5 Stroke, part 2

Question 1

Target door-to-scan time for stroke

Answer 1

Noncontrast CT in ≤20 minutes

Question 2

Target door-to-need time

Answer 2

IV thrombolytics in ≤60 minutes
(secondary goal of ≤45 minutes)

Question 3

This is superior to non-contrast CT or other types of MRI in the detection of acute infarction

Answer 3

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

Question 4

MRI may be beneficial when

Answer 4

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

Question 5

Remarks on the identifying intracranial large-vessel stenosis or occulsion

Answer 5

1. May benefit from endovascular therapies
2. Would need vascular imaging (typically CT angiography of the head and neck)
3. But such imaging should not delay thrombolytic administration
4. 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

Question 6

The area of irreversible brain infarct

Answer 6

Core

Question 7

The area of ischemic tissue that may potentially be salvageable, [regardless of the time of onset of symptoms?]

Answer 7

Penumbra

Question 8

Top priority in the management of stroke patients

Answer 8

Assessment of airway, breathing, and circulation
Immediate life threats must be addressed before other interventions are undertaken.
Actively manage airway if necessary.

Question 9

O2 supplementation should only be given to keep O2 sats ____

Answer 9

≥95%

Question 10

The only laboratory test result required prior to thrombolytic therapy

Answer 10

Bedside glucose
Unless the patient is taking oral anticoagulants or heparin,
or if there’s a strong suspicion of thrombocytopenia or other bleeding diathesis.

Question 11

What to look for in CBC of stroke patients?

Answer 11

Polycythemia,
thrombocytosis, or
thrombocytopenia

Question 12

Electrolyte-imbalance stroke mimics

Answer 12

Hyponatremia and hypercalcemia

Question 13

Chest x-ray in stroke

Answer 13

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

Question 14

Remarks on BP control in thrombolysis

Answer 14

1. Targets are SBP ≤185 and DBP ≤110
2. 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

Question 15

How to administer Nicardipine

Answer 15

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.

Question 16

Use nicardipine with caution in patients with

Answer 16

myocardial infarction
congestive heart failure
concurrent use of fentanyl (hypotension)
renal insufficiency
hepatic insufficiency
(may need to adjust starting dose)

Question 17

Nicardipine is contraindicated in

Answer 17

patients with severe aortic stenosis

Question 18

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 ______

Answer 18

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

Question 19

Frequency of BP monitoring in thrombolytic therapy

Answer 19

Time after start of rTPA infusion:
0-2 h: every 15 minutes
3-8 h: every 30 minutes
9-24 h: every 60 minutes

Question 20

Target blood glucose levels in stroke

Answer 20

140 - 180 mg/dL

Question 21

Aspirin recommendations

Answer 21

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.

Question 22

What is the CHANCE trial

Answer 22

“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