Newly Published
Clinical Focus Review  |   October 2019
Personalizing the Definition of Hypotension to Protect the Brain
Author Notes
  • From the Department of Anesthesiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois (K.M.B., A.H., R.H., B.D., C.L., C.W.H.); and the Department of Anesthesiology, Ann and Robert Lurie Children's Hospital, Chicago, Illinois (K.M.B.).
  • Submitted for publication May 2, 2019. Accepted for publication September 9, 2019.
    Submitted for publication May 2, 2019. Accepted for publication September 9, 2019.×
  • Correspondence: Address correspondence to Dr. Hogue: Northwestern University Feinberg School of Medicine, 251 E. Huron Street, Feinberg Pavilion, Suite 5-704, Chicago, Illinois 60611. charles.hogue@nm.org. Information on purchasing reprints may be found at www.anesthesiology.org or on the masthead page at the beginning of this issue. Anesthesiology‘s articles are made freely accessible to all readers, for personal use only, 6 months from the cover date of the issue.
Article Information
Cardiovascular Anesthesia / Central and Peripheral Nervous Systems / Endocrine and Metabolic Systems / Neurosurgical Anesthesia / Clinical Focus Review
Clinical Focus Review   |   October 2019
Personalizing the Definition of Hypotension to Protect the Brain
Anesthesiology Newly Published on October 21, 2019. doi:https://doi.org/10.1097/ALN.0000000000003005
Anesthesiology Newly Published on October 21, 2019. doi:https://doi.org/10.1097/ALN.0000000000003005
Originally championed by Harvey Cushing in the early 1900s, the measurement of blood pressure during anesthesia and surgery became widespread in the 1920s.1,2  Physicians soon recognized the relationship between intraoperative hypotension and adverse patient outcomes.3  Nonetheless, over a century later there is presently no agreement on a universally accepted definition of hypotension.4  In this focused review, we will briefly discuss a common approach for defining hypotension based on arbitrary or population-driven thresholds. We then will propose a novel method for potentially defining hypotension individually based on monitoring cerebral blood flow autoregulation.
The controversy regarding how to best define intraoperative hypotension was highlighted in a systematic review by Bijker et al.,4  who identified 130 manuscripts that utilized 140 different definitions for this term. The most frequently used definition (12.9% of articles) was a relative decrease in systolic blood pressure more than 20% from baseline followed by the combination of systolic blood pressure of less than 100 mmHg or a more than 30% decrease from baseline (7.9% of articles). These definitions, however, were mostly based on opinion and historical precedent. Further, determining a true “baseline” blood pressure is challenging in an operative setting.