Using preoperative shock indexes to predict low blood pressure after spinal anesthesia for cesarean delivery

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

Observational Marmara University · NCT07500519

This study will see if simple blood-pressure-based shock indexes taken before surgery can predict which pregnant people having an elective cesarean with spinal anesthesia will develop low blood pressure after the block.

Quick facts

Study typeObservational
Enrollment300 (estimated)
Ages18 Years and up
SexFemale
SponsorMarmara University Academic / other
Locations1 site (Istanbul)
Trial IDNCT07500519 on ClinicalTrials.gov

What this trial studies

This is a prospective observational study enrolling pregnant people scheduled for elective cesarean delivery under spinal anesthesia. Preoperative Shock Index (SI) and Modified Shock Index (MSI) will be measured, and blood pressure and hemodynamic variables will be monitored throughout the perioperative period. Researchers will record occurrences and severity of post-spinal hypotension and analyze how well SI and MSI predict those events. The study aims to identify optimal cutoff values that could be used in clinical practice for risk stratification.

Who should consider this trial

Good fit: Pregnant people older than 18 years with ASA physical status II–III scheduled for elective cesarean section under spinal anesthesia (and with BMI ≤30) are ideal candidates.

Not a fit: Patients with ASA IV status, significant cardiovascular/respiratory/hepatic/renal/metabolic disease, BMI >30, mental incapacity, substance addiction, or those undergoing emergency cesarean or with massive bleeding/coagulopathy are unlikely to benefit from this study's findings.

Why it matters

Potential benefit: If successful, this could help clinicians identify patients at higher risk for post-spinal hypotension so they can apply preventive measures to improve maternal and fetal safety.

How similar studies have performed: Prior observational studies have suggested that SI and MSI can predict post-spinal hypotension in obstetric populations, but results and optimal cutoff values have been variable and not universally adopted.

Eligibility criteria

Show full inclusion / exclusion criteria
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

Where this trial is running

Istanbul

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Spinal AnesthesiaPregnancyHypotension PostproceduralHypotensionCesarean SectionShock Index
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.