Comparison of Pleth Variability Index vs. Diastolic Shock Index for Predicting Hypotension During Anesthesia Induction

May 24, 2025 updated by: Ahmet Yuksek, Kocaeli City Hospital

Comparison of the Effectiveness of Pleth Variability Index and Diastolic Shock Index in Predicting Hypotension During Anesthesia Induction

This study aims to explore the frequent occurrence of hypotension during anesthesia induction due to anesthetic drugs or fasting. Predicting this condition is important for patient safety and anesthesia management. The study examines two indices: the Pleth Variability Index (PVI), derived from pulse oximeter readings, and the Diastolic Shock Index (DSI), calculated using heart rate and diastolic blood pressure. While PVI is a well-known method, DSI has been less explored in predicting anesthesia-related hypotension. The study aims to compare the effectiveness of these two indices in forecasting hypotension during anesthesia induction.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Hypotension is frequently observed during anesthesia induction due to the effects of anesthetic drugs on hemodynamics and the requirement of a specific fasting period before surgery. Induction-related hypotension can lead to decreased tissue perfusion and, consequently, secondary organ damage. Predicting anesthesia-induced hypotension in advance contributes to better anesthesia management and patient safety (1). Induction-related hypotension is defined as arterial hypotension occurring within the first 20 minutes after anesthesia induction or until the start of the surgery. Arterial hypotension is identified when mean systolic arterial pressure (MAP) decrease > 20% or MAP <65 mmHg or when norepinephrine is administered at a dose >;6 mcg/min at least once during this period (2).

The peripheral perfusion index (PI) is a simple, cost-effective monitoring method derived from non-invasive plethysmographic data using pulse oximetry. It provides an assessment of fluid status based on respiratory changes in pulse oximeter waves, with higher PI values indicating lower arterial tone. Changes in PI are interpreted as signs of vascular tone or fluid deficit issues in patients. The ratio of the highest and lowest PI values yields the Pleth Variability Index (PVI) (3,4). PVI can be used to predict hypotension during anesthesia induction (5).

Cardiac output (CO) is calculated by multiplying systemic vascular resistance (SVR) and heart rate (HR). In septic and shock patients, CO may be low, often due to decreased SVR. The autonomic system tries to maintain CO by increasing HR in response to the reduced SVR (6). Systolic and diastolic shock indices are obtained by dividing the HR by systolic and diastolic blood pressures, respectively. The diastolic shock index has been evaluated in studies to predict vasopressor response in septic patients (7). A high shock index has been associated with early vasopressor initiation and better prognosis. However, no study has yet examined the predictive power of the diastolic shock index, which is related to sympathetic response and systemic vascular resistance, for hypotension following anesthesia induction.

Moreover, the diastolic shock index has not been compared with the more commonly used PVI in terms of their ability to predict hypotension. Therefore, our study aims to test the success of diastolic shock index and PVI measurements in predicting anesthesia-induced hypotension

Study Type

Observational

Enrollment (Actual)

126

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
    • Izmıt
      • Kocaeli, Izmıt, Turkey, 41100
        • Kocaeli 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

Sampling Method

Non-Probability Sample

Study Population

Patients who will undergo elective lumbar spine surgery in Kocaeli City Hospital operating rooms constitute the study universe.

Description

Inclusion Criteria:

  1. Patients with a preoperative fasting period of at least 6 hours
  2. Patients scheduled for elective surgery under general anesthesia
  3. Patients aged 18-65 with ASA classification I-III
  4. Patients undergoing lumbar spinal surgery

Exclusion Criteria:

  1. Patients who do not agree to participate in the study
  2. Emergency surgeries
  3. Patients who will undergo surgery under spinal anesthesia
  4. Patients diagnosed with autonomic neuropathy
  5. Patients undergoing surgery with inotropic support

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
General Anesthesia Group
This group includes all study patients who underwent elective lumbar spine surgery under general anesthesia. In these patients, both PVI and DSI measurements will be performed before and during anesthesia induction.
Diagnostic test: Pulse variability index measurement
Peripheral perfusion index (PI) is an easy-to-implement and low-cost monitoring procedure obtained by interpreting non-invasive data obtained from pulse oximetry via plethysmography. It is a tool that allows interpretation of fluid status through changes in pulse oximetry waves caused by respiration. High perfusion indices are interpreted as low arterial tone. Changes in perfusion index are interpreted as indicators of vascular tone or fluid deficit problems in patients. The ratio of the highest and lowest PI values gives the Pleth Variability Index (PVI) (3,4). Hypotension can be predicted during anesthesia induction with PVI
Other Names:
  • PVI
Other: Diastolic shock index
The Diastolic Shock Index (DSI) is a hemodynamic parameter calculated by dividing the heart rate (HR) by the diastolic blood pressure (DBP). It reflects the balance between cardiac output and systemic vascular resistance, particularly in critically ill patients. A higher DSI can indicate impaired vascular resistance and may be useful for predicting the need for vasopressor support, especially in conditions like septic shock. However, its application in predicting hypotension during anesthesia induction is still under investigation.
Other Names:
  • DSI

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Prediction of anesthesia-induced hypotension
Time Frame: First 20 minutes after induction of anesthesia
Anesthesia-induced hypotension is a significant drop in blood pressure that occurs during the induction or maintenance of anesthesia.Arterial hypotension was defined as systolic blood pressure (SBP) ; 90 mmHg in at least one measurement during this period or norepinephrine administered at a dose of ;6 mcg/min at lea
First 20 minutes after induction of anesthesia

Collaborators and Investigators

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

Sponsor

Kocaeli City Hospital

Investigators

  • Principal Investigator: AYŞE ŞENCAN, MD, Kocaeli City Hospital
  • Study Director: Ahmet Yuksek, Associate Proffessor, Kocaeli 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

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)

August 8, 2024

Primary Completion (Actual)

February 15, 2025

Study Completion (Actual)

March 15, 2025

Study Registration Dates

First Submitted

September 6, 2024

First Submitted That Met QC Criteria

September 6, 2024

First Posted (Actual)

September 19, 2024

Study Record Updates

Last Update Posted (Actual)

May 30, 2025

Last Update Submitted That Met QC Criteria

May 24, 2025

Last Verified

May 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2024-69

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Sharing of patient data is prohibited by the institution and may be requested from the institution with appropriate request.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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