If you think that just ANY nurse can speak to the standard of care in issues related to a health care setting, think again. When you are considering accepting a case to act as a testifying expert witness, there are many things to consider.
Prior to accepting any case, you should obtain some initial details about the setting/nurse role and the incident, and you the expert should ensure you have the experience and competency in the clinical area where the case incident occurred. Once you confirm you have this experience, you can be sure that you will be confident in evaluating and are able to opine on the case. Also, some states require that the nursing expert be in the exact same clinical setting with the same credentials and certifications as the nurse in question; at the time of the incident and present time. The retaining attorney will know if any special qualifications are needed. If you do not match these criteria, you may not qualify or could even be disqualified as an expert.
Other things to consider prior to accepting a case is what is needed; typically, there are medical records to review, and the attorney may want a verbal report, a signed affidavit and/or written report. You should know if the case is located in a different state then where you are currently living and consider if you would be able to travel should the need arise to testify.
Finally, deadlines, can you meet the deadlines that the attorney is requesting for the case? If you are not confident in all of these areas on a case by case basis, then you should likely decline to take on the case.
American Association of Legal Nurse Consultants (2013). The Nurse Expert Witness: guidelines for practice.