For more than 10 years, Elliott Bennett-Guerrero, MD, has lectured on anesthesiology and directed perioperative research at Duke University. In addition to these responsibilities, Elliott Bennett-Guerrero has overseen several clinical studies as a principal investigator.

2.  For more than 10 years, Elliott Bennett-
Guerrero, MD, has lectured on anesthesiology
and directed perioperative research at Duke
University. In addition to these responsibilities,
Elliott Bennett-Guerrero has overseen several
clinical studies as a principal investigator.
Clinical studies are comprised of four testing
levels that determine the approval or
disapproval of a particular drug or treatment,
with each stage answering a series of research
questions. The following is a general summary
of each phase:

3.  Phase I —During the initial evaluation of the
medicine or procedure’s safety, researchers
utilize a small test group to determine a
dosage range and discover any side
effects.
Phase II —This period provides additional
insight on safety and assesses the drug or
treatment’s efficacy. Lasting up to several
years, Phase II involves a larger number of
participants.

4.  Phase III —The third phase includes
continued supervision of safety, efficacy,
and any side effects. Further, researchers
compare results to existing products and
procedures.
Phase IV —Lastly, researchers conduct
aftermarket observation to identify and
issues linked to long-term use or involving
certain populations segments.