tPA

Question 1

Indications - tPA

Answer 1

❑ Management of acute MI through lysis of thrombi obstructing coronary arteries.
❑ Management of acute ischemic stroke through lysis of thrombi obstructing cerebral arteries.

Question 2

Dosage - tPA for a STEMI

Answer 2

STEMI: Accelerated infusion (1.5 hours) – Give 15 mg IV bolus; then 0.75 mg/kg over the next 30 min (not to exceed 50 mg); then 0.5 mg/kg over 60 min (not to exceed 35 mg); Max total dose or 100mg

Question 3

Dosage tPA - for an acute ischemic stroke

Answer 3

Acute Ischemic Stroke: Give 0.9 mg/kg (maximum 90 mg) IV, infused over 60 minutes; give 10% of total dose as an initial IV bolus over 1 min; give remaining 90% of total dose IV over next 60 minutes.

Question 4

Contraindications - tPA

Exclusion Characteristics of Patients With Ischemic Stroke Who Could Be Treated With tPA Within 3 Hours From Symptom Onset:

Answer 4

❑ Head trauma or prior stroke in previous 3 months
❑ Symptoms suggest subarachnoid hemorrhage
❑ Arterial puncture at non-compressible site in previous 7 days
❑ History of previous intracranial hemorrhage
❑ Elevated blood pressure (systolic > 185 mm Hg or diastolic > 110 mm Hg)
❑ Evidence of active bleeding on examination
❑ Acute bleeding diathesis, including but not limited to
▪ Platelet count < 100 000/mm3
▪ Heparin received within 48 hours, resulting in aPTT > upper limit of normal
▪ Current use of anticoagulant with > INR 1.7 or PT 15 seconds
❑ Blood glucose concentration < 2.7 mmol/L
❑ CT demonstrates multilobar infarction (hypodensity > 1/3 cerebral hemisphere)

Question 5

Contraindications - tPA

Additional Exclusion Characteristics of Patients With Ischemic Stroke Who Could Be Treated With tPA From 3 to 4.5 Hours From Symptom Onset:

Answer 5

❑ Age > 80 years
❑ Severe stroke (NIHSS > 25)
❑ Taking an oral anticoagulant regardless of INR
❑ History of both diabetes and prior ischemic stroke

Question 6

Contraindications - tPA

For fibrinolytic use in STEMI

Answer 6

❑ Any prior intracranial hemorrhage
❑ Known structural cerebral vascular lesion (e.g., AVM)
❑ Known malignant intracranial neoplasm (primary or metastatic)
❑ Ischemic stroke within 3 months EXCEPT acute ischemic stroke within 3 hours
❑ Suspected aortic dissection
❑ Active bleeding or bleeding diathesis (excluding menses)
❑ Significant closed head trauma or facial trauma within 3 months