| Course | NR 569 Differential Diagnosis in Acute Care Practicum |
|---|---|
| Week | 5 |
| Paper type | Diagnostic test rationale memo |
| Length | About 880 words, 4 pages |
| Format | Memo with APA 7 citations |
| School | Chamberlain University |
| Program | MSN, Adult-Gerontology Acute Care NP (AGACNP) |
| Updated | October 2026 |
Free sample paper for NR 569 Week 5
Memorandum
To: Supervising physician, Hospital Medicine Service
From: Acute care nurse practitioner student
Date: Hospital day 2, 17:00
Re: Request for brain MRI tonight, with the expected effect of each result
The Current List
As of 16:30 on hospital day 2, the list for the 47-year-old admitted after gastric bypass has three entries. (1) Wernicke encephalopathy, now first after this afternoon's examination found nystagmus on gaze to both sides and incomplete abduction in both eyes, with no skew. (2) Stroke in the posterior circulation, now second; symmetric eye findings make it less likely but do not remove it. (3) Dehydration with potassium and magnesium losses, present and being corrected, but not an explanation for the eyes or the gait.
The Request
I am asking for MRI of the brain without contrast, with diffusion-weighted and FLAIR sequences, tonight. Timing matters for two reasons. First, the patient started thiamine at 200 mg by vein every eight hours at 16:00, and the lesions this study can show may begin to fade with treatment. Second, if this is a stroke, its management changes with every hour. The scanner is open overnight, and the patient now follows simple commands and can lie still for about 20 minutes with support.
One Branch per Result
Table 1
Expected Effect of Each MRI Result on the Current List
| Result | What it would mean | The list that would be left |
|---|---|---|
| Symmetric FLAIR signal in the medial thalami, the area around the cerebral aqueduct or the mammillary bodies, with no diffusion restriction in a vascular territory | Strong support for thiamine deficiency; stroke now unlikely | 1. Wernicke encephalopathy 2. Volume depletion and electrolyte loss |
| Diffusion restriction in a cerebellar or brainstem vascular territory | Stroke established; thiamine deficiency may still coexist | 1. Posterior circulation stroke 2. Wernicke encephalopathy 3. Volume depletion |
| Normal study, or nonspecific signal that fits neither pattern | Neither entry removed | 1. Wernicke encephalopathy 2. Posterior circulation stroke, lower 3. Volume depletion |
The Positive Branch
If the study shows the symmetric pattern, the case for thiamine deficiency becomes strong. In a comparison of patients with acute thiamine deficiency, people who drank heavily without the disease and healthy controls, MRI had a specificity of 93% (Antunez et al., 1998). The European guideline recommends MRI to support the diagnosis in drinkers and nondrinkers alike (Galvin et al., 2010). A study with this pattern and clean diffusion images would also move the stroke well down, since the symmetric thalamic and periaqueductal changes do not fit a single vascular territory.
The Stroke Branch
If diffusion restriction appears in the territory of a vertebral, basilar or cerebellar artery, stroke moves to first. It would not remove thiamine deficiency: the patient's eye and gait findings are symmetric, the deficiency setting is still present, and both can coexist. The neurology team would be paged, and the time of last known normal would need to be reconstructed from the sibling's account.
The Equivocal Branch
This branch is the one I expect most often, and it is the one a rationale most often leaves out. A normal study does not exclude thiamine deficiency: MRI was abnormal in only 53% of patients with the acute disease in the comparison above (Antunez et al., 1998), and characteristic lesions appeared in fewer than half of the published bariatric cases that had MRI (Aasheim, 2008). A normal study also does not fully exclude a small posterior stroke in the first day or two. In a cohort of patients with acute vestibular symptoms, initial diffusion images missed some strokes that later imaging confirmed (Kattah et al., 2009).
Under this branch, the list stays in its current order and the decision rests on the clinical course: whether the eye findings and gait improve over 48 hours of high-dose thiamine. A repeat examination at 24 and 48 hours, written down each time with the same three elements, becomes the next test.
Why This Study and Not Another
A head CT was done on admission and was normal. CT is of little use here: it showed abnormalities in only 13% of patients with acute thiamine deficiency in the same comparison (Antunez et al., 1998), and it misses most small posterior strokes. A whole blood thiamine level has already been added to the triage sample collected before any thiamine was given, but it is sent out and will not return for several days, so it cannot guide tonight's decisions. CT angiography would be the next step only if the stroke branch occurs.
Written to Be Acted On
If you approve, I will place the order, arrange a nurse to accompany the patient, confirm that the patient has no implanted devices or metal fragments, and note in the chart the time of the last eye examination so the MRI result can be read alongside it.
What Is Not Argued Here
This memo does not argue whether to give thiamine; that has already started and does not depend on the result. It does not argue about the vomiting, which the CT has explained as a narrowing at the pouch outlet and the surgical team will address. And it does not claim that a positive study would end the diagnostic work, since the whole blood thiamine level and the response to treatment remain outstanding.
