How to manage a patient receiving Lexiscan (regadenoson)?

Management of Patients Receiving Lexiscan (Regadenoson)

Regadenoson (Lexiscan) should be administered with careful monitoring for potential cardiovascular adverse events, with aminophylline readily available to reverse severe reactions. 1

Pre-Administration Assessment

• Screen for contraindications:

  • Second or third-degree AV block without functioning pacemaker
  • Sinus node disease
  • Uncontrolled hypertension or hypotension
  • Active bronchospasm or severe COPD
  • Recent use of methylxanthines (caffeine, theophylline) within 12 hours 2

• Baseline vital sign measurement:

  • Blood pressure
  • Heart rate
  • Oxygen saturation
  • Respiratory rate

Administration Protocol

1. Preparation:

   • Ensure IV access is patent
   • Have emergency equipment readily available
   • Prepare aminophylline (100mg) for potential reversal 3
   • Ensure continuous cardiac monitoring and pulse oximetry 1

2. Dosing:

   • Administer as a 0.4mg (5mL) rapid IV bolus over approximately 10 seconds 2
   • Follow immediately with 5mL saline flush

3. Monitoring During Administration:

   • Continuous ECG monitoring for arrhythmias
   • Frequent blood pressure measurements (every 1-2 minutes initially)
   • Continuous pulse oximetry
   • Monitor for respiratory symptoms

Expected Physiologic Response

• Increase in heart rate (typically 20-25 bpm)
• Mild decrease in blood pressure (systolic 5-24 mmHg, diastolic 8-15 mmHg)
• Coronary vasodilation (desired effect) 3

Common Side Effects Management

• Dyspnea (most common, up to 70% of patients) 4:

  • Reassure patient this is expected and transient
  • Provide supplemental oxygen if needed

• Chest discomfort (27% of patients) 5:

  • Differentiate from true angina
  • Monitor ECG for ischemic changes

• Headache (15% of patients) 5:

  • Reassure patient this is expected and transient
  • Consider acetaminophen after procedure if persistent

• Flushing:

  • Reassure patient this is expected and transient

Management of Adverse Reactions

Mild to Moderate Reactions

• Continue monitoring
• Provide supportive care
• Most side effects resolve within minutes after administration

Severe Reactions

1. Severe hypotension:

   • Place patient in Trendelenburg position
   • Administer IV fluid bolus
   • Consider aminophylline 100mg IV over 1-2 minutes 3

2. Bronchospasm:

   • Administer bronchodilator therapy
   • Consider aminophylline 100mg IV over 1-2 minutes
   • Provide supplemental oxygen

3. Advanced heart block or significant arrhythmias 6:

   • Administer aminophylline 100mg IV over 1-2 minutes
   • Have atropine ready for symptomatic bradycardia
   • Prepare for potential advanced cardiac life support

4. Cardiac arrest (rare but reported) 6:

   • Initiate ACLS protocol
   • Administer aminophylline if not already given

Special Populations

Patients with Pulmonary Hypertension

• Generally well-tolerated despite theoretical concerns
• Monitor closely for hemodynamic changes 4

Patients with Reactive Airway Disease

• Can be used with caution in mild-to-moderate disease
• Pre-treatment with bronchodilators recommended
• Have rescue medications readily available 7

Patients with Coronary Artery Disease

• Monitor closely for ischemic ECG changes
• Be prepared to treat angina if it develops

Post-Administration Monitoring

• Continue cardiac monitoring until vital signs return to baseline
• Document any adverse reactions
• Ensure patient is stable before discharge
• Provide instructions regarding potential delayed reactions

Key Pitfalls to Avoid

1. Failure to screen for contraindications, particularly recent methylxanthine use which can reduce effectiveness 2

2. Inadequate monitoring during and after administration

3. Delayed recognition of serious adverse events like advanced heart block 6

4. Not having aminophylline immediately available for reversal of severe reactions

5. Misinterpreting dyspnea (common side effect) as a severe reaction when it may be an expected response

By following this structured approach to regadenoson administration, clinicians can maximize safety while obtaining the diagnostic benefits of pharmacologic stress testing.