Impact of Pleth Variability Index-Guided Acute Normovolemic Hemodilution on Intraoperative Fluid Management and Postoperative Complications in Cardiac Surgery

March 7, 2026 updated by: eralp çevikkalp, Bursa City Hospital
Acute normovolemic hemodilution (ANH) is a widely used blood conservation strategy in cardiac surgery aimed at reducing intraoperative blood loss and the need for allogeneic blood transfusion. However, inadequate or excessive fluid replacement during ANH may lead to hemodynamic instability and other complications. The Pleth Variability Index (PVI) is a noninvasive dynamic parameter that can predict fluid responsiveness and guide goal-directed fluid therapy during surgery. This study aims to evaluate whether performing ANH under intraoperative PVI guidance in cardiac surgery allows more precise fluid management and reduces allogenic blood transfusion and the risk of perioperative complications.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Acute normovolemic hemodilution (ANH) is a blood conservation strategy used to reduce intraoperative blood loss and minimize the need for allogeneic blood transfusion. The technique involves withdrawing a predetermined volume of whole blood from the patient before surgery and replacing it with crystalloid or colloid solutions to maintain intravascular volume. Consequently, blood lost during surgery contains a lower hemoglobin concentration due to hemodilution, and the patient's hemoglobin level is subsequently restored through reinfusion of the collected autologous blood after the surgical procedure [1]. Based on available evidence, the European Society of Anaesthesiology recommends the use of ANH in perioperative bleeding management guidelines to reduce the need for allogeneic blood transfusion [2].

Although ANH is generally considered a safe technique, inadequate or excessive intravenous fluid replacement may lead to several potential adverse effects, including hemodynamic instability, anemia, increased myocardial oxygen consumption due to high cardiac output, dilutional coagulopathy, electrolyte imbalance, and renal dysfunction [3].

The Pleth Variability Index (PVI) is a noninvasive monitoring parameter derived from pulse oximetry that evaluates fluid responsiveness by analyzing respiratory variations in the plethysmographic waveform amplitude [4]. Particularly in patients receiving positive pressure ventilation, PVI can serve as a useful indicator for assessing intravascular volume status. As a dynamic and continuously monitored parameter, PVI has been shown to predict fluid responsiveness and facilitate goal-directed fluid therapy. Studies have demonstrated that PVI-guided fluid management may reduce the total volume of administered fluids compared with conventional fluid administration strategies [5].

Currently, no standardized protocol exists for the implementation of ANH, and its application often depends on institutional or local procedural guidelines [6]. Traditionally, ANH is performed using a 1:3 fluid replacement ratio during acute blood withdrawal, and the amount of blood to be collected is calculated using the formula:

ANH volume = (patient Hb - target Hb) / mean Hb × blood volume,

or is determined according to clinical interpretation of hemodynamic parameters [7].

However, ignoring patient-specific physiological responses may limit the effectiveness of ANH. Therefore, the use of a dynamic parameter such as PVI-whose effectiveness has been demonstrated in intraoperative goal-directed fluid therapy-may improve patient safety and enable a more physiological approach to hemodilution.

The primary aim of this study was to evaluate whether performing acute normovolemic hemodilution under PVI guidance during the intraoperative period in cardiac surgery provides more precise volume management. The secondary aim was to assess its effectiveness in reducing allogenic blood transfusion and the risk of complications.

Study Type

Interventional

Enrollment (Actual)

80

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Turkey (Türkiye)
    • Nilüfer
      • Bursa, Nilüfer, Turkey (Türkiye), 16110
        • Bursa City Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • ASA (American Society of Anesthesiologists) score II-III,
  • ejection fraction (LVEF) >45%,
  • NYHA (New York Heart Association) class I-III,
  • hematocrit value >35%,
  • and patients who have not had a myocardial infarction in the last three months.

