A stroke occurs when blood flow to a part of the brain is disrupted, either by an ischemic clot blocking a vessel or a hemorrhagic rupture causing bleeding. The phrase “Time is Brain” underscores the urgency, as every minute delays treatment and results in the death of millions of neurons, leading to permanent neurological damage. The primary goal of the stroke team is to rapidly assess the patient, determine the stroke type, and implement treatment to salvage as much brain tissue as possible. This process is quantified by standardized time benchmarks, ensuring the patient receives prompt, effective care.
The First Critical Time Goal for Neurologic Assessment
The first benchmark in stroke care is the time from a patient’s arrival at the emergency department, known as “door time,” to the initial neurologic assessment by a physician or stroke team member. The widely recognized standard for this Door-to-Physician/Stroke Team Assessment is within 10 minutes of arrival. This initial assessment is primarily a rapid triage to confirm stroke symptoms and activate the specialized stroke protocol.
This 10-minute window is for a focused, high-speed evaluation, not a full medical workup. The team must quickly establish the patient’s “last known well” time, which dictates eligibility for time-sensitive therapies. A standardized tool, such as the National Institutes of Health Stroke Scale (NIHSS), is used to quantify the severity of the neurological deficit.
The NIHSS assesses specific functions, producing a numerical score that guides subsequent decisions. This initial evaluation must confirm the presence of an acute stroke syndrome and determine the patient’s immediate stability. The findings inform the next, equally urgent step: determining the cause of the stroke through imaging.
The NIHSS assesses:
- Level of consciousness
- Vision
- Motor strength
- Sensation
- Coordination
- Language ability
Diagnostic Imaging Benchmarks
Following the initial neurological assessment, the next critical time goal is the acquisition of diagnostic imaging to differentiate between the two main types of stroke. The standard benchmark for Door-to-CT/MRI Completion is 20 to 25 minutes from the patient’s arrival. This rapid imaging is necessary because the treatment for an ischemic stroke is the opposite of the treatment for a hemorrhagic stroke.
Non-contrast Computed Tomography (CT) is the preferred initial imaging modality due to its speed and availability. Its primary role in this early phase is to quickly rule out a hemorrhage, which would disqualify the patient from receiving clot-busting medications. While CT is excellent for detecting fresh blood, it may not immediately show signs of a small, early ischemic injury.
If the initial CT scan is negative for hemorrhage, further imaging may be performed to locate the clot. This often includes a CT Angiography (CTA), which involves injecting a contrast dye to visualize the blood vessels and identify a Large Vessel Occlusion (LVO). The goal is to have the CT scan interpreted by a qualified physician, ideally within 45 minutes of the patient’s arrival, to move swiftly toward treatment implementation.
Treatment Implementation Benchmarks
Once diagnostic imaging confirms an ischemic stroke and the patient meets all criteria, the focus shifts to delivering reperfusion therapy. The Door-to-Needle (D2N) time measures the period from hospital arrival to the start of thrombolytic therapy, typically set at a maximum of 60 minutes. This time goal is paramount because the effectiveness of the clot-busting drug, tissue plasminogen activator (tPA), is highly time-dependent, with the strongest benefit seen when administered within the first 4.5 hours of symptom onset.
Hospitals are continually striving to improve this metric, with some centers achieving median D2N times of 30 to 45 minutes. For patients with a confirmed LVO, a distinct time metric is activated for endovascular thrombectomy, a procedure where a catheter is threaded through the arteries to physically remove the clot. The goal for this procedure is Door-to-Puncture (DTP), which is the time from arrival to the first puncture of the patient’s groin artery, often targeted for 90 minutes.
Achieving these aggressive time benchmarks requires seamless coordination across emergency medical services, the emergency department, radiology, and the specialized stroke team. Every minute saved in the D2N and DTP times correlates directly with a higher likelihood of the patient recovering with less disability. These metrics represent the final steps of the rapid assessment, moving from diagnosis directly to a life-saving intervention.