1. Stroke: Management of Adverse Effects
Presented by: F. Covert RN, BSN

2. Vasodilator Therapy

3. Review: Blood Pressure
Blood pressure is the amount of force (pressure) applied to the artery walls.
Systolic: The force applied to arterial walls during ventricular systole.
Diastolic: The force applied to arterial walls during ventricular diastole.

4. Hypertension
Chronic hypertension aggravates atherosclerosis and increases vascular resistance (vasoconstriction) within the brain.
Positive effects: Increased vascular resistance protects the brain from the damaging effects of systemic hypertension.
Negative effects: Predisposes the brain to cerebral ischemia by impairing vasodilator responsiveness. When diastolic BP exceeds 120mmHg, the ischemic brain is at high risk of hemorrhage.

5. Acute on Chronic Hypertension
Acute increases in blood pressure superimposed on a chronic hypertensive state.
Approximately 50% of all patients positive for an acute ischemic stroke will have a history of preexisting hypertension.
On average these individuals will have higher blood pressures post acute stroke than those who were previously normotensive.

6. Blood Pressure Management
Treatment of hypertension should be done very cautiously.
Neurological deterioration has been associated with precipitous decreases in blood pressure induced by emergency antihypertensive treatment.
When blood pressure drops below the lower limit of cerebral blood flow auto-regulation it causes more widespread cerebral hypoperfusion.

7. Blood Pressure Monitoring Ischemic Stroke: Post tPA
Vital Signs:
Every 15 minutes for 2 hours from start of tPA then,
Every 30 minutes for 6 hours then,
Hourly for the next 16 hours
Temperature is monitored every 4 hours for 24 hours.

8. Blood Pressure Monitoring Hemorrhagic Stroke: Intra-cerebral Bleed
Vital Signs:
Hourly for 24 hours then,
Every 4 hours ongoing

9. Utilized in Ischemic and Hemorrhagic Stroke Standing Orders
Labetalol (Trandate)
Potent alpha and beta blocker
Slows heart rate and decreases peripheral vascular resistance
Use cautiously in patients with constrictive airway diseases
IVP: Given over 1-2 minutes in 10mg increments, can be repeated every minutes (max dose 300mg)
Drip: Give a 10mg bolus, followed by a drip started at 2-8mg/min
Can be administered in ICU/CCU, ED, PACU, AMB Surgery, Radiology, Cardiology
Utilized in Ischemic and Hemorrhagic Stroke Standing Orders

10. Nicardipine (Cardene)
Calcium channel blocker
Decreases systemic vascular resistance and blood pressure
Administered as an IV infusion, started at 5mg/hour and may be increased by 2.5mg/hour every 15 minutes (max 15mg/hour)
Contraindicated for patient’s with conduction deficits (i.e. Second/Third degree heart blocks)
Can be administered in ICU/CCU and ED
Utilized in Ischemic and Hemorrhagic Stroke Standing Orders

11. Nitroprusside (Nipride)
Potent vasodilator used in emergent hypertensive conditions
Acts directly on venous and arterial smooth muscle
Administer as an IV drip beginning at 0.3mcg/kg/min, titrate by 0.2mcg/kg/min to desired MAP (max 10mcg/kg/min)
Monitor closely for cyanide toxicity
Can be administered in ICU/CCU and ED
Utilized in the Hemorrhagic Stroke Standing Orders, recommended for consideration in Ischemic Strokes.

12. Cyanide Toxicity
Signs and Symptoms: Nausea, vomiting, diaphoresis, apprehension, headache, restlessness, muscle twitching, dizziness, palpitations, retrosternal pain and/or abdominal pain.
If this occurs, stop the infusion and symptoms should resolve within 10 minutes, if not then effects are from another source.

13. Utilized in the Hemorrhagic Stroke Standing Orders.
Enalapril (Vasotec)
An ACE-inhibitor that prevents the conversion angiotensin I to II, preventing vasoconstriction
Decreases peripheral arterial and venous resistance
Administered IVP at mg every 6 hours as needed
Contraindicated in patients with hypersensitivity or allergy to ACE-inhibitors
Can be administered in ICU/CCU, ED, PACU, 2CN, AMB Surgery, Radiology, Cardiology
Utilized in the Hemorrhagic Stroke Standing Orders.

14. Hydralazine (Apresoline)
Potent vasodilator with direct vasodilating effects on the arterioles
Administered IVP in doses of 5-20mg every six hours as needed
Contraindicated in patient’s with Rheumatic Heart disease
Can be administered in ICU/CCU, PACU, ED, AMB Surgery, 2CN, Birthing Center, Radiology, Cardiology
Utilized in Hemorrhagic Stroke Standing Orders.

15. Volume Expansion

16. Post-Hemorrhagic Stroke
Patients are at an increased risk for cerebral vasospasm after spontaneous subarachnoid hemorrhage
Medically induced hypertension has proven to reduce vasospasm post bleed
Methods:
Intra-vascular volume expansion: Used to stabilize vessel walls from spasm/collapse
Vasopressor support: Vessels are less likely to spasm while acutely constricted
Administration of anti-diuretics: Assist in the retention of fluids to stabilize vessel walls

17. Cerebral Ischemia
Utilization of intra-vascular volume expansion and induced hypertension are effective in reversing ischemic deficits from vasospasm, provided that the treatment commences before the cerebral infarction occurs. If not, ultimately it can be used to prevent further ischemic damage to the cerebrum post infarct.

18. References
Phillips, S. (2004). Pathophysiology and management of hypertension in acute ischemic stroke. Hypertension, 23,
Miller, E.L., Murray, L., Richards, L., et al. (2010). Comprehensive overview of nursing and interdisciplinary rehabilitation care of the stroke patient. Stroke, 41,
I.V. Push Medication Guidelines. Garden City Hospital department of pharmacy (2010).