**6. Thrombolysis**

The goal of reperfusion therapy for acute ischaemic stroke is prompt restoration of blood flow to regions of brain that are ischemic but not yet infarcted. This reduces the volume of brain damage, reduces oedema and improves outcome. The use of intravenous recombinant tissue plasminogen activator was approved by the US FDA in 1996 for use in acute ischaemic stroke patients presenting within 3 hours of stroke onset [50]. Its use is associated with favourable outcomes although increased risk of intracranial haemorrhage has been observed [16].

Intravenous recombinant tissue plasminogen activator (IV rt-PA) is administered when an acute stroke patient meets all of the inclusion criteria and none of the absolute exclusion criteria. The dose of the IV rt-PA is 0.9 mg/kg (maximum dose 90 mg). Infuse 0.9 mg/kg over 60 minutes, with 10% of the dose given as a bolus over one minute. Patient should be admitted into the intensive care unit or stroke unit for close monitoring. The infusion should be discontinued if the patient develops severe headache, acute hypertension, nausea, or vomiting or has a worsening neurological examination. An emergent CT scan should be requested for. Blood pressure monitoring and neurological assessment are carried out every 15mins during and after the administration of the IV rt-PA infusion for 2 hours, then every 30 minutes for 6 hours, then hourly until 24 hours after IV rt-PA treatment [16].

#### **Inclusion criteria**

28 days. Clopidogrel at a dose of 75 mg was found to have a risk reduction of 8.7% in the prevention of cerebrovascular and cardiovascular events [42]. Various studies have shown that the combination of dipyridamole and aspirin is superior to aspirin alone as an antithrombotic

Heparin is not indicated for routine use in the treatment of acute ischaemic stroke. Some of the indications for its use include cerebral venous thrombosis, acute infarct with high grade carotid stenosis, cardiogenic emboli with high risk of recurrence, hypercoagulable states such as protein C deficiency, protein S deficiency, antithrombin III deficiency and antiphospholipid antibody syndrome. Other anticoagulants include warfarin which is useful in the prevention of stroke recurrence in atrial fibrillation patients [45]. Dabigatran has also been found

Statins have been observed to be efficacious in both primary and secondary prevention of stroke independent of cholesterol levels. This might be due to other beneficial effects of statins such as stabilization of atherosclerotic plaques, improvement of endothelial function, antioxidant properties, increased nitric oxide bioavailability, inhibition of inflammatory responses and immunomodulatory actions [47, 48]. The use of Statin early in stroke patients has been found to be strongly associated with improved post stroke survival, and discontinuation of

The goal of reperfusion therapy for acute ischaemic stroke is prompt restoration of blood flow to regions of brain that are ischemic but not yet infarcted. This reduces the volume of brain damage, reduces oedema and improves outcome. The use of intravenous recombinant tissue plasminogen activator was approved by the US FDA in 1996 for use in acute ischaemic stroke patients presenting within 3 hours of stroke onset [50]. Its use is associated with favourable outcomes although increased risk of intracranial haemorrhage has been observed [16].

Intravenous recombinant tissue plasminogen activator (IV rt-PA) is administered when an acute stroke patient meets all of the inclusion criteria and none of the absolute exclusion criteria. The dose of the IV rt-PA is 0.9 mg/kg (maximum dose 90 mg). Infuse 0.9 mg/kg over 60 minutes, with 10% of the dose given as a bolus over one minute. Patient should be admitted into the intensive care unit or stroke unit for close monitoring. The infusion should be discontinued if the patient develops severe headache, acute hypertension, nausea, or vomiting or has a worsening neurological examination. An emergent CT scan should be requested for. Blood pressure monitoring and neurological assessment are carried out every 15mins during and after the administration of the IV rt-PA infusion for 2 hours, then every 30 minutes for

6 hours, then hourly until 24 hours after IV rt-PA treatment [16].

to reduce the occurrence of stroke among non-valvular atrial fibrillation patients [46].

statin, even for a brief period, has been associated with worsened survival [49].

therapy after cerebral ischemia of arterial origin [43, 44].

