ACLS: Asthma Exacerbation Treatment

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Table 1. Asthma Exacerbation Classifications

• Note* - PEF of Predicted/personal best

Initial/Prep/Goals

• EMS providers should have prehospital/hospital protocols that allow administration of:
  • Supplemental oxygen
    • Correct significant hypoxemia in moderate or severe exacerbations
  • Repetitive or continuous administration of SABA
    • Reverses airflow obstruction rapidly
  • Oral systemic corticosteroids
    • Decreases airway inflammation in moderate/severe exacerbations
    • Used in patients who fail to respond promptly and completely to SABA treatment
• Monitor response to therapy with serial assessments
  • For children:
    • No single measure is best for assessing severity or predicting hospital admission
    • Lung function measures (FEV1 or PEF) useful in children ≥ 5 years old
      • These measures may not be obtainable during an exacerbation
    • Pulse oximetry may be useful for assessing initial severity
    • * Pulse oximetry of < 92-94 % is predictive of the need for hospitalization*
    • Signs/symptoms scores may be helpful
    • Signs/symptoms after 1-2 hrs of initial treatment (moderate-severe exacerbation) have > 84% chance of requiring hospitalization
  • For adults:
    • Repeat FEV₁ or PEF at 1 hour and beyond
      • Strongest single predictor of hospitalization
      • Measures may not be easily obtained during severe exacerbations
    • Use pulse oximetry for patients:
      • In severe distress
      • Have FEV1 or PEF < 40% predicted
      • Not able to perform pulmonary function testing
    • Only repeat assessments after initial treatment are useful in predicting the need for hospitalization
      • Signs and symptoms scores at 1 hour after initial treatments improve the ability to predict the need for hospitalization
    • The presence of drowsiness is a useful predictor of impending respiratory failure ⇒ consider immediate transfer to a facility equipped to offer ventilatory support
    • Consider adjunctive treatments in severe exacerbations (FEV1 or PEF < 40 percent predicted post treatment):
      • IV MgSO₄
      • Heliox
• Cardiac Arrest due to Asthma Exacerbation (COR, LOE)
  • Asthma is the acute cause of death for > 3500 adults/year
  • Severe exacerbations of asthma can lead to
    • Respiratory distress, CO₂ retention, air trapping
      • Results in acute, life-threatening respiratory acidosis/high intrathoracic pressure
      • Profound acidemia and decreased venous return from elevated intrathoracic pressure are likely causes of cardiac arrest in asthma
  • If asthmatic with cardiac arrest, prompt evaluation for tension pneumothorax if: (COR 1, LOE C-LD)
    • Sudden peak inspiratory pressure elevations
    • Ventilation difficulties
  • Ventilation strategy:
    • Low respiratory rate and tidal volume is recommended in asthmatic with cardiac arrest (COR 2a, LOE C-LD)
      • Potential effects of intrinsic auto-PEEP
      • Barotrauma risk
    • If increased auto-PEEP or sudden decrease in BP in asthmatics on assisted ventilation in a peri-arrest state
      • Disconnect from bag mask or ventilator with compression of chest wall to relieve air-trapping (COR 2a, LOE C-LD)
• ED Management
  • Oxygen
  • Inhaled Beta-agonists
  • Inhaled muscarinic antagonists
  • Systemic glucocorticoids
  • MgSO4
  • Re-assess after treatments
• Life-threatening Management
  • Treat as above and consider:
    • Mechanical ventilation, NIPPV
    • Parenteral Beta-agonists
      • Usually avoided in adults
      • Indications: suspected anaphylaxis, unable to use inhalation therapy

