What is the recommended treatment for a patient requiring breathing treatments, specifically using racemic epinephrine inhalation solution?

Racemic Epinephrine Breathing Treatments

For acute upper airway obstruction (croup/laryngotracheobronchitis), administer racemic epinephrine 2.25% solution at 0.5 mL in 2 mL normal saline via nebulizer, which can be repeated as needed for symptomatic relief, though effects last only 1-2 hours. 1

Primary Indication: Croup and Acute Airway Edema

• Racemic epinephrine is the treatment of choice for laryngotracheobronchitis (croup) with acute airway edema. 1
• The standard dose is 0.05 mL/kg of 2.25% racemic epinephrine solution (maximum 0.5 mL) diluted in 2 mL normal saline, delivered by nebulizer. 1
• Many institutions use a standardized 0.5 mL dose for all patients regardless of weight for simplicity. 1
• If racemic epinephrine is unavailable, substitute single-isomer L-epinephrine (1:1000) at 0.5 mL/kg up to 5 mL maximum. 1

Clinical Response and Duration

• Nebulized racemic epinephrine produces significant clinical improvement at 10 and 30 minutes post-treatment in croup patients. 2
• The effect is transient, lasting only 1-2 hours, so prepare for definitive management or repeat dosing. 3
• Clinical scores return to baseline by 120 minutes, requiring repeat treatments or escalation of care. 2
• Patients should be observed for at least 2-3 hours after treatment due to the risk of rebound airway obstruction. 2

Post-Extubation Stridor

• Inhaled epinephrine should be used to treat post-extubation stridor in conscious patients. 1
• Administer 1 mg nebulized epinephrine immediately for symptomatic relief in patients with significant respiratory distress. 3
• Up to 15% of extubated patients require reintubation within 48 hours, so extubation should be considered a "trial" with active planning for potential reintubation. 3

Use in Bronchospasm (Limited Role)

• Racemic epinephrine is NOT recommended for routine treatment of asthma or bronchiolitis. 1
• For bronchiolitis, there is insufficient evidence to support routine use in inpatients, though some outpatient benefit over placebo exists. 1
• Racemic epinephrine provides less bronchoprotection than albuterol and may be less effective for acute bronchospasm. 4
• In severe asthma exacerbations unresponsive to standard therapy, racemic epinephrine has been used successfully as rescue therapy, but this is not standard practice. 5

Administration Technique

• Deliver via standard jet nebulizer with oxygen or air as the driving gas. 1
• In patients with CO2 retention and acidosis, drive the nebulizer with air (not high-flow oxygen) to prevent worsening hypercapnia. 1, 6
• Treatment can be repeated every 20-30 minutes as needed based on clinical response. 1, 2

Safety Profile

• Racemic epinephrine administered via nebulizer produces minimal cardiovascular effects in both normal subjects and patients with airway obstruction. 7
• No clinically significant changes in pulse rate or blood pressure occur with standard doses. 8, 7
• Mild side effects (tremor, tachycardia) are infrequent and transient. 7
• The nebulized route is safer than parenteral epinephrine for airway obstruction. 8

Critical Pitfalls

• Do not discharge patients immediately after treatment—observe for at least 2-3 hours due to short duration of action and risk of rebound obstruction. 2
• Do not use racemic epinephrine as first-line therapy for asthma or COPD exacerbations—albuterol and ipratropium are superior. 1
• If stridor indicates at least 50% airway narrowing, prepare for definitive airway management as nebulized epinephrine may only provide temporary relief. 3
• Racemic epinephrine treats symptoms but not underlying inflammation—add corticosteroids for inflammatory causes of airway edema. 3