Susan R. Winkler, Pharm.D., BCPS
Spring 1998

Cerebrovascular Disease

  1. Intoduction
  2. Classification of Cerebrovascular Disease
  3. Ischemic/Embolic Stroke
  4. Treatment of Cerebrovascular Disease
  5. Hemorrhagic Stroke (SAH)
  6. Case 1
  7. Case 2

Goals and Objectives:

1. List the types of cerebrovascular disease (CVD) and the major causes of each.

2. Discuss the risk factors associated with CVD.

3. Explain the pathophysiology of ischemic and hemorrhagic stroke.

4. Discuss the pharmacologic interventions in CVD.

5. List the goals of therapy in CVD.

Required Reading:

Bradberry JC. Stroke, in Dipiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM (eds): Pharmacotherapy: A Pathophysiologic Approach. Third Edition. New York, Elsevier, 1997. Chapter 20, pp. 435-458.

 

I. INTRODUCTION

Cerebrovascular disease (CVD) includes all disorders in which an area of the brain is transiently or permanently affected by ischemia or bleeding and one or more of the cerebral blood vessels are involved in the pathological process.

CVD is the third leading cause of death after heart disease and malignancy and it is estimated that an average of 500,000 new strokes will occur each year in the USA. CVD is the most disabling of all neurologic diseases. Approximately 50% of survivors have a residual neurologic deficit and greater than 25% require chronic care.

Stroke incidence and mortality are declining primarily due to the successful treatment of HTN and control of risk factors.

 

II. CLASSIFICATION OF CEREBROVASCULAR DISEASE

 

III. ISCHEMIC/EMBOLIC STROKE

A. ANATOMY

1. Carotid Artery distribution-carotid arteries perfuse the majority of the cerebrum

Common Carotid Artery-->splits into the Internal Carotid Artery and the External Carotid Artery, then the Internal Carotid Artery-->divides into the Anterior Cerebral Artery (ACA) and the Middle Cerebral Artery (MCA); both a left and right side are present

a. ACA-supplies the medial surface of the frontal lobe, parietal lobe and occipital lobe

b. MCA-the largest branch of the internal carotid artery

2. Vertebrobasilar Artery distribution-perfuses base of cerebrum and majority of cerebellum

2 Vertebral Arteries-->join to form the Basilar Artery-->branching from the Basilar Artery are the 2 Posterior Cerebral Arteries (PCA)

a. Basilar Artery and PCA-supply the occipital lobe, brain stem and cerebellum

B. CLASSIFICATION OF ISCHEMIC EVENTS

(These are based on the temporal course and eventual outcome.)

1. Transient Ischemic Attacks (TIAs)

a. episodes of a temporary reduction in perfusion to a focal region of the brain causing a short-lived disturbance of function

b. the patient experiences a temporary focal neurological deficit such as slurred speech, aphasia, amaurosis fugax (monocular blindness), or weakness or paralysis of a limb

c. onset is rapid; usually onset is less than 5 minutes

d. duration usually 2-15 minutes; can last up to 24 hours

e. symptoms (vary depending on the CNS anatomy involved)

  1. sensation of swelling or numbness of the hand, arm, or one side of the face or tongue
  2. loss of strength in an arm, hand or leg
  3. difficulties in speaking or reading

f. no neurological deficit remains after the attack

g. one episode in a lifetime to > 20 in one day

h. may be the only warning of an impending stroke

2. Reversible Ischemic Neurological Deficit (RIND)

a. focal brain ischemia in which the deficit improves over a maximum of 72 hours

b. deficits may not completely resolve in all cases

3. Cerebral Infarction

a. permanent neurological disorder; the patient presents with fixed deficits

b. can present in 3 forms:

1. stable-the neurological deficit is permanent and will not improve or deteriorate

2. improving-return of previously lost neurological function over several days to weeks

3. progressing-the neurological status continues to deteriorate following the initial onset of focal deficits; may see a stabilization period, followed by further progression

C. PATHOPHYSIOLOGY

1. Atherosclerosis and subsequent plaque formation results in arterial narrowing or occlusion and is the most common cause of arterial stenosis.

2. Thrombus formation is most likely to occur in areas where atherosclerosis and plaque deposition have caused the greatest narrowing of vessels.

