What is the management for status asthmaticus?

Management of Status Asthmaticus

Status asthmaticus requires immediate, aggressive treatment with high-flow oxygen (40-60%), nebulized beta-agonists (salbutamol 5 mg or terbutaline 10 mg), and systemic corticosteroids (prednisolone 30-60 mg orally OR hydrocortisone 200 mg IV) administered simultaneously without delay. 1, 2

Initial Recognition and Assessment

Recognize life-threatening features that mandate immediate hospital admission and intensive intervention 1:

• Silent chest, cyanosis, or feeble respiratory effort 3
• Altered mental status: confusion, exhaustion, or coma 3, 1
• Cardiovascular instability: bradycardia, hypotension, or pulse >110 beats/min 3
• Severe respiratory distress: inability to complete sentences in one breath, respiratory rate >25 breaths/min 3
• Peak expiratory flow (PEF) <33% of predicted or personal best 3, 1
• Oxygen saturation <92% despite supplemental oxygen 1

Arterial blood gas analysis should be obtained in all hospitalized patients, with particular concern for 3:

• Normal or elevated PaCO₂ (5-6 kPa or higher) in a breathless patient—indicates impending respiratory failure 3
• Severe hypoxia: PaO₂ <8 kPa despite oxygen therapy 3
• Low pH or elevated H⁺ 3

Immediate Management Protocol (First 15-30 Minutes)

Oxygen Therapy

Deliver 40-60% oxygen via face mask immediately to maintain SaO₂ >90% (>95% in pregnancy or cardiac disease) 1, 2. Continue oxygen throughout treatment 3.

Inhaled Beta-Agonists

Administer salbutamol 5 mg OR terbutaline 10 mg via oxygen-driven nebulizer 3, 4:

• This is first-line therapy for all patients 1, 2
• Use oxygen as the driving gas for nebulization 3
• If no nebulizer available, give 2 puffs repeated 10-20 times via large-volume spacer 3
• Half doses for young children (<15 kg) 2, 4

Systemic Corticosteroids

Give prednisolone 30-60 mg orally OR hydrocortisone 200 mg IV (or both) immediately 3, 1:

• Clinical benefits require 6-12 hours minimum, making early administration critical 1
• Do not delay—administer simultaneously with bronchodilators 3, 5
• For children: prednisolone 1-2 mg/kg/day (maximum 60 mg/day) 6

Additional Therapy for Life-Threatening Features

If any life-threatening features are present, immediately add 3:

• Ipratropium bromide 0.5 mg nebulized with the beta-agonist 3
• IV aminophylline 250 mg over 20 minutes OR salbutamol/terbutaline 250 µg IV over 10 minutes 3
  • Critical caveat: Do NOT give bolus aminophylline to patients already taking oral theophyllines 3
• IV magnesium sulfate should be considered for life-threatening exacerbations 2, 7

Monitoring Response (15-30 Minutes After Initial Treatment)

Measure and record PEF 15-30 minutes after starting treatment 3, 1:

If Improving:

• Continue high-flow oxygen 1
• Give nebulized beta-agonists every 4 hours 3, 1
• Continue prednisolone 30-60 mg daily OR IV hydrocortisone 200 mg every 6 hours 1
• Monitor PEF before and after each bronchodilator treatment 2

If NOT Improving:

• Increase frequency of nebulized beta-agonists to every 15-30 minutes 3, 2
• Arrange immediate hospital admission 3
• Consider IV magnesium sulfate if not already given 2
• Reassess for mechanical ventilation needs 1

Hospital Admission Criteria

Absolute indications for admission 1, 2:

• Any life-threatening features present 3, 1
• Any severe features persist after initial treatment 3, 1
• PEF <33% predicted after initial treatment 1

Lower threshold for admission in patients 3:

• Presenting in afternoon/evening rather than morning 3
• With recent nocturnal symptoms or symptom worsening 3
• With previous severe attacks, especially rapid-onset 3
• Where concern exists about severity assessment or social circumstances 3

Inpatient Management

Ongoing Pharmacotherapy

Continue aggressive treatment 1, 2:

• Nebulized beta-agonists: every 4 hours if improving, every 15 minutes if not 1
• Systemic corticosteroids: prednisolone 30-60 mg daily OR IV hydrocortisone 200 mg every 6 hours for seriously ill or vomiting patients 3, 1
• Oxygen therapy: maintain SaO₂ >92% 1

Additional Investigations

Obtain 3:

• Chest radiography to exclude pneumothorax, consolidation, or pulmonary edema 3
• Plasma electrolytes and urea (beta-agonists can cause hypokalemia) 3, 4
• Blood count 3
• ECG in older patients 3

Mechanical Ventilation Considerations

Indications for intubation (based on clinical judgment) 8:

• Cardiac or respiratory arrest (absolute indication) 8
• Exhaustion and fatigue despite maximal therapy 8
• Deteriorating mental status 8
• Refractory hypoxemia 8
• Increasing hypercapnia 8
• Hemodynamic instability 8

Ventilation strategy 1, 8, 9:

• Intubation should be performed by an anesthetist 1
• Use permissive hypercapnia strategy to limit minute ventilation and prolong expiratory time 1, 8, 9
• Avoid excessive lung inflation to prevent barotrauma and hypotension 1, 10
• Sedation (propofol, benzodiazepines, opioids) for ventilator synchrony 1, 8
• Avoid neuromuscular blockade due to risk of ICU myopathy 8, 10, 9

Discharge Criteria

Do not discharge until ALL criteria met 1, 2:

• Patient stable on discharge medication for 24 hours 2
• PEF >75% of predicted or personal best 1, 2
• Diurnal PEF variability <25% 1
• No nocturnal symptoms 1
• Clinical stability maintained for 24-48 hours 1, 6

Discharge Planning and Follow-Up

At discharge, ensure 1, 2:

• Continue prednisolone for 5-10 days total course 1
• Initiate or optimize inhaled corticosteroid controller therapy 1
• Provide written asthma action plan 1, 2, 6
• Verify correct inhaler technique 1, 6
• Provide PEF meter for home monitoring 1
• Follow-up with primary care within 1 week 2
• Specialist respiratory clinic follow-up within 4 weeks 2

Critical Pitfalls to Avoid

• Underestimating severity: Patients, relatives, and physicians commonly underestimate attack severity due to failure to make objective measurements (PEF) 3, 6
• Delayed corticosteroid administration: Benefits require 6-12 hours, so any delay worsens outcomes 1
• Sedation in acute asthma: Avoid sedatives in non-intubated patients as they can precipitate respiratory arrest 6
• Overreliance on bronchodilators alone: Anti-inflammatory treatment (corticosteroids) is essential 6
• Premature discharge: Mortality is high in discharged patients who haven't met all stability criteria 3, 1
• Aminophylline in patients on theophyllines: Can cause toxicity 3
• Hypokalemia from beta-agonists: Monitor electrolytes, though supplementation rarely needed 4, 7