Hypotension Prediction Index in Major Gastrointestinal Surgery

Study Overview
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Brief Summary
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Intraoperative hypotension (IOH) is defined as a mean arterial pressure (MAP) of < 65mmHg during surgery. Patients undergoing major gastrointestinal (GI) surgery, such as esophagectomy with reconstruction, are at a high-risk of IOH because such surgeries typically require more than 3h to complete and require blood transfusion or inotrope administration. Critically, these surgeries involve organ removal or substitute connection, which require wound or flap anastomosis. IOH is believed to be associated with postoperative anastomosis necrosis. It increases the risk of postoperative intrathoracic or abdominal infection, resulting in septic shock, postoperative major organ dysfunction and mortality. The data of TWA-MAP< 65mmHg in the HPI guidance group will be significantly lower than that in the group without HPI guidance.

Detailed Description
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Intraoperative hypotension (IOH) is defined as a mean arterial pressure (MAP) of < 65mmHg during surgery. Patients undergoing major gastrointestinal (GI) surgery, such as esophagectomy with reconstruction, are at a high-risk of IOH because such surgeries typically require more than 3h to complete and require blood transfusion or inotrope administration. Critically, these surgeries involve organ removal or substitute connection, which require wound or flap anastomosis. IOH is believed to be associated with postoperative anastomosis necrosis. It increases the risk of postoperative intrathoracic or abdominal infection, resulting in septic shock, postoperative major organ dysfunction and mortality. The Hypotension Prediction Index (HPI) is an algorithm made commercially available in 2019. On the basis of arterial waveform features, HPI predicts hypotension defined as MAP < 65 mmHg for at least 1 min. In two previous randomized trials(RCTs), the primary outcome was the severity and duration of hypotension, defined as a time-weighted average mean arterial pressure (TWA-MAP) less than 65 mmHg (formula: (total area under MAP<65mmHg(mmHg*hours))/(surgery length (hours));normal range:0.01-0.5mmHg).A higher data of TWA-MAP<65mmHg indicates severe and longer IOH. However, according to the results of the previous two RCTs, the effects of HPI guidance during surgery remain inconclusive. We aim to investigate whether HPI guidance can be used to reduce the duration and severity of hypotension during major GI surgery. Our hypothesis is that the data of TWA-MAP< 65mmHg in the HPI guidance group will be significantly lower than that in the group without HPI guidance. Postoperative major complications and mortality will be followed. Methods: Sixty patients aged 20 to 80 years undergoing elective GI surgery will be randomized to receive hemodynamic management with or without HPI guidance. Clinicians caring for patients assigned to the HPI guidance group will be alerted when the index exceeded 85 (range 0 to 100) indicating the later occurrence of MAP< 65mmHg for at least minutes and a treatment protocol based on advanced hemodynamic parameters recommended vasopressor or inotrope, fluid administration, or observation. Primary outcome is the data of TWA-MAP<65mmHg. Postoperative complications will be recorded on postoperative day 3,7 and 30. The mortality rate from the time of hospitalization to postoperative 30 days will be recorded. The data of TWA-MAP< 65mmHg in the HPI guidance group will be significantly lower than that in the group without HPI guidance.

Official Title
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Investigation of the Effect of Applying Hypotension Prediction Index Guidance for Prevention of Intraoperative Hypotension During Major Gastrointestinal Surgery: A Randomized Trial

Conditions
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the Effect of Hypotension Prediction Index Application

Intervention / Treatment
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* Device: hypotension prediction index guided
* Device: without hypotesion prediction index guided


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients receiving elective major gastrointestinal surgery Exclusion Criteria: emergent surgery pregnant women

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 80 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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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Single Group Assignment
Interventional Model Description: using hypotension prediction index guided in the operation
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: patients with hypotension prediction index guided<br>Patients receiving hypotension prediction index guided. In this group, they will be alerted when the index exceeded 85 (range 0 to 100) indicating the later occurrence of MAP< 65mmHg for at least minutes and a treatment protocol based on advanced hemodynamic parameters recommended vasopressor or inotrope, fluid administration, or observation. | Device: hypotension prediction index guided<br>* patients receiving hypotension prediction index monitoring and let the anesthesiologist' alerted the coming intraoperatiobe hypotension<br>|
| Other: patients without hypotension prediction index gudied<br>Patients will receive usual care during the operation without hypotension prediction index alerted. | Device: without hypotesion prediction index guided<br>* patients receiving usual care without hypotension prediction index monitoring but with usual arterial line care<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| time-weighted average mean arterial pressure less than 65 mmHg | .A higher data of time-weighted average mean arterial pressure less than 65 mmHg indicates severe and longer intraoperative hypotension | during the operation |