3. Platelet Aggregation

a. exposed subendothelium after injury to vessel

b. vessel collagen is exposed to blood triggering "activation" of platelets

c. release of ADP from activated platelets causes platelet aggregation

d. consolidation of platelet-plug by RBCs, coagulation factors, and formation of fibrin network

e. Thromboxane A2 (TX A2) is produced by platelets and endothelium promoting platelet aggregation and vasoconstriction

4. Coagulation Cascade

a. a series of enzyme complexes located on the surface of platelets and endothelium which lead to thrombin production

b. Thrombin (IIa) then converts Fibrinogen to Fibrin

D. CLINICAL PRESENTATION

Clinically, symptoms depend on the area of cerebral circulation affected and on the extent to which it is affected.

1. Internal Carotid Artery occlusion:

a. no characteristic clinical picture

b. may range from a TIA to infarction of a major portion of the ipsilateral (on the same side) hemisphere

c. if adequate intracranial collateral circulation is present, may see no signs or symptoms

d. Neurological symptoms:

  1. monoparesis to hemiparesis with or without a defect in vision
  2. impairment of speech or language
  3. transient monocular blindness

2. Middle Cerebral Artery occlusion:

a. most occlusions in the first portion of this artery are due to emboli and typically produce a neurological deficit

b. opportunity for collateral circulation is restricted to anastomotic blood flow from the anterior and posterior cerebral arteries on the surface of the brain

c. Neurological symptoms:

  1. hemiplegia (paralysis of one side of the body)
  2. hemisensory deficit
  3. hemianopsia (blindness in 1/2 of the visual field)
  4. aphasia (if infarct is in the dominant hemisphere)

3. Anterior Cerebral Artery occlusion:

a. Neurological symptoms:

  1. weakness of the opposite leg with or without sensory involvement
  2. apraxia (particularly of gait)
  3. possible cognitive impairment

4. Vertebrobasilar system:

a. Neurological symptoms:

  1. severe vertigo, nausea, vomiting, dysphagia, ipsilateral cerebellar ataxia
  2. decreased pain and temperature discrimination
  3. diplopia, visual field loss, gaze palsies

E. RISK FACTORS

1. Hypertension-most important risk factor for all stroke types; no defined BP indicating increased stroke risk, but risk increases proportionately as BP increases.

2. Heart Disease

  1. CHF
  2. CAD
  3. AFib
  4. Rheumatic Heart Disease
  5. LVH

3. TIAs, prior stroke, carotid bruits

4. Increased hematocrit, increased fibrinogen

5. Sickle Cell Disease

6. Lifestyle Factors

  1. Age (older)
  2. Alcohol abuse
  3. Cigarette smoking
  4. Drug abuse
  5. Genetic factors
  6. Males

7. Diabetes Mellitus

8. Migraine HA’s

9. Retinal emboli

IV. TREATMENT OF CEREBROVASCULAR DISEASE

A. GOALS OF THERAPY

1. Stroke prevention through risk-factor reduction.

2. Prevention of initial or recurrent stroke by modifying the underlying pathologic process.

3. Reduction of secondary brain damage by maintaining adequate perfusion to marginally ischemic areas and decreasing edema.

B. TREATMENT OF TRANSIENT ISCHEMIC ATTACKS

1. Eliminate or control risk factors.

2. Education of patient regarding risk-factor reduction and signs and symptoms of TIAs and mild stroke.

3. Surgical Interventions

a. Carotid Endarterectomy (CEA)

  1. surgical removal of the atheromatous plaque
  2. reserved for patients with an ulcerated lesion or clot that occludes > 70% of blood flow in the carotid artery
  3. may decrease risk of stroke by 60% over the two years following the procedure
  4. vertebral endarterectomy no longer used

4. Endovascular procedures

a. Balloon Angioplasty

  1. consists of placing a small deflated balloon in the stenosed vessel
  2. the balloon is then inflated pressing the atheromatous plaque against the wall
  3. has a risk of dislodging emboli that can be carried to the brain or retina

b. Stent Placement

  1. experimental procedure
  2. consists of placing a stainless steel coil into the vessel which then sticks to wall of artery

5. Antiplatelet Agents

a. Aspirin

1.Mechanism of Action

  1. inhibition of platelet aggregation
  2. decreases release of vasoactive substances from platelets
  3. irreversible inactivation of platelet cyclooxygenase; effect lasts for the life of the platelet (5-7 days)

