Makindo Medical Notes.com

Related Subjects: |Hypertension |Cardiac Thrombolysis |Stroke Thrombolysis |Alteplase |Tenecteplase |Streptokinase |Reteplase

Time is brain so Thrombolysis as quickly and as safely as possible

CLINICAL FINDINGS - ALL MUST BE NO TO THROMBOLYSE

• Is the patient comatose ?
• Are there rapidly resolving symptoms
• Is there pathology likely (e.g. brain tumour , septic embolus etc)
• Is there Uncontrolled hypertension (systolic >185mg or diastolic >110mg) even despite treatment
• Is the N.I.H. Score < 4 or >=25 (caution >22)
• Is there Fixed head or eye deviation

EXCLUSION CRITERIA ALL MUST BE NO TO THROMBOLYSE

• Seizure at stroke onset
• Symptoms suggestive of SAH even if CT normal
• Recent puncture of an artery or non-compressible blood-vessel (e.g. subclavian or jugular vein puncture) or lumbar puncture within 7 days
• Traumatic cardiopulmonary resuscitation less than 10 days
• Surgery or visceral biopsy within previous 4 weeks
• History of recent bleeding
• Pregnant or could they be or childbirth within the previous 4 weeks
• Breastfeeding - can treat if agrees to stop breastfeeding temporarily
• Head injury at the time of stroke or in past 3 months
• Significant trauma(fracture or internal injuries) in past 3 months
• Major surgery in past 3 months
• Ischaemic Stroke within the last 3 months
• Haemorrhagic stroke at any time in the past
• Documented ulcerative gastrointestinal disease during the last 3 months, oesophageal varices, active peptic ulcer disease
• Severe liver disease, including hepatic failure, cirrhosis, portal hypertension ( oesophageal varices) and active hepatitis, Pancreatitis
• Neoplasm with increased bleeding risk
• Intracranial neoplasm, Arteriovenous malformation,or aneurysm
• Endocarditis, pericarditis, arterial-aneurysm, arterial/venous malformations aortic aneurysm or ventricular aneurysm
• Any known bleeding problem/ blood disorder
• Haemorrhagic retinopathy (e.g. untreated proliferative diabetic retinopathy)
• History of any past stroke and diabetes mellitus
• On Warfarin (INR>1.4) or equivalent anticoagulation
• Administration of Heparin or equivalent within the previous 48 hours and an APTT exceeding the upper limit of normal for laboratory

CT FINDINGS - ALL MUST BE NO TO THROMBOLYSE

• CT Hypodensity or sulcal effacement in >1/3 of MCA territory
• Evidence of Haemorrhage, tumour , abscess, developed stroke
• Evidence of Arteriovenous Malformation or Aneurysm
• CT evidence of old stroke in a patient with diabetes
• (Hyperdense artery sign is not a contraindication to thrombolysis)

INCLUSION CRITERIA - ALL MUST BE YES

• CT compatible with acute ischaemic stroke or normal
• Thrombolysis can be given within 3 hrs of stroke onset if over 80 or 4.5 hours if less than 80
• Patient is independent
• Verbal or written informed consent or assent available

LAB FINDINGS - ALL MUST BE NO TO THROMBOLYSE

• Blood glucose <3 mmols/l or >22 mmols/l
• Platelet count < 100,000/mm3
• Hb < 10 g/dl or Haematocrit <25% - If there is no clinical reason whatsoever to suspect abnormal result thrombolysis should not be delayed to wait for the results. FBC can usually be done in an A&E analyser
• Abnormal INR >1.4 or APTT > 36 seconds - If there is no clinical reason whatsoever to suspect an abnormal FBC or INR thrombolysis should not be delayed to wait for the results

NOTE

• There is an increased risk of intracranial haemorrhage in the following patients. These are contraindications to stroke thrombolysis
• Patients with severe neurological deficit (e.g., NIHSS > 22) at presentation.
• Patients with major early infarct signs on a CT scan (e.g., substantial oedema, mass effect, or midline shift).
• Diabetics who have had a previous stroke

