Volume 6, Issue 8, August – 2021 International Journal of Innovative Science and Research Technology

ISSN No:-2456-2165

Risk Factor Analysis of Post-Operating Cognitive

Dysfunction in Elderly Patients
Aditya Barih Farhan1, Nancy Margarita Rehatta1, Yunias Setiawati2, Widodo J. Pudjirahardjo3
1
Anesthesiology dan Intensive Therapy Department, Medical Faculty of Airlangga University,Surabaya, Indonesia
2
Psychiatric Department, Medical Faculty of Airlangga University, Surabaya, Indonesia
3
Public Health Faculty of Airlangga University, Surabaya, Indonesia

Abstract:- million people. WHO revealed a significant increase in the

Background: The elderly population is increasing as the elderly population in Europe, and the number of elderly is
quality of health care improves. Globally, 50% of all expected to double in 2050. This will also increase the
elderly people are estimated to have had at least one proportion of patients who will receive health services
surgical procedure and postoperative cognitive including anesthesia and intensive treatment. Globally, 50%
dysfunction (POCD) is one of the most common of all elderly people are estimated to undergo at least one
postoperative complications and is often poorly surgical procedure and postoperative cognitive dysfunction
understood in the medical field. this population. (POCD) is one of the most common and often poorly
Although the issue of POCD has been reported in the understood postoperative complications in this part of the
literature for more than a century and it remains an population (Kotekar, N., et., al., 2016; Lim B.G and Lee,
interest in anesthetic research today. Until now, there I.O., 2020; Brummel N.E. and Ferrante L.E., 2018).
are no studies that can explain the specific mechanism of
POCD due to old age. Surgery and anesthesia are also Elderly patients often require a higher level of care
risk factors for POCD. than younger patients during the perioperative period, with
higher health care costs. In addition, elderly patients tend to
Methods: This is an observational analytical study with a have perioperative comorbidities and sometimes
cross-sectional design. This study involved 61 patients accompanied by a decrease in physiological function and
who were evaluated from May to July 2021. Cognitive cognitive function so that it can have an impact on
evaluation using the MMSE was carried out perioperative outcomes and the quality of surgical healing.
preoperatively and postoperatively. Patients with Manifestations of postoperative cognitive dysfunction
abnormal MMSE (score <24) were excluded from the (POCD) may include impaired memory, attention, or
study. Evaluation of delirium was performed before concentration. Although the issue of POCD has been
postoperative cognitive evaluation with CAM score, if reported in the literature for more than century and remains
delirium occur, the subject was excluded from the study. of interest in anesthetic research today. It is estimated that
Risk factor data were tested bivariate. about 41% of elderly patients show some cognitive
impairment after surgery under anesthesia. With the
Results: In 61 patients who were evaluated from May to increasing number of elderly undergoing surgery under
July 2021. There were 8 patients who were excluded general anesthesia worldwide, the problem with POCD after
from the study because 3 patients had abnormal MMSE surgery is an important topic in clinical medicine
values before surgery and 5 patients had postoperative (Andriyanto, L., et., al., 2012; Detweiler M.B., 2017; Lim
delirium so that they were excluded. The bivariate B.G and Lee, I.O., 2020; Chan S.P., et., al., 2019).
analysis showed that the ASA score and the number of
comorbidities were risk factors for the occurrence of Although POCD has been studied more than 30 years
POCD (p=0.001 and p=0.002, respectively). ago, to date there are no studies that can explain the specific
mechanism of DKPO due to old age. Old age is synonymous
Conclusion: The number of comorbidities and the ASA with decreased productivity, which also means a decrease in
score were significant as risk factors for postoperative patient independence, which manifests with certain organ
cognitive dysfunction. dysfunctions. Surgery and anesthesia are also risk factors for
DKPO. In surgery, risk factors are associated with a stress
Keywords:- Postoperative Cognitive Dysfunction, Risk response that increases the secretion of catecholamines and
Factors, Elderly, MMSE. cortisol (Lee S.J., et., al., 2020).

