Intraoperative Hypotension and Metabolomics in Major Upper Gastrointestinal Surgery

Study Overview
=================
Brief Summary
-----------------
We will investigate the effect of hypotension prediction index guidance on intraoperative hypotension and metabolomics in patients undergoing major upper gastrointestinal surgery

Detailed Description
-----------------
Intraoperative hypotension (IOH) has been shown to increase the risk of postoperative morbidity and mortality. The Hypotension prediction index (HPI) guidance is an algorithm that can predict impending hypotension, defined as mean arterial pressure below 65mmHg. Patients undergoing major upper abdominal surgery are at high risk of IOH occurrence, because the surgical procedures involve organ removal like intestinal resection and vessel or organ anastomoses or reconstruction, often associated with high blood loss. However, the effectivity of applying HPI for reducing the duration and severity of IOH and postoperative morbidity and mortality in short term within 30 days after surgery and long term within 1 year remains inconclusive. Postoperative ileus (POI) generally defines absence of flatus within 72 hours after surgery. POI is known as the most important factor to slow patient recovery, increase postoperative morbidity and prolong the hospital stay following major upper abdominal surgery. Metabolomics can investigate the small molecule changes in response to certain stimulus, such as different environments. Metabolomics involves the comprehensive analysis of metabolites. In recent years, metabolomics has several applications in the early diagnosis and prevention of health and disease. However, the association between the POI occurrence and the metabolites in the presence and absence HPI guidance have not yet been investigated. The proposed strategy and specific objectives of this 2 years project using a randomized controlled trial are as the follows: To clarify the effect of HPI application on intraoperative hypotension prevention and postoperative complications in patients undergoing major upper abdominal surgery To clarify the relationship of POI occurrence to presence and absence of HPI guidance To Explore differences in metabolites in presence or absence of HPI guidance. Explore the potential metabolites associated with POI in different intraoperative environment in using HPI and no HPI guidance.

Official Title
-----------------
Investigating the Effect of Hypotension Prediction Index Guidance on Intraoperative Hypotension and the Relationships Between the Metabolomic Profile and Postoperative Ileus in Patients Undergoing Major Upper Abdominal Surgery: a Randomized Controlled Trial

Conditions
-----------------
the Intraoperative Hypotension

Intervention / Treatment
-----------------
* Procedure: hypotension prediction index guidance
* Procedure: no hypotension prediction index guidance


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: elective upper gastrointestinal surgery Exclusion Criteria: no laparoscopic surgery

Ages Eligible for Study
-----------------
Minimum Age: 20 Years
Maximum Age: 80 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: patients with/without hypotension prediction index guidance
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: hypotension prediction index guided<br>patients with hypotension prediction index guidance | Procedure: hypotension prediction index guidance<br>* using hypotension prediction index guidance to prevent intraoperative hypotension<br>|
| Active Comparator: no hypotension prediction index guided<br>patients without hypotension prediction index guidance | Procedure: no hypotension prediction index guidance<br>* silencing hypotension prediction index guidance during surgery<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| time weighted average mean arterial pressure less than 65 mmHg | the severity and duration of hypotension during surgery | surgery |