Administration of Alteplase

The recommended dose of alteplase for the treatment of acute ischaemic stroke is 0.9 mg alteplase/kg body weight to a maximum of 90 mg infused intravenously over 60 minutes, with 10% of the total dose administered as an initial intravenous bolus. Alteplase comes as a vial with powder for reconstitution and diluent. Please see the body-weight chart in the appendix of this policy. Consent Information (thanks to Bedford stroke Service)

PATIENTS MUST BE CONTINUOUSLY MONITORED PRIOR TO AND DURING DRUG ADMINISTRATION, AND for at least 24 hours following administration for potential side effects and complications.

• Total dose: 0.9mg/kg. MAXIMUM DOSE IS 90 MG.
• Should be prescribed by, and administration supervised by a doctor (Registrar or above) once the approval has been obtained from the Stroke consultant.
• 10% of total dose given as an I.V. push over 2 minutes by the EM Middle grade or more senior Doctor
• Give the remaining 90% of dose I.V. over 60 minutes via infusion pump which should be set up by the EM Nursing staff.

In the first 24 hours immediately after stroke thrombolysis

• DO NOT Put down a Nasogastric tube unless absolutely necessary
• DO NOT Insert a Urinary Catheter unless absolutely necessary
• DO NOT Give IM injection
• Avoid central lines unless absolutely necessary - discuss with POW/Stroke Consultant
• Do Not Give Aspirin, Persantin, Asasantin, Dipyridamole, Warfarin, Phenindone, Acenocoumaral, Plavix, Clopidogrel, Heparin, Enoxaparin, Ibuprofen, Diclofenac, Naproxen or other NSAIDS (Paracetamol IV/Oral/PR is safe for analgesia or pyrexia)

Pretreatment.

• Monitor blood pressure every 15 minutes. It should be below 185/110 mm Hg. If over 185/110, BP may be treated with nitroglycerin paste and/or one or two 10-20mg doses of labetalol given IV push within one hour.
• If these measures do not reduce BP below 185/110 and keep it down, the patient should not be treated with rt-PA.

During and after treatment.

• Monitor blood pressure for the first 24 hours after starting treatment: Every 15 minutes for 2 hours after starting the infusion, then every 30 minutes for 6 hours, then every hour for 18 hours.
• If diastolic BP > 140 mm Hg, start an intravenous infusion of sodium nitroprusside (0.5 to 10 m g/kg/min).
• If systolic BP > 230 mm Hg and/or diastolic BP is 121-140 mm Hg, give labetalol 20 mg intravenously over 1 to 2 minutes. The dose may be repeated and/or doubled every 10 minutes, up to 150 mg.
• Alternatively, following the first bolus of labetalol, an intravenous infusion of 2 to 8 mg/min labetalol may be initiated and continued until the desired BP is reached. If a satisfactory response is not obtained, use sodium nitroprusside.
• If systolic BP is 180 to 230 mm Hg and/or diastolic BP is 105 to 120 mm Hg on two readings 5 to 10 minutes apart, give labetalol 10 mg intravenously over 1 to 2 minutes.
• The dose may be repeated or doubled every 10 to 20 minutes, up to 150 mg. Alternatively, following the first bolus of labetalol, an intravenous infusion of 2 to 8 mg/min labetalol may be initiated and continued until the desired blood pressure is reached.
• Monitor blood pressure every 15 minutes during the antihypertensive therapy. Observe for hypotension.
• If, in the clinical judgment of the treating physician, an intracranial haemorrhage is suspected, the administration of rt-PA should be discontinued and an emergency CT scan or another diagnostic imaging method sensitive for the presence of intracranial haemorrhage should be obtained.

