Gregory Hare


Scientist, Li Ka Shing Knowledge Institute


Dr. Hare is a Staff Anesthesiologist, Professor of Anesthesia, at St. Michael’s Hospital 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. His 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. Cahill, LS, Gazdzinski, LM, Tsui, AK, Zhou, YQ, Portnoy, S, Liu, E et al.. Functional and anatomical evidence of cerebral tissue hypoxia in young sickle cell anemia mice. J. Cereb. Blood Flow Metab. 2016; :. doi: 10.1177/0271678X16649194. PubMed PMID:27165012 .
  2. Hare, GM. Studying propofol-induced cardioprotection: from mechanism to clinical phenomenon and back again. Can J Anaesth. 2016;63 (4):392-396. doi: 10.1007/s12630-015-0581-y. PubMed PMID:26721647 .
  3. Vorobeichik, L, Hare, GM, Zirkle, M, Garavaglia, MM. Airway Management of Incidental Vallecular Cysts in Adults. A A Case Rep. 2015;5 (12):223-7. doi: 10.1213/XAA.0000000000000222. PubMed PMID:26657703 .
  4. Morrison, MA, Tam, F, Garavaglia, MM, Golestanirad, L, Hare, GM, Cusimano, MD et al.. A novel tablet computer platform for advanced language mapping during awake craniotomy procedures. J. Neurosurg. 2016;124 (4):938-44. doi: 10.3171/2015.4.JNS15312. PubMed PMID:26473779 .
  5. Baker, JE, Pavenski, K, Pirani, RA, White, A, Kataoka, M, Waddell, JP et al.. Universal tranexamic acid therapy to minimize transfusion for major joint arthroplasty: a retrospective analysis of protocol implementation. Can J Anaesth. 2015;62 (11):1179-87. doi: 10.1007/s12630-015-0460-6. PubMed PMID:26335903 .
  6. Garavaglia, MM, Das, S, Hare, GM. Selective Right Lower Lobe Isolation to Control CO2 in a Patient With Raised ICP Undergoing Craniotomy. J Neurosurg Anesthesiol. 2015;27 (3):270-1. doi: 10.1097/ANA.0000000000000137. PubMed PMID:25373720 .
  7. Curley, GF, Shehata, N, Mazer, CD, Hare, GM, Friedrich, JO. Transfusion triggers for guiding RBC transfusion for cardiovascular surgery: a systematic review and meta-analysis*. Crit. Care Med. 2014;42 (12):2611-24. doi: 10.1097/CCM.0000000000000548. PubMed PMID:25167086 .
  8. Beattie, WS, Hare, GM. Beta-blockers are the old BLACK. Can J Anaesth. 2014;61 (9):787-93. doi: 10.1007/s12630-014-0199-5. PubMed PMID:25074592 .
  9. Tsui, AK, Marsden, PA, Mazer, CD, Sled, JG, Lee, KM, Henkelman, RM et al.. Differential HIF and NOS responses to acute anemia: defining organ-specific hemoglobin thresholds for tissue hypoxia. Am. J. Physiol. Regul. Integr. Comp. Physiol. 2014;307 (1):R13-25. doi: 10.1152/ajpregu.00411.2013. PubMed PMID:24760996 .
  10. Ashes, C, Judelman, S, Wijeysundera, D, Tait, G, Hare, GM, Mazer, CD et al.. In reply. Anesthesiology. 2014;120 (5):1287-8. doi: 10.1097/ALN.0000000000000196. PubMed PMID:24755798 .
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Affiliations & Other Activities

  • Scientist in the Keenan Research Centre for Biomedical Science of St. Michael’s Hospital
  • Professor, Anesthesia, University of Toronto
  • Professor, Physiology, University of Toronto
  • Associate Member, Institute of Medical Science, University of Toronto