**5.8. Anticoagulant therapy**

234 Essentials of Accident and Emergency Medicine

**5.9. Statins**

**6. Thrombolysis**

Diagnosis of ischemic stroke causing measurable neurological deficit

Onset of symptoms <3 hours before beginning treatment

Aged ≥18 years

#### **Exclusion criteria**

Significant head trauma or prior stroke in previous 3 months

Symptoms suggest subarachnoid haemorrhage

Arterial puncture at non-compressible site in previous 7 days

History of previous intracranial haemorrhage

Intracranial neoplasm, arteriovenous malformation, or aneurysm

Recent intracranial or intraspinal surgery

Elevated blood pressure (systolic >185 mm Hg or diastolic >110 mm Hg)

Active internal bleeding

Acute bleeding diathesis, including but not limited to

Platelet count <100,000/mm<sup>3</sup>

Heparin received within 48 hours, resulting in abnormally elevated aPTT greater than the upper limit of normal

#### **Relative exclusion criteria**

 Recent experience suggests that under some circumstances—with careful consideration and weighting of risk to benefit—patients may receive fibrinolytic therapy despite 1 or more relative contraindications. Consider risk to benefit of IV rt-PA administration carefully if any of these relative contraindications are present:

Only minor or rapidly improving stroke symptoms (clearing spontaneously)

Pregnancy

Seizure at onset with postictal residual neurological impairments

Major surgery or serious trauma within previous 14 days

Recent gastrointestinal or urinary tract haemorrhage (within previous 21 days)

Recent acute myocardial infarction (within previous 3 months)

Adapted from Guidelines for the early management of patients with acute ischaemic stroke. Stroke 2013.

The checklist includes some FDA-approved indications and contraindications for administration of IV rt-PA for acute ischemic stroke. Recent guideline revisions have modified the original FDA-approved indications. A physician with expertise in acute stroke care may modify this list.

Onset time is defined as either the witnessed onset of symptoms or the time last known normal if symptom onset was not witnessed.

In patients without recent use of oral anticoagulants or heparin, treatment with IV rt-PA can be initiated before availability of coagulation test results but should be discontinued if INR is >1.7 or PT is abnormally elevated by local laboratory standards.

In patients without history of thrombocytopenia, treatment with IV rt-PA can be initiated before availability of platelet count but should be discontinued if platelet count is <100,000/mm<sup>3</sup> .

aPTT indicates activated partial thromboplastin time; CT, computed tomography; ECT, ecarin clotting time; FDA, Food and Drug Administration; INR, international normalized ratio; IV, intravenous; PT, partial thromboplastin time; rt-PA, recombinant tissue plasminogen activator; and TT, thrombin time.

**Table 1.** Inclusion and exclusion characteristics of patients with ischemic stroke who could be treated with IV rtPA within 3 hours from symptom onset.

#### **Inclusion criteria**

Diagnosis of ischemic stroke causing measurable neurological deficit

Onset of symptoms within 3 to 4.5 hours before beginning treatment

**Relative exclusion criteria**

Aged >80 years

Severe stroke (NIHSS>25)

Taking an oral anticoagulant regardless of INR

History of both diabetes and prior ischemic stroke

INR indicates international normalized ratio; IV, intravenous; NIHSS, National Institutes of Health Stroke Scale; and rt-PA, recombinant tissue plasminogen activator.

stroke with an incidence of 2.5% and 1.2% respectively [54]. The risk of DVT/PE is increased in immobile and elderly patients with severe stroke [55]. Pressure sores are also common and have been attributed to poor nursing care. Stroke patients should therefore be turned frequently at 2-hourly interval to prevent this complication. Water bed can also be used.