Medical/Pharmaceutical

• Short-Acting Beta2-Agonists (SABA)
  • Albuterol
    • Nebulizer solution (0.63 mg/3 mL, 1.25 mg/3 mL, 2.5 mg/3 mL, 5.0 mg/mL)
      • Pediatric dose (< 12 yo)
        • 0.15 mg/kg (minimum dose 2.5 mg) q20min for 3 doses, then 0.15-0.3 mg/kg (up to 10 mg) q1-4h PRN OR
        • 0.5 mg/kg/hr by continuous nebulization
      • Adult dose
        • 2.5-5 mg q20min for 3 doses, then 2.5-10 mg q1-4h PRN OR 10-15 mg/hr continuously
    • Meter dosed inhaler (MDI) (90 mcg/puff)
      • Pediatric dose (< 12 yo)
        • 4-8 puffs q20min for 3 doses, then q1-4h inhalation maneuver PRN
        • Use a valved holding chamber (VHC)
        • Add mask in children < 4 years
      • Adult dose
        • 4-8 puffs q20min (up to 4 hrs), then q1-4h PRN
    • NOTES:
      • Only selective beta2 agonists should be used
      • For optimal delivery, dilute aerosols to minimum of 3 mL at gas flow of 6-8 L/min
      • Use large volume nebulizers for continuous administration
      • You may mix with ipratropium nebulizer solution
      • In mild-to-moderate exacerbations, MDI plus VHC is as effective as nebulized therapy
      • Use appropriate administration technique and coaching by trained personnel
  • Bitolterol
    • Nebulizer solution (2 mg/mL)
      • Pediatric dose (< 12 yo)
        • See albuterol dose
        • Bitolterol is half as potent as albuterol on mg basis
      • Adult dose
        • See albuterol dose
    • MDI (370 mcg/puff)
      • Pediatric dose (< 12 yo)
        • See albuterol MDI dose
      • Adult dose
        • See albuterol MDI dose
    • NOTES:
      • NOT studied in severe asthma exacerbations
      • Do not mix with other drugs
  • Levalbuterol (R-albuterol)
    • Nebulizer solution (0.63 mg/3 mL, 1.25 mg/0.5 mL, 1.25 mg/3 mL)
      • Pediatric dose (< 12 yo): 0.075 mg/kg (min dose 1.25 mg) q20min for 3 doses, then 0.075-0.15 mg/kg (up to 5 mg) q1-4h PRN
      • Adult dose: 1.25-2.5 mg q20min for 3 doses, then 1.25-5 mg q1-4h PRN
    • MDI (45 mcg/puff)
      • Pediatric dose (< 12 yo)
        • See albuterol MDI dose
      • Adult dose
        • See albuterol MDI dose
    • NOTES:
      • Levalbuterol administered in 1/2 the mg dose of albuterol provides comparable efficacy and safety
      • No studies on continuous nebulization
  • Pirbuterol
    • MDI (200 mcg/puff)
      • Pediatric dose (< 12 yo)
        • See albuterol MDI dose; thought to be as potent as albuterol on a mg basis
      • Adult dose
        • See albuterol MDI dose
      • NOTES:
        • Has not been studied in severe asthma exacerbations
• Systemic (injected) Beta2-Agonists
  • Epinephrine 1:1,000 (1 mg/mL)
    • Pediatric dose (< 12 yo): 0.01 mg/kg (up to 0.3-0.5 mg) q20min for 3 doses subcut
    • Adult dose: 0.3-0.5 mg q20min for 3 doses subcut
  • Terbutaline (1 mg/mL)
    • Pediatric dose (< 12 yo): 0.01 mg/kg q20min for 3 doses, then q2-6h PRN subcut
    • Adult dose: 0.25 mg q20min for 3 doses subcut
  • NOTES:
    • No proven advantage of systemic therapy over aerosol
• Anticholinergics
  • Ipratropium bromide
    • Nebulizer solution (0.25 mg/mL)
      • Pediatric dose (< 12 yo): 0.25-0.5 mg q20min for 3 doses, then PRN
      • Adult dose: 0.5 mg q20min for 3 doses, then PRN
    • MDI (18 mcg/puff)
      • Pediatric dose (< 12 yo): 4-8 puffs q20min as needed up to 3 hrs
      • Adult dose: 8 puffs q20min PRN up to 3 hrs
    • NOTES:
      • May mix in same nebulizer as albuterol
      • DO NOT use as first-line therapy
      • Should be added to SABA therapy for severe exacerbations
      • NO benefit has been seen when ipratropium is used once patient is hospitalized
      • Use VHC and face mask for children < 4 years old
  • Ipratropium with albuterol
    • Nebulizer solution (3 mL vial: 0.5 mg ipratropium bromide/2.5 mg albuterol)
      • Pediatric dose (< 12 yo): 1.5-3 mL q20min for 3 doses, then PRN
      • Adult dose: 3 mL q20min for 3 doses, then PRN
    • MDI (18 mcg ipratropium bromide/90 mcg albuterol per puff)
      • Pediatric dose (< 12 yo): 4-8 puffs q20min PRN up to 3 hrs
      • Adult dose: 8 puffs q20min PRN (up to 3 hrs)
    • NOTES:
      • May be used for up to 3 hrs in initial mgmt. of severe exacerbations
      • NO benefit has been seen when ipratropium is used once patient is hospitalized
      • Should use with VHC and face mask for children < 4 years
• Systemic Corticosteroids
  • Prednisone, Methylprednisolone, Prednisolone
    • Pediatric dose (< 12 yo): 1-2 mg/kg in 2 divided doses (max 60 mg/day) until PEF is 70% of predicted or personal best
    • Adult dose: 40-80 mg/day in 1-2 divided doses until PEF reaches 70% of predicted or personal best
    • NOTES:
      • For outpatient “burst”:
        • Adults: 40-60 mg in single or 2 divided doses for total of 5-10 days
        • Children: 1-2 mg/ kg/day max 60 mg/day for 3-10 days
      • No known advantage for higher doses of corticosteroids in severe asthma exacerbations
      • No known advantage for IV administration versus oral therapy provided gastrointestinal transit or absorption time is not compromised
      • The total course of systemic corticosteroids for an asthma exacerbation requiring an ED visit or hospitalization may last from 3-10 days
      • NO taper dose is needed for systemic corticosteroid regimen < 1 week in duration
        • For slightly longer courses (i.e., up to 10 days), taper dose is typically NOT required, especially if using ICS
      • ICSs can be started at any point in the treatment of an asthma exacerbation

