What is the management of status asthmaticus?

Management of Status Asthmaticus

Immediately administer high-dose oxygen (40-60%), nebulized salbutamol 5 mg or terbutaline 10 mg via oxygen-driven nebulizer, and systemic corticosteroids (prednisolone 30-60 mg orally or IV hydrocortisone 200 mg) as first-line therapy for all patients with status asthmaticus. 1, 2

Initial Assessment and Recognition

Recognize life-threatening features that require immediate aggressive intervention: 2

• Silent chest, cyanosis, or feeble respiratory effort
• Bradycardia, hypotension, confusion, exhaustion, or coma
• Oxygen saturation <92% despite supplemental oxygen
• Cannot complete sentences in one breath
• Pulse >110 beats/min
• Respirations >25 breaths/min
• Peak expiratory flow (PEF) <50% predicted or best

Any single life-threatening feature mandates immediate hospital admission and intensive monitoring. 1, 2

Immediate Management Protocol

First-Line Therapy (Administer Simultaneously)

Oxygen: Deliver 40-60% oxygen to all patients immediately to maintain saturation >90% (>95% in pregnancy or heart disease). 1, 3

Nebulized Beta-Agonists: Give salbutamol 5 mg or terbutaline 10 mg via oxygen-driven nebulizer. If no nebulizer is available, deliver 2 puffs via large-volume spacer and repeat 10-20 times. 1

Systemic Corticosteroids: Administer prednisolone 30-60 mg orally OR IV hydrocortisone 200 mg (or both) immediately—clinical benefits require 6-12 hours minimum, so early administration is critical. 1, 2, 4

Monitoring Response at 15-30 Minutes

Reassess PEF, vital signs, and clinical features after initial nebulizer treatment. 1, 2

If severe features persist or PEF remains <50% predicted: 1, 2

• Repeat nebulized beta-agonist immediately
• Add ipratropium bromide 0.5 mg to nebulizer (provides additional bronchodilation in refractory cases) 1, 5
• Arrange immediate hospital admission
• Continue nebulized beta-agonists every 15-30 minutes as needed (up to every 15 minutes for severe cases) 1

Second-Line Therapy for Life-Threatening Features

If life-threatening features are present or patient fails to improve with first-line therapy: 1, 6

Add IV aminophylline 250 mg over 20 minutes OR IV/subcutaneous salbutamol or terbutaline 250 µg over 10 minutes. 1

Critical caveat: Do NOT give bolus aminophylline to patients already taking oral theophyllines—risk of toxicity. 1, 6

Hospital Admission Criteria

Absolute indications for admission: 1, 2

• Any life-threatening features present
• Any severe features persist after initial treatment
• PEF <33% predicted after initial treatment

Lower threshold for admission if: 1, 2

• Attack occurs in afternoon or evening (higher risk)
• Recent nocturnal symptoms or worsening symptoms
• Previous severe attacks, especially with rapid onset
• Recent hospital admission or ICU admission
• Patient expresses concern about their condition

Intensive Care Unit Transfer Criteria

Transfer to ICU for intensive monitoring if: 1

• Deteriorating PEF despite treatment
• Worsening or persisting hypoxia (PaO₂ <8 kPa) despite 60% oxygen
• Hypercapnia (PaCO₂ >6 kPa)
• Exhaustion, feeble respiration, confusion, or drowsiness
• Coma or respiratory arrest

Inpatient Management

Continue high-dose therapy: 1, 2

• Nebulized beta-agonists every 4 hours if improving, or every 15 minutes if not improving
• Prednisolone 30-60 mg daily OR IV hydrocortisone 200 mg every 6 hours for seriously ill or vomiting patients
• Continue oxygen therapy with monitoring
• Measure and record PEF every 15-30 minutes initially, then according to response

Additional investigations: 1

• Chest radiography to exclude pneumothorax, consolidation, or pulmonary edema
• Plasma electrolytes, urea, blood count
• Electrocardiography in older patients
• Arterial blood gas if severe (low pH or high PaCO₂ indicates life-threatening disease)

Mechanical Ventilation Strategy

If mechanical ventilation becomes necessary (worsening hypoxia/hypercapnia, drowsiness, unconsciousness, respiratory arrest): 1, 7

• Intubation should be performed by an anesthetist
• Use permissive hypercapnia strategy: Limit minute ventilation and prolong expiratory time to avoid dynamic hyperinflation, even if this results in elevated CO₂ 7
• Avoid excessive lung inflation to prevent barotrauma and hypotension
• Use sedation (opioids, benzodiazepines, or propofol) for ventilator synchrony
• Avoid neuromuscular blockade when possible—associated with increased risk of ICU myopathy 7

Therapies to AVOID

Do not routinely use: 1

• Antibiotics (only if bacterial infection confirmed—sinusitis, pneumonia)
• Sedation in non-intubated patients (contraindicated—may precipitate respiratory failure)
• Percussive physiotherapy (unnecessary and potentially harmful)

Discharge Criteria and Follow-Up

Do not discharge until: 1, 2

• PEF >75% predicted or personal best
• Diurnal PEF variability <25%
• No nocturnal symptoms
• Clinical stability maintained for 24-48 hours

At discharge, ensure: 2, 3

• Continue prednisolone for 5-10 days total course
• Initiate or optimize inhaled corticosteroid controller therapy
• Provide written asthma action plan
• Verify correct inhaler technique
• Provide PEF meter for home monitoring
• Arrange follow-up within 24-48 hours for severe exacerbations, within 1-2 weeks for pulmonary consultation

Critical warning: Discharged patients after severe exacerbations have 14% mortality at 3 years and require very close medical follow-up. 7

Common Pitfalls

Underestimating severity: Patients with severe or life-threatening asthma may be distressed and not display all expected abnormalities—the presence of ANY life-threatening feature should trigger maximum intervention. 1

Delayed corticosteroid administration: Benefits require 6-12 hours minimum, so any delay worsens outcomes. 4

Inadequate oxygen delivery: Always use oxygen-driven nebulizers in hospital settings, not air-driven. 1

Premature discharge: Wheezing persistence or PEF <50% predicted indicates incomplete resolution and predicts early relapse. 2