2. Efficacy

  1. ASA has shown clinically significant reductions (22-24%) in stroke risk and death in randomized trials in patients who have experienced a previous TIA or stroke (secondary prevention)
  2. doses have ranged from 50 to 1500 mg/day
  3. more recent trials have evaluated lower doses (30 to 325 mg/day); results indicate that lower doses may be as beneficial with less adverse effects
  4. some studies suggest that ASA is more effective in men than in women (due to small number of women in studies??)
  5. role in primary prevention unclear

b. Dipyridamole (PERSANTINE)

1. Mechanism of Action

  1. weak inhibitor of platelet aggregation
  2. inhibits platelet phosphodiesterase

2. Efficacy

  1. clinical trials have not supported the use of dipyridamole in cerebral ischemia
  2. no additive effect found with aspirin

c. Sulfinpyrazone (ANTURANE)

1. Mechanism of Action

  1. reversible inhibition of cyclooxygenase

2. Efficacy

  1. clinical trials have not supported use

d. Ticlopidine (TICLID)

1. Mechanism of Action

  1. inhibits ADP-induced platelet aggregation
  2. inhibits platelet aggregation induced by collagen, PAF, epinephrine and thrombin
  3. bleeding time prolonged
  4. minimal effect on cyclooxygenase

2. Efficacy

  1. has been shown to reduce the incidence of stroke by approximately 22% in patients who have experienced previous TIAs or stroke
  2. may be more effective than aspirin with less GI effects
  3. no gender difference seen with ticlopidine as with ASA
  4. dosed at 500 mg/day divided into 2 doses (250 mg PO BID)
  5. adverse effects:

1. diarrhea

2. rash

3. increased total serum cholesterol (ratio of HDL:TChol unchanged)

4. neutropenia occurred in 1-2% of patients; must monitor CBC every 2 weeks for the first 3 months of therapy

RECOMMENDATIONS

  1. ASA has been proven to be beneficial in the secondary prevention of TIAs and in decreasing major cerebrovascular events and death; however, the correct dosage is still unknown.
  2. The currently recommended dose of aspirin is 325-975 mg/day.
  3. The role of aspirin in the primary prevention of TIAs and stroke is still unclear.
  4. Ticlopidine has been proven to be effective in the secondary prevention of TIAs and stroke. Due to side effects and cost, it should be reserved for those patients who fail or cannot tolerate ASA.

6. Anticoagulation

a. Warfarin

1. no studies that prove the superiority of anticoagulants over antiplatelet agents

2. may reduce the risk of stroke in patients with a prior MI

3. may be useful in those patients who continue to be symptomatic despite antiplatelet therapy

4. the major exception is in patients with cerebral embolism of cardiac origin

a. chronic anticoagulation with warfarin has been shown to prevent cerebrovascular events in patients with NVAF

b. INR adjusted to between 2.0-3.0

C. Treatment of Acute Cerebral Infarction/Ischemic Stroke

1. Accurate diagnosis is key! A CT Scan must be done to rule out a hemorrhagic stroke before initiation of any treatment.

  1. most patients do not have impaired consciousness in the first 24 hours
  2. if consciousness is impaired, suspect a stroke-related seizure, hemorrhage, hypoxia or increased intracranial pressure

2. Supportive care

  1. Maintain adequate tissue oxygenation: May require airway support and ventilatory assistance. Check for possible aspiration pneumonia.
  2. BP: In most cases, BP should not be lowered. If severe HTN, lower BP cautiously as neurological status may worsen when BP is lowered.
  3. Volume status: Correct for hypovolemia and keep electrolytes in the normal range.
  4. Fever: treat and look for source of fever.
  5. Hypoglycemia/hyperglycemia: Keep under control. Hyperglycemia may worsen the ischemic injury.
  6. DVT Prophylaxis: This is a must as stroke patients have a high risk for DVT! It is important to use either sc heparin 5,000 IU q. 8 or 12 hrs. or sc enoxaparin 30 mg q. 12 hrs. plus early ambulation!