I. INTRODUCTION The impact of impaired cognition for patients varies, it

can be in the form of minor disturbances that may not be felt
The population of elderly patients is increasing in line by the patient but can also hinder the mobilization and
with the increase quality of health services in Indonesia and rehabilitation of postoperative patients and increase patient
throughout the world. By 2030, the population of the United dependence. Furthermore, postoperative decline in cognitive
States aged 65 years and over is predicted to double to 70 function was also associated with an increased risk of death

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Volume 6, Issue 8, August – 2021 International Journal of Innovative Science and Research Technology
ISSN No:-2456-2165
one year postoperatively. The purpose of this study was to III. RESULTS
analyze the risk factors for the incidence of postoperative
cognitive dysfunction in elderly patients (Andriyanto, L., et This study involved 61 patients who were evaluated
al., 2012; Sahana S., et al., 2020). from May to July 2021. There were 8 patients who were
excluded from the study because 3 patients had abnormal
II. METHODS MMSE values before surgery and 5 patients experienced
postoperative delirium so that cognitive evaluation could not
This is a cross sectional study of elderly patient who be carried out. Of the 53 patients evaluated, 20 patients
needs anesthesia while surgery in elective operating room (37.7%) experienced POCD and 33 patients (62.3%) did not
Dr. Soetomo Academic Hospital from May untill July 2021. experience POCD. The proportion of POCD events is shown
Patients were enrolled consecutively unless exclusion in Figure 1.
criteria were applied. The inclusion criteria include age > 60
years, patients with ASA Score II-III and can communicate
well (not deaf, not mute, not mentally retarded, and not
senile) while completing the cognitive test. The subject will POCD
be excluded if refused to be research subjects; patients who 37.70%
has abnormal MMSE evaluation and history of Craniotomy
and Psychiatric disorder. If the patient died after surgery or
decreasing condition so that can’t be evaluated such as No
postoperative delirium (POD) will be dropped out. The POCD;
patient will undergo cognitive evaluation 72 hours after 62.30%
surgery and the patient observed in post anesthesia care unit
(PACU)

Ethical considerations Figure 1. Frequency of POCD

Informed consent for access to medical records and
interview to get medical history was obtained from each From 53 study subjects we evaluated the patient's
patient. Written informed consent was obtained from recent education. As shown in Figure 2, which shows that
participants 1 day before elective surgery. These processes most of the patients have a secondary education
and research protocols were approved by ethical committee background/equivalent. Details of educational background
in Dr Soetomo Academic Hospital (0198/KEPK/V/2021). consisted of 6 patients (11.5%) who did not finish
elementary school, 11 patients graduated from elementary
Statistical analysis school/equivalent (21.6%), 19 patients graduated from
Bivariate analysis was conducted to determine the junior high school/equivalent (36.2%), 10 patients graduated
relationship of two independent variable with one dependent from high school/ equivalent (19.2%), while the other 6
variable. P value of <0.05 indicates a significant value. Data patients (11.5%) were able to take and complete the
analysis was performed using SPSS ver.26.0 (SPSS, undergraduate level of study. Based on bivariate analysis,
Chicago, IL). there was no significant difference between the last
education and the incidence of POCD (p = 0.226).

11% 11%
Not finished elementary school
21% 21%
Elementary school
Junior High School
Senior High School
36%
Undergraduate

