PostoperAtive Neurocognitive Dysfunction After Major Abdominal Surgery (PANDS)

Study Overview
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Brief Summary
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Predisposing and precipitating factors for perioperative delirium for the elderly remain elusive. This research will be conducted to determine risk factors of postoperative delirium.

Detailed Description
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The investigators hypothesize that preoperative anxiety and sleep disturbance are critical risk factors for postoperative delirium in elderly patients undergoing elective major abdominal surgery, and thus this single-center, prospective cohort study is designed to verify the relationship between preoperative anxiety and sleep disturbance and postoperative delirium in high-risk patients. This study intends to include 400 participants over 60 years old undergoing elective abdominal major surgery. The primary outcome is incidence of delirium at 7 days postoperatively, and the secondary outcomes include postoperative sleep disturbance, delirium severity, pain intensity, analgesic drug consumption, postoperative hospital stay, and 30-day postoperative Number Rating Scale (NRS) pain score, mini-intelligence test assessment, and health-related quality of life.

Official Title
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Postoperative Neurocognitive Dysfunction After Major Abdominal Surgery: A Prospective Observational Cohort Study

Conditions
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Elective Major Abdominal Surgery

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 60 to 90 years old to receive elective major surgery (expected operation time over 2 hours); , American society of Aneshesiologists（ASA）physical status I-III; Exclusion Criteria: Mini-Mental State Examination (MMES) score < 15; Renal failure (requiring dialysis) or liver failure (Child-Pugh score > 5); Severe impairment due to structural or hypoxic brain injury, more than 2 days in ICU one month before surgery; Underwent major heart, lung or abdominal surgery within 1 year; Positive for Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or symptomatic (e.g. fever, cough, loss of taste/smell); The cognitive assessment cannot be completed because the subject is blind, deaf, or unable to communicate in the local language; Long-term follow-up unavailable (homelessness, active psychosis or substance abuse).

Ages Eligible for Study
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Minimum Age: 60 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Prospective observational cohorts<br>patients undergoing elective major surgery (estimated operation time over 2 hours) | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of delirium during first 7 days after surgery | The result of 3-minute Diagnostic Interview for Confusion Assessment Method (3D-CAM) is positive. | Up to 7 postoperative days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sleep quality | Athens Insomnia Scale (AIS) includes 8 items, and each item is rated on an ordinal scale of 0-3, (with 0 corresponding to no problem at all and 3 to a very serious problem). A maximum total score of 24 indicates the most severe symptoms of insomnia, while a cut-off point of ≥6 represents a minimum criterion for the confirmation of insomnia symptoms. | Postoperative 1, 3, 7 days | 
| Hospital Anxiety and Depression | Hospital Anxiety and Depression Scale (HADS) consists of two independent subscales, anxiety subscale of Hospital Anxiety and Depression Scale (HADS-A) and depression subscale of Hospital Anxiety and Depression Scale(HADS-D), each with seven items that measures symptoms of anxiety and depression, respectively. Each item is rated on a scale from 0-3 with the possible total scores from each subscale ranging from 0-21. Participants scoring 8-10 will be categorized as having moderate symptoms of depression and/or anxiety and participants scoring 11-21 as having severe symptoms. | Up to 7 postoperative days | 
| Alexithymia | Toronto Alexithymia Scale (TAS-20) is a 20-item self-report questionnaire rated on a five-point response format ranging from 1 to 5 and the total score is computed based on all 20 items. There are three commonly referenced thresholds for the TAS-20 total score, where the first ranges from 20 to 50, the second from 51 to 60, and the last ranging from 61 to 100, which refers to as No Alexithymia, Low Alexithymia, and High Alexithymia, respectively. | Up to 7 postoperative days | 
| Ruminative thinking | Ruminative thinking will be measured by the Ruminative Response Scale, a 22 item self-report scale assessing the propensity to ruminate in response to depression. Each item is rated on a four-point scale ranging from one (almost never) to four (always). Higher scores indicate higher levels of rumination. | Up to 7 postoperative days | 
| Pain intensity | Number Rating Scale (NRS) is composed of 11 numbers from 0 to 10 where 0 is no pain or hurt and 10 is the most or worst pain. Participants use these 11 numbers to describe the intensity of pain. The higher the number, the more severe the pain. | Up to 3 postoperative days | 
| Postoperative adverse complications | Include but limited to hospital readmissions 30 days after surgery, unplaned reoperations, stroke, kidney failure, and wound infections. | Up to 30 days after surgery | 
| All-cause mortality at 30 days after surgery | The ratio of total deaths from all causes to the population | At 30 days after surgery | 
| The Mini-Mental State Examination (MMSE) | The Mini-Mental State Examination (MMSE) will be used before surgery to establish a cognitive function baseline of participants, and at discharge to explore any association with postoperative delirium (POD), which is a 30-point questionnaire, and the sum of all item points produces total scores of MMSE, ranging from 0 to 30. A higher score indicates better cognitive function. In this study, the investigators set a score of less than 15 as the threshold for neurocognitive dysfunction. | up to 90 postoperative days | 
| The abbreviated mental test score (AMTS) | The abbreviated mental test score (AMTS) will be administered by telephone at 90 days after surgery postoperatively to identify long-term cognitive consequences of anaesthesia and POD, which includes 10 questions, each question scores 1 point, participants with AMTS scores between 8-10 will be classified as cognitively normal while those with score < 8 will be identified as possible neurocognitive dysfunction. | At 90 days after surgery |