Newly Published
Perioperative Medicine  |   May 2019
Postoperative Delirium and Postoperative Cognitive Dysfunction: Overlap and Divergence
Author Notes
  • From the Alzheimer’s Disease and Memory Disorders Center, Rhode Island Hospital, Providence, Rhode Island (L.A.D.); Institute for Aging Research, Hebrew SeniorLife, Boston, Massachusetts (A.M.R., R.Y.G., S.K.I.); Harvard Medical School, Boston, Massachusetts (A.M.R., E.R.M., Z.X., L.J.K., K.V.V., S.K.I.); Departments of Medicine (E.R.M., S.K.I.) and Anesthesia and Critical Care (L.J.K.), Beth Israel Deaconess Medical Center, Boston, Massachusetts; Department of Anesthesia, Massachusetts General Hospital, Boston, Massachusetts (Z.X.); Department of Anesthesiology, Perioperative, and Pain Medicine, Brigham and Women’s Hospital, Boston, Massachusetts (K.V.V.); Departments of Psychiatry and Human Behavior (R.N.J.) and Neurology (L.A.D., R.N.J.), Brown University Warren Alpert Medical School, Providence, Rhode Island.
  • This work was presented in part at the Alzheimer’s Association International Conference, London, United Kingdom (July 15, 2017).
    This work was presented in part at the Alzheimer’s Association International Conference, London, United Kingdom (July 15, 2017).×
  • S.K.I. and R.N.J. contributed equally to this article.
    S.K.I. and R.N.J. contributed equally to this article.×
  • Submitted for publication May 25, 2018. Accepted for publication February 28, 2019.
    Submitted for publication May 25, 2018. Accepted for publication February 28, 2019.×
  • *Members of the Successful Aging after Elective Surgery (SAGES) Study Group are listed in appendix 1.
    Members of the Successful Aging after Elective Surgery (SAGES) Study Group are listed in appendix 1.×
  • Acknowledgments: The authors gratefully acknowledge the contributions of the patients, family members, nurses, physicians, staff members, and members of the Executive Committee who participated in the Successful Aging after Elective Surgery (SAGES) Study (see appendix 1). This work is dedicated to the memory of Joshua Bryan Inouye Helfand and Jane Ann McDowell, R.N., M.S.N.
    Acknowledgments: The authors gratefully acknowledge the contributions of the patients, family members, nurses, physicians, staff members, and members of the Executive Committee who participated in the Successful Aging after Elective Surgery (SAGES) Study (see appendix 1). This work is dedicated to the memory of Joshua Bryan Inouye Helfand and Jane Ann McDowell, R.N., M.S.N.×
  • Research Support: This work was supported by the National Institutes of Health (Bethesda, Maryland) grant Nos. P01AG031720 (to Dr. Inouye), K07AG041835 (to Dr. Inouye), R24AG054259 (to Dr. Inouye), R01AG044518 (to Drs. Inouye and Jones), R01AG030618 (to Dr. Marcantonio), K24AG035075 (to Dr. Marcantonio), and T32AG023480 (to Dr. Racine). Dr. Inouye holds the Milton and Shirley F. Levy Family Chair. The funding sources had no role in the design, conduct, or reporting of this study.
    Research Support: This work was supported by the National Institutes of Health (Bethesda, Maryland) grant Nos. P01AG031720 (to Dr. Inouye), K07AG041835 (to Dr. Inouye), R24AG054259 (to Dr. Inouye), R01AG044518 (to Drs. Inouye and Jones), R01AG030618 (to Dr. Marcantonio), K24AG035075 (to Dr. Marcantonio), and T32AG023480 (to Dr. Racine). Dr. Inouye holds the Milton and Shirley F. Levy Family Chair. The funding sources had no role in the design, conduct, or reporting of this study.×
  • Competing Interests: The authors declare no competing interests.
    Competing Interests: The authors declare no competing interests.×
  • Correspondence: Address correspondence to Dr. Daiello: Alzheimer’s Disease and Memory Disorders Center, Rhode Island Hospital, 593 Eddy Street, Providence, Rhode Island 02903. lori_daiello@brown.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 / Central and Peripheral Nervous Systems / Geriatric Anesthesia
Perioperative Medicine   |   May 2019
Postoperative Delirium and Postoperative Cognitive Dysfunction: Overlap and Divergence
Anesthesiology Newly Published on May 28, 2019. doi:10.1097/ALN.0000000000002729
Anesthesiology Newly Published on May 28, 2019. doi:10.1097/ALN.0000000000002729
Abstract

Editor’s Perspective:

What We Already Know about This Topic:

  • Postoperative delirium and postoperative cognitive dysfunction both occur in a substantial number of older surgical patients

  • Postoperative delirium and postoperative cognitive dysfunction share risk factors and may co-occur, although their relationship is unclear

What This Article Tells Us That Is New:

  • Postoperative delirium increased the risk of postoperative cognitive dysfunction at 1 month postoperatively but there was no association between postoperative delirium and cognitive dysfunction at 2 and 6 months after major noncardiac surgery

  • Postoperative delirium and longer-term postoperative cognitive dysfunction may be different disorders

Background: Postoperative delirium and postoperative cognitive dysfunction share risk factors and may co-occur, but their relationship is not well established. The primary goals of this study were to describe the prevalence of postoperative cognitive dysfunction and to investigate its association with in-hospital delirium. The authors hypothesized that delirium would be a significant risk factor for postoperative cognitive dysfunction during follow-up.

Methods: This study used data from an observational study of cognitive outcomes after major noncardiac surgery, the Successful Aging after Elective Surgery study. Postoperative delirium was evaluated each hospital day with confusion assessment method–based interviews supplemented by chart reviews. Postoperative cognitive dysfunction was determined using methods adapted from the International Study of Postoperative Cognitive Dysfunction. Associations between delirium and postoperative cognitive dysfunction were examined at 1, 2, and 6 months.

Results: One hundred thirty-four of 560 participants (24%) developed delirium during hospitalization. Slightly fewer than half (47%, 256 of 548) met the International Study of Postoperative Cognitive Dysfunction-defined threshold for postoperative cognitive dysfunction at 1 month, but this proportion decreased at 2 months (23%, 123 of 536) and 6 months (16%, 85 of 528). At each follow-up, the level of agreement between delirium and postoperative cognitive dysfunction was poor (kappa less than .08) and correlations were small (r less than .16). The relative risk of postoperative cognitive dysfunction was significantly elevated for patients with a history of postoperative delirium at 1 month (relative risk = 1.34; 95% CI, 1.07–1.67), but not 2 months (relative risk = 1.08; 95% CI, 0.72–1.64), or 6 months (relative risk = 1.21; 95% CI, 0.71–2.09).

Conclusions: Delirium significantly increased the risk of postoperative cognitive dysfunction in the first postoperative month; this relationship did not hold in longer-term follow-up. At each evaluation, postoperative cognitive dysfunction was more common among patients without delirium. Postoperative delirium and postoperative cognitive dysfunction may be distinct manifestations of perioperative neurocognitive deficits.