Blood Tests for Acute Ischemic Stroke in a 12-Year-Old
All pediatric patients presenting with acute ischemic stroke require an immediate core panel of blood tests including complete blood count with platelets, coagulation studies (PT/INR and aPTT), blood glucose, serum electrolytes, renal function tests, and cardiac markers, along with a 12-lead ECG. 1, 2
Immediate Essential Blood Tests (Do Not Delay Treatment)
Core Laboratory Panel - All Patients
Blood glucose must be checked immediately as hypoglycemia can perfectly mimic stroke symptoms and requires immediate exclusion before proceeding with any other interventions 1, 2, 3
Complete blood count with platelet count is essential to detect thrombocytopenia (which contraindicates thrombolytic therapy), anemia, polycythemia, or thrombocytosis that could influence treatment decisions 1, 2
Coagulation studies (PT/INR and aPTT) are critical to identify coagulopathies and assess for anticoagulant use, especially before considering thrombolytic therapy 1, 2
Serum electrolytes and renal function tests (including creatinine and eGFR) are necessary to identify metabolic derangements that can mimic stroke and guide medication dosing 1, 2
Cardiac markers (troponin) must be obtained as acute myocardial infarction can cause stroke and stroke can precipitate myocardial ischemia 1, 2, 4
Critical Timing Caveat
Thrombolytic therapy should NOT be delayed while awaiting laboratory results UNLESS there is clinical suspicion of bleeding abnormality, thrombocytopenia, known heparin/warfarin use, or anticoagulant use is uncertain. 1, 2 This is a common pitfall—labs should be drawn stat but treatment proceeds simultaneously.
Additional Tests for Pediatric Stroke Patients
Given the patient's age (12 years), additional considerations beyond standard adult protocols are warranted:
Selected Patient Testing
Hepatic function tests should be obtained to assess liver function and guide medication dosing 1
Toxicology screen and blood alcohol level if history is uncertain or suggested by examination findings 1
Pregnancy test in post-menarchal females 1
Arterial blood gas if hypoxia is suspected based on oxygen saturation monitoring 1
Pediatric-Specific Considerations
In a 12-year-old with stroke, consider testing for conditions more common in pediatric populations:
Thrombophilia workup may be appropriate in young patients lacking traditional atherosclerotic risk factors, though not routinely recommended for all arterial thrombosis 4
Complete blood count should be carefully reviewed even if platelet count is not greatly elevated, as essential thrombocythemia can present with platelet counts under 600×10⁹/L and cause stroke in young patients 5
Cardiac Evaluation
Mandatory Cardiac Testing
12-lead ECG is mandatory to assess cardiac rhythm, detect atrial fibrillation/flutter, and identify structural heart disease 1, 2, 4
Continuous cardiac monitoring for at least 24 hours is recommended for all ischemic stroke patients, as cardiac arrhythmias are common after large ischemic strokes 4
Timeline for Completion
The complete diagnostic evaluation should be completed or underway within 48 hours of symptom onset, but acute treatment must not be delayed while awaiting results 2, 3, 4
Common Pitfalls to Avoid
Never delay thrombolytic therapy waiting for coagulation studies unless there is specific clinical suspicion of bleeding disorder, known anticoagulant use, or thrombocytopenia 1
Do not skip glucose testing—it is the only stroke mimic requiring immediate exclusion 2, 3
Read the complete blood count carefully in young stroke patients, as essential thrombocythemia can be missed when platelet elevation is modest 5