References
Aasheim, E. T. (2008). Wernicke encephalopathy after bariatric surgery: A systematic review. Annals of Surgery, 248(5), 714-720. https://doi.org/10.1097/SLA.0b013e3181884308
Antunez, E., Estruch, R., Cardenal, C., Nicolas, J. M., Fernandez-Sola, J., & Urbano-Marquez, A. (1998). Usefulness of CT and MR imaging in the diagnosis of acute Wernicke's encephalopathy. American Journal of Roentgenology, 171(4), 1131-1137. https://doi.org/10.2214/ajr.171.4.9763009
Galvin, R., Brathen, G., Ivashynka, A., Hillbom, M., Tanasescu, R., & Leone, M. A. (2010). EFNS guidelines for diagnosis, therapy and prevention of Wernicke encephalopathy. European Journal of Neurology, 17(12), 1408-1418. https://doi.org/10.1111/j.1468-1331.2010.03153.x
Kattah, J. C., Talkad, A. V., Wang, D. Z., Hsieh, Y.-H., & Newman-Toker, D. E. (2009). HINTS to diagnose stroke in the acute vestibular syndrome: Three-step bedside oculomotor examination more sensitive than early MRI diffusion-weighted imaging. Stroke, 40(11), 3504-3510. https://doi.org/10.1161/STROKEAHA.109.551234
What the NR 569 Week 5 assignment asks for
The Week 5 rationale usually asks you to request one diagnostic study for your patient and justify it to a supervising clinician. Expect one to two pages in memo or letter form. The current list goes at the top so the request makes sense against it. The study should be named precisely enough to order, with the timing and setting. Most rubrics then want a branch for each result: positive, negative and the indeterminate result that settles nothing, with the list each one would leave. Some sections ask why a cheaper or faster test will not do. Many also ask what the rationale does not argue, so the request stays narrow.
How the NR 569 Week 5 example is put together
The sample opens with a dated list of three entries, then asks for MRI without contrast with diffusion and FLAIR sequences tonight, explaining that thiamine has started and that a stroke would change management by the hour. A table gives three result branches and the list each would leave. Each branch is then argued with figures, including MRI specificity of 93% for thiamine deficiency and sensitivity of about half, so a normal study removes neither entry. A section explains why the admission CT and the pending thiamine level cannot settle the question. The memo closes with the practical steps the writer will take and with what the request does not cover, such as thiamine dosing and the vomiting.
Where the points sit in the NR 569 Week 5 rubric
Credit in this rationale centers on the branches. A memo that explains the disease instead of the request scores lowest, so this sample spends its length on what each result would do to the list. The indeterminate branch carries its own marks, because it is the most likely outcome and the most often missed; the equivocal row here gives the list it would leave and the next step. A request with a time and setting meets the practicality row. Branches that would leave a different list each time show the study is worth ordering. Addressing a named reader and stating what the writer will do on approval completes the communication criterion.
NR 569 Week 5 help from the desk
A typical NR 569 Week 5 shortfall is a page of pathophysiology with the request tucked into the last line. Close behind is a branch set with only positive and negative outcomes, leaving out the equivocal result that happens most often. Requests with no timing lose practicality marks, as do studies the unit cannot perform. If every result would leave the same list, the test looks habitual. Rationales addressed to no one read like essays. If your patient needs a different study, send the current list and the test you have in mind; a rationale can be laid out with a branch for each result and the list it leaves.
Get a NR 569 Week 5 example written to your instructions
Upload the Week 5 instructions together with your current list and the rubric rows, and a custom example is written against them and returned inside 24 to 48 hours, the first one free. If your section names the investigation, say so, because the branches change entirely depending on whether the study was chosen by you or handed to you.
More NR 569 papers and AGACNP samples
- NR 569 Week 1: Fever and Back Pain Discussion Post
- NR 569 Week 2: Undifferentiated Presentation Write-Up
- NR 569 Week 3: Differential Narrowing Memo
- NR 569 Week 4: Discriminating Feature Brief
- NR 569 Week 6: Reasoning Journal Entry
- NR 569 Week 7: Revised Differential Note
- NR 569 Week 8: Diagnostic Accuracy Review
- NR 567 Week 5: ICU Sedation and Analgesia Plan
NR 569 Week 5 questions, answered
Does the rationale have to include sensitivity and specificity?
Only where your section asks for figures, and many do not. The row being marked here is whether each result is tied to a list, which can be argued without arithmetic at all. If numbers are required, send the values your classroom supplies, because a figure attached to a published study and a figure invented for an assignment are marked differently.
What if the study I want is not available where I am?
Say so in the document and the rationale gets stronger, not weaker. Writing the request you would make, the substitute actually obtainable, and what the substitute cannot settle gives a marker three things to score instead of one. Sections assessing feasibility read an unavailable study named without comment as a gap rather than as ambition.
Who is the rationale addressed to?
Whoever your instructions name, and if they name nobody, a supervising clinician on the unit is the usual default. The addressee decides the register and the length: somebody who already knows the patient needs the list and the branches, while a reader who does not needs two lines of background first. Say which one applies when you send the assignment.
Where can I find a free NR 569 Week 5 sample paper?
Read the full rationale memo for the overnight MRI on this page, including the three-branch table and the equivocal branch most writers leave out.
Does a normal MRI rule out Wernicke encephalopathy in the NR 569 Week 5 memo?
No. The memo cites MRI sensitivity of about half for the acute disease, so a normal scan leaves it on the list and shifts the decision to the response to thiamine.