Emergency Medicine · Year 3 · from Emergency Medicine

Case 2: Severe Asthma Exacerbation with Impending Respiratory Failure

Patient Demographics

  • Age: 28 years
  • Sex: Male
  • Occupation: Graduate student

Chief Complaint

"I can't breathe... my inhaler... isn't working."

History of Present Illness

A 28-year-old male with history of severe persistent asthma presents with progressive dyspnea over 6 hours. He has been using his rescue inhaler "every 20 minutes" without relief. He had an upper respiratory infection 3 days ago. He was intubated for asthma 2 years ago. Currently unable to speak in full sentences.

Initial Assessment

ESI Level: 1 - Impending respiratory failure

Vital Signs:

  • Heart rate: 132 bpm
  • Blood pressure: 142/88 mmHg
  • Respiratory rate: 36 breaths/min
  • SpO2: 88% on room air
  • Peak flow: Unable to perform

First Impression:

  • Tripod position
  • Severe respiratory distress
  • Speaking single words between gasps
  • Diaphoretic, exhausted appearance

Physical Examination

Pulmonary:

  • Severe accessory muscle use
  • Paradoxical abdominal breathing (concerning)
  • Bilateral diffuse expiratory wheezes
  • Prolonged expiratory phase
  • OMINOUS: Decreasing breath sounds ("silent chest" developing)

Cardiovascular:

  • Tachycardic
  • Pulsus paradoxus: 18 mmHg

Mental Status:

  • Alert but anxious
  • Difficulty following commands (fatigue)

Severity Assessment

Signs of Impending Respiratory Failure:

  • Previous intubation (major risk factor)
  • Unable to speak in sentences
  • Exhaustion/fatigue
  • Decreasing air movement despite effort
  • Paradoxical breathing
  • Altered mental status (developing)

Management

Immediate Treatment (concurrent, not sequential):

  1. Continuous nebulized albuterol (10-15mg/hour)
  2. Ipratropium bromide 0.5mg nebulized (first 3 doses)
  3. IV methylprednisolone 125mg
  4. Magnesium sulfate 2g IV over 20 minutes
  5. Heliox 70:30 initiated (if available)
  6. IV access x2
  7. Prepare for intubation (ketamine, succinylcholine at bedside)

Response at 30 minutes:

  • Slight improvement: SpO2 91% on high-flow
  • Still severe distress
  • Peak flow: 90 L/min (15% predicted)

BiPAP Trial:

  • Settings: IPAP 12, EPAP 5
  • Patient cooperative
  • SpO2 improved to 94%
  • Respiratory rate decreased to 28
  • Visible reduction in accessory muscle use

Response at 60 minutes:

  • Significant improvement
  • Speaking in short phrases
  • Peak flow: 180 L/min (30% predicted)

Arterial Blood Gas (60 minutes)

  • pH: 7.34
  • pCO2: 48 mmHg
  • pO2: 72 mmHg
  • HCO3: 24 mEq/L

Note: Normalizing CO2 in severe asthma can indicate fatigue - but clinical picture improving

Continued Management

Hours 2-4:

  • Continuous nebs transitioned to q1h nebs
  • BiPAP weaned to nasal cannula
  • Repeat steroids: Prednisone 60mg PO
  • Peak flow improved to 320 L/min (55% predicted)

Disposition:

  • Admitted to step-down unit (prior intubation = high risk)
  • Continued bronchodilators and steroids
  • Peak flow monitoring q4h
  • Pulmonology consultation for outpatient follow-up

Discharge (Day 3)

Medications:

  • Prednisone 40mg daily x5 days
  • Albuterol MDI with spacer PRN
  • Budesonide/formoterol (controller) - uptitrated

Education:

  • Asthma action plan reviewed
  • Peak flow meter prescribed
  • Follow-up in 1 week

Teaching Points

  1. Prior intubation = high risk: These patients can decompensate rapidly
  2. Silent chest is ominous: Indicates severe obstruction, not improvement
  3. Continuous nebs in severe exacerbation: Don't wait between treatments
  4. Magnesium for severe asthma: IV MgSO4 provides additional bronchodilation
  5. BiPAP before intubation: Can often avoid intubation if patient cooperative
  6. Normal CO2 in acute asthma is concerning: Usually hyperventilate; normal suggests fatigue
  7. Ketamine for intubation: Bronchodilatory properties make it ideal for asthmatic patients

Clinical Image

Image Description: Chest radiograph demonstrating hyperinflated lung fields with flattened diaphragms, consistent with severe obstructive lung disease (acute asthma exacerbation).

Attribution: Image from Radiopaedia.org, Case courtesy of Dr. Jeremy Jones. Licensed under CC BY-NC-SA 3.0. Source: https://radiopaedia.org/cases/asthma-exacerbation-chest-radiograph

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