tPA should be considered in ischemic stroke within how many hours of symptom onset?

tPA should be considered in ischemic stroke within how many hours of symptom onset?

• A. 1 hour
• B. 3 hours
• C. 4.5 hours
• D. 6 hours

Answer: (B)

The main concept here is the time window for giving IV thrombolysis in ischemic stroke. Administering tPA as soon as possible after symptom onset improves outcomes by dissolving the clot before much brain tissue dies, so time is critical. The strongest, most consistent evidence supports treating within three hours of onset. Trials showed that patients given tPA within this window had better functional outcomes than those who did not, with an acceptable risk of bleeding. As time from onset increases, the benefits diminish and the risk of hemorrhagic transformation rises, making treatment less favorable. Acknowledging newer guidelines, some suggest that select patients may be considered up to 4.5 hours after onset, but this is not as universally applicable and requires careful patient selection. Outside the three-hour window, the overall benefit is greatly reduced, which is why the three-hour mark is the best general answer.

The main concept here is the time window for giving IV thrombolysis in ischemic stroke. Administering tPA as soon as possible after symptom onset improves outcomes by dissolving the clot before much brain tissue dies, so time is critical.

The strongest, most consistent evidence supports treating within three hours of onset. Trials showed that patients given tPA within this window had better functional outcomes than those who did not, with an acceptable risk of bleeding. As time from onset increases, the benefits diminish and the risk of hemorrhagic transformation rises, making treatment less favorable.

Acknowledging newer guidelines, some suggest that select patients may be considered up to 4.5 hours after onset, but this is not as universally applicable and requires careful patient selection. Outside the three-hour window, the overall benefit is greatly reduced, which is why the three-hour mark is the best general answer.