Original Research
The Prevalence and Impact of Undiagnosed Mild Cognitive Impairment in Elderly Patients Undergoing Thoracic Surgery: A Prospective Cohort Study

https://doi.org/10.1053/j.jvca.2020.03.011Get rights and content

Objectives

The objective of this study was to explore the prevalence of undiagnosed mild cognitive impairment (MCI) and its association with adverse outcomes in elderly patients undergoing thoracic surgery.

Setting

Large tertiary medical center.

Participants

The authors enrolled 170 patients aged 65 years or older who were scheduled for thoracic surgery between November 7, 2018, and April 1, 2019, at the Shanghai Chest Hospital. Patients with a history of schizophrenia or dementia disease, uncorrected vision or hearing impairment, and refusal to participate were excluded.

Interventions

A total of 154 elderly patients completed the Chinese version of the Montreal Cognitive Assessment (MoCA) test preoperatively and were included in the final analysis. They were categorized into a normal group (MoCA ≥ 26 scores, group N) and an abnormal group (MoCA < 26 scores, group AN) based on test results. Delirium was assessed with the Confusion Assessment Method twice daily during the first 3 postoperative days.

Measurements and Main Results

The primary outcome was the incidence of postoperative delirium (POD). Secondary outcomes included the incidence of postoperative pulmonary complications (PPCs), cardiovascular complications, other complications, intensive care unit (ICU) stay, and the hospital length of stay (LOS). The incidence of MCI before thoracic surgery in elderly patients was 49.4% (76 of 154). Compared with group N, MCI could increase the incidence of POD (14.1% v 30.3%, p = 0.016) and median LOS (4 d v 5 d, p = 0.016). However, the differences in pulmonary complications, cardiovascular and other complications, and ICU stay were not significant. Multivariable logistic regression analysis showed preoperative MCI (OR = 2.573, 95% CI =1.092 to 6.060, p = 0.031) as an independent risk factor of POD. Compared with the elderly patients without POD, POD could increase the risk of PPCs (17.5% v 35.3%, p = 0.026) and median LOS (4 d v 5 d, p < 0.001).

Conclusions

The incidence of MCI before thoracic surgery in elderly patients was higher and associated with a higher rate of adverse postoperative outcomes. The findings may be important for preoperative patient counseling, operative planning, and eventually reducing potential risk exposure and related outcomes.

Section snippets

Methods and Materials

This prospective cohort study enrolled 170 elderly patients from November 7, 2018, to April, 1, 2019, at the Shanghai Chest Hospital. Patients with a history of schizophrenia or dementia, uncorrected vision or hearing impairment, and refusal to participate were excluded. A total of 154 elderly patients completed the Chinese version of the MoCA test preoperatively and were included in the final analysis. This study was approved by the Institutional Review Board (KS1862) of Shanghai Jiao Tong

Results

A total of 154 elderly patients aged 65 years or older scheduled for thoracic surgery were included in the final analysis (Fig 1). The incidence of MCI and postoperative delirium in elderly patients was 49.4% (76 of 154) and 22% (34 of 154), respectively. There were no significant differences in demographic and baseline characteristics between the 2 groups (Table 1).

Compared with group N, MCI could increase the incidence of POD (14.1% v 30.3%, p = 0.016) and median LOS (4 d v 5 d, p = 0.016).

Discussion

The incidence of MCI before thoracic surgery in elderly patients was higher and associated with a higher rate of POD and prolonged median LOS. In addition, compared with the elderly patients without POD, POD could increase the risk of PPCs and median LOS. Preoperative MCI screening may help to provide interventions for patients at greatest risk of adverse outcomes after surgery, thereby benefiting them.

The Chinese version of the MoCA scale is mainly used to evaluate MCI in elderly patients,

Conclusions

The incidence of MCI before thoracic surgery in elderly patients was higher and associated with a higher rate of postoperative adverse outcomes. The findings may be important for preoperative patient counseling, operative planning, and eventually reducing potential risk exposure and related outcomes.

Acknowledgements

The authors would like to thank the nurse anesthesiologists in the operating room of the Shanghai Chest Hospital, Shanghai, the People's Republic of China, for their involvement and support.

Conflict of Interest

None of the authors has financial relationships with any companies or entities that make products pertinent to the paper.

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    This work was supported by the Shanghai Municipal Science and Technology Committee (Western Medicine Guided Project) 16411967600 Fund and Shanghai Municipal Commission of Health and Family Planning Project 201840319.

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