Newly Published
Perioperative Medicine  |   November 2019
Preoperative Risk and the Association between Hypotension and Postoperative Acute Kidney Injury
Author Notes
  • From the University of Michigan Medical School, Departments of Anesthesiology (M.R.M., A.M.S., M.L.B., D.A.C., A.J., M.C.E., L.S., K.K.T., S.K.) and Internal Medicine (M.H.), Ann Arbor, Michigan; University of Virginia Health System, Department of Anesthesiology and Neurosurgery, Charlottesville, Virginia (B.I.N.); Vanderbilt University Medical Center, Department of Anesthesiology, Division of Anesthesiology Critical Care Medicine, Nashville, Tennessee (R.E.F.); Columbia University Medical Center, Department of Anesthesiology, New York, New York (M.K.); and University of Chicago Medical Center, Department of Anesthesia and Critical Care, Chicago, Illinois (G.R.).
  • Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are available in both the HTML and PDF versions of this article. Links to the digital files are provided in the HTML text of this article on the Journal’s Web site (www.anesthesiology.org).
    Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are available in both the HTML and PDF versions of this article. Links to the digital files are provided in the HTML text of this article on the Journal’s Web site (www.anesthesiology.org).×
  • The authors have presented preliminary findings from this study within conference abstracts at annual meetings of the American Society of Anesthesiology, October 24, 2016 (Chicago, Illinois), the International Anesthesia Research Society, May 5, 2017 (Washington, D.C.), and the American Society of Anesthesiology, October 20, 2017 (Boston, Massachusetts).
    The authors have presented preliminary findings from this study within conference abstracts at annual meetings of the American Society of Anesthesiology, October 24, 2016 (Chicago, Illinois), the International Anesthesia Research Society, May 5, 2017 (Washington, D.C.), and the American Society of Anesthesiology, October 20, 2017 (Boston, Massachusetts).×
  • *Members of Multicenter Perioperative Outcomes Group Investigators are listed in appendix 1.
    Members of Multicenter Perioperative Outcomes Group Investigators are listed in appendix 1.×
  • Submitted for publication February 15, 2019. Accepted for publication October 16, 2019.
    Submitted for publication February 15, 2019. Accepted for publication October 16, 2019.×
  • Correspondence: Address correspondence to Dr. Mathis: University of Michigan, 1500 East Medical Center Drive, 1H247 UH, SPC 5048, Ann Arbor, Michigan 48109-5048. mathism@med.umich.edu. 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
Perioperative Medicine / Cardiovascular Anesthesia / Patient Safety
Perioperative Medicine   |   November 2019
Preoperative Risk and the Association between Hypotension and Postoperative Acute Kidney Injury
Anesthesiology Newly Published on November 26, 2019. doi:https://doi.org/10.1097/ALN.0000000000003063
Anesthesiology Newly Published on November 26, 2019. doi:https://doi.org/10.1097/ALN.0000000000003063
Abstract

Editor’s Perspective:

What We Already Know about This Topic:

  • Acute kidney injury occurs in 13% of patients undergoing major surgery and is associated with a six-fold increased risk of mortality.

  • Single-center studies have demonstrated an association between intraoperative hypotension and acute kidney injury.

What This Article Tells Us That Is New:

  • In a large cohort of noncardiac surgical patients, the incidence of acute kidney injury was 9%.

  • Major factors identifying patients at risk for acute kidney injury included anemia, estimated glomerular filtration rate, elevated risk surgery, American Society of Anesthesiologists Physical Status, and expected anesthesia duration.

  • The relationship between hypotension and acute kidney injury varied by underlying patient and procedural risk. Patients with low risk demonstrated no associated increased risk of acute kidney injury across all blood pressure ranges, whereas patients with the highest baseline risk demonstrated an association between even mild absolute intraoperative hypotension ranges and acute kidney injury.

Background: Despite the significant healthcare impact of acute kidney injury, little is known regarding prevention. Single-center data have implicated hypotension in developing postoperative acute kidney injury. The generalizability of this finding and the interaction between hypotension and baseline patient disease burden remain unknown. The authors sought to determine whether the association between intraoperative hypotension and acute kidney injury varies by preoperative risk.

Methods: Major noncardiac surgical procedures performed on adult patients across eight hospitals between 2008 and 2015 were reviewed. Derivation and validation cohorts were used, and cases were stratified into preoperative risk quartiles based upon comorbidities and surgical procedure. After preoperative risk stratification, associations between intraoperative hypotension and acute kidney injury were analyzed. Hypotension was defined as the lowest mean arterial pressure range achieved for more than 10 min; ranges were defined as absolute (mmHg) or relative (percentage of decrease from baseline).

Results: Among 138,021 cases reviewed, 12,431 (9.0%) developed postoperative acute kidney injury. Major risk factors included anemia, estimated glomerular filtration rate, surgery type, American Society of Anesthesiologists Physical Status, and expected anesthesia duration. Using such factors and others for risk stratification, patients with low baseline risk demonstrated no associations between intraoperative hypotension and acute kidney injury. Patients with medium risk demonstrated associations between severe-range intraoperative hypotension (mean arterial pressure less than 50 mmHg) and acute kidney injury (adjusted odds ratio, 2.62; 95% CI, 1.65 to 4.16 in validation cohort). In patients with the highest risk, mild hypotension ranges (mean arterial pressure 55 to 59 mmHg) were associated with acute kidney injury (adjusted odds ratio, 1.34; 95% CI, 1.16 to 1.56). Compared with absolute hypotension, relative hypotension demonstrated weak associations with acute kidney injury not replicable in the validation cohort.

Conclusions: Adult patients undergoing noncardiac surgery demonstrate varying associations with distinct levels of hypotension when stratified by preoperative risk factors. Specific levels of absolute hypotension, but not relative hypotension, are an important independent risk factor for acute kidney injury.