Stroke Flashcards
Thrombolysis, which drug and time window
Alteplase. Start within 4,5 hours from symptom onset. Best efficacy within 3 hours.
Alteplase - Dose and route
0,9 mg/kg (max 90mg) - 10% of total dose by bolus followed by remaining of total dose as infusion over 1 hour
Alteplase - MoA
Recombinant forms of human tissue plasminogen activator(t-PA) enzyme, converts plasminogen to plasmin and cause fibrinolysis
Alteplase - Adverse effects
Hemorrhage
Arrhythmias (Bradycardia, Tachycardia)
Alteplase - Contraindications
- Unknown time of onset of symptoms or onset of symptoms after 4,5 hours
- CT that shows intracranial bleeding
- Previous intracranial bleeding
- Known AV- malformation, aneurysm, or intracranial neoplasm
- Blood glucose < 2,8 mmol/L or >22 mmol/L
- Surgery or trauma within last 21 days
- Aortic dissection
- Risk of bleeding, anticoagulation therapy. Can give if INR<1,8
- Systolic blood pressure > 185 mmHg, Diastolic blood pressure > 110 mmHg
Prehospital treatment
- Observe vital function
- Give oxygen 7-10 L/min with mask or 2-3 L/min with nasal catheterization if saturation is <95%
- Slightly raised upper body (15-20 degrees), or position the pt sideways if unconscious
- Give IV fluids (max 1000 mL) if dehydrated, Lower BP if it exceeds 220/120
- Paracetamol 1 g PO if temp >37,5 °C. Don’t give PO if suspicion of swallowing problems.
Medical Treatment of Stroke
Prevent complications of bedridden pts: infections (pneumonia, UTI, skin), DVT with pulmonary embolism.
Heparin (subc), pneumatic compression stockings
BP: lower if it exceeds 220/120 (Esmolol- 500mcg/kg over 1 min IV), malignant HTN, myocardial ischemia, or if BP >185/110 and thrombolytic therapy is anticipated
Fever: antipyretic and surface cooling.
Serum glucose: keep <10,0 mmol/L (180 mg/dL), and above at least 3,3 mmol/L /60 mg/dL) Insulin infusion if necessary.
IV isotonic fluids: maintain intravascular V
Water restriction and IV mannitol: cerebral edema –> brain herniation. Raise the serum osmolarity, but avoid hypovolemia –> hypotension and worsening of infarction. May also perform hemicraniectomy.
Mannitol: 150 mg/ml 0,50-1g per kg
Cerebellar infarction: mimic labyrinthitis because of prominent vertigo and vomiting. Head or neck pain –> cerebellar stroke due to vertebral artery dissection. Small amounts of cerebellar edema can increase the ICP by obstructing CSF flow –> hydrocephalus or compress brainstem –> coma and respiratory arrest; surgical
Antithrombotic treatment
Platelet inhibition: all pts not receiving thrombolytic treatment should get Aspirin 250-300 mg initially in water-soluble form asap –> 75 mg daily
Anticoagulation: pts with acute stroke and atrial fibrillation –> aspirin + anticoagulation (heparin/LMWH) can be started after 4-7 days; more efficient as long-term prophylaxis.
Deep venous thrombosis prophylaxis: Dalteparin 5000 U or enoxaparin 40 mg subcutaneously is recommended
Enoxaparin - Dose and route
40mg x 1 subcutaneoulsy
Enoxaparin - MoA
Inactivate factor X
Enoxaparin - Adverse effects
Bleeding caused by excessive anticoagulation
Heparin induced thrombocytopenia(HIT)
Enoxaparin - Contraindications
Recent bleeding
Recent trauma or surgery
Bacterial endocarditis
Peptic ulcers
Secondary prophylaxis
Antiplatelet agents:
Aspirin (75mg x 1)/Dipyridamole (200mg x 2) and Clopidogrel (75mg x 1)
Anticoagulation agents:
Warfarin for patients with prosthetic heart valve and INR should be less than 2,5. Newer anticoagulation drugs such as Dabigatran, rivaroxaban and apixaban.
Lipidreducing agents:
Statins is recommended for every patient with ischemic stroke if LDL > 2,0 mmol/l.
- Surgery: Carotid endarterectomy (Carotid stenosis), Encovascular stening (carotid disease)
Dipyridamole - MoA
Inhibiting platelet adhesion to the vessel wall.
Dipyridamole - Adverse effects
Headache
Dizziness
Nausea
Thrombocytopenia
Dipyridamole - Contraindications
Caution in patients with hypotension, coronary artery disease.
Clopidogrel - MoA
Adenosine diphosphate inhibitor
Clopidogrel - Adverse effects
Bleeding
Neutropenia
Clopidogrel - Contraindications
Previous intracranial bleeding
Thrombocytopenia
Neutropenia
Lever damage
Warfarin - Dose and route
7,5 mg orally
Warfarin - MoA
Vitamin K antagonist
Warfarin - Adverse effects
Bleeding (mild nose bleed to life threatening hemorrhage)
Fetal warfarin syndrome (bone deformities and bleeding.
Warfarin - Contraindications
Pregnancy (Crosses the placenta and can cause fetal hemorrhage + fetal warfarin syndrome)
Warfarin - Interactions
Interacts with drugs that induce or inhibit cyt P450.
