What is the standard regimen for thrombolysis (tissue plasminogen activator) in acute ischemic stroke?

Standard Regimen for Thrombolysis in Acute Ischemic Stroke

The standard regimen for thrombolysis in acute ischemic stroke is intravenous alteplase (tPA) at a dose of 0.9 mg/kg (not to exceed 90 mg total dose), with 10% of the total dose administered as an initial intravenous bolus over 1 minute and the remainder infused over 60 minutes. 1, 2

Time Window and Eligibility

• Treatment should be initiated as soon as possible but within 3 hours of symptom onset (Grade 1A recommendation) 3
• Treatment may be considered within 3-4.5 hours of symptom onset (Grade 2C recommendation) 3
• Treatment is not recommended beyond 4.5 hours of symptom onset (Grade 1B recommendation) 3, 4

Pre-Treatment Assessment

• Exclude intracranial hemorrhage with neuroimaging (typically non-contrast CT)
• Ensure blood pressure is ≤185/110 mmHg before initiating IV thrombolysis 1
• Check for contraindications:
  • Active internal bleeding
  • Recent intracranial or intraspinal surgery or serious head trauma
  • Intracranial conditions that may increase bleeding risk
  • Bleeding diathesis
  • Current severe uncontrolled hypertension
  • Current intracranial hemorrhage
  • Subarachnoid hemorrhage
  • Major surgery within prior 14 days
  • Gastrointestinal or genitourinary hemorrhage within previous 21 days 1, 2

Administration Protocol

1. Calculate dose based on patient weight: 0.9 mg/kg (maximum 90 mg)
2. Administer 10% of total dose as IV bolus over 1 minute
3. Infuse remaining 90% of dose over 60 minutes 1, 2

Post-Treatment Management

• Maintain blood pressure below 180/105 mmHg during and for 24 hours after treatment 1
• Options for blood pressure control include labetalol, nicardipine, and clevidipine 1
• Perform neurological assessments:
  • Every 15 minutes during infusion and for 2 hours
  • Every 30 minutes for the next 6 hours
  • Hourly until 24 hours after treatment 1
• Delay aspirin for 24 hours after thrombolysis 1

Monitoring for Complications

• Symptomatic intracerebral hemorrhage (sICH) occurs in approximately 5-8% of treated patients 3, 1
• Angioedema should be managed with antihistamines, glucocorticoids, and standard airway management as needed 1
• Monitor for bleeding complications and manage with an individualized approach 1

Important Considerations

• Door-to-needle time should be less than 60 minutes in 90% of treated patients 1
• If patients are eligible for IV tPA, they should begin receiving it before being transported for additional imaging or transferred for endovascular treatment 3
• Standard-dose tPA (0.9 mg/kg) has shown better outcomes than lower doses without increasing hemorrhage risk 5

Clinical Outcomes

• Number needed to treat (NNT) is 8 (95% CI 4 to 31) for better long-term functional outcome 1
• Approximately 35-43% of treated patients achieve functional independence at 30-90 days 6
• 30-day mortality rate is approximately 13% 6

Common Pitfalls to Avoid

1. Delaying treatment while waiting for additional tests (begin tPA if eligible while arranging further imaging)
2. Excluding patients with mild or rapidly improving symptoms (these are still potential candidates)
3. Inadequate blood pressure control before and after thrombolysis
4. Administering anticoagulants within 24 hours of tPA administration
5. Missing the narrow therapeutic window due to delays in patient presentation (only 15% of stroke patients typically arrive within the 3-hour window) 7

Following this standardized protocol for thrombolysis in acute ischemic stroke optimizes the chances for favorable outcomes while minimizing the risk of complications.