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. He was elected as a Fellow of the American College of Critical Care Medicine in 2019.
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 (ESICM), where he is an active member of the Sepsis and Inflammation, Cardiovascular Dynamics, and Ethics Sections and the Global Intensive Care Working Group.
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. More recently, he has acted as a site investigator for expanded access trials for Angiotensin II, and expects to lead additional trials in new sepsis therapeutics in the near future.
He is a site liaison for the award-winning open-access Critical Care Project website, and is the content director for the Tulane Critical Care Project website. In addition, he presently serves on the Editorial Board of the ESICM Academy, and acts as Scientific Content Editor for the Global Sepsis Alliance.
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. He has been invited to serve as faculty for the first ESICM ALIVE symposium to be held in Kampala, Uganda in June 2019, bringing state-of-the-art sepsis education to lower- and middle-income countries.
Dr. Nielsen treats critically ill patients at the University Medical Center – New Orleans, where he also serves as the Medical Director of the Medical Intensive Care Unit. He is actively involved in administrative and quality improvement initiatives at UMCNO, including multiple efforts to support physician and staff wellbeing – one of these initiatives is the first reported hospital-only Death Café.
Outside of the hospital setting, Dr. Nielsen teaches an undergraduate honors college symposium at Tulane University on literature authored by physicians, is a long-standing volunteer with Animal Rescue New Orleans, a member of the executive board of the Mystic Krewe of Barkus, an occasional marathon runner, and a proud pet parent to 3 cats and 3 rescue dogs.
View Dr. Nielsen's publications at his PubMed page.