Updated July 2026 · 9 min read

Acute Ischemic Stroke & Thrombolytics: The ICU Nurse's Guide

Part of the ICU Emergencies Hub — browse every related guide in one place.

In an ischemic stroke, a clot has shut off blood flow to part of the brain and roughly two million neurons die every minute the vessel stays blocked. Everything the stroke team does is a race against that clock. The nurse is the person who documents the last-known-well time, runs the neuro checks that catch a deterioration, and manages the fragile window after a clot-busting drug goes into a brain that could just as easily bleed.

Time is brain: the last-known-well clock

The single most important number in a stroke workup is not a lab value — it is the last-known-well (LKW) time: the last moment the patient was seen at their neurologic baseline. Thrombolytic eligibility is measured from LKW, not from when symptoms were discovered. A patient who wakes with deficits is timed from when they went to sleep well, which is why "wake-up strokes" are often outside the standard window unless advanced imaging reopens the door. When you take report or witness the onset, nail down that time and the source of it, because it drives every downstream decision.

Confirm it is ischemic before anything else

An ischemic stroke and a hemorrhagic stroke can look identical at the bedside, and the treatments are opposite — one gets a clot-buster, the other would be killed by it. So the first stop is a non-contrast head CT, whose main early job is to rule out hemorrhage. CT angiography then hunts for a large-vessel occlusion that a thrombectomy could pull. While imaging happens, the team is scoring the deficit with the NIH Stroke Scale (NIHSS), checking a glucose (hypoglycemia is a classic stroke mimic — always check it), and screening for the thrombolytic exclusions below.

Alteplase vs. tenecteplase

Two thrombolytics are used to dissolve the clot. Both convert plasminogen to plasmin to break down fibrin; the practical difference is how they are given.

Dosing for stroke is weight-based and is not the same as the cardiac dosing of these drugs — a critical, oft-drilled safety point. Verify the stroke-specific dose and weight independently, because a decimal error here bleeds into the brain.

Who cannot get the drug: the exclusion screen

Thrombolytics are dangerous in the wrong patient. The team screens a long list; the ones a nurse most often surfaces include:

These are relative and absolute in the actual protocol — the point for the bedside nurse is to have the labs, the pressure, and the history ready so the decision is not held up.

The blood-pressure tightrope

Blood-pressure management flips depending on whether the patient gets a lytic, and it is one of the most nurse-owned parts of stroke care.

That last point trips people up: the same 190/100 that is an emergency to fix before tPA can be intentionally left alone in a patient who did not get tPA. The plan comes from the team and the eligibility, not from a single number.

After the drug: the post-lytic watch

Once the thrombolytic is in, the nurse runs a tight protocol built around one fear — intracranial hemorrhage. Typical elements:

• Frequent neuro checks and vitals on a set schedule (often every 15 minutes early, then spacing out) — you are looking for any decline in the NIHSS or level of consciousness.
• Blood pressure kept under the post-lytic ceiling, treated promptly if it climbs.
• No antiplatelets or anticoagulants for ~24 hours, and generally no arterial punctures, central lines, or NG tubes during the early window unless essential — each is a bleeding opportunity.
• Watch for signs of a bleed: sudden headache, new or worsening deficit, dropping level of consciousness, nausea/vomiting, or an acute blood-pressure spike. Any of these means stop any infusion, alert the team, and prepare for an emergent CT.

Angioedema and the airway

Alteplase can trigger orolingual angioedema — swelling of the tongue and lips, sometimes one-sided — usually early in the infusion. It is easy to miss because the patient may already have facial weakness. Keep looking at the mouth; a swelling tongue is an airway emergency that can require stopping the drug and calling for airway support.

Thrombectomy: the other reperfusion

For a large-vessel occlusion, mechanical thrombectomy — threading a catheter up to physically remove the clot — can be done in a longer window than IV lytics, sometimes up to 24 hours in selected patients guided by perfusion imaging. Many patients get the drug and go to the angio suite. Your role includes prepping for transfer, maintaining the pressure targets, and resuming intensive neuro monitoring afterward, watching both for reperfusion injury and for groin-site bleeding.

Bottom line

Ischemic stroke is a stopwatch. Fix the last-known-well time, get the CT that rules out a bleed, control the pressure to the eligibility window, and verify the stroke dose of alteplase or tenecteplase. Then the job becomes vigilance: frequent neuro checks, a hard blood-pressure ceiling, no new punctures, and treating any new headache, vomiting, or deficit as a hemorrhage until a scan says otherwise. For the pressure tools you will reach for, see our related pieces on managing subarachnoid hemorrhage and vasospasm and the ICP crisis in traumatic brain injury, and on status epilepticus, which can complicate any acute brain injury.

This article is general educational information for licensed clinicians and students, not medical advice or a substitute for your institution's protocols, pharmacy guidance, or a provider's orders. Always follow facility policy and verify doses independently.