3. Pharmacologic Therapy

  1. Recombinant Tissure Plasminogen Activator (r-tPA) Protocol--(For Select Patients Only!!)

1. efficacy is influenced by the length of time between the onset of the stroke and the initiation of treatment

2. rapid diagnosis and immediate administration of tPA increases its efficacy and may limit the potential for hemorrhagic conversion of ischemic stroke

3. Inclusion Criteria:

  1. ischemic stroke within 3 hours
  1. SBP < 185; DBP < 110

4. Exclusion Criteria:

  1. isolated neurological deficit
  2. another stroke or serious head injury within the previous 3 months
  3. INR > 1.7
  4. use of heparin in the prior 48 hours
  5. major surgery in the prior 14 days
  6. platelet count < 100,000/mm3

5. tPA dose:

  1. 0.9 mg/kg body weight; max. dose 90 mg
  2. give 10% of the dose as a bolus over 1-2 minutes and the rest as a continuous infusion over 1 hour
  3. No antiplatelets or anticoagulants within 24 hours!!

6. Results:

  1. improved outcome with regard to disability and death that persists 3 months after therapy
  2. there is a higher incidence of intracerebral hemorrhage (6.4% vs. 0.6%)
  1. Intra-arterial Thrombolysis

1. early clot lysis and recanalization in about 50% of the patients with intra-arterial streptokinase and urokinase

2. intra-arterial r-pro UK 6 mg given within 6 hours of the stroke resulted in a 58% recanalization rate vs. 14% with placebo

3. main concern is hemorrhagic transformation of the ischemic lesion

4. risk of bleeding may increase with concomitant heparin

5. should still be considered investigational until further data collected

  1. Heparin

1. useful for progressing stroke; questionable role in stable or improving stroke

2. dosing: 50-70 U/kg as a loading dose, followed by 10-25 U/kg/hour; goal PTT 1.5-2.0X control

3. may opt to not use a loading dose in these patients

4. major concerns are conversion of an ischemic stroke into a hemorrhagic stroke secondary to heparin, bleeding and thrombocytopenia

5. careful selection of patients is important

  1. Low-Molecular Weight Heparin (LMWH)

1. Org 10172 has been studied in acute stroke patients

2. synthetic low-molecular-weight fraction of heparin

3. undergoing investigation in several clinical trials

4. less risk of hemorrhage(?) and thrombocytopenia(?)

5. cannot be recommended for treatment until the results of an ongoing multicenter study are reported

  1. Ancrod (ARVIN)

1. derived from the venom of the Malayan pit viper snake

2. enzyme that breaks down fibrinogen to a soluble ancrod-fibrin complex without allowing stabilization of fibrin (fibrin is not cross-linked)

3. may stimulate tPA activation from vascular endothelium

4. causes fibrinolysis soon after administration; low risk of hemorrhagic complications

5. dose: 0.5 U/kg in NS over 6 hours; administered for 7 days following stroke in the clinical trials; titrate to a fibrinogen level of 0.5-1.0 g/L

6. cannot recommend for use until further clinical trials are completed; role in therapy not yet established

4. Investigational Therapies for Acute Ischemic Stroke

  1. Dextran Infusion

1. decreased blood viscosity by volume expansion

2. decreased platelet function

3. decreased blood interaction with endothelium

  1. Prostacyclin

1. potent vasodilator and platelet suppressant

2. has fibrinolytic activity

  1. Calcium Channel Blockers

1. may increase CBF by smooth muscle relaxation

2. may preserve neuronal function by preventing the calcium influx into neurons that occurs during ischemia

3. nimodipine 30 mg PO every 6 hours for 28 days used in clinical trials; nicardipine also evaluated

4. role in therapy not fully known at this time; seems to work best if initiated within 6-8 hours of symptom onset

  1. Hemodilution

1. utilize albumin and fluids to decrease hematocrit to 30- 35% which decreases blood viscosity

2. questionable role in therapy

  1. 21-Aminosteroids (Tirilazad Mesylate-FREEDOX)

1. during ischemia, free radicals are formed which initiate lipid peroxidation

2. 21-aminosteroids are potent inhibitors of lipid peroxidation

3. doses up to 6.0 mg/kg/day divided into 4 doses IV x 5 days have been shown to be beneficial in clinical trials

4. role in therapy not yet defined; studies still ongoing

V. HEMORRHAGIC STROKE (SAH)

Subarachnoid hemorrhage occurs in approximately 26,000 North Americans per year. Most patients range in age from 20-70 years old; however, SAH occurs most frequently in those who are 50-60 years old. The initial hemorrhage is fatal in 20-30% of patients and will ultimately be fatal in 50% of patients. SAH causes permanent neurological disability in 20-50% of survivors. Two-thirds of patients with successful aneurysm clipping never return to the same quality of life as before the SAH. Unlike other types of cerebrovascular diseases, the incidence of SAH has remained about the same for the last 20 years.

