PE, PEF, Sa02, other tests as needed
Admit to hospital intensive care
-see below
Moderate Exacerbation:
PEF or FEV % predicted or personal best
PE: moderate symptoms
Treatment:
Inhaled SABA every 60 mins
Oral systemic corticosteroids
Continue treatment 1-3 hrs provided there is improvement: make decision in < 4 hours
Severe Exacerbation:
PEF or FEV1 < 40% predicted or personal best
PE: Severe symptoms at rest, accessory muscle use, chest retraction
History: high-risk for asthma related death
No improvement after initial treatment
Treatment:
Oxygen
Nebulized SABA+Ipratropium hourly or continuous
Oral systemic corticosteroids
Consider adjunct therapies

21. Management of Acute Exacerbations: Hospital Setting CONTINUATION
Moderate exacerbation
Severe Exacerbation
Good Response
Response sustained for 1 hr after last treatment
No risk factors
S/Sx: no distress, normal PE
PEF > 70% predicted or personal best
Sa02 >90%
Incomplete Response
Within 1 hr &/or (+) risk factors
S/Sx: mild to moderate
PEF or FEV % predicted or personal best
Sa02 not improving
Poor Response
Within 1 hr &/or (+) risk factors
S/Sx: severe drowsiness, confusion
PEF < 40% predicted or personal best
ABG: paC02 >42mm Hg
Individualize decision re: hospitalization
Discharge Home
Continue inhaled SABA
Continue oral steroids
Consider initiation of ICS
Patient education:
Review medications, including inhaler technique
Review/ initiate action plan
Recommend close medical follow-up
Admit to ICU:
Continue inhaled SABA+ inhaled anti-cholinergic
Consider SQ,IV or IM B2-agonist
IV steroids
IV aminophylline
Continue oxygen
Possible intubation/mechanical ventilation
Admit to Hospital
Oxygen
Inhaled SABA
Systemic (oral or IV) corticosteroids
Consider adjunct therapies
Monitor vital signs, FEV1, PEF saO2
IMPROVE
Discharge Home
( see below)
improve

22. Criteria for ICU Admission
Lack of response to initial therapy in ER
Presence of confusion, drowsiness, other signs of impending arrest or loss of consciousness
Impending respiratory arrest:
PaO2 < 60 mmHg on supplemental oxygen
PaCO2 > 45 mmHg

23. Management of Acute Exacerbations: Hospital Setting CONTINUATION
Admit to Hospital
IMPROVE
Discharge home
-Continue inhaled SABAs
Continue oral systemic steroids
Continue on ICS
Patient education:
Review medications, including inhaler technique
Review/ initiate action plan
Recommend close medical follow-up
Before discharge, schedule follow-up appointment with primary care provider and/or asthma specialist in 1-4 weeks.

24. Key FEV- Forced Expiratory Volume in 1 second
ICS- Inhaled Corticosteroids
PCo2- Partial pressure Carbon Dioxide
PEF- Peak Expiratory Flow
SABA- Short Acting Beta2 agonist
SaO2- Oxygen Saturation

25. ADDITIONAL PATIENT EDUCATION
Home Assessment

26. Management of Asthma Exacerbations: Home Treatment
Assess Severity
Initial Treatment
Inhaled SABA: up to two treatment 20 min apart of 2-6 puffs of MDI or nebulizer treatment
Good Response
No wheezing or dyspnea
PEF > 80% predicted or personal best
Contact clinician for follow-up Instructions & further management
May continue inhaled SABA over 3-4 hrs for hrs
Consider short course of oral systemic corticosteroids
Incomplete Response
Persistent wheezing & dyspnea (tachypnea)
PEF 50-79% predicted or personal best
Add oral systemic corticosteroids
Continue inhaled SABA
Contact clinician urgently (this day) for further instructions
Poor Response
Marked Wheezing & dyspnea
PEF <50% predicted or personal best
Add oral systemic corticosteroids
Report inhaled SABA immediately
If distress is severe & non-responsive to initial treatment: call your doctor AND ambulance transport
To ER

27. REFERENCE
Philippine Concensus Report on Asthma Diagnosis and Management 2009 by PCCP Council on Bronchial Asthma

28. PREPARED BY: COORDINATED WITH: Section of Pulmonary Medicine
Emergency Department