Surgical/Procedural

• Bronchoscopy
  • May be useful with mucous plug removal (View Video)
• Ventilatory Support
  • Indicated in respiratory failure:
    • Inability to maintain respiratory effort i.e., extreme fatigue
    • Depressed mental status
    • Cyanosis
    • Accessory muscle use; chest wall retractions
    • Brief, fragmented speech
    • Inability to lie supine
    • Agitation
    • Rapid, shallow breathing (RR > 25-30 breaths per minute)
  • Intubation and mechanical ventilation
    • If must intubate, use largest tube possible (decreased resistance)
    • Rapid sequence intubation (RSI) is the preferred approach for securing the airway
      • Consider ketamine (1-2 mg/kg) for induction (secondary to bronchodilation effects)
    • Consider delayed sequence intubation if unable to pre-oxygenate adequately
      • Induction with ketamine (1-1.5mg/kg)
      • Incline head of bed to 30°
      • Oxygenate with non-rebreather mask or nasal intermittent positive pressure ventilation for 3 minutes
      • Proceed with paralysis and intubation
  • Mechanical ventilation
    • Goal: minimize airway pressures while maintaining adequate oxygenation
    • Permissive hypercapnia to maintain respiratory drive
    • Synchronized intermittent mechanical ventilation
    • Low tidal volume (< 10 cc/kg)
    • Ventilation I:E ratio= I:E 1:2 1:3
    • No PEEP
    • Peak pressures < 40 cm H₂0
  • Caution with mechanical ventilation due to risk of:
    • Cardiovascular collapse
    • Barotrauma
• NOT recommended in the ED or hospital setting
  • Methylxanthines
  • Antibiotics (except as needed for comorbid conditions)
  • Aggressive hydration
  • Chest physical therapy
  • Mucolytics
  • Sedation
  • Inhaled ipratropium bromide
    • Useful adjunctive therapy in the ED, BUT NOT beneficial for hospitalized for a severe exacerbation

