Risk factors for postoperative delirium in patients undergoing orthopedic procedures: a systematic review and meta-analysis

Rio Suzuki, Aina Nakanishi, Masahiro Masuya, Keiko Fukuroku, Yukari Taneda, Yutaka Matsuura

Abstract

Delirium is a common complication in surgical patients following operative procedures; it often occurs in patients undergoing lower-extremity surgery. It is essential to identify and prevent the risk factors for postoperative delirium (POD) in these cases. We aimed to determine the risk factors for POD in patients who underwent lower-extremity surgery through a systematic review and meta-analysis. 

Introduction

Delirium, characterized by disturbances in attention, acute changes from baseline attention and awareness, and disturbances in cognition, is a common complication in patients who have undergone surgery [1]. Incidence rates vary across clinical departments, with orthopedic surgery patients experiencing delirium ranging from 12% to 51%, notably higher than the 11% and 14% observed in general ward adimission[2].

Materials and methods

In this study, we evaluated risk factors for delirium in patients undergoing lower-extremity orthopedic surgery by integrating results from previous studies. This meta-analysis was not registered but was performed following the preferred reporting items for systematic reviews and meta-analysis (PRISMA) 2020 statement (S1 Table).

Results

The database search identified 2,599 records using predefined search keywords. A total of 568 studies were excluded due to duplication and screened by reviewing the title and/or abstract following the inclusion and exclusion criteria. 

Discussion

This study revealed the risk factors for delirium in patients who underwent lower-extremity surgery through a systematic review and meta-analysis. We identified 27 studies, including 11 prospective and 16 retrospective cohort studies, and extracted 67 factors associated with POD from characteristics.

Conclusion

In conclusion, 20 factors were revealed to be associated with POD following orthopedic surgery. Several factors identified in this study were related to abnormal neurotransmitter secretion and reduced cerebral perfusion, which are associated with POD. 

Citation: Suzuki R, Nakanishi A, Masuya M, Fukuroku K, Taneda Y, Matsuura Y (2025) Risk factors for postoperative delirium in patients undergoing orthopedic procedures: a systematic review and meta-analysis. PLoS ONE 20(4): e0321025. https://doi.org/10.1371/journal.pone.0321025

Editor: Amirhossein Ghaseminejad-Raeini, Tehran University of Medical Sciences Endocrinology and Metabolism Research Institute, IRAN, ISLAMIC REPUBLIC OF

Received: October 10, 2024; Accepted: February 27, 2025; Published: April 1, 2025

Copyright: © 2025 Suzuki et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the manuscript and its Supporting Information files

Funding: JSPS KAKENHI Grant Numbers JP22K10813 and JP22K10838.
Competing interests: No.