| Course | NU652 AGACNP Acute Care Diagnosis and Management II |
|---|---|
| Unit | Unit 3 |
| Paper type | Revised differential worksheet |
| Length | About 630 words, 5 pages double-spaced |
| Format | APA 7 student paper |
| School | Purdue University Global |
| Program | MSN |
| Updated | September 2026 |
Free sample paper for NU652 Unit 3
Seventy-Two Hours of Cefazolin and a Pen Line That Has Not Moved: A Revised Differential Worksheet for a Red Left Shin
[Student Name]
Purdue University Global
NU652: AGACNP Acute Care Diagnosis and Management II
Unit 3 Revised Differential Worksheet
[Instructor Name]
[Date]
The patient is composite; values and hours are bracketed.
Working Label Under Review
Working diagnosis on admission: left leg cellulitis. Reason for review on day [three]: erythema unchanged at [72] hours of intravenous cefazolin; no fever at any point; white count [7.8]; heart rate [76]; no lymphangitis or tender inguinal nodes.
Patient: Mr. [D.], [62] years old, with obesity, hypertension and chronic venous insufficiency, admitted from clinic after his wife noticed his left shin "had gone red." He works long shifts standing at a print shop.
Ranked Differential
1. Venous stasis dermatitis. Supporting: hemosiderin staining and pitting edema in both legs, the right with milder changes of the same kind; scaling and itch rather than pain; warmth mild. Weakening: the left is clearly worse than the right. Separating test: response to elevation and compression over [48] hours, with dermatology review. Result: redness paler after [24] hours of elevation.
2. Deep vein thrombosis, left leg. Supporting: unilateral swelling greater on the left, calf circumference [3] cm larger. Weakening: long-standing bilateral edema, no new pain in the calf. Separating test: his Wells score of [1] places him in the unlikely group, where a negative D-dimer would end the search (Wells et al., 2003); his D-dimer was mildly raised, as inflammation often makes it, so a compression duplex was done. Result: no thrombosis.
3. Cellulitis. Supporting: a red, warm leg. Weakening: no fever, no leukocytosis, no tachycardia, no spread in [72] hours of an active antibiotic, and changes present in both legs. Separating test: the ALT-70 score (Raff et al., 2017). With asymmetry counted, he scores [3]; if the bilateral changes are taken as symmetric, he scores [0]. Either way he sits in the range where pseudocellulitis is at least as likely as cellulitis.
4. Contact dermatitis. Supporting: he began applying an over-the-counter antibiotic ointment to a scratch on the shin [five] days before admission. Weakening: no vesicles and no sharp border. Separating test: stop the ointment and watch; patch testing later if it recurs.
5. Lipodermatosclerosis, acute phase. Supporting: chronic venous disease, tender induration above the ankle. Weakening: the redness extends higher than is typical. Separating test: dermatology examination.
6. Gout or inflammatory arthritis of the ankle. Weakening: no joint involvement on exam. Separating test: none needed unless the ankle becomes involved.
Must-Not-Miss, Ranked by Consequence
Necrotizing soft tissue infection. It appears here regardless of probability because missing it is fatal. Against it: no pain out of proportion, no crepitus, no bullae or skin necrosis, stable vital signs. His LRINEC score, calculated from C-reactive protein, white count, hemoglobin, sodium, creatinine and glucose, is [0], in the low-risk range (Wong et al., 2004). Trigger to reopen: rapidly spreading redness, severe pain, fever or a rising white count.
Revised Plan
The unchanged redness after three days of a drug that should have worked is the most informative finding in the chart, not a reason to add a second antibiotic.
1. Stop cefazolin; no second antibiotic.
2. Leg elevation, compression once the duplex is negative, and an emollient.
3. Stop the antibiotic ointment.
4. Dermatology consultation.
5. Recheck the leg with the pen line at [24] and [48] hours; resume antibiotics if redness spreads or fever appears.
Misdiagnosed lower extremity cellulitis is common. In a review of patients admitted for it, about 30 percent turned out to have another condition, and more than nine in ten of those received antibiotics they did not need (Weng et al., 2017). This worksheet exists to prevent the same outcome for Mr. [D.].
