What is the treatment approach for a 50-year-old female with a mild respiratory allergic history who acutely developed high-grade fever and respiratory distress characterized by shallow and difficult breathing?

Emergency Management of Acute Respiratory Distress with Fever in a Patient with Allergic History

This patient requires immediate assessment for acute severe asthma exacerbation versus anaphylaxis, with priority given to oxygen therapy, nebulized bronchodilators (salbutamol 5 mg or terbutaline 10 mg), and systemic corticosteroids (prednisolone 30-60 mg orally or IV hydrocortisone 200 mg) as first-line treatment. 1, 2

Immediate Assessment and Severity Classification

Assess for acute severe asthma features immediately:

• Inability to complete sentences in one breath 1, 2
• Pulse >110 beats/min 1, 2
• Respiratory rate >25 breaths/min 1, 2
• Peak expiratory flow (PEF) <50% predicted or best 1, 2
• Diminished breath sounds 2

Identify life-threatening features requiring ICU consideration:

• Silent chest, cyanosis, or feeble respiratory effort 1, 2
• Bradycardia, hypotension, confusion, exhaustion, or coma 1, 2
• Oxygen saturation <92% despite supplemental oxygen 2

The presence of high-grade fever with acute respiratory distress in this context suggests either an infectious trigger for asthma exacerbation or a severe allergic reaction. 1

First-Line Emergency Treatment

Initiate treatment immediately without delay:

Oxygen Therapy

• Administer 40-60% oxygen via face mask to all patients with acute severe respiratory distress 1
• Target oxygen saturation ≥92% 1, 2

Nebulized Bronchodilators

• Salbutamol 5 mg OR terbutaline 10 mg via oxygen-driven nebulizer 1, 2, 3
• If no nebulizer available, give 2 puffs of β-agonist via large volume spacer and repeat 10-20 times 1
• Treatment takes approximately 5-15 minutes 4

Systemic Corticosteroids

• Prednisolone 30-60 mg orally OR IV hydrocortisone 200 mg 1, 2, 3
• Administer immediately—do not delay for diagnostic workup 1

Reassessment at 15-30 Minutes

Monitor response to initial treatment:

• Repeat PEF measurement if patient able to perform 1
• Reassess vital signs, work of breathing, and ability to speak 1, 2
• Check oxygen saturation 1, 2

If severe features persist after initial treatment:

• Arrange immediate hospital admission 1, 2
• Repeat nebulized bronchodilators more frequently (every 15-30 minutes) 1, 3
• Add ipratropium 0.5 mg nebulized to the β-agonist 1, 3

Life-Threatening Features Management

If life-threatening features are present:

• Add ipratropium 0.5 mg nebulized immediately 1, 3
• Consider IV aminophylline 250 mg over 20 minutes (caution if patient already on theophyllines) 1
• Obtain chest radiography to exclude pneumothorax 1
• Consider IV magnesium sulfate for severe exacerbations unresponsive to initial treatment 1
• Patient must be accompanied by a nurse or doctor at all times 1

Transfer to ICU if:

• Deteriorating PEF or worsening exhaustion 1
• Persistent hypoxia or hypercapnia 1
• Confusion, drowsiness, coma, or respiratory arrest 1

Anaphylaxis Consideration

If anaphylaxis is suspected (rapid onset, multisystem involvement):

• Intramuscular epinephrine is the immediate treatment of choice 5, 6
• Administer IM epinephrine 0.3-0.5 mg (1:1000 solution) into anterolateral thigh 6
• IV epinephrine should be used for patients in shock, either as bolus or infusion, along with fluid resuscitation 6

The distinction is critical: anaphylaxis typically presents with rapid onset (minutes), often with urticaria, angioedema, or gastrointestinal symptoms, whereas asthma exacerbation may have a more gradual onset over hours to days. 6

Hospital Admission Criteria

Absolute criteria for admission:

• Any life-threatening features present 1, 2
• Any features of acute severe asthma persist after initial treatment 1, 2
• PEF <33% predicted after initial treatment 1, 2

Lower threshold for admission if:

• Attack occurs in afternoon or evening 1, 2
• Recent nocturnal symptoms 1, 2
• Recent hospital admission or previous severe attacks 1, 2
• Patient expresses concern about their condition 1, 2

Common Pitfalls to Avoid

Critical errors that increase mortality:

• Underestimating severity—patients may not have all abnormalities but presence of any severe feature warrants aggressive treatment 1, 2
• Delaying corticosteroids—these should be given immediately, not after "trying bronchodilators first" 1, 2
• Withholding oxygen due to concerns about CO2 retention—hypoxemia is immediately life-threatening 1
• Using treatments NOT recommended: antibiotics (unless comorbid infection confirmed), aggressive hydration, chest physical therapy, mucolytics, or sedation 1

Monitoring During Treatment

Continuous monitoring required:

• Pulse oximetry to maintain SaO2 ≥92% 1, 2
• Repeated lung function measures (FEV1 or PEF) at 1 hour and beyond are the strongest predictor of hospitalization need 1
• Serial vital signs and work of breathing assessment 1, 2
• Presence of drowsiness is a useful predictor of impending respiratory failure 1

Follow-Up After Stabilization

For patients requiring admission:

• Continue nebulized β-agonist every 4 hours if improving, or more frequently if not 1, 3
• Continue prednisolone 30-60 mg daily for 5-10 days total 2, 3
• Review within 24 hours for severe exacerbations 2
• Initiate or step up inhaled corticosteroid therapy 1, 2
• Provide written asthma action plan 1, 2
• Arrange pulmonary follow-up within 1-4 weeks 1, 2