Disposition

1. Admission Criteria
   • ICU: status asthmaticus, increasing PaCO₂, impending or actual respiratory arrest
   • Infants without response to SABA or SaO₂ < 91%
   • Patients who deteriorate in ED, have persistent vital sign abnormalities, or were already on maximal outpatient therapy (steroids)
   • Pregnant patients with severe disease after 24th week (for fetal monitoring)
   • Patients who have PEF < 40% despite appropriate medical management
   • Consider admission for intermediate responders (PEF 40-69% after treatment in ED) depending on patient
2. Consults
   • Critical Care if impending respiratory failure
3. Discharge/follow-up instructions
   • Provide the following to prevent relapse of exacerbation:
     • Referral to follow-up asthma care within 1-4 weeks
     • Encourage patient to contact his/her asthma care provider during the first 3-5 days post-discharge
     • Follow-up to review asthma action plan, adherence, environmental control, and to consider standpoint of therapy
     • Consider referral to an asthma self-management education program
     • An ED asthma discharge plan
     • Review of inhaler technique
     • Consideration of initiating ICS
4. Preventative management
   • Early treatment at home is the best initial strategy for managing asthma exacerbations
   • Instruct patient to:
     • Use a written asthma action plan
       • Make notes of when and how to treat signs of an exacerbation
     • Recognize early indicators of an exacerbation
       • Identify worsening PEF
     • Adjust their medication accordingly
       • Increase SABA dosing and add a short course of oral systemic corticosteroids in some cases
     • Remove or withdraw from all known allergens/irritants
       • Identify all possible allergens/triggers with allergy testing as needed
     • Monitor response to treatment and promptly communicate with the clinician about any serious health deterioration
       • Let health care providers know if there is a decreased efficacy in the treatment regime or if medications are not working to relieve symptoms
   • The following home remedies are NOT recommended
     • Drinking large volumes of fluid
     • Breathing warm, moist air
     • Using over the counter medications (e.g., antihistamines or cold remedies)
     • Using pursed-lip/other forms of breathing to remain calm

Related Topics

1. ACLS: Asthma Exacerbation Overview
2. Asthma: Stepwise Treatment Algorithm
3. Asthma in Pregnancy: Acute Treatment in the Emergency Department
4. Asthma: Acute Treatment Modalities

References

1. NIH. Asthma Management Guidelines: Focused Updates 2020. Available at: https://www.nhlbi.nih.gov/sites/default/files/publications/AsthmaManagementGuidelinesReport-2-4-21.pdf. [Accessed May 2022]
2. Global Strategy for Asthma Management and Prevention, Global Initiative for Asthma (GINA) 2015. Available at: http://www.ginasthma.org/. [Accessed May 2022]
3. Panchal AR, Bartos JA, Cabanas JG, et al. Part 3: Adult Basic and Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. Oct 2020;142(16 Suppl 2):S366-S468
4. Olin JT, Wechsler ME. Asthma: Pathogenesis and Novel Drugs for Treatment. BMJ Nov 24, 2014;349:g5517
5. Kat JR, Chawla D. Ketamine for management of acute exacerbations of asthma in children. Cochrane Database Syst Rev. Nov 14, 2012;11:CD009293
6. Weingart SD, Trueger NS, Wong N, et al. Delayed Sequence Intubation: A Prospective Observational Study. Ann Emerg Med. Apr 2015;65(4):349-355
7. Pollart SM, Compton RM, Elward KS. Management of Acute Asthma Exacerbations. Am Fam Physician. Jul 1, 2011;84(1):40-47
8. National Heart, Lung, and Blood Institute. National Asthma Education and Prevention Program. Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma- Full Report 2007. Available at: https://www.nhlbi.nih.gov/health-topics/guidelines-for-diagnosis-management-of-asthma. [Accessed May 2022]
9. Expert Panel Report 3 (EPR-3): Guidelines for the diagnosis and Management of Asthma- Summary Report 2007. J Allergy Clin Immunol. Jun 2008;121(6):1330
10. Castillo JR, Peters SP, Busse WW. Asthma Exacerbations: Pathogenesis, Prevention, and Treatment. J Allergy Clin Immunol Pract. Jul-Aug 2017; 5(4): 918-927

Contributor(s)

1. Williams, Barbara, MD, LT, MC, USN
2. Cherian, Geo, MD

Updated/Reviewed: May 2022