Asthma Exacerbation Management in the ER

Aka: Asthma Exacerbation Management in the ER, Emergency Management of Asthma Exacerbation

1. See Also
   1. Asthma Exacerbation
   2. Asthma Education
   3. Asthma Management
   4. Asthma Exacerbation Home Management
   5. Asthma Inpatient Management
   6. Status Asthmaticus
   7. Asthma Exacerbation Severity Evaluation
2. History
   1. Current Episode
      1. Onset?
      2. Trigger?
      3. Medications?
         1. Which ones and when were they taken?
         2. Response (Symptoms and Peak Flow)?
   2. Asthma History
      1. Baseline medications?
         1. Consistent use of controller medication (i.e. Inhaled Corticosteroid or combination such as Advair)?
         2. Frequency of rescue inhaler use (e.g. Albuterol)
      2. Last Systemic Corticosteroid use?
      3. Frequency of symptoms (Wheezing, cough, or Dyspnea)?
      4. Frequency of episodes requiring medical care?
         1. Emergency visits?
         2. Hospitalizations?
         3. Intensive care unit admissions?
         4. Intubations?
   3. Other history
      1. Tobacco exposure (including passive smoking)?
      2. Other medications or herbal use?
      3. Other medical problems?
         1. Adults
            1. COPD
            2. Coronary Artery Disease
            3. Venous Thromboembolism
            4. Sleep Apnea
            5. Pulmonary Hypertension
         2. Children
            1. Bronchopulmonary Dysplasia
            2. Pulmonary Hypertension
            3. Bronchiolitis
            4. Atopy (Asthma, eczema, Allergic Rhinitis)
3. Pathophysiology: Presentations
   1. Bronchospasm predominant
      1. Fast-on, Fast-off exacerbation (typically severe presentations respond quickly to beta agonists)
      2. Responds to beta agonists (Albuterol, Atrovent) and Magnesium
   2. Airway edema predominant
      1. Poorly responsive to beta agonists (Albuterol, Atrovent)
      2. Associated with poor underlying Asthma control (e.g. no controller medication use)
      3. Responds to Corticosteroids, Epinephrine
4. Evaluation: Initial Assessment
   1. See Asthma Exacerbation Severity Evaluation
   2. See Asthma Evaluation
   3. See Asthma Management
   4. See Pediatric Assessment Triangle
   5. Vital Signs
      1. Heart Rate
      2. Respiratory Rate
      3. Peak Expiratory Flow Rate (PEF) or FEV1
         1. Ability to comply with test by age 5-6 years old
         2. Peak expiratory flow <40% of predicted suggests a severe exacerbation
      4. Oxygen Saturation
         1. Poor indicator of need for admission or prognosis
         2. Oximetry may transiently drop as airway obstruction decreases (due to initial increase in V-Q mismatch)
      5. End-tidal CO2
         1. Should be suppressed in an Asthma Exacerbation
         2. Higher than normal End-tidal CO2 may predict impending respiratory failure (specific but not sensitive)
   6. Respiratory Status
      1. Increased work of breathing (e.g. flaring and retractions)
      2. Lung auscultation (Wheezing, rales, rhonchi)
      3. Assess accessory muscle use
      4. Chest XRay
         1. See Chest XRay in Asthma
         2. Low yield in acute exacerbations
         3. Associated with antibiotic overuse (Atelectasis with Asthma may resemble Pneumonia)
         4. Indications
            1. Consider if admitting for Asthma Exacerbation
            2. Pneumonia suspected
            3. Barotrauma (e.g. risk of Pneumothorax)
            4. Fever
            5. Pulmonary Rales
            6. New onset Wheezing (first Asthma episode)
            7. Failed response to therapy
   7. Assessment if patient in extremis
      1. Arterial Blood Gas
         1. Decisions should be made clinically (e.g. intubation)
         2. ABG may be considered in near respiratory failure (typically not indicated)
5. Management: Step 1
   1. Inhaled Short-acting Beta Agonist (Nebulized Albuterol)
      1. One dose up to every 15-20 minutes for one hour (rapid sequence nebs)
      2. Continuous nebulizer dosing (15-25 mg/h) has no advantage over intermittent nebulizer dosing
      3. Metered Dose Inhalers at 4-8 puffs per use with proper use is equivalent to nebulizer
   2. Anticholinergic (Ipratropium Bromide or Atrovent)
      1. Smooth muscle relaxant
      2. Add to Nebulized Albuterol (consider as duoneb)
      3. Indication: FEV1 or PEF <40-50% of predicted (Moderate to Severe Asthma Exacerbation)
         1. Associated with a decreased rate of hospitalization for Asthma Exacerbation
         2. Used in pediatric emergency departments down to age 4-6 months
   3. Systemic Corticosteroid (oral, IV or IM)
      1. Indications
         1. Severe episode (FEV1 or PEF <40-50% predicted) or
         2. No immediate response to immediate management or
         3. Oral Corticosteroid recently taken by patient
      2. Oral Preparations
         1. Tapering not needed if use <2 weeks
         2. Prednisone or Prednisolone 1-2 mg/kg IV daily or divided twice daily to 40-60 mg/day orally for 3-5 days
         3. Dexamethasone 0.6 mg/kg (up to 10 mg) orally daily for 2 days
            1. Consider for children with adverse effects on Prednisone (e.g. hyperactivity)
      3. Intravenous preparations
