Acute Ischemic Stroke Management: Medications, Dosages, and Duration
IV Alteplase (rtPA) - Primary Reperfusion Therapy
Administer IV alteplase 0.9 mg/kg (maximum 90 mg) for eligible patients within 4.5 hours of symptom onset, with 10% given as a bolus over 1 minute and the remaining 90% infused over 60 minutes. 1, 2, 3
Dosing Protocol
- Total dose calculation: 0.9 mg/kg body weight, capped at 90 mg maximum regardless of weight 1, 3
- Initial bolus: 10% of calculated dose (0.09 mg/kg) administered IV push over exactly 1 minute 1, 2, 3
- Continuous infusion: Remaining 90% (0.81 mg/kg) infused over 60 minutes 1, 2, 3
Time Windows and Eligibility
- 0-3 hour window: All eligible adults ≥18 years, including those >80 years old, with no upper age limit 1, 2
- 3-4.5 hour window: Exclude if age >80 years, current oral anticoagulant use (regardless of INR), NIHSS >25, or history of both diabetes AND prior stroke 1, 2
Blood Pressure Management
Pre-Treatment Requirements
Blood pressure must be lowered to <185/110 mmHg before initiating alteplase and maintained <180/105 mmHg for 24 hours post-treatment. 1, 3
Antihypertensive Medications and Dosing
For BP >185/110 mmHg (pre-treatment):
- Labetalol: 10-20 mg IV over 1-2 minutes, may repeat once 1
- Nicardipine: 5 mg/hour IV infusion initially, titrate up by 2.5 mg/hour every 5-15 minutes to maximum 15 mg/hour 1
- Nitropaste: 1-2 inches topically 1
During and after rtPA infusion:
For systolic BP 180-230 mmHg OR diastolic BP 105-120 mmHg:
- Labetalol 10 mg IV over 1-2 minutes, may repeat or double every 10-20 minutes to maximum 300 mg, OR start labetalol drip at 2-8 mg/minute 1
For systolic BP >230 mmHg OR diastolic BP 121-140 mmHg:
For diastolic BP >140 mmHg:
- Sodium nitroprusside 0.5 mcg/kg/minute IV infusion initially, titrate to desired effect 1
Monitoring Schedule
- Every 15 minutes for first 2 hours from start of rtPA 1
- Every 30 minutes for next 6 hours 1
- Every hour for remaining 16 hours (total 24 hours) 1
Temperature Management
Treat temperatures >99.6°F (37.5°C) with acetaminophen; identify and treat sources of hyperthermia. 1
- Antipyretic dosing: Acetaminophen as ordered for temperature >99.6°F 1
- Target: Maintain normothermia; peak temperature >39°C associated with increased in-hospital mortality 1
- Duration: Monitor temperature every 4 hours or as required throughout acute phase 1
Glucose Management
Treat hypoglycemia (blood glucose <60 mg/dL) immediately; maintain blood glucose 140-180 mg/dL during first 24 hours. 1
- Hypoglycemia treatment: IV dextrose for glucose <60 mg/dL 1, 4
- Hyperglycemia management: Target range 140-180 mg/dL to prevent worse outcomes 1
- Critical threshold: Baseline glucose >11.1 mmol/L (200 mg/dL) associated with 36% risk of symptomatic intracranial hemorrhage with thrombolysis 2
Fluid Management
Administer IV normal saline at 75-100 mL/hour; correct hypovolemia to maintain systemic perfusion. 1, 4
- Standard rate: Normal saline 75-100 mL/hour 1
- Hypovolemia correction: Increase rate as needed to restore adequate perfusion 1, 4
- Duration: Continue throughout acute phase with intake/output monitoring 1
Antithrombotic Therapy
Withhold all antithrombotic agents (aspirin, clopidogrel, heparin, warfarin) for 24 hours after rtPA, then initiate as ordered. 1
For Non-Thrombolysis Patients
- Aspirin 150-300 mg: Administer as soon as possible within 48 hours after CT/MRI excludes hemorrhage 1
- Timing: Antithrombotics should be ordered within first 24 hours of hospital admission 1
Post-Thrombolysis Protocol
- No antithrombotics for 24 hours after rtPA completion 1
- Follow-up imaging: Obtain CT or MRI at 24 hours before starting anticoagulant or antiplatelet therapy 2
Oxygen Therapy
Provide supplemental oxygen to maintain oxygen saturation ≥92-94%. 1, 4
- Delivery method: Nasal cannula at 2-3 L/minute for O2 saturation <92% 1
- Target: Maintain oxygen saturation ≥94% 4
- Duration: Continue as needed based on continuous monitoring 1
Neurological Monitoring Protocol
For Thrombolysis-Treated Patients
- Neurological assessment and vital signs (except temperature):
For Non-Thrombolysis Patients
- In ICU: Every hour with neurological checks or more frequently if necessary 1
- In non-ICU: Minimum every 4 hours depending on patient condition 1
Emergency Response Triggers
Call physician immediately for:
- Systolic BP >185 mmHg (pre-rtPA) or >180 mmHg (post-rtPA) 1
- Diastolic BP >105 mmHg (pre-rtPA) or >105 mmHg (post-rtPA) 1
- Severe headache, acute hypertension, nausea, or vomiting during infusion (stop rtPA immediately and obtain emergent CT) 2
- Worsening stroke symptoms or neurological decline 1
Cardiac Monitoring
- Continuous cardiac monitoring: Up to 72 hours or more for thrombolysis patients; 24-48 hours for non-thrombolysis patients 1
- Purpose: Detect atrial fibrillation and life-threatening arrhythmias 1
Activity and Positioning
- Bed rest: Mandatory during acute phase 1
- Head of bed elevation: 25-30° traditionally used for potential increased intracranial pressure; ≥30° if aspiration risk due to dysphagia 1
- NPO status: Keep patient NPO including oral medications until swallowing assessment completed 1
Critical Pitfalls to Avoid
- Never delay rtPA administration to assess for mechanical thrombectomy eligibility 2
- Never administer aspirin or antithrombotics before brain imaging excludes hemorrhage 4
- Never aggressively lower blood pressure in suspected ischemic stroke unless BP >220/120 mmHg (non-thrombolysis candidates) 1, 4
- Never place nasogastric tubes, bladder catheters, or arterial lines during the 24-hour monitoring period after rtPA 2
- Never give rtPA if blood pressure cannot be controlled below 185/110 mmHg pre-treatment 1