Acute ischaemic stroke

Intravenous thrombolysis within 4.5 hours of onset in eligible patients; benefit falls sharply with time, hence the emphasis on door-to-needle intervals.
Mechanical thrombectomy for large vessel occlusion within 6 hours, and out to 24 hours in selected patients where advanced imaging shows salvageable tissue.
Permissive hypertension in patients not receiving thrombolysis — treat only above roughly 220/120 mmHg. Lowering pressure reduces collateral flow to the penumbra.
After thrombolysis, keep blood pressure below 180/105 mmHg to limit haemorrhagic transformation.
Decompressive hemicraniectomy within 48 hours for malignant middle cerebral artery infarction reduces mortality substantially. Survival with significant disability is the common outcome, so this is a decision requiring explicit discussion with family.