Using an esophageal acoustic sensor (ResQ) versus pulse pressure variation (PPV) to predict fluid needs during major surgery
A Prospective, Single-Center, Single-Arm, Paired-Comparison, Open-Label, Non-Inferiority Confirmatory Trial to Evaluate the Efficacy and Safety of ResQ by Comparing Fluid Responsiveness Prediction Performance of the Acoustic Variability Index (AVI) Versus Pulse Pressure Variation (PPV) in Mechanically Ventilated Patients
This study will test whether the ResQ device's Acoustic Variability Index (AVI) can predict if adults on mechanical ventilation during major abdominal or pelvic surgery need more IV fluids as accurately as the standard pulse pressure variation (PPV) method.
Quick facts
| Study type | Observational |
|---|---|
| Enrollment | 122 (estimated) |
| Ages | 19 Years and up |
| Sex | All |
| Sponsor | Signal House Co., Ltd. Industry-sponsored |
| Locations | 1 site (Seoul, Seoul) |
| Trial ID | NCT07516470 on ClinicalTrials.gov |
What this trial studies
This observational study compares a new esophageal acoustic index (AVI) from the ResQ device with the standard arterial pulse pressure variation (PPV) for predicting fluid responsiveness in mechanically ventilated adults undergoing major abdominal, retroperitoneal, or pelvic surgery. Participants will have a soft esophageal probe placed to record heart and lung sounds while standard hemodynamic monitors (PPV, cardiac output, stroke volume variation, pleth variability index) record baseline values. A set bolus of IV fluid will be given per routine care and cardiac function will be measured before and after the bolus to classify fluid responsiveness. The study will also record device-related safety events to determine whether ResQ can provide reliable, real-time information for intraoperative fluid management.
Who should consider this trial
Good fit: Adults aged 19 or older scheduled for planned major abdominal, retroperitoneal, or pelvic surgery under general anesthesia with mechanical ventilation (ASA I–III) who will receive intraoperative hemodynamic monitoring are eligible.
Not a fit: Patients who are not mechanically ventilated, are pregnant or breastfeeding, undergoing emergency procedures, or whose ventilation settings fall outside the specified range are unlikely to benefit from this device in this trial.
Why it matters
Potential benefit: If successful, ResQ could give clinicians a reliable, real-time way to guide fluid management during surgery and reduce unnecessary or missed fluid administration.
How similar studies have performed: PPV is an established predictor of fluid responsiveness, but using esophageal acoustic AVI measured by ResQ is a novel approach with only limited prior clinical data.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: To participate in this study, individuals must meet all of the following criteria: * Adults aged 19 years or older. * If female, not pregnant or breastfeeding. * Scheduled for a planned surgery of major organs in the abdominal, retroperitoneal, or pelvic cavities (e.g., hepatobiliary and pancreatic, small intestine, large intestine, kidney, uterus) under general anesthesia with mechanical ventilation * Classified as American Society of Anesthesiologists (ASA) Class I, II, or III. (Note: Excluded regardless of class if any exclusion criteria are met) * Scheduled to receive mechanical ventilation in a volume-controlled or pressure-controlled mode in the operating room or intensive care unit, with an anticipated tidal volume of 6-8 mL/kg (Ideal Body Weight), respiratory rate of 8-14 breaths/min, and PEEP of 0-5 cmH2O * Scheduled for hemodynamic monitoring to measure the comparison indices during surgery * Able to understand the study's purpose and procedures and communicate clearly with the investigator and research staff * Voluntarily signed the written informed consent form before participating in the study Exclusion Criteria: Individuals meeting any of the following criteria will be excluded from participation: * Undergoing emergency or unplanned surgery * Anticipated to have difficulty with the application of general anesthesia or mechanical ventilation * Anticipated to experience massive bleeding of 1 L or more during surgery. * Undergoing a reoperation due to the same underlying disease * History of severe esophageal damage (e.g., esophageal varices or stricture) that makes inserting the probe difficult * Inability to have an arterial catheter inserted, making the measurement of Stroke Volume Variation (SVV) and Pulse Pressure Variation (PPV) difficult * Condition where a fluid challenge is contraindicated or considered high risk (e.g., clinical signs of fluid overload, pulmonary congestion, or pulmonary edema; acute exacerbation of heart failure or renal failure; or a hemodynamically unstable state) * Body Mass Index (BMI) greater than 30 kg/m² * Uncontrolled coagulopathy prior to surgery (e.g., Platelet count \< 100,000/μL or INR \> 2) * Arrhythmias, such as atrial fibrillation/flutter or premature atrial/ventricular contractions (\>2 per 10 seconds), that make it difficult for the variability index to operate accurately * Other cardiovascular history that makes accurate cardiac output measurement impossible (e.g., severe valvular disease, history of intracardiac shunt surgery, or structural heart surgery) * Pregnant or lactating women * Any other condition deemed unsuitable for study participation by the investigator
Where this trial is running
Seoul, Seoul
- Asan Medical Center — Seoul, Seoul, South Korea (Recruiting)
Study contacts
- Principal investigator: Hye-Mee Kwon, MD, PhD — Asan Medical Center
- Study coordinator: Hye-Mee Kwon, MD, PhD
- Email: hyemee.kwon@amc.seoul.kr
- Phone: +82-3010-1438
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.