Which patient is a candidate for immediate tissue plasminogen activator (tPA) administration according to the American Heart Association Stroke Council guidelines?

tPA Candidate Selection for Acute Ischemic Stroke

The patient with dysarthria and right-sided motor and sensory deficits that began 2 hours prior to arrival with a blood pressure of 175/90 mm Hg is the only candidate for immediate tPA administration.

Analysis of Each Patient

Patient A: Warfarin with INR 2.1

• Not a candidate. Current use of anticoagulants with INR >1.7 is an absolute exclusion criterion for tPA administration 1
• The AHA/ASA guidelines explicitly state that patients taking oral anticoagulants with INR >1.7 cannot receive tPA 1
• This patient's INR of 2.1 exceeds the threshold, making them ineligible regardless of the favorable time window (45 minutes) 1

Patient B: Decreased Mentation with Glucose 45 mg/dL

• Not a candidate. Blood glucose concentration <50 mg/dL (2.7 mmol/L) is an absolute exclusion criterion 1
• Hypoglycemia is a stroke mimic that must be corrected before considering thrombolytic therapy 2
• The neurological symptoms may resolve entirely with glucose correction, making this patient ineligible until hypoglycemia is treated and symptoms reassessed 2

Patient C: History of Intracranial Hemorrhage 5 Years Ago

• Not a candidate. History of previous intracranial hemorrhage is an absolute exclusion criterion with no time limitation 1
• The AHA/ASA guidelines state "No history of previous intracranial hemorrhage" as a requirement for tPA eligibility 1
• This contraindication persists indefinitely, regardless of how remote the hemorrhage occurred 1

Patient D: Subdural Hematoma 2 Months Ago

• Not a candidate. Recent intracranial or intraspinal surgery is an exclusion criterion 1
• While the guidelines specify "recent" surgery, a subdural hematoma requiring treatment 2 months ago represents significant recent intracranial pathology 1
• The standard exclusion for major surgery is 14 days, but intracranial hemorrhage history creates permanent ineligibility 1

Patient E: BP 175/90 mm Hg, 2 Hours from Onset ✓

• This is the candidate. All inclusion criteria are met and no exclusion criteria are present 1
• Time window: 2 hours is well within the 3-hour window (Class I, Level A evidence) and even within the extended 3-4.5 hour window 1
• Blood pressure: 175/90 mm Hg is below the threshold of 185/110 mm Hg required for tPA eligibility 1
• The patient has measurable neurological deficits (dysarthria, motor and sensory deficits) that are not rapidly improving 1
• No contraindications are mentioned (no anticoagulation, no recent surgery, no prior hemorrhage, no hypoglycemia) 1

Critical Blood Pressure Management

For eligible patients, blood pressure must be maintained below 185/110 mm Hg before and during tPA administration 1:

• Patient E's BP of 175/90 mm Hg meets this requirement without intervention 1
• If BP exceeds 185/110 mm Hg, antihypertensive agents should be used to lower it safely before starting tPA 1
• Blood pressure stability must be assessed—patients requiring continuous sodium nitroprusside infusion may not be sufficiently stable for tPA 1

Time-Dependent Treatment Priorities

The door-to-needle time should be within 60 minutes of hospital arrival 1:

• Earlier treatment within 90 minutes of onset provides the best outcomes 1
• Treatment between 90-180 minutes remains beneficial but with slightly reduced odds ratios for favorable outcomes 1
• The extended 3-4.5 hour window has additional exclusion criteria (age >80, NIHSS >25, combination of diabetes and prior stroke) 1

Common Pitfalls to Avoid

• Do not delay tPA for patients on warfarin if INR results are pending—treatment can begin but must be discontinued if INR returns >1.7 1
• Always correct hypoglycemia before considering tPA, as it is a treatable stroke mimic 2
• Never overlook history of intracranial hemorrhage, regardless of how remote—this is a permanent contraindication 1
• Avoid aggressive blood pressure lowering in patients not receiving tPA, as this may worsen ischemia 2