Dr Karlsen is a neonatal nurse practitioner who has been involved in neonatal care in a variety of settings including transport, education, patient care, and simulation for more than 35 years. She is the founder of the internationally recognized S.T.A.B.L.E. Program and author and developer of The S.T.A.B.L.E. Program Pretransport / Postresuscitation stabilization neonatal education course, The S.T.A.B.L.E. - Cardiac Module course (book and slide program), the STABLEize(TM) app (for Apple and Android), The S.T.A.B.L.E. Program's Gestational Age and Physical Assessment of the Newborn slide program, and the Neonatal Stabilization Scenarios Guidebook, based on The S.T.A.B.L.E. Program curriculum. More than 650,000 students have completed a S.T.A.B.L.E. Program course, and the Program is taught in more than 45 countries.

Dr Karlsen serves as the Program Director for S.T.A.B.L.E., and she travels domestically and internationally to teach The S.T.A.B.L.E. Program curriculums and Instructor Courses. Since 1985, her clinical affiliation is the Level 4 neonatal intensive care unit at Intermountain Healthcare Primary Children's Hospital in Salt Lake City, Utah, where she serves as a neonatal nurse practitioner on the cardiac patient team.

Dr Karlsen is the recipient of numerous awards and recognition: the AWHONN/Johnson & Johnson 2003 Childbirth Nursing Award, the March of Dimes 2004 Leadership in Healthcare Nurse Award, the University of Utah College of Nursing 2005 Outstanding Doctoral Student Award, the 2010 National Association of Neonatal Nurse Practitioners NNP Excellence Award, and the 2014 National Perinatal Association, The Individual Contribution to Maternal & Child Health at the National and International Level Award. In 2019, she was awarded a Fellowship in the American Academy of Nursing to recognize her worldwide impact on improving neonatal outcomes through the S.T.A.B.L.E. Program's interprofessional neonatal education.