A stroke is a sudden interruption of blood flow to the brain. This blockage, most commonly caused by a clot (ischemic stroke), deprives brain cells of oxygen and nutrients, leading to rapid cell death. Because approximately 1.9 million neurons are lost every minute a stroke goes untreated, the concept of “Time is Brain” governs hospital decisions. To combat this rapid neurological damage, hospitals use a standardized procedure known as the stroke protocol.
This protocol ensures patients bypass typical emergency room waiting times and move directly into a coordinated, time-dependent treatment pathway. This highly synchronized effort aims to diagnose the stroke type and initiate life-saving intervention in minutes, minimizing permanent disability and maximizing recovery.
Activating the Code Stroke Response
The process often begins before the patient arrives, as Emergency Medical Services (EMS) use standardized tools like the FAST acronym (Face drooping, Arm weakness, Speech difficulty, Time to call) to recognize symptoms. This pre-hospital alert allows the hospital to mobilize its specialized team while the patient is en route, ensuring an immediate response upon arrival.
Upon arrival, the hospital declares a “Code Stroke,” instantly summoning a specialized team of neurologists, emergency physicians, nurses, and radiology technicians. The patient is moved directly to the imaging suite, bypassing traditional examination rooms, with the goal of performing initial imaging within minutes.
The initial rapid assessment includes a neurological evaluation using the National Institutes of Health Stroke Scale (NIHSS). This standardized tool quantifies the severity of the neurological deficit by testing motor function, language, consciousness, and sensation. The NIHSS score helps the stroke team quickly decide on the appropriate treatment path and determine eligibility for clot-busting therapies. This rapid mobilization is designed to meet strict benchmarks, such as a median door-to-needle time of 30 minutes for administering medication.
Rapid Imaging: Identifying the Type of Stroke
Immediately after assessment, the patient is rushed to the Computed Tomography (CT) scanner for the foundational diagnostic step. The primary goal of this initial non-contrast CT scan is to definitively rule out a hemorrhagic stroke (bleeding in the brain). Since hemorrhage is a direct contraindication for the most common acute stroke treatment, this distinction must be made quickly and accurately.
If the non-contrast CT confirms no bleeding, the team proceeds to advanced imaging, often involving CT Angiography (CTA) and CT Perfusion scans. The CTA uses contrast dye to visualize blood vessels, precisely locating an arterial blockage and determining if it is a large vessel occlusion (LVO). The presence of an LVO suggests the patient may be a candidate for a catheter-based procedure.
The CT Perfusion scan measures blood flow and transit time through the brain tissue. This specialized imaging identifies the ischemic core (irreversibly damaged tissue) and the surrounding penumbra (salvageable tissue). Analyzing the size difference between these two areas, known as mismatch, is a determining factor for treatment eligibility, especially for patients presenting outside the standard early time window.
Time-Sensitive Treatments: Thrombolysis and Removal
The rapid imaging results dictate the next steps, which focus on reperfusion, or restoring blood flow to the affected brain region. For patients with an ischemic stroke who do not have a large vessel occlusion, the standard intervention is intravenous thrombolysis, using a drug like tissue plasminogen activator (tPA). This medication dissolves the blood clot causing the blockage and significantly improves outcomes if administered promptly.
The administration of tPA is governed by strict time constraints; the strongest benefit occurs within three hours of symptom onset. An extended window of up to four and a half hours may be considered for selected patients, but this introduces additional exclusion criteria. The treatment is contraindicated if the patient has a high bleeding risk, such as recent major surgery, a history of intracranial hemorrhage, or is taking certain anticoagulants.
For patients diagnosed with a large vessel occlusion, the primary treatment is mechanical thrombectomy, a procedure to physically remove the clot. This involves inserting a catheter into an artery, usually in the groin, and navigating it to the blocked artery in the brain. A device, typically a stent retriever, is deployed to capture and pull the obstruction out of the vessel, restoring blood flow.
Mechanical thrombectomy has a longer treatment window than tPA, generally extending up to six hours from the time the patient was last known to be well. In select patients, based on advanced imaging confirming salvageable brain tissue, this intervention can be performed up to 24 hours after symptom onset. The stroke team makes the decision to use tPA, thrombectomy, or both almost instantaneously after reviewing the imaging and clinical status.
Stabilization and Specialized Stroke Unit Care
Once the acute intervention is complete, the patient is transferred to a specialized Stroke Unit or Intensive Care Unit for continuous monitoring and stabilization. The goal is to prevent secondary brain injury by meticulously controlling the patient’s physiological environment, including blood pressure, blood sugar levels, and body temperature. Maintaining blood pressure within a narrow range is important, as extremes can increase bleeding risk or reduce blood flow to vulnerable tissue. Patients are monitored frequently for signs of neurological deterioration.
An early, mandatory step is performing a swallowing screen, as many stroke survivors experience dysphagia (difficulty swallowing). Failure to detect this can lead to aspiration pneumonia. Following stabilization, the focus shifts to recovery with early consultation from an interdisciplinary rehabilitation team, including physical, occupational, and speech therapists. This coordinated care on a specialized unit improves functional outcomes and reduces mortality compared to general hospital care.