5 Stroke, part 2 Flashcards
Target door-to-scan time for stroke
Noncontrast CT in ≤20 minutes
Target door-to-needle time
IV thrombolytics in ≤60 minutes
(secondary goal of ≤45 minutes)
This is superior to non-contrast CT or other types of MRI in the detection of acute infarction
Diffusion-weighted MRI
however, this is limited by patient-specific contraindications and CT’s suprior rapid availability. Therefore, in the vast majority of EDs, a non-contrast CT is the only imaging study necessary prior to administration of thrombolytics
MRI may be beneficial when
the time of stroke symptom onset is uncertain.
One trial found that patietns with ischemic stroke seen with diffusion-weighted MRI, but no hyperintensity of the parenchyma seen on fluid-attenuated inversion recover, benefited from IV thrombolytic therapy
Remarks on the identifying intracranial large-vessel stenosis or occulsion
- May benefit from endovascular therapies
- Would need vascular imaging (typically CT angiography of the head and neck)
- But such imaging should not delay thrombolytic administration
- and such imaging may be done in patients with no history of renal insufficiency even if serum creatinine level is unknown because these studies are NOT associated with significantly increased risk of acute kidney injury
The area of irreversible brain infarct
Core
The area of ischemic tissue that may potentially be salvageable, [regardless of the time of onset of symptoms?]
Penumbra
Top priority in the management of stroke patients
Assessment of airway, breathing, and circulation
Immediate life threats must be addressed before other interventions are undertaken.
Actively manage airway if necessary.
O2 supplementation should only be given to keep O2 sats ____
≥95%
The only laboratory test result required prior to thrombolytic therapy
Bedside glucose
Unless the patient is taking oral anticoagulants or heparin,
or if there’s a strong suspicion of thrombocytopenia or other bleeding diathesis.
What to look for in CBC of stroke patients?
Polycythemia,
thrombocytosis, or
thrombocytopenia
Electrolyte-imbalance stroke mimics
Hyponatremia and hypercalcemia
Chest x-ray in stroke
Routine chest radiography in asymptomatic patients is not recommended and should be reserved only for situations where a cardiopulmonary contraindication to thrombolytics is suspected or if immediate management would be significantly impacted by chest radiography findigns
Remarks on BP control in thrombolysis
- Targets are SBP ≤185 and DBP ≤110
- If target BPs cannot be achieved, then the patient is no longer a candidate for rTPA thearpy, as there will be increased risk for hemorrhagic transformation of ischemic stroke
How to administer Nicardipine
Start at 5 mg/hour,
titrate by 2.5 mg/hour at 5- to 15-min intervals;
max dose of 15 mg/hour;
when desired BP is attained, reduce to 3 mg/hour.
Use nicardipine with caution in patients with
myocardial infarction
congestive heart failure
concurrent use of fentanyl (hypotension)
renal insufficiency
hepatic insufficiency
(may need to adjust starting dose)
Nicardipine is contraindicated in
patients with severe aortic stenosis
If blood pressure is not controlled by nicardipine (and labetalol or clevidipine if available), or if diastolic BP is >140 mm Hg, then we may consider starting ______
Sodium nitroprusside infusion
0.5 - 10 mcg/kg/min
Continuous arterial monitoring advised;
use with caution in patients with hepatic or renal insufficiency.
Increases intracranial pressure
Pregnancy Category C
Frequency of BP monitoring in thrombolytic therapy
Time after start of rTPA infusion:
0-2 h: every 15 minutes
3-8 h: every 30 minutes
9-24 h: every 60 minutes
Target blood glucose levels in stroke
140 - 180 mg/dL
Aspirin recommendations
Administer oral (or by rectum if swallowing impairment is present) aspirin (160 - 300 mg) within 24 to 48 hours after stroke onset unless thrombolytics have been given within the prior 24 hours.
What is the CHANCE trial
“Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events”
Found that mild stroke patients who received clopidogrel along with aspirin within 24 hours had fewer recurrent strokes and better functional outcomes
