🫀 Physiological Adaptation · Lesson 6 of 10 · 8 min

Stroke Windows and Rising Intracranial Pressure

🧠 A stroke client's family says symptoms started 'around breakfast'. The thrombolytic window is measured from the last time the client was known to be normal, not from when someone noticed. That one question decides whether the drug can be given.

💡 Key idea

Last known well starts the clock; CT before thrombolytics; NPO until swallow screened. Rising ICP shows first as a change in consciousness; Cushing's triad is late. Head up 30, midline, no straining.

🧠 Why it matters

STROKE recognition: FAST, face droop, arm drift, speech difficulty, time to call. Establish the LAST KNOWN WELL time; IV thrombolytics (alteplase or tenecteplase) are given within 4.5 hours of last known well for ischemic stroke, after a CT scan rules out hemorrhage and the blood pressure is controlled below about 185/110; later than that, only selected clients with favorable advanced imaging qualify, and a large-vessel clot may still be removed by thrombectomy up to 24 hours. Keep NPO until a swallow screen is passed, position with the head elevated, and monitor neuro status closely. A LEFT-hemisphere stroke causes right-sided weakness and aphasia; a RIGHT-hemisphere stroke causes left-sided weakness, neglect, impulsivity and poor safety judgment. INCREASED INTRACRANIAL PRESSURE: early signs are a change in LEVEL OF CONSCIOUSNESS (the earliest and most sensitive), restlessness, headache, vomiting and pupil changes; late signs are CUSHING'S TRIAD (widened pulse pressure with hypertension, bradycardia, irregular respirations), fixed dilated pupils and posturing. Interventions: head of bed at 30 degrees with the head midline, avoid hip flexion beyond 90 degrees, prevent coughing, straining and Valsalva (stool softeners), suction for no more than 10 to 15 seconds with hyperoxygenation, space nursing activities apart, treat fever, maintain normal PaCO2, and give osmotic therapy such as mannitol or hypertonic saline as ordered. SEIZURES: protect the head, turn to the side, loosen clothing, time it, never restrain or put anything in the mouth; status epilepticus, a seizure over 5 minutes, is treated with IV lorazepam.

🏥 In the real world

🕐 The family says the client was 'fine at dinner' at 1900 and found slurred and weak at 0600. Last known well is 1900, eleven hours ago, so the standard thrombolytic window has closed and only advanced imaging can show whether the clot can still be treated; the nurse's documentation of that time shapes the whole treatment plan. Sleep-onset strokes are why the question is 'when were they last normal', not 'when did you notice'.

📌 Takeaways

Thrombolytics within 4.5 hours of last known well, after CT excludes bleeding
Left brain stroke: right weakness, aphasia; right brain stroke: left weakness, neglect
ICP: LOC change first, Cushing's triad late; HOB 30, midline, no Valsalva

📖 Terms in this lesson

Cushing's triad: Hypertension with a widened pulse pressure, bradycardia and irregular breathing: a late sign of rising intracranial pressure.

Last known well: The last time a stroke client was seen normal, which starts the clock for thrombolytic eligibility.

Status epilepticus: A seizure lasting more than five minutes or repeated seizures without recovery, treated with IV lorazepam.

FAST (stroke recognition): Face drooping, Arm weakness, Speech difficulty, Time to call for help and note the time: the public stroke screen (BE FAST adds Balance and Eyes).

Thrombolytics (alteplase, tenecteplase): Dissolve the clot in ischemic stroke (within 4.5 hours of last known well), heart attack and massive pulmonary embolism; rule out bleeding and recent surgery first, control blood pressure, avoid IM injections and needless punctures, and stop the infusion for any bleeding or neurologic change.

Levetiracetam: A widely used seizure drug with few interactions and no routine blood levels; the defining side effects are drowsiness and behavior changes (irritability, aggression, depression), the dose drops in kidney disease, and it must never be stopped suddenly.

Carbidopa-levodopa: The main Parkinson disease drug, which replaces dopamine; give it on time (doses can wear off between them), rise slowly for orthostatic hypotension, expect harmless dark urine and sweat, report new jerky movements or compulsive behaviors, and separate high-protein meals from the dose.

Pyridostigmine: The myasthenia gravis drug that keeps acetylcholine at the muscle; give it 30 to 60 minutes before meals to power chewing and swallowing, and tell too little (myasthenic crisis) from too much (cholinergic crisis with SLUDGE), since both cause weakness, and atropine is the antidote.

Mannitol: An osmotic diuretic that pulls water out of a swollen brain to lower intracranial pressure; inspect the bag for crystals and infuse through a filter, follow serum osmolality, sodium and urine output, and watch for fluid overload, pulmonary edema or dehydration.

✅ Test yourself

Which assessment finding is the EARLIEST indicator of increasing intracranial pressure?

Widened pulse pressure
Decreased level of consciousness
Fixed and dilated pupils
Bradycardia

Answer: B · Decreased level of consciousness

A change in level of consciousness appears first; Cushing's triad and pupil changes are late signs.

A client with suspected ischemic stroke arrives at 1030. The spouse says symptoms were noticed at 0900 but the client was last seen normal at 2200 the night before. Why is the client outside the standard window for IV thrombolytics?

The last known well time exceeds the 4.5-hour window
Thrombolytics are only given for hemorrhagic stroke
The client needs an MRI first
Thrombolytics require fasting

Answer: A · The last known well time exceeds the 4.5-hour window

The standard window counts from last known well; 2200 to 1030 is 12.5 hours, well beyond 4.5 hours.

Which nursing intervention is appropriate for a client with increased intracranial pressure?

Elevate the head of the bed to 30 degrees
Keep the head of the bed flat
Cluster all care activities together to allow long rest periods
Encourage vigorous coughing to clear secretions

Answer: A · Elevate the head of the bed to 30 degrees

Head elevation with neutral alignment promotes venous drainage. Clustered care, coughing and flat positioning all raise pressure.

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