References
Raff, A. B., Weng, Q. Y., Cohen, J. M., Gunasekera, N., Okhovat, J., Vedak, P., Joyce, C., Kroshinsky, D., & Mostaghimi, A. (2017). A predictive model for diagnosis of lower extremity cellulitis: A cross-sectional study. Journal of the American Academy of Dermatology, 76(4), 618-625. https://doi.org/10.1016/j.jaad.2016.12.044
Wells, P. S., Anderson, D. R., Rodger, M., Forgie, M., Kearon, C., Dreyer, J., Kovacs, G., Mitchell, M., Lewandowski, B., & Kovacs, M. J. (2003). Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis. New England Journal of Medicine, 349(13), 1227-1235. https://doi.org/10.1056/NEJMoa023153
Weng, Q. Y., Raff, A. B., Cohen, J. M., Gunasekera, N., Okhovat, J., Vedak, P., Joyce, C., Kroshinsky, D., & Mostaghimi, A. (2017). Costs and consequences associated with misdiagnosed lower extremity cellulitis. JAMA Dermatology, 153(2), 141-146. https://doi.org/10.1001/jamadermatol.2016.3816
Wong, C.-H., Khin, L.-W., Heng, K.-S., Tan, K.-C., & Low, C.-O. (2004). The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis) score: A tool for distinguishing necrotizing fasciitis from other soft tissue infections. Critical Care Medicine, 32(7), 1535-1541. https://doi.org/10.1097/01.CCM.0000129486.35458.7D
The Purdue Global NU652 Unit 3 instructions
The Unit 3 assignment asks you to revisit a working diagnosis that no longer fits and build a revised differential. You restate the original label and the findings that put it in doubt, list the alternatives in order of probability, give the evidence for and against each, name the test or observation that would separate them and identify any must-not-miss diagnosis separately from the ranking. Most prompts accept or prefer a table. The worksheet is usually one to two pages. A revised plan based on the new ranking is expected, and scores such as Wells or ALT-70 should be applied and interpreted. Include the history details that could point to a mimic, such as new topical products, since they often carry the answer.
How the NU 652 Unit 3 example is put together
The example opens with a header that restates the working label and the three findings that triggered the review. The ranked list follows, with each entry giving its supporting and weakening findings in the same format, so the new leader is argued rather than assumed. Separating tests are specific: elevation and compression, a D-dimer and duplex, the ALT-70 score, stopping an ointment. Necrotizing infection is placed on its own line ranked by consequence, with a LRINEC score and triggers to reopen it. A highlighted sentence explains why unchanged redness is the most informative finding. The revised plan stops cefazolin and names what would restart it.
Reading the NU652 Unit 3 grading rubric
The Unit 3 rubric usually looks at the quality of the ranked differential, the use of supporting and refuting evidence, the separating tests, the handling of must-not-miss diagnoses and the revised plan. The differential earns full credit when it is ranked with reasons, not listed. Evidence counts when weakening findings are given the same weight as supporting ones. Separating tests are judged on whether each would actually change the ranking. Must-not-miss conditions should be addressed explicitly, with criteria for reopening. The revised plan earns points when it follows from the new ranking, including stopping treatment for a diagnosis the worksheet no longer supports.
NU652 Unit 3 help from the desk
A common mistake is adding a second antibiotic when cellulitis does not respond, rather than questioning the diagnosis. Another is ranking the differential without giving the evidence against each option. Students often list tests that would not separate the diagnoses. Scores such as Wells are sometimes applied incorrectly, for example by sending a low-probability patient straight to imaging. Necrotizing infection is either left out or ranked highly without justification. Some worksheets omit the contact history, such as a new ointment. And a revised plan that keeps every original order in place suggests the revision did not change anything. Finally, date and time the reassessments with the pen line, since the whole argument rests on a comparison over time.
Get an NU652 Unit 3 example written to your instructions
Worksheets differ by section in their column headings and in how many alternatives they expect, so the template weighs as heavily as the patient. Pass along both, plus the rubric, and a first worksheet built to them comes back in 24-48h at no charge, ranked on findings, with a must-not-miss row set apart. The paper above is an original model document written by our desk, not a submitted student paper and not an official Purdue University Global document.
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NU652 Unit 3 questions, answered
How many alternatives should a revised differential list?
Usually four to six, ranked, plus any must-not-miss condition that falls outside the top of the ranking. Longer lists tend to dilute the reasoning because each entry receives less support. The sample lists six entries, five ranked and one set apart, and explains why two other candidates, lymphedema and erythema migrans, were considered and left off, which shows the ranking was deliberate.
Is it wrong to keep the original diagnosis at the top?
Not if the findings support it. A revised differential can conclude that the working label still leads, as long as it shows the alternatives were weighed and says what evidence kept the original in place. The weakness instructors look for is a label kept by default rather than on evidence, and the sample's structure makes that difference visible.
Can the worksheet be a table instead of paragraphs?
Most sections accept or even expect a table, since it lets a reader compare supporting and weakening findings across rows. Some prompts also ask for a short narrative beneath it. The sample adopts the format your instructor's template shows, and where none is provided, it uses the six-column table described here with a brief plan underneath.
Where can I find a free NU652 Unit 3 sample paper?
This page contains the full NU652 Unit 3 revised differential worksheet, with six ranked diagnoses, separating tests, a must-not-miss line and the revised plan. If your patient's working diagnosis is different, a free worksheet can be written from your case.
What is the ALT-70 score in NU652 Unit 3?
A four-item score for suspected leg cellulitis: asymmetry 3 points, white count of 10,000 or more 1 point, heart rate of 90 or more 1 point, and age 70 or older 2 points. Totals of 0 to 2 make pseudocellulitis likely.