A. PATHOPHYSIOLOGY

1. SAH occurs when blood is released into the subarachnoid space surrounding the brain and spinal cord.

B. ETIOLOGY

1. trauma

2. ruptured intracranial aneurysms (75-80%)

  1. Associated with disorders such as congenital weakening of blood vessels, bacterial or fungal infections and hypertension.
  2. The walls of the cerebral blood vessels become weak and an aneurysm forms.
  3. Blood can leak out slowly if the vessel wall is fragile or rapidly if the aneurysm ruptures. The escape of blood into the subarachnoid space causes irritation and damage to brain tissue.

3. arteriovenous malformation (AVM) (4-5%)

  1. An abnormal collection of blood vessels where arterial blood flows directly into draining veins.

4. vasculitis

5. tumor

6. anticoagulants

7. coagulation disorders (ie. hemophilia)

8. no known cause (14-22%)

C. RISK FACTORS FOR SAH

1. hypertension

2. cigarette smoking (3-10X greater risk than in nonsmokers)

3. oral contraceptive use/estrogen use

4. alcohol consumption (binge drinking)

5. pregnancy and parturition/straining exercises

6. drug abuse (cocaine)

D. CLINICAL PRESENTATION

1. Symptoms

  1. severe headache-"the worst headache of my life"
  2. nausea and vomiting
  3. neck pain
  4. nuchal rigidity
  5. photophobia, diplopia
  6. seizures

2. Grading of the severity of SAH

  1. relates to the clinical status of the patient and to the outcome
  2. Hunt and Hess Scale frequently used in clinical practice
  3. Hunt and Hess Scale for Rating Severity of SAH

1. Grade I -----minor headache, minor neck stiffness

2. Grade II ----severe headache, severe neck stiffness, cranial nerve signs, photophobia

3. Grade III ---drowsiness, confusion, mild paresis, mild dysphagia

4. Grade IV ---stuporous, moderate to severe hemiparesis, dysphagia

5. Grade V ----coma, decerebrate rigidity, symptoms of acute midbrain syndrome

3. Diagnosis

  1. Computed Tomography (CT Scan)-used to demonstrate the presence of blood in the subarachnoid space.
  2. Lumbar Puncture (LP)-look for bloody CSF that does not clear.
  3. Angiography-used to establish the presence of an aneurysm and precisely locate it for surgery.

E. COMPLICATIONS AND TREATMENT MEASURES IN SAH

1. Rebleeding

  1. Usually occurs within 2 weeks of the SAH; however, the maximal frequency of rebleeding is in the first day after SAH.
  2. Rebleeding within 2 days occurs in 20% of patients and is associated with 60-70% mortality.
  3. The cause is usually due to rupture of the clot that surrounds the original hemorrhage site.
  4. Symptoms

1. sudden onset of severe headache

2. rapid rise in BP

3. decreased level of consciousness

  1. Prevention of Rebleeding

1. General

  1. Avoid anticoagulants and antiplatelet drugs including salicylates, nonsteroidal anti-inflammatory drugs, ticlopidine, heparin and warfarin.
  2. Avoid rapid reduction of intracranial pressure.
  3. Keep BP low, but avoid a rapid reduction.

2. Surgery

  1. Early surgery-surgical intervention within 3 days of SAH. Eliminates the risk of rebleeding and removal of the clot may decrease the risk of delayed cerebral ischemia.
  2. Late surgery-intervention more than 3 days after SAH.

3. Antifibrinolytic Therapy (controversial)

  1. Aminocaproic acid (Amicar)-blocks activation of plasminogen to plasmin and inhibits the activity of plasmin on the fibrin clot.
  2. Dose: 5 grams IV bolus, followed by a continuous infusion of 1-2 gms/hour for 14-21 days

2. Hydrocephalus

  1. May develop within 1 day or may be delayed for weeks after the initial hemorrhage. The risk of hydrocephalus is associated with the volume and location of blood within the subarachnoid space and ventricular system.
  2. Acute hydrocephalus occurs within 24 hours of the initial hemorrhage and causes a decreased level of consciousness and focal neurological deficits. Late hydrocephalus causes dementia, gait disturbances, and incontinence.
  3. Treatment of Hydrocephalus