Figure 2. Frequency of patient based on education level

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Volume 6, Issue 8, August – 2021 International Journal of Innovative Science and Research Technology
ISSN No:-2456-2165
Table 1. Characteristics of subject study
POCD N
Characteristics Mean/Median p value
Yes No
Age (year) 64 (60-79) 66 (60-79) 64 (60-76) 0.0001
BMI (kg/m2) 23+3.8 22.79  4.25 23.7  3.68 0.200
Gender 0.0001
Male 12 (60%) 21 (63.6%) 33
Female 8 (40%) 12 (36.4%) 20
Comorbidity number 3(1-4) 4 (2-4) 3 (1-4) 0.0001
Surgery type 0.0001
Otorhinolaryngology 2 (10%) 6 (18.2%) 8
Urology 6 (30%) 8 (24.2%) 14
Digestive 3 (15%) 7 (21.2%) 10
Orthopedic 7 (35%) 5 (15.2%) 12
Ophthalmology 1 (5%) 2 (6.1%) 3
Vascular 1 (5%) 1 (3%) 2
Gynecology 0 4 (12.1%) 4
ASA Score 0.0001
ASA 2 8 (40%) 27 (81.2%) 35
ASA 3 12 (60%) 6 (18.2%) 18
Anesthesia type 0.0001
General 11 (55%) 20 (60%) 31
Regional 6 (30.3%) 10 (30.3%) 16
Combination 3 (15%) 3 (9.1%) 6
*p value normality: Kolmogorov-Smirnov test

Analysis of risk factors for the occurrence of POCD was carried out by using a bivariate test on predetermined variables.
Based on the bivariate test, it was found that the number of comorbidities and the ASA score had statistically significant
differences (p = 0.001 and p = 0.002), while other variables including type of surgery and type of anesthesia did not have a
statistically significant value with a p value respectively 0.873 and 0.609. Complete data on the risk factor bivariate test can be
seen in table 2 below.

Table 2. Risk factors for POCD

Variables POCD p value
Yes No
Gender 0.791
Male 12 (60%) 21 (63.6%)
Female 8 (40%) 12 (36.4%)
Comorbidity number 4 (2-4) 3 (1-4) 0.001*
Surgery type 0.873
Otorhinolaryngology 2 (10%) 6 (18.2%)
Urology 6 (30%) 8 (24.2%)
Digestive 3 (15%) 7 (21.2%)
Orthopedic 7 (35%) 5 (15.2%)
Ophthalmology 1 (5%) 2 (6.1%)
Vascular 1 (5%) 1 (3%)
Gynecology 0 4 (12.1%)
ASA Score 0.002*
ASA 2 8 (40%) 27 (81.2%)
ASA 3 12 (60%) 6 (18.2%)
Anesthesia type 0.609
General 11 (55%) 20 (60.6%)
Regional 6 (30%) 10 (30.3%)
Combination 3 (15%) 3 (9.1%)
*p<0.05 significant difference

In the bivariate test of risk factors for the incidence of and p=0.002, respectively. Meanwhile, in the bivariate test,
POCD and bivariate were carried out. The bivariate test of the surgical risk factors including the type of surgery did not
patient risk factors including the number of comorbidities have statistical significance with p-values of 0.873. In the
and the ASA score had statistical significance with p=0.001 bivariate test of anesthetic risk factors by taking into account

