Stroke protocol

IMPLEMENTATION OF AN ACUTE STROKE TEAM AND ACUTE STROKE PROTOCOLS... 

The two MRI methods are already part of an advanced routine MRI stroke-protocol. At least, the H MRS study could be performed in the framework of such a protocol without further equipment. As... 

Schellinger PD, Jansen O, Fiebach JB et al (1999). A standardized MRI stroke protocol comparison with CT in hyperacute intracerebral hemorrhage. Stroke 30 765-768 Schellinger PD, Thomalla G, Fiehler J et al (2007). MRI-based and CT-based thrombolytic therapy in acute stroke within and beyond established time windows an analysis of 1210 patients. 

Multislice scanners allow flexibility in designing a rapid and efficient CTA protocol for acute ischemic stroke without causing a significant delay in the institution of thrombolytic therapy. At our institution, the acute ischemic stroke protocol consists of (1) unenhanced head CT, (2) one-pass CTA of the head and neck, and (3) CTP of the head at 1-2 nonoverlapping levels with 4-8 cm of brain coverage (with a 64-slice CT scanner). Of note, using the 64-slice CT scanner, the intracranial and extracranial vasculature from arch to vertex can be imaged in one-pass in less than 15 s. 

Table 5.2 Sample acute stroke protocol for 64-section multidetector row CT (MDCT) scanner NCCT, vertex-to-arch CTA and biphasic acquisition (one cine image per second for 40 s followed by nine additional cine images obtained at 3-s intervals) CTP...

The technical considerations and interpretation of the second portion of the acute stroke protocol, CTA, is discussed in detail in Chap. 4. Importantly, however, the source images from the CTA vascular acquisition (CTA-SI) also supply clinically relevant data concerning tissue level perfusion. It has been theoretically modeled that the CTA-SI are predominantly blood volume, rather than blood flow weighted [20, 27,70], The potential utihty of the CTA-SI series in the assessment of brain perfusion is discussed in detail below. This perfused blood volume technique requires the assumption of an approximately steady state level of contrast during the period of image acquisition [27], It is for this reason - in order to approach a steady state - that protocols call for a biphasic contrast injection to achieve a better approximation of the steady state [71, 72]. More complex methods of achieving uniform contrast concentration with smaller doses have been proposed that may eventually become standard, such as exponentially decelerated injection rates [73] and biphasic boluses constructed after analysis of test bolus kinetics [72, 74]. 

Obtain Acute Stroke Protocol packet and review responsibilities as outlined on cover Document vital signs Document time patient last seen well... 

These studies raise the possibility that, one day, imaging-based treatment protocols may allow for intravenous thrombolysis in patients well outside of the now-accepted 3-hour window, provided they demonstrate substantial diffusion-perfusion mismatch. Such protocols could allow for treatment of a vastly larger number of patients than are currently treated. It has been estimated that only 1-7% of acute stroke patients currently receive thrombolytic medication, and that, in up to 95% of cases, they are ineligible because they present outside of the 3-hour time window. As many as 80% of patients who present 6 hours after stroke onset may demonstrate a significant diffusion-perfusion mismatch. "... 

Ribo M, Molina CA, Rovira A, Quintana M, Delgado P, Montaner J, Grive E, Arenillas JE, Alvarez-Sabin J. Safety and efficacy of intravenous tissue plasminogen activator stroke treatment in the 3- to 6-hour window using multimodal transcranial Doppler/MRI selection protocol. Stroke 2005 36 602-606. 

Based primarily on the study protocol of the 1995 NINDS rt-PA study.Many centers would also exclude patients with known documented endocarditis or aortic dissection, and those with CT hypoattenuation in more than one third of the middle cerebral artery territory. There are insufficient data to support the use of rt-PA for ischemic stroke in pregnancy or in the pediatric population (age <18 years). 

ECASS-II was designed to test a lower dose of rt-PA (0.9 mg/kg) during the same 0-6-hours time period after stroke onset, using similar inclusion criteria as in ECASS-I. ° The primary endpoint was the proportion with a favorable outcome on the mRS scale (defined as a score of 0 or 1). There was no difference in this outcome between rt-PA-treated and placebo controls (40% vs. 37%, p = 0.28). A separate analysis of the 158 subjects enrolled within 3 hours of stroke onset also showed no difference in the proportion with a favorable outcome (42% vs. 38%, p = 0.63) this result, however, must be treated with caution because in ECASS-II there was a substantially lower number of patients treated within 3 hours of stroke onset, compared to the 1995 NINDS rt-PA study. Parenchymal hematoma on post-treatment CT was seen in 12% of rt-PA-treated and 3% of placebo patients (p < 0.001). The 90-day mortality rate was 11 % for the rt-PA group and 11 % for the placebo group (p = 0.54). Protocol violations were much less frequent in ECASS-II compared to ECASS-I (9% vs. 18%), probably because of standardized training in CT interpretation at the study sites. 

Patient care areas Acute stroke teams Written care protocols Emergency medical services Emergency department Stroke unit... 

There are few transformations that can, in a single stroke, provide the structural and stereochemical complexities that are attained through a Diels-Alder cydoaddition. It is little surprise then that numerous studies have appeared in the past decade that aim to develop a catalytic asymmetric Diels-Alder process. It is only in a few instances, however, that these catalytic asymmetric protocols have been applied to target-oriented synthesis. Several impres-... 

Stroke, like myocardial infarction, is a medical emergency. Rapid care by well trained teams in facilities allowing neuroimaging 24 hours a day is the key to better prognosis. Certain drugs have already proven to be beneficial, but much progress remains to be made in developing clinical research protocols. 

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