Perioperative Salivary Alpha-amylase as a Predictor of Delirium After Lower Extremity Vascular Bypass Surgery

The aim of this study is to evaluate the role of salivary Alpha-amylase as a predictor biomarker of POD in elderly patients undergoing limb bypass surgery.

Study Overview

• Status: Completed
• Conditions: Delirium; Lower Extremity; Salivary Alpha-amylase; Vascular Bypass Surgery
• Intervention / Treatment: Diagnostic test: Salivary Alpha-amylase

Detailed Description

Delirium is a neuropsychiatric syndrome that is characterized by the sudden onset of altered awareness, decreased ability to maintain attention, and disorders of the mental process. The pathophysiology of Postoperative delirium (POD) is related to postoperative neuroinflammation.

Biomarkers not only indicate a certain pathological state, but also provide information about disease activity and progression. Although several biomarkers are reported to predict POD, biomarkers with high sensitivity and specificity are still lacking.

Biochemical parameters associated with complement cascade (C3a, C3, C5a) and inflammatory response (IL-17A, IL-33, E-selectin, MMP9) were involved in neurocognitive regulation.

Salivary alpha amylase (SAA) enzyme is one of the most important enzyme compositions in the saliva that accounts for 40% to 50% of the total salivary proteins, and most of it is secreted from the parotid gland. SAA is locally produced by the highly differentiated epithelial acinar cells of the exocrine salivary glands, mostly of the parotid glands and plays an important role in carbohydrate hydrolysis.

• Study Type: Observational
• Enrollment (Actual): 60

Contacts and Locations

Study Locations

• Egypt
  • El-Gharbia
    • Tanta, El-Gharbia, Egypt, 31527
      • Tanta University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

60 patients aged ≥ 65 years, both sexes, American Society of Anesthesiologists (ASA) physical status III, undergoing lower extremity vascular surgery under general anesthesia.

Description

Inclusion Criteria:

• Age ≥ 65 years.
• Both sexes.
• American Society of Anesthesiologists (ASA) physical status III.
• Undergoing lower extremity vascular surgery under general anesthesia.

Exclusion Criteria:

• Patients who used any medication that could affect salivary glands (such as antihypertensive, antidepressants or antipsychotic drugs).
• Inability to communicate.
• History of psychiatric diseases or previous stroke
• Previous history of pod.
• Those with smoking and drinking habits.
• Pregnant female.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Postoperative delirium (POD) group; Patients who will develop postoperative delirium	Diagnostic test: Salivary Alpha-amylase; Saliva samples will be obtained using a saliva collection system and salivary Alpha-amylase (SAA) level will be measured preoperatively, immediately postoperative, at the end of the 1st, 2nd, and 3rd postoperative days. For sampling, the swab will be placed into the patient's mouth for 2-5min by a specially trained nurse. A minimum of 0.2mL of saliva will be needed as per the manufacturer's recommendations to saturate the swab.
No Postoperative delirium (POD) group; Patients who will not develop postoperative delirium	Diagnostic test: Salivary Alpha-amylase; Saliva samples will be obtained using a saliva collection system and salivary Alpha-amylase (SAA) level will be measured preoperatively, immediately postoperative, at the end of the 1st, 2nd, and 3rd postoperative days. For sampling, the swab will be placed into the patient's mouth for 2-5min by a specially trained nurse. A minimum of 0.2mL of saliva will be needed as per the manufacturer's recommendations to saturate the swab.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The accuracy of salivary alpha-amylase as a predictor of postoperative delirium	The accuracy of salivary alpha-amylase will be measured by saliva samples which will be obtained using a saliva collection system and SAA level will be measured preoperatively, immediately postoperative, at the end of the 1st, 2nd, and 3rd postoperative days.	3rd day postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation of salivary alpha-amylase with C-reactive protein	Correlation of salivary alpha-amylase with C-reactive protein will be assessed.	24 hours postoperatively
Correlation of salivary alpha-amylase with average pain score	Correlation of salivary alpha-amylase with average pain score will be assessed. Pain score will be assessed using numeric rating scale (NRS) score. NRS (0 represents "no pain" while 10 represents "the worst pain imaginable.	24 hours postoperatively
Correlation of salivary alpha-amylase with morphine consumption	Correlation of salivary alpha-amylase with morphine consumption will be assessed.	24 hours postoperatively
Incidence of postoperative delirium	Incidence of postoperative delirium will be measured.	first 5 days after surgery

Collaborators and Investigators

• Sponsor: Tanta University

Study record dates

Study Major Dates

• Study Start (Actual): February 10, 2024
• Primary Completion (Actual): June 17, 2025
• Study Completion (Actual): June 19, 2025

Study Registration Dates

• First Submitted: January 27, 2024
• First Submitted That Met QC Criteria: January 27, 2024
• First Posted (Actual): February 5, 2024

Study Record Updates

• Last Update Posted (Estimated): June 25, 2025
• Last Update Submitted That Met QC Criteria: June 23, 2025
• Last Verified: October 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Mental Disorders; Confusion; Neurobehavioral Manifestations; Neurocognitive Disorders; Delirium
• Other Study ID Numbers: 36264PR462/12/23

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The data will be available upon a reasonable request from the corresponding author after the end of study for one year.
• IPD Sharing Time Frame: After the end of study for one year.
• IPD Sharing Access Criteria: The data will be available upon a reasonable request from the corresponding author.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No