Dr. Nielsen earned his medical degree from the Duke University School of Medicine, and his M.Sc. in Control of Infectious Disease from the London School of Hygiene and Tropical Medicine. He completed his residency in Internal Medicine at Oregon Health Sciences University, where he also completed his fellowship in Critical Care Medicine. He initially was a member of the faculty of the Tulane University School of Medicine as an Assistant Professor from 2009-2013, at which time he departed to complete a second fellowship at the Harvard Joint Program in Transfusion Medicine. He rejoined the faculty of the Tulane School of Medicine in 2015, and was promoted to Associate Professor of Medicine in 2017.
Dr. Nielsen is board certified in Internal Medicine, Critical Care Medicine, and Transfusion Medicine. He is a member of the Society for Critical Care Medicine and the European Society of Intensive Care Medicine, where he is an active member of the Sepsis and Inflammation, Cardiovascular Dynamics, and Ethics Sections.
Dr. Nielsen’s main research interests are focused around the nexus between transfusion medicine and critical illness, specifically the behavior of the microcirculation under conditions of severe physiological stress, the effects of blood transfusion on tissue oxygenation and the microcirculation, and potential immunomodulatory effects of plasma containing blood products. He also has an active research interest in complex coagulopathies and thrombosis, and the viscoelastic tools for their assessment.
He is a site liaison for the award-winning open-access Critical Care Project website project, and is the content director for the Tulane Critical Care Project website. In addition, he presently serves as one of the three international editors of Concise Critical Appraisals for the Society for Critical Care Medicine, and recently was the lead author of the PACT teaching module on Sepsis for the European Society of Intensive Care Medicine. Dr. Nielsen was a faculty member for the inaugural Haitian
Acute and Emergency Care Conference, and is actively involved in the future development of this conference, as well as other projects in collaboration with St. Luc’s Hospital in Port-au-Prince and a group of U.S.-based colleagues.
Dr. Nielsen treats critically ill patients at the University Medical Center of New Orleans, where he also serves as the Associate Medical Director of the Medical Intensive Care Unit. He is actively involved in administrative and quality improvement initiatives at UMCNO, including initiatives in patient-centered care and the incorporation of palliative medicine into post-ICU care.
Outside of the hospital setting, Dr. Nielsen teaches an undergraduate course at Tulane University on literature authored by physicians, is a long-standing volunteer with Animal Rescue New Orleans, a member of the Krewe of Orpheus, an occasional marathon runner, and a proud pet parent to 3 cats and 3 rescue dogs.