Diagnostic Criteria and Assessment

The diagnosis and assessment of asthma exacerbation require a multifaceted approach that includes clinical evaluation, objective measurements, and consideration of underlying triggers and comorbidities. Timely and accurate assessment guides the appropriate intervention, monitoring, and follow-up care.

 

Clinical Assessment

History and Physical Examination

A comprehensive assessment includes:

• Symptoms: Understanding the onset, duration, and nature of symptoms, including cough, wheezing, shortness of breath.
• Past Medical History: Previous exacerbations, hospitalizations, medication use, allergies, compliance with treatment.
• Examination: Respiratory rate, breath sounds (wheezing, decreased breath sounds), use of accessory muscles, cyanosis, oxygen saturation.

 

Pulmonary Function Tests

Spirometry

Spirometry assesses airflow limitation:

• Pre- and Post-Bronchodilator Testing: Evaluating response to bronchodilators can help in diagnosing reversible obstruction.
• Considerations: Not always feasible during acute exacerbation but valuable for baseline assessment.

Peak Flow Measurement

A quick and simple tool:

• Peak Expiratory Flow (PEF): Can be used at home or in clinical settings.
• Personal Best Monitoring: Comparing to personal best values provides individualized assessment.

 

Additional Investigations

Arterial Blood Gases (ABGs)

May be performed in severe exacerbations to assess:

• Oxygenation: Hypoxemia may indicate severe exacerbation.
• Carbon Dioxide Retention: Hypercapnia may signal impending respiratory failure.
• Blood Eosinophil Count
  • Description: Eosinophils are a type of white blood cell involved in allergic reactions and inflammation. An elevated eosinophil count may indicate a type of asthma that responds well to specific therapies like biologics.

Chest X-ray

Helpful in ruling out complications or other diagnoses:

• Pneumonia, Pneumothorax: Conditions that may mimic or complicate exacerbation.

Allergy Testing

Identifying specific allergens may guide preventive measures.

Severity Assessment

A combination of clinical and objective measures helps categorize severity:

Severity	Clinical Features	Spirometry/PEF	Additional Considerations
Mild	Increased symptoms, no distress	FEV1/PEF ≥ 70% predicted	Consider home management
Moderate	Difficulty speaking in full sentences	FEV1/PEF 40-69% predicted	Likely requires medical intervention
Severe	Severe distress, difficulty speaking short phrases	FEV1/PEF < 40% predicted	Hospitalization, possible ICU
Life-Threatening	Silent chest, confusion, loss of consciousness	FEV1/PEF < 25% predicted	Emergency intervention

 

Special Populations

Pediatrics

Assessment in children may require specific tools and considerations, including observation of feeding, activity level, and parental input.

Elderly

Consideration of comorbidities, medication interactions, and cognitive function is vital.

Asthma Severity Score (ASS)

The Asthma Severity Score is a validated tool that assesses the severity of asthma exacerbations based on specific clinical parameters. It can be used in various settings, including emergency departments, to guide treatment decisions.

Components of the ASS:

Parameter	Score 0	Score 1	Score 2	Score 3
Wheezing	None	End-expiratory	Throughout	Severe
Accessory Muscle Use	None	Mild	Moderate	Severe
PEF (% Predicted)	>70%	50-70%	30-50%	<30%

 

Severity Categories:

• Mild Exacerbation: Total score 0-3
• Moderate Exacerbation: Total score 4-6
• Severe Exacerbation: Total score 7-9

The ASS provides a standardized and objective means of assessing asthma exacerbation severity, aiding in timely and appropriate management.

Summary

The expanded diagnosis and assessment of asthma exacerbation involve a nuanced and individualized approach, integrating clinical, functional, and radiological evaluations. The inclusion of considerations for special populations ensures comprehensive care across the lifespan.