1. Surgery

  1. Surgery is the only treatment for hydrocephalus.
  2. A drain is placed to allow CSF to flow outward.
  1. External Ventricular Drain (EVD)
  2. Intraventricular Shunt to the peritoneum (VPS)
  3. Intraventricular Shunt to the aorta (VAS)

3. Delayed Cerebral Ischemia (secondary to vasospasm)

  1. Primary cause of permanent neurological deficits.
  2. Cerebral vasospasm develops in 20-40% of patients during the 2-3 weeks following a SAH and most commonly develops 5-12 days after the initial hemorrhage.
  3. The cause is not well understood; however, it may result from compromised autoregulation causing portions of the brain to become ischemic. It may also result from vasoactive substances that are released from degrading red blood cells (epinephrine, serotonin, and oxyhemoglobin) which may cause arterial narrowing.
  4. Treatment of Delayed Cerebral Ischemia

1. Volume expansion and induction of hypertension ("Triple H Therapy"-hydration, hypertension, hemodilution)

  1. Volume expansion: 0.9% NaCl and 5% serum albumin solutions are used. Endpoint is to maintain PAWP of 15-20 mmHg without causing pulmonary edema.
  2. Induction of hypertension: Dopamine and norepinephrine are used to elevate BP. The goal is to elevate SBP to 200-220 mmHg and maintain it for 7 to 14 days.

2. Calcium Channel Blockers (Nimodipine and Nicardipine)

  1. Mechanism of Action
  1. May improve clinical outcome by limiting fixed neurological deficits.
  2. May inhibit the rapid influx of calcium into ischemic neurons and prevent calcium-induced damage.
  3. May dilate penetrating blood vessels allowing blood to be shunted back to ischemic areas of the brain and re-establish some autoregulation of cerebral blood flow.
  1. Dose

Nimodipine 60 mg PO/NGT every 4 hours for 21 days.

Must be initiated within 3 days of SAH.

3. Angiography with Papaverine

  1. Papaverine, a non-selective muscle relaxant, is injected intra-arterially directly at the site of vasospasm. It is still considered experimental.

4. Angioplasty

4. Seizures

  1. Occur in 5 to 15% of patients with SAH.
  2. Prevention of Seizures

1. Anticonvulsants

  1. Phenytoin is preferred acutely as there is an IV dosage form available and it has minimal effects on mental status.
  2. Dose

1. Loading Dose: 15-20 mg/kg

2. Maintenance Dose: 5-7 mg/kg/day, based on side effects and serum concentrations

  1. If patients do not experience a seizure, may discontinue the anticonvulsant after 3-12 months.
  2. Phenobarbital and Valproic Acid are alternative agents.

Cases - Cerebrovascular disease/Neurosurgery

Case 1

A 57yo WM is brought to ER by paramedics. History is unknown, the following medications were found on the patient:

The patient was found unresponsive on the street. The resident has sent off appropriate labs, the vital signs are stable in this unconscious patient. Appropriate labs include: CBC, SMA-7, ABG, U/A, Pt/PTT).

1.What, if any, pharmacologic intervention would you recommend at this time?

The goals here are the basic management of the unresponsive patient until specific diagnosis can be established:

Can also include:

Lab results to date :

140 108 50
5.1 29 3.0

CBC WNL PT 13.7/12 control

Based upon physical findings and CT scan, the resident diagnoses cerebrovascular disease. What intervention would you recommend for:

2. Stroke in evolution (also known as progressing stroke)?

Maintain A-B-Cs

Consider hyperperfusion to maintain cerebral blood flow - this can be accomplished by infusion of hyperosmotic agents to force perfusion through compromised vessels, and example would include mannitol or hemodilution.

Once hemorrhage is ruled out, the patient can be started on anticoagulation for thromboembolic stroke - the most rapid onset, and therefore preferred, agent would be heparin infusion. The anticoagulation goal would be PTT 1.5-2 times baseline control. You might hesitate, though since the patient has a prescription vial for cimetidine.

Blood pressure should be closely regulated, whether hemorrhagic of thromboembolic stroke. A reasonable goal to maintain cerebral blood flow would be a systolic blood pressure of 130-150. The best agent to select would be one which is rapidly titratable, ie., sodium nitroprusside.

