Newly Published
Perioperative Medicine  |   March 2020
Defining an Intraoperative Hypotension Threshold in Association with De Novo Renal Replacement Therapy after Cardiac Surgery
Author Notes
  • From the Division of Cardiac Surgery (J.M.C.N., H.J., M. Boodhwani, M.R.) and the Division of Cardiac Anesthesiology (A.M.C., M. Bourke, L.Y.S.), Cardiocore Big Data Research Unit (L.Y.S.), University of Ottawa Heart Institute, Ottawa, Canada; the School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada (L.Y.S.), and the Cardiovascular Research Program, Institute for Clinical Evaluative Sciences, Toronto, Canada (L.Y.S.).
  • 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).×
  • Part of the work presented in this article has been presented at the American Heart Association Scientific Sessions in Anaheim, California, November 11 to 15, 2017.
    Part of the work presented in this article has been presented at the American Heart Association Scientific Sessions in Anaheim, California, November 11 to 15, 2017.×
  • J.M.C.N. and H.J. contributed equally to this article.
    J.M.C.N. and H.J. contributed equally to this article.×
  • Submitted for publication January 5, 2019. Accepted for publication February 14, 2020.
    Submitted for publication January 5, 2019. Accepted for publication February 14, 2020.×
  • Correspondence: Address correspondence to Dr. Sun: Dr. Louise Y. Sun, 40 Ruskin Street, Ottawa, Ontario, Canada. LSun@ottawaheart.ca. 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
Perioperative Medicine   |   March 2020
Defining an Intraoperative Hypotension Threshold in Association with De Novo Renal Replacement Therapy after Cardiac Surgery
Anesthesiology Newly Published on March 19, 2020. doi:https://doi.org/10.1097/ALN.0000000000003254
Anesthesiology Newly Published on March 19, 2020. doi:https://doi.org/10.1097/ALN.0000000000003254
Abstract

Background: Acute kidney injury (AKI) is a frequent and deadly complication after cardiac surgery. In the absence of effective therapies, a focus on risk factor identification and modification has been the mainstay of management. The authors sought to determine the impact of intraoperative hypotension on de novo postoperative renal replacement therapy in patients undergoing cardiac surgery, hypothesizing that prolonged periods of hypotension during and after cardiopulmonary bypass (CPB) were associated with an increased risk of renal replacement therapy.

Methods: Included in this single-center retrospective cohort study were adult patients who underwent cardiac surgery requiring CPB between November 2009 and April 2015. Excluded were patients who were dialysis dependent, underwent thoracic aorta or off-pump procedures, or died before receiving renal replacement therapy. Degrees of hypotension were defined by mean arterial pressure (MAP) as less than 55, 55 to 64, and 65 to 74 mmHg before, during, and after CPB. The primary outcome was de novo renal replacement therapy.

Results: Of 6,523 patient records, 336 (5.2%) required new postoperative renal replacement therapy. Each 10-min epoch of MAP less than 55 mmHg post-CPB was associated with an adjusted odds ratio of 1.13 (95% CI, 1.05 to 1.23; P = 0.002), and each 10-min epoch of MAP between 55 and 64 mmHg post-CPB was associated with an adjusted odds ratio of 1.12 (95% CI, 1.06 to 1.18; P = 0.0001) for renal replacement therapy. The authors did not observe an association between hypotension before and during CPB with renal replacement therapy.

Conclusions: MAP less than 65 mmHg for 10 min or more post-CPB is associated with an increased risk of de novo postoperative renal replacement therapy. The association between intraoperative hypotension and AKI was weaker in comparison to factors such as renal insufficiency, heart failure, obesity, anemia, complex or emergent surgery, and new-onset postoperative atrial fibrillation. Nonetheless, post-CPB hypotension is a potentially easier modifiable risk factor that warrants further investigation.

Editor’s Perspective:

What We Already Know about This Topic:

  • Patients undergoing cardiac surgery with cardiopulmonary bypass are at risk for acute kidney injury requiring de novo renal replacement therapy

  • The specific association between pre–, during, and post–cardiopulmonary bypass hypotension and de novo renal replacement therapy remains unclear

What This Article Tells Us That Is New:

  • Varying definitions of hypotension before and during cardiopulmonary bypass are not associated with renal replacement therapy

  • Mean arterial pressure less than 55 or between 55 and 64 mmHg for 10 or more minutes after cardiopulmonary bypass is associated with renal replacement therapy

  • The association of post–cardiopulmonary bypass hypotension with renal replacement therapy is weaker than nonmodifiable procedure and patient risk factors