What is the recommended inpatient management for a patient admitted with an acute asthma exacerbation?

Inpatient Management of Acute Asthma Exacerbation

Immediate First-Line Treatment (First 15–30 Minutes)

Administer high-dose inhaled short-acting β₂-agonist (albuterol 5 mg or terbutaline 10 mg via oxygen-driven nebulizer, or 4–8 puffs via MDI with spacer) every 20 minutes for three doses, together with systemic corticosteroids (prednisolone 40–60 mg orally or IV hydrocortisone 200 mg) and supplemental oxygen to maintain SaO₂ >90% (>95% in pregnancy or cardiac disease). 1, 2

• Record peak expiratory flow (PEF) or FEV₁ before treatment and again 15–30 minutes after the first bronchodilator dose to guide escalation decisions 1
• For children, give prednisolone 1–2 mg/kg (maximum 40–60 mg) orally; use half the adult bronchodilator dose (2.5 mg albuterol) for those weighing <15 kg 1
• Oral corticosteroids are as effective as intravenous and are preferred unless the patient cannot tolerate oral intake 1
• Never delay corticosteroid administration while "trying bronchodilators first"—both must be given immediately, as clinical benefits require a minimum of 6–12 hours to manifest 1

Severity Assessment and Risk Stratification

Objective measurement of airflow obstruction is mandatory—failure to obtain PEF or FEV₁ is the most common preventable cause of asthma-related death 1

Severe exacerbation indicators: 1

• Inability to speak a full sentence in one breath
• Respiratory rate >25 breaths/min (adults) or >50 breaths/min (children)
• Heart rate >110 bpm (adults) or >140 bpm (children)
• PEF <50% of predicted or personal best

Life-threatening indicators requiring immediate ICU consideration: 1

• PEF <33% of predicted
• Silent chest, cyanosis, or markedly feeble respiratory effort
• Altered mental status (confusion, drowsiness, exhaustion)
• Bradycardia or hypotension
• Normal or elevated PaCO₂ ≥42 mmHg in a breathless patient

Escalation Protocol After Initial Three Doses (If No Improvement)

Add ipratropium bromide 0.5 mg to the nebulizer (or 8 puffs via MDI) every 20 minutes for three doses, then every 4–6 hours until clinical response. 1, 2

• The combination of β₂-agonist plus ipratropium reduces hospitalizations, particularly in patients with severe airflow obstruction 1
• Increase β₂-agonist frequency to every 15–30 minutes or switch to continuous nebulization (10–15 mg/hour for adults) for markedly severe cases 1
• Continue oxygen to maintain SaO₂ >90% and maintain systemic corticosteroid therapy 1
• Give IV hydrocortisone 200 mg every 6 hours in patients who are vomiting or critically ill 1

For refractory severe asthma (PEF <40% after 1 hour of intensive treatment or life-threatening features): 1

• Administer IV magnesium sulfate 2 g over 20 minutes for adults (25–75 mg/kg up to 2 g for children) 1
• Consider IV aminophylline 250 mg over 20 minutes (or IV salbutamol/terbutaline 250 µg over 10 minutes) 1
• Do NOT give a bolus aminophylline to patients already on oral theophylline due to heightened toxicity without added benefit 1, 3

Continuous Monitoring Throughout Hospitalization

• Provide continuous pulse oximetry, aiming for SaO₂ >92% 1, 4
• Measure PEF or FEV₁ before and after each bronchodilator dose and at least every 4 hours thereafter 1, 4
• Obtain arterial blood gases when life-threatening features appear or when PaCO₂ concerns arise—a normal or elevated PaCO₂ in a breathless asthmatic is a marker of life-threatening attack 1, 4
• Perform chest radiography to rule out pneumothorax, pneumomediastinum, consolidation, or pulmonary edema in patients not responding to therapy 1

Hospital Admission and ICU Transfer Criteria

Immediate admission required for: 1

• Any life-threatening feature present (PEF <33%, silent chest, altered mental status, respiratory acidosis)
• Severe attack features persisting after initial intensive treatment
• PEF <50% predicted after 1–2 hours of intensive treatment

Lower threshold for admission if: 1

• Presentation in afternoon or evening
• Recent nocturnal symptoms or worsening pattern
• Previous severe attacks requiring intubation or ICU care
• ≥2 hospitalizations or ≥3 emergency department visits in past year
• Poor social circumstances or inadequate support systems

ICU transfer indicated by: 1

• Deteriorating PEF despite therapy
• Worsening or persistent hypoxia/hypercapnia
• Exhaustion, altered consciousness, or impending respiratory arrest

Discharge Planning

Patients should not be discharged until: 5, 1

• PEF ≥70–75% of predicted or personal best
• PEF diurnal variability <25%
• Minimal or absent symptoms
• Stable for 30–60 minutes after last bronchodilator dose
• Patient has been on discharge medications for at least 24 hours

At discharge, ensure: 5, 1

• Verify and document correct inhaler technique
• Provide a written self-management plan with PEF zones
• Supply a peak flow meter if patient does not already have one
• Continue oral corticosteroids for 5–10 days (no taper needed for courses <10 days)
• Initiate or increase inhaled corticosteroids at higher dosage than before admission
• Arrange primary care follow-up within 1 week
• Arrange respiratory specialist follow-up within 4 weeks

Critical Pitfalls to Avoid

Sedatives of any kind are absolutely contraindicated in acute asthma—their use can precipitate respiratory collapse and is potentially fatal. 5, 1

• Do not underestimate severity by relying solely on subjective clinical impression; always measure PEF or FEV₁ objectively 1
• Do not delay corticosteroid administration while "trying bronchodilators first" 1
• Do not give aminophylline bolus to patients already on oral theophylline 1, 3
• Do not delay intubation once respiratory failure is imminent—transfer to ICU should be accompanied by a physician prepared to intubate 1
• Antibiotics are not indicated unless there is strong evidence of bacterial infection (e.g., pneumonia or sinusitis) 5, 1
• Avoid aggressive hydration in older children and adults, methylxanthines (except as rescue therapy), chest physiotherapy, and mucolytics 5, 1