Emergency Management of Acute Ischaemic Stroke http://dx.doi.org/10.5772/intechopen.75305 237

Ischaemic stroke remains the commonest type of stroke worldwide. Its successful treatment is dependent on prompt restoration of blood flow to the penumbral tissue. Other supportive therapies have also been helpful in ensuring a favourable outcome. This was an overview of

This refers to bleeding into the brain parenchyma. Intracerebral haemorrhage is a devastating disease with increased morbidity and mortality constituting 15% of all stroke types [56, 57]. Factors associated with increased mortality include large clots, low Glasgow Coma Scale score, intraventricular haemorrhage and haematoma expansion. The causes of haematoma growth include a past history of stroke, liver disease, hyperglycaemia and hypertension [58]. The com-

Causes of ICH have been classified into primary and secondary. Hypertension remains the most common modifiable risk factor for the development of ICH [59, 60] while cerebral amyloid angiopathy is the second most frequent risk factor in ICH leading to lobar haemorrhages . Other risk factors include increasing age, anticoagulation therapy, AV malformations, and aneurysms [61].

The symptoms are usually sudden in onset; most times occurring during exercise or emotional stress although it can also occur during routine activity [61, 62]. It is difficult, on the basis of clinical presentation, to distinguish ICH from ischaemic stroke as they may look similar.

Presentation of ICH differs depending on the size and location of the ICH. Symptoms that may suggest ICH include severe headache, vomiting, seizures, reduced level of consciousness. Headache is more frequent in patients with large haematomas and has been attributed to raised intracranial pressure and traction on the meningeal pain fibres. Small, deep haematomas rarely present with headache. [61]. About 15–23% of patients tend to have haematoma

expansion and neurological deterioration in the first few hours of the event [63, 64].

mon sites for ICH include the basal ganglia, thalamus, brain stem and the cerebellum.

**9. Conclusion**

**10.1. Introduction**

**10.2. Causes**

**10.3. Clinical features**

the management of the condition.

**10. Intracerebral haemorrhage (ICH)**

**Table 2.** Additional inclusion and exclusion characteristics of patients with acute ischemic stroke who could be treated with IV rt-PA within 3 to 4.5 hours from symptom onset.

Placement of nasogastric tubes, indwelling bladder catheters, or intra-arterial pressure catheters should be delayed if the patient can be safely managed without them. A follow-up CT or MRI scan should be obtained at 24 hours after IV rt-PA before commencing anticoagulants or antiplatelets (**Tables 1** and **2**).

#### **7. Endovascular treatments**

This modality of treatment for acute ischaemic stroke is fast emerging. Mechanical clot retrieval with MERCI device (Mechanical Embolus Removal in Cerebral Ischaemia) has been employed. Other interventions have included mechanical clot aspiration with the Penumbra system. The Penumbra System (PS) is a new embolectomy device specifically designed to remove the thrombus in acute ischemic stroke secondary to large vessel thromboembolism. The device removes the thrombus through two mechanisms: aspiration and extraction [16]. Earlier trials, Trevo versus Merci Retrievers for Thrombectomy Revascularization of Large Vessel Occlusions in Acute Ischaemic Stroke (TREVO 2) and SWIFT, showed significantly higher recanalization rates associated with stent retriever devices compared to the first generation Merci Retriever [51, 52].

#### **8. Complications**

Patients who have sustained a stroke are prone to developing complications. About 30–60% of patients after acute ischaemic stroke develop these complications. The most frequent complications include respiratory and urinary tract infections, deep vein thrombosis (DVT) and pulmonary embolism (PE) [53]. Pulmonary embolism occurs in about 10% of patients post stroke. Deep vein thrombosis and pulmonary embolism tend to occur in the first three months post stroke with an incidence of 2.5% and 1.2% respectively [54]. The risk of DVT/PE is increased in immobile and elderly patients with severe stroke [55]. Pressure sores are also common and have been attributed to poor nursing care. Stroke patients should therefore be turned frequently at 2-hourly interval to prevent this complication. Water bed can also be used.
