Contraindications for TPA Administration

• General Contraindications

  • Risk of causing a bleed is higher than the possibility of dissolving a clot.

  • TPA is contraindicated if the time since onset of symptoms is longer than four and a half hours.

  • If the exact time of symptom onset is unknown, supportive therapy is preferred to weigh the risks and benefits of TPA use.

• Specific Contraindications

  • INR Threshold

  • TPA is contraindicated for patients with an INR (International Normalized Ratio) greater than 1.7.

  • Patients on anticoagulation therapy with elevated INR are at a significant risk for bleeding, making TPA unsafe.

  • Recent Head Trauma

  • Contraindicated in patients who have experienced a stroke or major head injury within the past three months.

TPA Administration and Protocols

• Weight-based Calculation

  • TPA doses are calculated based on patient weight, although exact calculations are rarely tested on exams.

• IV Requirements

  • A minimum of two IV sites is required for TPA administration:

  • One for TPA infusion.

  • One for fluids.

  • More than two IV sites are encouraged if possible.

• Infusion Protocol

  • Ten percent of the TPA dose must be administered within the first minute.

  • The remaining ninety percent of the dose is given over one hour.

• Monitoring During Administration

  • Continuous monitoring of vital signs, including blood pressure, is essential.

  • Frequent neurological checks during TPA infusion:

  • Every 15 minutes during the infusion.

  • Every 30 minutes for the first 6 hours post-infusion.

  • Every hour for 24 hours after infusion.

• Blood Pressure Management

  • Maintain blood pressure below $185/110$ mmHg during TPA infusion to ensure adequate perfusion to the brain.

  • Higher blood pressure is necessary to allow blood flow past the clot for adequate brain perfusion.

Case Example

• Patient Case

  • Described a patient who experienced a severe headache and loss of peripheral vision.

  • High blood pressure was a factor, resulting from not taking medication and consuming alcohol, which thinned the blood.

Post-Stroke Management

• Transitional Care Focus

  • Management of self-care deficits, especially swallowing and prevention of aspiration.

  • Education regarding dietary modifications, such as pureed foods and thickened liquids.

  • Communication strategies for addressing confusion.

• Positioning Recommendations

  • Position the head of the bed elevated between 30 to 45 degrees to prevent aspiration.

• Early Intervention Techniques

  • Focus on proper hand positioning and limb mobility to preserve function.

Types of Stroke: Hemorrhagic vs. Ischemic

• Intracerebral Hemorrhage

  • Major cause is spontaneous rupture of small vessels due to uncontrolled hypertension.

  • More common in older adults.

  • Other causes include:

  • AVMs (arteriovenous malformations).

  • Trauma, brain tumors, certain illicit drugs.

• Subarachnoid Hemorrhage

  • Defined as bleeding into the space between the brain and skull.

  • Causes include:

  • Ruptured aneurysms.

  • Congenital AVMs.

  • Trauma and hypertension.

  • Complications include increased intracranial pressure (ICP), loss of consciousness (LOC), and vasospasms.

Aneurysms

• Aneurysms involve weakening and ballooning of artery walls, often due to:

  • Atherosclerosis, hypertension, congenital defects, trauma, and aging.

  • Hemorrhagic strokes can lead to:

  • Compression of brain tissue.

  • Increased ICP and secondary ischemia.

Arteriovenous Malformations (AVMs)

• Congenital blood vessel abnormalities characterized by a tangle of arteries and veins without a capillary bed.

  • Can lead to hemorrhagic strokes if ruptured.

  • Patients often unaware of these malformations until stroke symptoms occur.

Signs and Symptoms of AVMs

• If the patient is conscious:

  • Severe and sudden headache.

  • Nausea and vomiting due to increased ICP.

  • Changes in LOC and possible seizures.

Initial Assessment for Stroke

• Use NIH Stroke Scale assessments and non-contrast CT to differentiate between ischemic and hemorrhagic strokes.

• After determining stroke type, cerebral angiography may be performed to identify possible aneurysms or AVMs.

Management of Hemorrhagic Stroke

• Limited interventions focus predominantly on support.

• Emphasis on prevention of complications such as rebleeding and addressing increases in ICP early on.

Complications of Hemorrhagic Stroke

• Vasospasms

  • Characterized by narrowing of cerebral arteries, especially after subarachnoid hemorrhages.

  • Peak risk occurs between three and fourteen days post-hemorrhage.

  • Signs include worsened headache, decreased LOC, and new neurological deficits.

  • New deficits indicate possible vasospasm.

• Medical Management for Vasospasms

  • Calcium channel blocker: Nimodipine (n-i-m-o-d-i-p-i-n).

  • Surgical interventions to clip aneurysms or AVMs can prevent further bleeding and complications.