Answered By: Michael Pujals Last Updated: Jul 17, 2014 Views: 52
In APA I think this would be a Authored report, from nongovernmental organization (#33 in section 7.03 of the APA manual).
The format would be:
Author. (Year). Report title. Retrieved from NGO website name: URL
In this particular case:
Westphal, C., Wavra, T. (2005). Acute and critical care choices guide to advance directives. Retrieved from the American Association of Critical Care Nurses website: document URL goes here.