         1. Methylprednisolone (Solu-medrol) 1 mg/kg/dose (up to 60 mg) IV every 6 hours (or 80 mg IV every 8 hours)
   4. Oxygen indications
      1. Oxygen Saturation to keep Oxygen Saturation >92%
   5. Intubation and Mechanical Ventilation Indications
      1. Impending or actual respiratory arrest
      2. Intubation in Asthma has many risks including barotrauma (Exercise caution)
   6. Consider Additional measures for severe exacerbation
      1. See Status Asthmaticus
      2. Inhaled Corticosteroids (3 inhalations in <30 min)
         1. Effective for adults and children in acute attacks
         2. In study, showed even better efficacy than Systemic Corticosteroids
         3. Most effective if used early in treatment plan
         4. Rodrigo (2006) Chest 130:1301-11
   7. Consider adjunctive measures in moderate to severe exacerbations
      1. Magnesium Sulfate
         1. Dose: 40-75 mg/kg IV (up to 2 grams) for 1 dose
         2. Smooth muscle relaxant and histamine release inhibitor
         3. Variable efficacy
         4. Monitor for Sedation, Hypotension
      2. Nebulized Lidocaine for refractory, spasmodic cough
         1. Consider alternative diagnoses for spasmodic cough (e.g. Pertussis)
6. Management: Step 2 - Reassess
   1. Criteria: Repeat measures in initial evaluation
   2. Base management on severity of episode
      1. Moderate episode (PEF 40-70% of predicted)
         1. Nebulized Albuterol hourly
         2. Oral Systemic Corticosteroids
         3. Continue management for 1-3 hours while improving
         4. Decide within 4 hours on admission versus discharge
      2. Severe episode (PEF <40% predicted, accessory muscle use and retractions, severe rest symptoms)
         1. See Status Asthmaticus
         2. ABC Management
         3. Nebulized Albuterol hourly or continuous
         4. Nebulized Epinephrine
            1. Racemic Epinephrine 2.25% solution 0.5 ml nebulized or
            2. Standard Epinephrine 1:1000 solution 5 ml nebulized
            3. Consider in cases where patient does not respond to Albuterol and Atrovent nebs
               1. Lack of response to standard nebs suggests airway edema which may be better treated by Epinephrine
               2. In children, consider croup and Bronchiolitis as etiologies with poor response to standard Bronchodilators
            4. Weibe and Herbert in Majoewsky (2012) EM: Rap 12(8): 6-7
         5. Ipratroprium bromide added to nebulizer every 4 hours
         6. Oxygen to keep Oxygen Saturation >92%
         7. Consider Status Asthmaticus management in Step 2b
         8. Systemic Corticosteroids
            1. Prednisone 1-2 mg/kg/day qd-bid
            2. Maximum: 40-60 mg/day for 5-10 days
            3. No tapering needed if use less than 2 weeks
7. Management: Step 3a - Good Response
   1. Indications
      1. Response sustained >60 minutes after last treatment
      2. Normal physical examination and no distress
      3. FEV1 or PEF >70%
      4. Oxygen Saturation >92%
   2. Management: Discharge Home
      1. Continue Inhaled Beta Agonist
      2. Corticosteroids
         1. Oral Systemic Corticosteroids or
         2. Methylprednisolone 160 mg IM Depot injection (adults)
            1. As effective as 8 day taper on oral steroids
            2. Lahn (2004) Chest 126:362-8
      3. Patient Education on medications and plan
      4. Establish close follow-up
8. Management: Step 3b - Incomplete response in 1-3 hours
   1. Indications
      1. FEV1 or PEF 40-70%
      2. High risk patient with mild to moderate symptoms
      3. Oxygen Saturation not improved
   2. Management: Admit to hospital
      1. See Asthma Inpatient Management
9. Management: Step 3c - Poor response within 1 hour
   1. Indications
      1. High risk patient with severe symptoms
      2. FEV1 or PEF <40%
      3. pCO2 >42 mmHg
      4. pO2 <60 mmHg
   2. Management: Admit to Intensive Care Unit
      1. Admit to Intensive Care Unit
      2. See Asthma Inpatient Management
      3. Consider Additional measures for severe exacerbation
         1. See Status Asthmaticus
10. Precautions: Avoid potentially harmful interventions
    1. Theophylline or Aminophylline
       1. No benefit over inhaled beta-agonists
       2. Narrow therapeutic window
       3. Rare indication may be a patient in such distress that will not tolerate the nebulizer
    2. Agents effectively used in Asthma maintenance that may worsen an Asthma Exacerbation
       1. Long acting beta agonists
       2. Leukotriene modifying agents (e.g. Montelukast)
11. Management: Disposition
    1. Relapse rate (bounce-back) is 7-15% after emergency department discharge
    2. Discuss with patients prior to discharge the potential for relapse and the indications for urgent or emergent re-evaluation
       1. All Asthma patients should have an Asthma action plan (typically generated at routine clinic visits)
       2. Asthma patients should have scheduled follow-up with their primary medical provider at a short interval from ER discharge
12. References
    1. Fuchs and Yamamoto (2011) APLS, Jones and Bartlett, Burlington, p. 62-71
    2. (1997) Management of Asthma, NIH 97-4053
    3. (1995) Global Strategy for Asthma, NIH 95-3659
    4. Pollart (2011) Am Fam Physician 84(1): 40-7