In Elderly Patients, Does Goal-directed Fluid Management Using the Carotid Corrected Flow Time (CC-FT) Index, Compared to Routine Fluid Management, Affect the Occurrence of Post-induction Hypotension?

Effect of Carotid Corrected Flow Time-Guided Volume Management on Post-Induction Hypotension in Elderly Patients

This study aims to find out whether using a simple ultrasound measurement of blood flow in the neck artery can help doctors decide how much fluid to give older patients before general anesthesia, and thereby reduce the drop in blood pressure that commonly occurs after anesthesia induction. Older adults are more likely to experience low blood pressure during anesthesia, and such drops have been linked to kidney injury, heart injury, and even death after surgery. Giving too little fluid can worsen organ blood supply, while giving too much can cause fluid overload, lung swelling, and heart strain. Currently, doctors often rely on static measures such as central venous pressure, or on invasive dynamic measures such as pulse pressure variation, but these have limited accuracy or require expensive equipment and invasive procedures. Carotid corrected flow time (FTc), measured non-invasively with ultrasound, reflects left ventricular preload and has shown promise for predicting fluid responsiveness, including in spontaneously breathing patients. However, evidence in older adults undergoing abdominal surgery remains limited to observational studies, and higher-level evidence from randomized trials is needed. We therefore plan a single-center, prospective, randomized, parallel-controlled trial in 70 patients aged 65 years or older scheduled for elective abdominal surgery under general anesthesia. Participants will be randomly assigned 1:1 to an FTc-guided prehydration group or a conventional fluid group. In the intervention group, if FTc falls below 340.7 ms, 250 mL of lactated Ringer's solution will be infused over 15 minutes, and FTc will be re-measured until it reaches at least 340.7 ms, in addition to a background infusion of 6 mL/kg/h started 30 minutes before induction. The control group will receive the same background infusion without FTc-guided adjustment. The primary outcome is the incidence of post-induction hypotension, defined as mean arterial pressure below 65 mmHg or a decrease of more than 20% from baseline within 15 minutes after induction. Secondary outcomes include the area under the curve of mean arterial pressure change from baseline during induction, intraoperative use of vasoactive agents, actual pre-induction fluid volume, postoperative pulmonary complications (pulmonary edema), acute kidney injury, myocardial injury, adverse events in the post-anesthesia care unit, time to first flatus and defecation, and all-cause mortality within 30 days after surgery.

Primary Hypothesis

Compared with conventional fluid management, carotid FTc-guided prehydration before anesthesia induction will reduce the incidence of post-induction hypotension in older patients undergoing elective abdominal surgery under general anesthesia.

Study Overview

• Status: Not yet recruiting
• Conditions: Aged; Hypotension (MeSH: D007022)
• Intervention / Treatment: Other: CC-FT Guided Fluid Management Group; Other: Conventional Fluid Management Group

• Study Type: Interventional
• Enrollment (Estimated): 70
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Zhihong LU Zhihong LU; Phone Number: 86029-84775343; Email: deerlu23@163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 65 years and older (Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

Age ≥ 65 years;

Scheduled for elective abdominal surgery under general anesthesia.

Exclusion Criteria:

ASA physical status > III;

BMI > 30 kg/m² or < 18.5 kg/m²;

History of neck surgery or neck trauma;

History of peripheral arterial disease or arteriosclerosis, carotid artery stenosis exceeding one-third of the lumen, or significant anatomical variation of the carotid artery;

NYHA functional class > III;

History of cardiomyopathy or valvular heart disease;

Non-sinus rhythm;

Concomitant hypotension due to conditions such as septic shock;

Refusal to participate in the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: CC-FT Guided Fluid Management Group; atients will receive fluid management guided by the Carotid Corrected Flow Time (CC-FT) index during anesthesia induction.	Other: CC-FT Guided Fluid Management Group; Patients will receive fluid management guided by the Carotid Corrected Flow Time (CC-FT) index during anesthesia induction.
Active Comparator: Conventional Fluid Management Group; Patients will receive routine fluid management based on standard clinical parameters during anesthesia induction.	Other: Conventional Fluid Management Group; Patients will receive routine fluid management based on standard clinical parameters during anesthesia induction.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
ncidence of post-induction hypotension	Incidence of MAP < 65 mmHg or a decrease of more than 20% from baseline	defined as within 15 minutes after induction

Collaborators and Investigators

• Sponsor: Zhihong LU

Study record dates

Study Major Dates

• Study Start (Estimated): November 25, 2026
• Primary Completion (Estimated): May 31, 2027
• Study Completion (Estimated): June 30, 2027

Study Registration Dates

• First Submitted: November 3, 2026
• First Submitted That Met QC Criteria: November 3, 2026
• First Posted (Actual): November 9, 2026

Study Record Updates

• Last Update Posted (Actual): November 9, 2026
• Last Update Submitted That Met QC Criteria: November 3, 2026
• Last Verified: November 1, 2026

More Information

Terms related to this study

• Keywords: Post-induction hypotension; Carotid Corrected Flow Time
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Hypotension
• Other Study ID Numbers: XJH-A-20261015

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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