Preoperative Shock Indexes and Post-Spinal Hypotension in Cesarean Surgery

March 25, 2026 updated by: Marmara University

Predictive Performance of Preoperative Shock Index and Modified Shock Index for Hypotension Following Spinal Anesthesia in Elective Cesarean Surgery

This prospective observational study aims to evaluate the predictive performance of preoperative Shock Index (SI) and Modified Shock Index (MSI) for hypotension following spinal anesthesia in elective cesarean surgery. Post-spinal hypotension is a common complication that can affect maternal and fetal outcomes, and early identification of at-risk patients is essential for effective perioperative management.

Study Overview

Status

Recruiting

Conditions

Detailed Description

This prospective observational study aims to evaluate the predictive performance of preoperative Shock Index (SI) and Modified Shock Index (MSI) for hypotension following spinal anesthesia in elective cesarean surgery. Post-spinal hypotension is a common complication that can affect maternal and fetal outcomes, and early identification of at-risk patients is essential for effective perioperative management.

Eligible pregnant women scheduled for elective cesarean surgery under spinal anesthesia will be assessed preoperatively for SI and MSI. Blood pressure and hemodynamic parameters will be monitored throughout the perioperative period to identify the occurrence and severity of hypotension. The study will analyze the ability of SI and MSI to predict hypotensive events and determine optimal cutoff values for clinical use.

The findings of this study may provide evidence to improve perioperative risk stratification, guide preventive interventions, and enhance maternal and fetal safety during elective cesarean surgery.

Study Type

Observational

Enrollment (Estimated)

300

Contacts and Locations

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

Study Contact

Study Contact Backup

Study Locations

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

The study population will consist of pregnant women undergoing elective cesarean surgery under spinal anesthesia at Marmara University School of Medicine, Department of Anesthesiology.

Description

Inclusion Criteria:

  • Patients over 18 years old
  • ASA II-III patients undergoing elective cesarean section

Exclusion Criteria:

  • ASA IV patients
  • Patients with known neurologic or psychiatric disorders
  • Patients with clinically significant cardiovascular, respiratory, hepatic, renal or metabolic disease
  • Patients with alcohol or drug addiction
  • Mentally disabled patients
  • Patients with BMI>30
  • Patients who develop massive bleeding or coagulopathy

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
Postspinal hypotension
All patients undergoing elective cesarean surgery under spinal anesthesia will be included in this study. Preoperative Shock Index (SI) and Modified Shock Index (MSI) will be calculated prior to anesthesia. Patients will be monitored during the surgery for hypotension. The patients who experience hypotension will be recorded as the post spinal hypotension group. The predictive performance of SI and MSI for post-spinal hypotension will be analyzed.
Post spinal non-hypotension
All patients undergoing elective cesarean surgery under spinal anesthesia will be included in this study. Preoperative Shock Index (SI) and Modified Shock Index (MSI) will be calculated prior to anesthesia. Patients will be monitored during the surgery for hypotension. The patients who do not experience hypotension will be recorded as the post spinal non-hypotension group. The predictive performance of SI and MSI for post-spinal hypotension will be analyzed

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Predictive performances of preoperative shock indexes for intraoperative hypotension
Time Frame: From induction of spinal anesthesia until end of surgery
The ability of preoperative SI and MSI to predict intraoperative hypotension will be evaluated using receiver operating characteristic (ROC) analysis; area under the curve (AUC), sensitivity, specificity, and optimal cutoff values will be reported. SI is calculated as heart rate ÷ systolic blood pressure (HR/SBP); MSI is calculated as heart rate ÷ mean arterial pressure (HR/MAP). Hypotension is defined as a decrease of SBP to <80% of baseline or SBP <100 mmHg, or MAP <80% of baseline or MAP <65 mmHg.
From induction of spinal anesthesia until end of surgery

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of intraoperative hypotension
Time Frame: From induction of spinal anesthesia until end of surgery (intraoperative period)
Proportion of patients meeting the predefined hypotension criteria during the intraoperative period.
From induction of spinal anesthesia until end of surgery (intraoperative period)
Requirement for vasopressor treatment (ephedrine)
Time Frame: From induction of spinal anesthesia until end of surgery
Proportion of patients who receive any vasopressor for hypotension and total number treated.
From induction of spinal anesthesia until end of surgery
Classification into hypotension vs. no-hypotension groups for comparison analyses
Time Frame: Intraoperative period
Number and proportion of patients classified as having developed hypotension vs not; used for subgroup analyses of baseline SI/MSI and outcomes.
Intraoperative period

Collaborators and Investigators

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

Sponsor

Marmara University

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)

October 15, 2025

Primary Completion (Estimated)

August 30, 2026

Study Completion (Estimated)

August 30, 2026

Study Registration Dates

First Submitted

March 18, 2026

First Submitted That Met QC Criteria

March 25, 2026

First Posted (Actual)

March 30, 2026

Study Record Updates

Last Update Posted (Actual)

March 30, 2026

Last Update Submitted That Met QC Criteria

March 25, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 09.2025.25-0289

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

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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