Why a first search found 9 records and a rebuilt one found 212, told as an NU325 Unit 3 board post with its terms, operators and limits shown. Searches like "nu 325 unit 3 assignment example", "nu325 unit 3 sample" and "nu325 unit 3 example" land here.
Cannula, Catheter, Resite, Replacement: Rebuilding a Search That First Returned Nine Results
NU325 · Unit 3 Discussion
Posted by [Student Name]
Composite search written for a model post. Result counts are bracketed because they change with the date searched.
Initial Post
My first attempt failed. I searched PubMed for "peripheral IV catheter replacement" as a quoted phrase and got [9] results. The literature on this topic uses at least four words for two ideas, and much of the trial work comes from Australia, where "cannula" and "resite" are ordinary terms.
The rebuilt strategy uses two concept lines:
Device: (peripheral intravenous catheter* OR peripheral venous catheter* OR cannula* OR PIVC)
Timing: ("clinically indicated" OR "routine replacement" OR resite OR "dwell time")
The two lines are joined with AND.
Why each change. Truncation with an asterisk catches catheter and catheters, cannula and cannulae. Synonyms sit inside parentheses by concept, so OR works within a concept and AND works between concepts; when I mixed them without parentheses, PubMed grouped the terms differently and the results made no sense. In PubMed I added the MeSH heading Catheterization, Peripheral, and in CINAHL its own subject headings, because subject headings capture indexed studies while keywords catch recent ones that are not yet indexed.
A trap I avoided: I almost added NOT central to exclude central lines, but that would have removed trials that mention central lines only in their exclusion criteria.
Limits: English, adults, published 2010 to [2025], which covers the major trials and the current Cochrane review. I did not limit by study design, because I want qualitative studies of patient experience as well as trials.
Results: PubMed [212], CINAHL [147], and the Cochrane review on clinically indicated versus routine replacement found directly in the Cochrane Library (Webster et al., 2019). Searching several databases with subject headings and keywords is recommended because no single database indexes everything (Melnyk & Fineout-Overholt, 2023).
How did you handle terms that differ between countries?
Reply to a Classmate
You used the free full-text limiter to keep your results manageable. I would drop it: it hides studies the library can get for you through interlibrary loan, and some of the most important trials are not free. A date or study-type limit narrows results without that bias.
References
Melnyk, B. M., & Fineout-Overholt, E. (2023). Evidence-based practice in nursing and healthcare: A guide to best practice (5th ed.). Wolters Kluwer.
Webster, J., Osborne, S., Rickard, C. M., & Marsh, N. (2019). Clinically-indicated replacement versus routine replacement of peripheral venous catheters. Cochrane Database of Systematic Reviews, 2019(1), CD007798. https://doi.org/10.1002/14651858.CD007798.pub5
How this NU325 Unit 3 example is structured
A before-and-after organizes the post, because the failed search teaches more than the finished one. Each change is given its reason. Truncation catches catheter and catheters, cannula and cannulae. Synonyms are grouped by concept inside parentheses so that each operator does a single job, and the post explains that mixing them without parentheses changed what PubMed returned. Controlled vocabulary is shown beside keywords, since subject headings capture indexed studies while keywords catch recent ones. The writer also notes a trap avoided: adding NOT central would have removed trials that mention central lines only in their exclusion criteria. Limits are justified one at a time, the date range as covering the major trials and the current Cochrane review. A classmate's free full-text limiter gets its own reply, a polite explanation of why it hides studies the library can supply.
Get an NU325 Unit 3 example written to your instructions
Search posts go faster once the question is fixed. Paste the PICOT question from Unit 2, the Unit 3 board prompt and its rubric, and list the databases the library offers. The sample post carries a reproducible string and counts in brackets, plus a reply aimed at one classmate's search. First sample free, 24-48h. 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.
NU325 Unit 3 questions, answered
What is the difference between a subject heading and a keyword?
A subject heading is a controlled term that indexers assign, such as a MeSH heading in PubMed or a CINAHL heading, so it gathers articles on a concept whatever words the authors chose. A keyword matches words in the title or abstract, which catches new articles not yet indexed. Strong searches combine both for each concept in the question.
Why do my searches return thousands of results or almost none?
Usually the operators. OR widens a search while AND narrows it, so synonyms belong together with OR and concepts are joined with AND. A single long phrase in quotation marks can return almost nothing, while one broad word returns everything. Build a line for each concept, test it alone, then combine the lines and add limits last.
Should a nursing search include studies from other countries?
Usually yes, if the settings are comparable. Much of the research on peripheral IV replacement comes from Australian hospitals, for example, and leaving it out would leave out the largest trials. Note where health systems, staffing or equipment differ, and consider whether those differences change how far a finding transfers to your unit.