Anaphylaxis

• Suspect an anaphylactic reaction if the patient develops: Rash, urticaria, bronchospasm, orolingual angioedema (face, lips and tongue swelling alone) hypotension, stridor, shock.
• Management: Stop Alteplase, Urgent medical assessment - airway, breathing and circulation, Adrenaline [US Epinephrine] 0.5-1ml 1 in 1000 im or sc NOT iv if anaphylaxis (dose depends on the severity of reaction - (Adrenaline is not usually required if isolated orolingual angioedema. This is commoner in those on an ACEI), Hydrocortisone 200mg iv, Chlorpheniramine 10mg iv, Salbutamol [US Albuterol] nebuliser 5mg.
• Fluid resuscitation IV N-Saline if shocked and consider repeat doses of Adrenaline [US Epinephrine] as required. Involve an anaesthetist immediately if orolingual angioedema is threatening airway.

Angioedema

Life threatening Bleeding

• IV fluids and packed cells as needed
• Begin with 10 units of cryoprecipitate and obtain fibrinogen levels.
• If the fibrinogen level is <1 g/L, administer a second 10 U of cryoprecipitate.
• If bleeding continues despite a fibrinogen >1 g/L, or if the fibrinogen level is <1 g/L after 20 U of cryoprecipitate, administer 2 U of FFP.
• If haemorrhage continues, administer platelets or antifibrinolytic agents such as aminocaproic acid or tranexamic acid

Suspect intracranial haemorrhage due to Alteplase

• Suspect if there is a fall in GCS, headache, Seizure, Increasing NIH score, Acute hypertension, Nausea and vomiting. Immediately Stop Alteplase. Arrange a CT scan. Check PT, APTT, platelet count, fibrinogen, and type and crossmatch if not already done so. Haematology advice is that Fibrinolysis will usually result in a low fibrinogen which can be replaced by one pool of cryoprecipitate.
• If the patient has received antiplatelet therapy such as Aspirin then a platelet transfusion should also be considered. Liaise with haematology. Discuss with neurosurgeons and document advice though surgical management would be unusual in this situation until coagulation sate normalised.
• Consider a second CT scan to assess the progression of intracranial haemorrhage. Inform Family and discuss prognosis which is usually very poor depending on the extent of bleeding

Extracranial haemorrhage

• Suspect extracranial haemorrhage if there is a drop in BP, tachycardia, shock, epistaxis, melaena, haematuria, haematemesis, abdominal pain and bruising or pain in flanks or thighs.
• Immediately stop the infusion of Alteplase. Use direct pressure if possible, to control bleeding from arterial or venous puncture sites.
• Check fibrinogen, PT, APTT, full blood count and arrange an appropriate cross match and urgent transfusion to match blood losses. Support circulation with fluids and blood transfusion as appropriate. Haematology advice is that if bleeding has been confirmed by imaging that blood should be taken for Group and save, FBC and coagulation screen.
• Fibrinolysis will usually result in low fibrinogen which can be replaced by one pool of cryoprecipitate. If the patient has received antiplatelet therapy such as Aspirin then a platelet transfusion should also be considered. Liaise with haematology.
• Consider transfusion of fresh frozen plasma and/or cryoprecipitate depending upon the results of a coagulation screen. Appropriate referral e.g. ENT for persisting epistaxis, Gastroenterology for melaena, haematemesis etc

Comments from the Alteplase datasheet - take haematology advice a potentially dangerous haemorrhage occurs in particular cerebral haemorrhage, the fibrinolytic therapy must be discontinued. In general, however, it is not necessary to replace the coagulation factors because of the short half-life and the minimal effect on the systemic coagulation factors. Most patients who have bleeding can be managed by interruption of thrombolytic and anticoagulant therapy, volume replacement, and manual pressure applied to an incompetent vessel. Protamine should be considered if Heparin has been administered within 4 hours of the onset of bleeding. In the few patients who fail to respond to these conservative measures, judicious use of transfusion products may be indicated. Transfusion of cryoprecipitate, fresh frozen plasma, and platelets should be considered with clinical and laboratory reassessment after each administration. A target fibrinogen level of 1 g/l is desirable with cryoprecipitate infusion

References

• Guidelines for the Early Management of Patients With AcuteIschemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke