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Medical-Surgical Nursing II · Chapter 3

Thrombolysis Clock: Last Known Well, the Screen and the Dose

The clock starts at last known well — the last moment anyone saw the patient at neurologic baseline — not at the moment somebody noticed. Set the times, enter the numbers, tick what the history actually contains, and the bench tells you whether this patient can be treated, what is blocking it, and exactly what you would hang. Change one field at a time and watch the verdict move.

1 · The clock

A patient who went to bed at 2200 fine and woke at 0600 with weakness was last known well at 2200 — that is eight hours, not one. Get a phone number for the person who saw them last, and get it before the patient leaves your area.

2 · The numbers

Which fibrinolytic

3 · Screen the history

Absolute exclusions
Haematologic exclusions
Extra exclusions that apply only in the 3–4.5 hour window
Relative — weigh risk against benefit

Where you are on the clock

3 h 10 minsince last known well
Thrombolysis window timeline A bar from zero to six hours since last known well, with the zero to three hour standard window, the three to four and a half hour extended window, and the region beyond four and a half hours where intravenous thrombolysis is not given. 0–3 h standard 3–4.5 h extended beyond 4.5 h

If you give it — the order

Total dose
70.2
mg
Bolus
7
mg over 1 min
Infusion
63.2
mg over 60 min

The next twenty-four hours

0–2 hBlood pressure and neurologic checks every 15 minutes during the infusion and for two hours from its start. Keep the pressure below 180/105 mmHg.
2–8 hChecks every 30 minutes for six hours.
8–24 hChecks hourly until twenty-four hours.
~20 min inInspect the tongue and lips for orolingual angioedema — one to five percent of patients, more common on an ACE inhibitor. Stop the infusion, protect the airway, and give antihistamine, corticosteroid and epinephrine per protocol.
ThroughoutNo antiplatelet or anticoagulant for 24 hours. No arterial punctures at non-compressible sites, no intramuscular injections, and defer urinary catheters and nasogastric tubes where clinically possible. Repeat imaging at 24 hours before any antithrombotic is started.
The one sequence you must knowSudden severe headache, acute hypertension, nausea and vomiting, or any new neurologic deterioration means stop the infusion, obtain an emergent non-contrast head CT, and notify the provider — in that order, and the first two can happen at the same time while someone else pages. Then anticipate a stat fibrinogen, type and crossmatch, reversal with cryoprecipitate or fibrinogen concentrate, and neurosurgical consultation.