Greg Hare

Cardiovascular and Respiratory Platform


Research Interests
Anemia, Hypoxia, Oxygen Delivery
Clinical Interests
Blood Conservation, Neuroanesthesia


  • MD, PhD, FRCPC

Professor, Departments of Anesthesia and Physiology, University of Toronto
Anesthesiologist, St. Michael’s Hospital
Adjunct Scientist, Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael’s Hospital

Research Synopsis

Dr. Gregory Hare is a Staff Anesthesiologist at St. Michael’s Hospital and a Professor in the Department of Anesthesia at the University of Toronto. His clinical focus is to develop multimodal and inter-professional approaches to optimize patient outcomes through patient blood management strategies.

Research Interests and Key Accomplishments 

Dr. Hare's long-term research goal is to define mechanisms of anemia-induced morbidity and mortality; and to design novel treatment strategies to prevent these adverse outcomes. His research is focused on defining adaptive, and maladaptive, cardiovascular mechanisms in experimental models of acute anemia using integrative whole animal models. These translational studies have defined mechanism of anemia-induced tissue hypoxia and mortality. Dr. Hare’s laboratory has identified integrative adaptive cellular (nNOS and HIF) and physiological mechanisms, which promote organism survival during acute anemia. In addition, their laboratory has demonstrated that acute beta-blockade interferes with adaptive cardiovascular mechanisms, which sustain cerebral oxygen delivery during anemia-possibly explaining the negative interaction between acute anemia and beta-blockade and the increased incidence of stroke in perioperative patients. The laboratory is currently focused on translational approaches to identify patient specific biomarkers of anemia-induced tissue hypoxia in order to identify when patients are at risk of anemia induced morbidity and mortality; and to derive patient specific therapies which  can reduce morbidity and mortality associated with both anemia and red blood cell transfusion. The overall clinical goal is to reduce morbidity and mortality associated with acute and chronic anemia in perioperative patients. 

Recent Publications

Hare GMT. Cellular oxygen sensing and the anesthesiologist: the Nobel-worthy discovery of hypoxia inducible factor and its implications in clinical practice. Can J Anaesth. 2020 Feb;67(2):174-176. Epub 2019 Nov 11. No abstract available.

Bao J, Shore EM, Simpson AN, Hare GMT, Sholzberg M, Robertson D. Delphi Approach for the Design of an Intraoperative Blood Conservation Pathway for Open Myomectomy. J Obstet Gynaecol Can. 2020 Jan;42(1):31-37. Epub 2019 Jul 8.

Ho A, Zaltzman J, Hare GMT, Chen L, Fu L, Tarlo SM, Vadas P. Severe and near-fatal anaphylactic reactions triggered by chlorhexidine-coated catheters in patients undergoing renal allograft surgery: a case series. Can J Anaesth. 2019 Dec;66(12):1483-1488. Epub 2019 Jul 1.

Rigamonti A, Garavaglia MM, Ma K, Crescini C, Mistry N, Thorpe K, Cusimano MD, Das S, Hare GMT, Mazer CD. Effect of bilateral scalp nerve blocks on postoperative pain and discharge times in patients undergoing supratentorial craniotomy and general anesthesia: a randomized-controlled trial. Can J Anaesth. 2019 Dec 26. [Epub ahead of print].

Duffin J, Hare GMT, Fisher JA. A mathematical model of cerebral blood flow control in anaemia and hypoxia. J Physiol. 2019 Dec 10. [Epub ahead of print].