Due to the patient's history of hypertension and acute stroke, nimodipine may be a very reasonable selection for acute intervention. The recommended dose acutely is 30mg Q6 hrs. Monitoring parameters and dose limitations for this dihydropyridine compound would include control of blood pressure and prevention of hypotension.

Steroids may be suggested for ischemia-associated cerebral edema, although benefit is questionable.

Anticonvulsant prophylaxis is a reasonable consideration.

An addition patient-specific concern in this particular patient involves his decreased renal function, and specific attention to drug selection and monitoring parameters.

3. Completed Stroke?

Maintain A-B-Cs

Maintain CBF (cerebral blood flow)

Blood pressure regulation

Theophylline and cimetidine assessment

Hyperperfusion once the stroke is completed is probably not beneficial. Occasionally clinicians will recommend hyperperfusion in selected very compromised patients, with the hope that this hyperperfusion will enhance formation of collateral circulation. This is very risky and should not be routinely recommended.

Antiplatelet therapy longer term for preventing further cerebrovascular problems is probably a good choice.

Need to consider anticonvulsants and steroids.

Over the next 24 hours the patient's symptoms resolve completely.

The prevailing diagnosis is TIA.

4. Discuss medical intervention in this patient, include advantages and disadvantages.

Control blood pressure

Anticoagulation-

Beneficial for new onset TIAs

Acutely with heparin/overlap with warfarin therapy change over to antiplatelet agents after 12 months

Consider cimetidine prescription in this patient -

? history of PUD, assess bleeding risk in patient with already mildly elevated

PT, increase in BUN prior to treatment

Consider patient education concerns and drug interaction.

Antiplatelet agents-

May be beneficial longer term with less risk of bleeding.

If symptoms of progressing disease, antiplatelet agents are probably not useful anticoagulation or surgical intervention may be indicated.

Neurology consultation differs with the resident - Neurology diagnoses cerebral edema secondary to tumor. The patient is then transferred to the Neurology Service. The patient deteriorates with signs of severely increased ICP.

5. Discuss the various modes of intervention for acute severe increased ICP in this unconscious patient.

A-B-Cs

Fluid restriction 1/2 to 2/3 maintenance.

Elevate head of the bed 30 degrees

Consider loop diuretic first, should be cautious about osmotic agents, due to decreased renal function.

Steroids dexamethasone 10mg IV Q6 hrs

Hyperventilation is fastest intervention to pCO2 24-28

May additionally consider:

Removal of CSF - via lumbar puncture/tap or shunt

barbiturate coma

surgical decompression of tumor is probably best, although drug therapy interventions would buy time to prepare the patient for emergent surgery.

Case 2.

A 57yo WM is brought to the ER by paramedics who found him in an alley - a victim of blunt trauma to his head and body. Past medical history is not available. The following medications were found on the patient:

Pertinent PE:

WDWN male responsive only to deep pain

bp 220/110 HR 105 RR 8 T 97.8

HEENT:

cor S1 S2 S3, no S4, ? mitral stenosis

1. CT scan reveals diffuse cerebral edema and no evidence of hematoma at this time. The physician asks you for recommendations to manage this patient's problem - be specific (drug, dose, monitoring parameters).

Make sure that basic A-B-Cs are maintained in this patient with complex medical history (from medications)

Management of cerebral edema:

a. Non-pharmacologic

bedrest

head of bed elevated 30 degrees

if intubated for ventilatory support (RR 8), use hyperventilation to pCO2 24-28

b. Pharmacologic

fluid restriction to 2/3 to 3/4 maintenance fluids

mannitol

0.25 - 0.5 gm/kg Q4 hrs IVPB using 20% solution

monitoring parameters:

  • fluid balance I/O
  • serum and urine osmolality
  • electrolytes, esp Na, K
  • renal function and urine output

additional considerations:

  • anticonvulsant prophylaxis for post-traumatic seizures
  • evaluate for other signs of trauma
  • antibiotics for open wound - need to cover skin flora, tetanus

2. Day 3 in the hospital, the patient develops R sided hemiparesis of upper and lower extremities. What are the risk factors for cerebrovascular disease in this patient?

Risk factors include possibly history of

3. How would you manage this patient's completed stroke?

Poor candidate for anticoagulation with recent trauma, and history of antacid use (consider potential GI bleed). Best alternative to help prevent further stroke injury would be aspirin. This patient should probably be treated since he has bilateral carotid bruits, and other risk factors.


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