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Volume 6, Issue 8, August – 2021 International Journal of Innovative Science and Research Technology
ISSN No:-2456-2165
the type of anesthetic used, the p value = 0.609, which non-cardiac surgery (Mohanty, 2016). When compared in
means there is no statistical significance. this study, the percentage was similar at 37.7% as was the
case in the study of Sahana et., al., which also had a similar
IV. DISCUSSION percentage of POCD incidence of 37.5% (in the general
anesthetic group). In another trial involving 200 elderly
A total of 53 patients who met the inclusion and patients showed that the incidence of anesthesia under
exclusion criteria were observed in this study. Detection of general anesthesia with sevoflurane (33.3%) and propofol
cognitive dysfunction using the MMSE found 20 patients (29.7%) (Cottrell, J.E and Hartung, J, 2020). This
had POCD. The number of research subjects who are male percentage range seems consistent in this study with other
with the most types of surgery are Urology 14 patients and studies.
Orthopedia 12 patients. The type of anesthesia observed was
divided into general anesthesia, regional anesthesia and Risk factors for POCD related to patients include
combination anesthesia groups. gender, number of comorbidities, status of
independence/dependence. In a study conducted by Kotekar,
Subject characteristics were arranged based on age, et., al., it was stated that women are more at risk of
body mass index, gender, educational history, number of developing POCD than men, which is thought to come from
comorbidities, type of surgery, ASA score and type of hormonal factors. (Kotekar, 2018) Furthermore, the article
anesthesia. Educational history can affect cognitive stability also explained that the risk factors for sex were lower than
with age and degradation of brain function. Educational the increase in age. In this study, the bivariate test showed
history should also be able to maintain the level of that there was no relationship between gender and age with
independence of an elderly person even though the incidence of POCD.
independence is associated with the presence or absence of
multiple comorbidities (Sahana, S., et., al., 2020). In this The patient's independence factor is closely related to
study, there were 6 patients (11.5%) who did not finish the level of education and cognitive abilities that are still
elementary school education, but most of the subjects' good in old age. In a study conducted by Riani and Halim
education history was junior high school/equivalent (36%) who noted that 47% of the total elderly in Indonesia are still
which is the minimum education required by the working (Riani, 2019). The condition of elderly patients
government through the 9-year compulsory education who are still working will maintain their cognitive function
program. With this Most of the population has sufficient compared to the elderly who are not working. In this study,
Education. neither the independence status nor the level of education
did not affect the incidence of POCD. This can be biased
The independence of elderly patients which in this with diverse educational backgrounds.
study was measured by the Barthel index can describe the
outcomes of patients who are hospitalized. By analyzing the Risk factors for the occurrence of POCD related to the
relationship between POCD and the independence of the operation process include the type of operation. Many
elderly, we can predict the outcome of surgery, the studies aim to identify the incidence of POCD in certain
rehabilitation process and postoperative recovery. In this types of operations. In this study, there were 7 types of
study, there were 9 patients who had mild dependence surgery which included ENT, urology, digestive, vascular,
before surgery. While the other 44 patients had a good level orthopedia, gynecology, and ophthalmology operations. The
of independence. The results of the analysis of the bivariate test did not show a significant relationship between
relationship between the Barthel index and the incidence of the type of surgery and the incidence of DKPO. Likewise,
POCD were not significant (p = 0.255) (Ryg, J., et., al., the presence of intraoperative events does not significantly
2018) cause POCD.
Although it was explained by Sahana et., al., that the
higher the age, the higher the chance of POCD occurring, in In the study of Zhang, Y., et., al., who evaluated the
this study, age had no significant effect on the incidence of risk factors for surgery, it was found that longer fasting
POCD (p=0.599). Battelli et., al., said that the extreme age triggers POCD while the duration of surgery, the incidence
of the condition decreased, namely above 80 years. In this of hypotension, bleeding, transfusion and a significant
study, the highest age was 79 years. The possibility of age decrease in Hb were not significant as risk factors for POCD
does not affect the incidence of POCD because there is no (Zhang, 2019).
extreme age group in this study. Obesity will affect the
inflammatory process that occurs and has the potential to Meanwhile, in a study by Shoair, O.A., et., al., in 2021
have a higher inflammatory response tendency when which selected geriatric subjects who underwent non-cardiac
compared to people who are not obese. In this study, there surgery and specialized in orthopedic surgery and simple
was only 1 patient with obesity, so it was not enough to be spine surgery compared to patients who did not receive
analyzed. surgery or anesthesia. The purpose of the study was to
determine the risk factors for the occurrence of POCD
Swartz stated that the POCD rate at discharge from the (Shoair, 2021).
hospital was between 36.6-41.4% (Swartz, 2017). While
Mohanty, et., al., stated that postoperative cognitive The variables studied in this study included education
impairment was 25.8% in patients aged over 60 years in level and type of anesthesia (which were divided into 3

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Volume 6, Issue 8, August – 2021 International Journal of Innovative Science and Research Technology
ISSN No:-2456-2165
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