You should look for scholarly or peer-reviewed sources to assist you in determining the best course of action for your patient.
In PubMed Central or Medline Plus or TRIP or STAT!Ref or any of the other nursing-focused resources, you can refine your results by limiting your search to full-text sources only and by narrowing the publication dates, for example, selecting only the last 5 years (see example).
It's important to understand the difference between Medline and PubMed. Medline is part of PubMed; when you search PubMed you are searching all of Medline, but if you only search Medline you will miss some material that is only in PubMed. The TRIP Database is a clinical search engine, which searches PubMed in addition to a variety of other sources, including clinician-submitted images, videos, patient information leaflets, educational courses, and news.
Once you have created your search string in PubMed, you can copy and paste it for searching in other databases.
Have you found an article that is right on point? Check out the bibliography of sources to which that author cited (end of the article). In this way, you will find more relevant sources. This is sometimes called citation tracing.
Levels of evidence (sometimes called hierarchy of evidence) are assigned to studies based on the methodological quality of their design, validity, and applicability to patient care.
Use PubMed'sto identify the medical terminology for the patient's problem, and find potential courses of treatment from the articles and studies retrieved.