|Noncontrast brain CT or brain MRI|
|Serum electrolytes/renal function tests*|
|Complete blood count, including platelet count*|
|Markers of cardiac ischemia*|
|Activated partial thromboplastin time*|
|TT and/or ECT if it is suspected the patient is taking direct thrombin inhibitors or direct factor Xa inhibitors|
|Hepatic function tests|
|Blood alcohol level|
|Arterial blood gas tests (if hypoxia is suspected)|
|Chest radiography (if lung disease is suspected)|
|Lumbar puncture (if subarachnoid hemorrhage is suspected and CT scan is negative for blood|
|Electroencephalogram (if seizures are suspected)|
CT indicates computed tomography; ECG, electrocardiogram; ECT, ecarin clotting time; INR, international normalized ratio; MRI, magnetic resonance imaging; and TT, thrombin time.
↵* Although it is desirable to know the results of these tests before giving intravenous recombinant tissue-type plasminogen activator, fibrinolytic therapy should not be delayed while awaiting the results unless (1) there is clinical suspicion of a bleeding abnormality or thrombocytopenia, (2) the patient has received heparin or warfarin, or (3) the patient has received other anticoagulants (direct thrombin inhibitors or direct factor Xa inhibitors).