Exclusion Criteria:

  • Emergency or redo surgery requirement,
  • LVEF (left ventricular ejection fraction) <35%,
  • severe LMCA (left main coronary artery) stenosis (>70%),
  • BMI <18.5,
  • severe comorbidity (endocarditis, advanced COPD (chronic obstructive pulmonary disease), CKD (chronic kidney disease), anemia, hypoalbuminemia, peripheral artery disease),
  • active DAPT /heparin use,
  • coagulopathy,
  • uncontrolled systemic diseases,
  • pregnancy,
  • malignancy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Group 1 (Conventional Group)
In patients undergoing the ANH protocol
Other: acute normovolemic hemodilution
ANH is performed by acute blood withdrawal, and the volume of blood to be collected is calculated using the following formula: ANH volume = (patient Hb - target Hb) / mean Hb × blood volume, Instead of the volume of blood withdrawn, crystalloid replacement will be administered at a ratio of 3:1 relative to the volume of blood withdrawn. During these procedures, the mean arterial pressure will be maintained at 65 mmHg. If it drops, blood collection will be stopped and fluid replacement will continue. Blood withdrawal will be resumed when the mean arterial pressure reaches 65 mmHg.
Experimental: Group 2 (PVI Group)
In patients undergoing PVI-guided ANH (Masimo SET® and rainbow® Pulse CO-Oximetry)
Other: PVI dependant acute normovolemic hemodilution
ANH is performed by acute blood withdrawal, and the volume of blood to be collected is calculated using the following formula: ANH volume = (patient Hb - target Hb) / mean Hb × blood volume, Instead of the volume of blood withdrawn, a PVI pulse probe will be applied and basal fluid replacement will be administered. A 250 mL crystalloid bolus will be given when PVI exceeds 13. If PVI exceeds 15, blood withdrawal will be temporarily discontinued and fluid replacement will be continued until the PVI decreases. During these procedures, the mean arterial pressure will be maintained at 65 mmHg. If it drops, blood collection will be stopped and fluid replacement will continue. Blood withdrawal will be resumed when the mean arterial pressure reaches 65 mmHg.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Fluid management
Time Frame: -during ANH -Total cristalloid amount during surgery -total cristalloid amount during CPB -postoperative cristalloid amount in first 24.hour
amount of crystalloid used during procedures
-during ANH -Total cristalloid amount during surgery -total cristalloid amount during CPB -postoperative cristalloid amount in first 24.hour

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Allogenic Blood Transfusion
Time Frame: -intraoperative -postoperative 24.hour
amount of blood product use
-intraoperative -postoperative 24.hour
Postoperative Complications
Time Frame: postoperative 24 hours

postoperative acute kidney injury, Incidence of AKI based on RIFLE (Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease)/KDIGO (Kidney Disease Improving Global Outcomes) criteria within first 24 hours post-op.

Postoperative pulmonary complications were evaluated using the EPCO criteria.
postoperative 24 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Bursa City Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

  • 1. C. Boer, M.I. Meesters, M. Milojevic, et al., 2017 EACTS/EACTA Guidelines on patient blood ma-nagement for adult cardiac surgery, J. Cardiothorac. Vasc. Anesth. 32 (1) (2018) 88-120 2. S.A. Kozek-Langenecker, A.B. Ahmed, A. Afshari, et al., Management of severe perioperative blee-ding: guidelines from the European Society of Anaesthesiology First update 2016, Eur. J. Anaesthe-siol. 34 (6) (2017) 332-395. 3. Monaco F, ANH Study Group. A Randomized Trial of Acute Normovolemic Hemodilution in Car-diac Surgery. N Engl J Med. 2025 Jun 12. Epub ahead of print. PMID: 40503713. 4. Cannesson M, Desebbe O, Rosamel P, et al. Pleth variability index to monitor the respiratory varia-tions in the plethysmographic waveform amplitude and predict fluid responsiveness in mechanically ventilated patients. Anesthesiology. 2008;108(3):664-671. 5. Mathew PJ, Sharma S. Goal-directed fluid therapy guided by Plethysmographic Variability Index (PVI) versus conventional liberal fluid administration in children during elective abdominal sur-gery: A randomized controlled trial. J Pediatr Surg. 2023 Apr;58(4):735-740. Epub 2022 Dec 16. PMID: 36631313. 6. Hasta Kan Yönetimi Rehberi: Modül 2- Perioperatif. 3.6.5. Akut normovolemik hemodilüsyon (ANH). Sayfa 76-78

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 1, 2025

Primary Completion (Actual)

March 1, 2026

Study Completion (Actual)

March 6, 2026

Study Registration Dates

First Submitted

March 7, 2026

First Submitted That Met QC Criteria

March 7, 2026

First Posted (Actual)

March 12, 2026

Study Record Updates

Last Update Posted (Actual)

March 12, 2026

Last Update Submitted That Met QC Criteria

March 7, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2025-KAEK-47 (Other Identifier: Clinical Research Ethics Committee of University of Health Sciences Bursa Faculty of Medicine)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared because of ethical and institutional restrictions related to patient confidentiality.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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