Most serious interactions are with drugs that increase the anticoagulant effect and place the patients at risk of hemorrhage, ex: Salicylates (by reducing prothrombin), cephalosporins
Decrease anticoagulant effect by inducing CYP enzymes that metabolize warfarin: rifampin, barbiturates
Cholestyramine inhibit absorption of warfarin from gut.
Amiodarone, cimetidine, erythromycin, fluconazole, gemifibrozil, isoniazid, metronidazole, sulfinpyrazone inhibit metabolism of warfarin –> increase the risk of bleeding.
Dabigatran - Dose and route
150 mg x 2 orally
Dabigatran - MoA
Direct thrombin inhibitor
Dabigatran - Adverse effects
Increased risk of bleeding
GI complains, dyspepsia, gastritis like symptoms
Dabigatran - Contraindications
Decreased kidney function
Active bleeding
Decreased liver function
Pregnancy and breast feeding
Dabigatran - Interactions
Pgp inhibitors such as amiodarone and verapamil increase the levels of dabigatran
Increased risk of bleeding with use of SSRI or SNRI
Atorvastatin - Dose and route
Normal start dose is 10 mg x 1 orally. Maximal dose is 80 mg x 1.
Atorvastatin - MoA
HMG-CoA Reductase Inhibitor
Atorvastatin - Adverse effects
GI problems; abdominal cramps, constipation, diarrhea, heartburn.
Hepatitis and elevated liver enzymes Rhabdomyolysis Muscle myopathy(earliest stage is myalgia, which consists of muscle ache or weakness without creatine kinase levels)
Myalgia can be followed by myositis or muscle inflammation accompanied by muscle pain, leakage of muscle creatine kinase into the plasma, and elevated creatine kinase levels
Atorvastatin - Contraindications
Because statins , fibric acid derivatives, and niacin may cause myopathies, the combined use of drugs should be undertaken with greater caution using lower doses of each agent employed
Atorvastatin - Interactions
Metabolized by CYP3A4, plasma levels increases strong by inhibitors of this isozyme; erythromycin, itraconazole, ritonavir
Stroke - Diagnosis
Facial drooping, Arm weakness, Speech difficulties, Time to call the ambulance
Check Vitals.
Clinical exam:
-Neurologic exam: localize anatomic site of stroke
- Carotid auscultation, Heart (murmur, dysrhythmia), Extremities (PE), Retina (effect of HTN and cholesterol emboli)
Imaging: immediately
- CT, MRI: Differentiate between hemorrhagic or ischemic stroke + exclude other causes
- CT- MRI angiography: vasculature of neck and intracranial vessels
- ECG: arrhythmia
- CXR
- Transthorasic/Esophageal Echo: Patent F.O, ASD
- Lab: CBC, glucose, CRP, ESR, electrolytes, BUN, INR, PT, PTT, Renal function tests, lipid profile
Holter Monitoring
Stroke pt at hospital >4,5 h <6h - Treatment
Stroke pt at hospital <4,5 h - Treatment
Mechanical thrombectomy
Aspirin
Thrombolysis
Intracerebral hemorrhage - Treatment
Correct coagulopathy:
- Pos takin VKAs: Prothrombin complex concentrated with vit K
- Dabigatra: Idarucizumab
- Xa inhibitors: PCC
- Thrombocytopenia: fresh plasma transfusion
Control HTN- Esmolol if high BP
Increased ICP, hydrocephalus: Osmotic agents
Cerebellar hematoma: Neurosurgery
SAH - Diagnosis
Thunderclap headache
Noncontrast CT within 72 h
LP:
- Blood in CSF –> rupture of aneurysm
- Yellow color of CSF within 6-12 h
X-Ray angiography: anatomic details of anerysm
Electrolyte monitoring: hyponatremia can occur
ECG: ST-segment and T wave changes, Prolonged QRS complex, peaked or deeply innervated T was
Echo: regional wall motion abnormalities
Troponin elevated
Coagulation and platelet count
SAH- Treatment
Aneurysm repair: clipped or coiled, placement of stent
Craniotomy: removing hematoma
Tranexamic acid
Hyponatremia: Oral salt + IV saline
Anticonvulsants as prophylactic therapy
BP should be lowered to 140 in pts with spontaneous ICH: Esmolol
Enoxaparin
Hydrocephalus: CSF drainage, permanent shunt placement
Vasospasm: Nimodipine
Tranexamic acid - MoA
Fibrinolytic (Thrombolytic) drug
Tranexamic acid - Adverse effects
Hemorrhage, Arrhythmia
Tranexamic acid - Interactions
Contraceptive pills –> increased risk of thrombosis
Tranexamic acid - Contraindication
Bleeding, recent surgery/trauma.
Tranexamic acid - Dose
1g IV immediately and 1g after 2 h and then every 6 h until the aneurysm is stabilized
Nimodipine - dose
60 mg PO every 4 h
Nimodipine - Adverse effects
Headache, flushing, hypotension
Nimodipine- Interaction
Excessive hypotensive effect with other hypotensive agents
Itraconazole increases conc
Carbamazepine decreases conc
Nimodipine - Contraindication
Allergic reaction to nimodipine, hypotension
Differential Diagnosis
Todds paralysis Abscess with seizure Tumor with bleed or seizure Toxic-metabolic insult with old cerebral lesion Hypoglycemia Subdural hematoma (acute) Multiple sclerosis cerebritis