Gregory Hare

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 Synopsis

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

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. doi: 10.1007/s12630-019-01558-7. [Epub ahead of print]
2. Duffin J, Hare GMT, Fisher JA. A mathematical model of cerebral blood flow control in anaemia and hypoxia. J Physiol. 2019 Dec 10. doi: 10.1113/JP279237. [Epub ahead of print]
3. Baron Shahaf D, Hare GMT, Baker AJ, Chenosia V, Priven L, Mistry N, Shahaf G. A New Index of Coordinated Posterior and Anterior Evoked EEG to Detect Recall Under Sedation - A Pilot Study.Sci Rep. 2019 Nov 28;9(1):17859. doi: 10.1038/s41598-019-54270-3.
4. 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. doi: 10.1007/s12630-019-01526-1. Epub 2019 Nov 11. No abstract available.
5. Mazer CD, Hare GMT, Connelly PW, Gilbert RE, Shehata N, Quan A, Teoh H, Leiter LA, Zinman B, Jüni P, Zuo F, Mistry N, Thorpe KE, Goldenberg RM, Yan AT, Connelly KA, Verma S. Effect of Empagliflozin on Erythropoietin Levels, Iron Stores and Red Blood Cell Morphology in Patients with Type 2 Diabetes and Coronary Artery Disease.Circulation. 2019 Nov 11. doi: 10.1161/CIRCULATIONAHA.119.04423 [Epub ahead of print]
6. Mistry N, Kei T, Pavenski K, Mazer CD, Hare GMT. In reply: Erythropoietin and iron: separating the builder from his blocks. Can J Anaesth. 2020 Mar;67(3):388-389. doi: 10.1007/s12630-019-01510-9. Epub 2019 Oct 21. No abstract available.
7. Cahill LS, Pilmeyer J, Yu LX, Steinman J, Hare GMT, Kassner A, Macgowan CK, Sled JG. Ultrasound Detection of Abnormal Cerebrovascular Morphology in a Mouse Model of Sickle Cell Disease Based on Wave Reflection. Ultrasound Med Biol. 2019 Dec;45(12):3269-3278. doi: 10.1016/j.ultrasmedbio.2019.08.017. Epub 2019 Sep 26.
8. 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. doi: 10.1016/j.jogc.2019.04.023. Epub 2019 Jul
9. 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. doi: 10.1007/s12630-019-01441-5. Epub 2019 Jul 1.
10. Mazer CD, Whitlock RP, Fergusson DA, Belley-Cote E, Connolly K, Khanykin B, Gregory AJ, de Médicis É, Carrier FM, McGuinness S, Young PJ, Byrne K, Villar JC, Royse A, Grocott HP, Seeberger MD, Mehta C, Lellouche F, Hare GMT, Painter TW, Fremes S, Syed S, Bagshaw SM, Hwang NC, Royse C, Hall J, Dai D, Mistry N, Thorpe K, Verma S, Jüni P, Shehata N; TRICS Investigators and Perioperative Anesthesia Clinical Trials Group. Six-Month Outcomes after Restrictive or Liberal Transfusion for Cardiac Surgery. N Engl J Med. 2018 Sep 27;379(13):1224-1233. doi: 10.1056/NEJMoa1808561. Epub 2018 Aug 26.

Appointments

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

Honours and Awards

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• 2018 – 2019 William Noble Fellowship Teaching Award, Department of Anesthesia, Faculty of Medicine, St. Michael’s Hospital.
• 2017 Research Recognition Award, Canadian Anesthesiologists’ Society.
• 2017 Richard Knill Research Award, Best Scientific Presentation, Canadian Anesthesiologists’ Society.