Superior Vena Cava Collapsibility Index for Predicting Fluid Responsiveness During High-risk Non-cardiac Surgery

NCT ID: NCT06188039

Last Updated: 2026-01-06

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 150 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-01-03
• Study Completion Date: 2025-11-18

Brief Summary

The goal of this prospective study is to validate the superior vena cava collapsibility index (SVC-CI) as a predictor of fluid responsiveness during laparotomy and open aortic surgery. The SVC-CI and patients' response to fluid will be assessed based on transesophageal echocardiography.

The study has three arms, in order to validate SVC-CI under the conditions of laparotomy, aortic cross clamping and high PEEP levels. One of the study arms will be an active comparator arm.

The data obtained from this study may help physicians guide intraoperative fluid therapy in a more efficient manner, in order to decrease perioperative mortality.

Detailed Description

Patients undergoing high-risk non-cardiac surgery, including acute laparotomies and open aortic surgery, are at high risk of postoperative complications and adverse cardiovascular events. Perioperative fluid therapy is a factor which is strongly associated with postoperative outcomes. To avoid both hypovolemia and excessive fluid administration a strategy of goal-directed fluid therapy (GDFT) has been coined. Traditionally in the setting of operating rooms GDFT relied on stroke-volume variation (SVV) measured by hemodynamic monitors, based on uncalibrated pulse contour cardiac output analysis (uAPCO). However in the described cohort of patients uAPCO methods show a significantly increased measurement error, which is mainly attributed to dynamic changes in peripheral vascular tone. Furthermore, frequent occurrence of arhytmias in those patients limits the use of SVV and all other dynamic indices of fluid responsiveness based on those methods. Superior vena cava collapsibility index (SVC-CI) is a parameter which is devoid of the above mentioned limitations. It relies on respiratory variation of superior vena cava during the respiratory cycle and is therefore reliable in patients with irregular heart rhytm and seems independent from changing afterload conditions.

The main purpose of this study is to validate SVC-CI in patients undergoing controlled mechanical ventilation during laparotomies and during open aortic surgery, with focus on elevated PEEP levels and aortic cross-clamping.

Conditions

Surgery; Fluid Responsiveness; Transesophageal Echocardiography

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: DIAGNOSTIC
• Blinding Strategy: NONE

Study Groups

Patients undergoing open aortic surgery with sinus rhythm

Arm to validate SVC-CI during open aortic surgery with special focus of predicting FR during aortic cross clamping (n=50).

Group Type: EXPERIMENTAL

Superior vena cava collapsibility index

Intervention Type: DIAGNOSTIC_TEST

After induction of general anaesthesia following interventions will be performed.

1. Insertion of a tranesophageal echocardiography probe

2. Measurement of SVC-CI

3. Measurement of LVOT-VTI prior to fluid bolus

4. Fluid bolus (250ml of crystalloid)

5. Measurement of LVOT-VTI after fluid bolus

Several volume trials per patient will be allowed, until safety criteria are met. In such cases further testing will be stopped.

Patients undergoing laparotomy and high PEEP

Arm designed to validate SVC-CI during laparotomy, ventilated with high PEEP levels (8-10cmH2O). PEEP will be raised transiently during measurements (n=50).

Group Type: EXPERIMENTAL

Superior vena cava collapsibility index

Intervention Type: DIAGNOSTIC_TEST

After induction of general anaesthesia following interventions will be performed.

1. Insertion of a tranesophageal echocardiography probe

2. Measurement of SVC-CI

3. Measurement of LVOT-VTI prior to fluid bolus

4. Fluid bolus (250ml of crystalloid)

5. Measurement of LVOT-VTI after fluid bolus

Several volume trials per patient will be allowed, until safety criteria are met. In such cases further testing will be stopped.

PEEP elevation

Intervention Type: OTHER

A transient elevation of positive end-expiratory pressure (PEEP) will be applied, in order to validate SVC-CI in the setting of elevated PEEP.

A PEEP level of 8-10cmH2O will be applied for 1 minute prior to every measurement of SVC-CI. Then the previous PEEP level will be reinstated.

Patients undergoing laparotomy with standard ventilatory settings

Arm designed as an active comparator with standard (protective) ventilatory settings (n=50). Tidal volumes (Vt) will be set for 8ml/kg.

Group Type: ACTIVE_COMPARATOR

Superior vena cava collapsibility index

Intervention Type: DIAGNOSTIC_TEST

After induction of general anaesthesia following interventions will be performed.

1. Insertion of a tranesophageal echocardiography probe

2. Measurement of SVC-CI

3. Measurement of LVOT-VTI prior to fluid bolus

4. Fluid bolus (250ml of crystalloid)

5. Measurement of LVOT-VTI after fluid bolus

Several volume trials per patient will be allowed, until safety criteria are met. In such cases further testing will be stopped.

Interventions

Superior vena cava collapsibility index

After induction of general anaesthesia following interventions will be performed.

1. Insertion of a tranesophageal echocardiography probe

2. Measurement of SVC-CI

3. Measurement of LVOT-VTI prior to fluid bolus

4. Fluid bolus (250ml of crystalloid)

5. Measurement of LVOT-VTI after fluid bolus

Several volume trials per patient will be allowed, until safety criteria are met. In such cases further testing will be stopped.

Intervention Type: DIAGNOSTIC_TEST

PEEP elevation

A transient elevation of positive end-expiratory pressure (PEEP) will be applied, in order to validate SVC-CI in the setting of elevated PEEP.

A PEEP level of 8-10cmH2O will be applied for 1 minute prior to every measurement of SVC-CI. Then the previous PEEP level will be reinstated.

Intervention Type: OTHER

Other Intervention Names

SVC-CI; fluid bolus; transesophageal echocardiography

Eligibility Criteria

Inclusion Criteria

• Signed ICF (informed consent form)
• Age > 18 years old Eligibility criteria for each arm (additionally to mandatory criteria)
• Arm 1 - Patients undergoing open aortic surgery
• Arm 2 - Patients undergoing laparotomy
• Arm 3 - Patients undergoing laparotomy with sinus rhytm

Exclusion Criteria

1. Patients who are deemed to be at risk of harm due to excessive fluid administration:

• End-stage renal disease (eGFR <15ml/kg/min)
• Decompensated heart failure
• Respiratory failure prior to surgery
• Other cases where the risk of harm from fluid overload is assessed to be significant by the investigator

2. Medical contraindication to the use of transesophageal echocardiography:

• Active ulcerative gastritis or bleeding from upper gastrointestinal tract
• Past history of esophageal or gastric surgery
• Esophageal varices or other esophageal disease (stricture, Barret's disease, perforation in the past, achalasia)

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Uniwersytecki Szpital Kliniczny w Opolu

OTHER

Sponsor Role: lead

Responsible Party

Tomasz Królicki, MD PhD

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Tomasz Królicki, MD, PhD

Role: STUDY_CHAIR

Uniwersytecki Szpital Kliniczny w Opolu

Locations

Opole University Hospital

Opole, , Poland

Countries

Poland

Other Identifiers

W27/KB/2023_TK

Identifier Type: -

Identifier Source: org_study_id