When should a patient with a history of severe asthma, chronic obstructive pulmonary disease (COPD), heart disease, or immunocompromised status be hospitalized for an asthma exacerbation?

Hospital Admission Criteria for Asthma Exacerbation

Patients with severe asthma exacerbations should be hospitalized when peak expiratory flow (PEF) remains <40% of predicted after initial bronchodilator treatment, or immediately if life-threatening features are present including PEF <33% predicted, silent chest, cyanosis, altered mental status, or PaCO₂ ≥42 mmHg. 1, 2

Immediate Mandatory Admission Criteria

Hospitalize immediately if any life-threatening features are present 3, 1:

• PEF <33% of predicted or personal best 1
• Silent chest on auscultation 1, 2
• Cyanosis or severe hypoxia (PaO₂ <8 kPa or SaO₂ <90%) 1, 2
• Altered mental status, confusion, or agitation 2
• Inability to speak or complete sentences 3, 2
• PaCO₂ ≥42 mmHg (indicating impending respiratory failure) 3, 2
• Feeble respiratory effort or poor respiratory effort 1, 2

Severity-Based Admission After Initial Treatment

The admission decision fundamentally depends on objective response to initial bronchodilator therapy (three doses over 60-90 minutes) 3, 1:

Admit to Hospital:

• PEF <40% predicted after initial treatment 1, 2
• PEF 40-69% predicted with persistent severe symptoms 1
• Persistent tachypnea (respiratory rate >25 breaths/min) 2
• Persistent tachycardia (heart rate >110 beats/min) 2
• Continued use of accessory muscles 3, 2
• Inability to complete sentences in one breath despite treatment 2

Safe for Discharge:

• PEF >70% predicted after initial treatment with minimal symptoms 1, 2
• PEF >75% predicted or personal best with sustained response 2
• Stable oxygen saturation 2

High-Risk Patients Requiring Lower Threshold for Admission

For patients with the following risk factors, use a lower threshold for admission even with moderate exacerbations 3, 1:

Previous Severe Asthma History:

• Previous intubation or ICU admission for asthma 3
• History of near-fatal asthma 1, 2
• Two or more hospitalizations in the past year 3
• Three or more ED visits in the past year 3
• Hospitalization or ED visit in the past month 3

Medication Use Patterns:

• Using >2 canisters of short-acting beta-agonist per month 3
• Difficulty perceiving airflow obstruction or severity 3

Comorbidities (as specified in your question):

• Chronic obstructive pulmonary disease (COPD) 3
• Heart disease or cardiovascular disease 3
• Immunocompromised status 3
• Other chronic lung disease 3
• Chronic psychiatric disease 3

Social and Behavioral Factors:

• Low socioeconomic status or inner-city residence 3
• Illicit drug use 3
• Major psychosocial problems 3
• Lack of written asthma action plan 3

Timing and Presentation Factors:

• Presentation in afternoon/evening rather than morning 1
• Recent deterioration or nocturnal symptoms 2

Special Population: Infants and Young Children

Infants and young children have higher risk of respiratory failure and require a lower threshold for admission 1, 2:

• Respiratory rate >60 breaths/min 1, 2
• SaO₂ <90-92% 1, 2
• Lack of response to short-acting β₂-agonists 1, 2

Complications Requiring Admission

Admit immediately if complications are present 2:

• Pneumothorax 2
• Consolidation suggesting pneumonia 2
• Pulmonary edema 2

Common Pitfalls to Avoid

• Do not rely solely on symptoms without objective PEF measurement—patients may have poor perception of severity 3
• Do not underestimate severity in patients with well-controlled baseline asthma—severe exacerbations can occur at any level of asthma severity 3
• Do not delay admission decisions—response to ED treatment is a better predictor of hospitalization need than initial presentation severity 3
• Do not discharge patients presenting in the evening without extended observation—timing of presentation affects risk 1
• Reassess after 60-90 minutes of treatment—initial severity alone should not determine disposition 3

Discharge Requirements When Admission Not Needed

If PEF >70-75% predicted with sustained response, patients may be discharged with 1, 2:

• Oral corticosteroids for 5-10 days 2
• Increased inhaled corticosteroids 2
• Written asthma action plan 2
• PEF meter with education 2
• Follow-up within 1 week 2