What are the diagnostic criteria for status asthmaticus?

From the Guidelines

Status asthmaticus is diagnosed when a severe asthma attack fails to respond to conventional therapy with bronchodilators, characterized by persistent severe respiratory distress despite initial treatment, with symptoms such as marked wheezing, severe dyspnea, accessory muscle use, inability to speak in complete sentences, and respiratory rate >30 breaths per minute. The diagnostic criteria for status asthmaticus include:

• Persistent severe respiratory distress despite initial treatment
• Symptoms such as marked wheezing, severe dyspnea, accessory muscle use, inability to speak in complete sentences, and respiratory rate >30 breaths per minute
• Objective measurements include oxygen saturation <90% on room air, peak expiratory flow rate (PEFR) or forced expiratory volume in 1 second (FEV1) <40% of predicted or personal best, and arterial blood gas showing hypoxemia (PaO2 <60 mmHg) and possibly hypercapnia (PaCO2 >42 mmHg), indicating respiratory failure 1. It is essential to note that the provided evidence from the American Family Physician study 1 focuses on asthma classification and management, but it does not directly address the diagnostic criteria for status asthmaticus. However, the key diagnostic criteria mentioned above are based on the clinical presentation and severity of the asthma attack. Patients with status asthmaticus typically require aggressive treatment, including multiple doses of short-acting beta-agonists, systemic corticosteroids, and may need adjunctive therapies like IV magnesium sulfate or heliox. Status asthmaticus represents a medical emergency requiring immediate intervention and often ICU admission, as the severe bronchospasm and airway inflammation create a life-threatening situation where respiratory muscles may fatigue, leading to respiratory arrest if not aggressively managed.

From the Research

Diagnostic Criteria for Status Asthmaticus

The diagnostic criteria for status asthmaticus include:

• Severe asthma unresponsive to repeated courses of beta-agonist therapy such as inhaled albuterol, levalbuterol, or subcutaneous epinephrine 2, 3
• Severe airflow obstruction, which may be predicted by:
  • Accessory muscle use
  • Pulsus paradoxus
  • Refusal to recline below 30°
  • A pulse >120 beats/min
  • Decreased breath sounds 2, 3
• More objective measures of airway obstruction via:
  • Peak flow (or forced expiratory volume in 1 second)
  • Pulse oximetry before oxygen administration 2, 3
• Patient history, including:
  • Current use of oral or inhaled corticosteroids
  • Number of hospitalizations, emergency room visits, intensive-care unit admissions, and intubations
  • Frequency of albuterol use
  • Presence of nighttime symptoms
  • Exercise intolerance
  • Current medications or illicit drug use
  • Exposure to allergens
  • Other significant medical conditions 2, 3

Triggers for Status Asthmaticus

Common triggers for status asthmaticus include:

• Upper respiratory infections 2, 3
• Medical nonadherence
• Allergen exposure (especially pets and mold) in severely atopic individuals
• Nonsteroidal anti-inflammatory exposure in patients with aspirin allergy
• Irritant inhalation (e.g., smoke, paint)
• Exercise
• Insufficient use of inhaled or oral corticosteroids 2, 3

Treatment and Management

Treatment for status asthmaticus typically involves:

• Administration of oral or parenteral corticosteroids as early as possible 2, 3
• Use of beta-agonist therapy such as inhaled albuterol, levalbuterol, or subcutaneous epinephrine
• Consideration of ipratropium bromide in combination with albuterol in the emergency department 3
• Score-based, respiratory therapist-driven pathways and protocols for pediatric asthma exacerbation 4