title: Association between Intraoperative Hypotension and Hypertension and 30-day Postoperative Mortality in Noncardiac Surgery.
abstract: BACKGROUND
  Although deviations in intraoperative blood pressure are assumed to be associated with postoperative mortality, critical blood pressure thresholds remain undefined. Therefore, the authors estimated the intraoperative thresholds of systolic blood pressure (SBP), mean blood pressure (MAP), and diastolic blood pressure (DBP) associated with increased risk-adjusted 30-day mortality.
  
  
  METHODS
  This retrospective cohort study combined intraoperative blood pressure data from six Veterans Affairs medical centers with 30-day outcomes to determine the risk-adjusted associations between intraoperative blood pressure and 30-day mortality. Deviations in blood pressure were assessed using three methods: (1) population thresholds (individual patient sum of area under threshold [AUT] or area over threshold 2 SDs from the mean of the population intraoperative blood pressure values), (2). absolute thresholds, and (3) percent change from baseline blood pressure.
  
  
  RESULTS
  Thirty-day mortality was associated with (1) population threshold: systolic AUT (odds ratio, 3.3; 95% CI, 2.2 to 4.8), mean AUT (2.8; 1.9 to 4.3), and diastolic AUT (2.4; 1.6 to 3.8). Approximate conversions of AUT into its separate components of pressure and time were SBP < 67 mmHg for more than 8.2 min, MAP < 49 mmHg for more than 3.9 min, DBP < 33 mmHg for more than 4.4 min. (2) Absolute threshold: SBP < 70 mmHg for more than or equal to 5 min (odds ratio, 2.9; 95% CI, 1.7 to 4.9), MAP < 49 mmHg for more than or equal to 5 min (2.4; 1.3 to 4.6), and DBP < 30 mmHg for more than or equal to 5 min (3.2; 1.8 to 5.5). (3) Percent change: MAP decreases to more than 50% from baseline for more than or equal to 5 min (2.7; 1.5 to 5.0). Intraoperative hypertension was not associated with 30-day mortality with any of these techniques.
  
  
  CONCLUSIONS
  Intraoperative hypotension, but not hypertension, is associated with increased 30-day operative mortality.
authors.affiliation: From the Emeritus Faculty, Durham VA Medical Center, Durham, North Carolina (T.G.M.); Department of Anesthesiology and Perioperative Medicine, University of Missouri, Columbia, Missouri (T.G.M.); Adult and Child Center for Outcomes Research and Delivery Science (ACCORDS), Aurora, Colorado (M.R.B., W.G.H.); Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora, Colorado (W.G.H.); Department of Anesthesiology, University of Pittsburgh School of Medicine, VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania (M.P.M.); Department of Anesthesiology and Pain Management, University of Texas Southwestern Medical Center, VA North Texas Health Care System, Dallas, Texas (S.T.J.S.-P.); Department of Anesthesiology and Critical Care Medicine, George Washington University School of Medicine, Washington DC VA Medical Center, Washington, D.C. (D.R.B.); Department of Anesthesiology, Baylor College of Medicine, Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas (J.D.N.); Department of Surgery, University of Alabama Birmingham, Birmingham VA Medical Center, Birmingham, Alabama (J.S.R.); Department of Surgery, University of Colorado School of Medicine, Aurora, Colorado (R.A.M.); and Department of Medicine (Cardiology), University of Colorado School of Medicine, Aurora, Colorado (K.E.H.).
authors.forename: Terri G
authors.initials: TG
authors.lastname: Monk
authors.forename: Michael R
authors.initials: MR
authors.lastname: Bronsert
authors.forename: William G
authors.initials: WG
authors.lastname: Henderson
authors.forename: Michael P
authors.initials: MP
authors.lastname: Mangione
authors.forename: S T John
authors.initials: ST
authors.lastname: Sum-Ping
authors.forename: Deyne R
authors.initials: DR
authors.lastname: Bentt
authors.forename: Jennifer D
authors.initials: JD
authors.lastname: Nguyen
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Richman
authors.forename: Robert A
authors.initials: RA
authors.lastname: Meguid
authors.forename: Karl E
authors.initials: KE
authors.lastname: Hammermeister
mesh_terms: D001795:Blood Pressure Determination / Q000401:mortality / Q000639:trends; D015331:Cohort Studies; D005260:Female; D006787:Hospitals, Veterans / Q000639:trends*; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000401:mortality*; D007022:Hypotension / Q000175:diagnosis / Q000401:mortality*; D008297:Male; D016343:Monitoring, Intraoperative / Q000401:mortality* / Q000639:trends*; D009026:Mortality / Q000639:trends; D011183:Postoperative Complications / Q000175:diagnosis / Q000401:mortality*; D012189:Retrospective Studies; D013997:Time Factors