Hemodynamic Determinants of Urine Output During Spinal Anesthesia

This clinical trial investigates the relationship between urine output and mean arterial pressure (MAP) during spinal anesthesia. The study aims to validate observations from animal models in humans by concurrently measuring hemoglobin levels, MAP, and urine output, focusing on the effects of Ringer's solution, to provide crucial insights into optimal fluid management during anesthesia with minimal complexity.

Study Overview

• Status: Completed
• Conditions: Urine Output Decreased
• Intervention / Treatment: Drug: Marcaine 0.5% Solution for Injection

Detailed Description

The proposed clinical trial aims to explore the relationship between urine output and mean arterial pressure (MAP) during spinal anesthesia, a subject that has not been thoroughly studied in humans despite previous research under general anesthesia. Studies have demonstrated that the diuretic response to intravenous volume loading, using Ringer's solution or 20% albumin, varies with MAP levels. Specifically, Ringer's solution shows a greater diuretic effect when MAP exceeds 70 mmHg, whereas 20% albumin is more effective at lower pressures. This differential response highlights the importance of considering MAP in the choice of fluid for managing hypovolemia and oliguria.

The study's relevance is highlighted by the physiological dynamics at play, particularly how high levels of anesthesia, which influence the sympathetic nervous system from the mid-thoracic region, might reduce MAP and consequently decrease urine output. While this hypothesis has been examined in animal studies, its validity in humans remains unconfirmed.

To address this, the trial will measure hemoglobin levels, MAP, and urine output simultaneously, aiming to establish a clear correlation among these variables during spinal anesthesia. This methodical approach seeks to yield significant insights with minimal additional effort, contrasting with the complexities inherent in more elaborate study designs.

• Study Type: Observational
• Enrollment (Actual): 30

Contacts and Locations

Study Locations

• Romania
  • Bucharest, Romania, 022328
    • "Prof CC Iliescu" Emergency Institue for Cardiovascular Diseases

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adult patients requiring spinal anesthesia for vascular surgery.

Description

Inclusion Criteria:

• Written informed consent provided by patients or their legally authorized representatives.
• Adults aged 18 years and older.

Exclusion Criteria:

• Contraindications to Spinal Anesthesia:

  • Patient refusal
  • Presence of coagulopathy.
  • Current use of anticoagulant or antiplatelet medications.
  • Critical or severe aortic stenosis or other fixed cardiac output states.
  • High risk of infection at the spinal needle insertion site.
  • Elevated intracranial pressure.
  • Allergy
  • Sepsis

• Procedures Not Amenable to Spinal Anesthesia:

  • Planned concurrent procedures that cannot be performed under spinal anesthesia.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Catheter-Assisted Urine Output Measurement Post-Spinal Anesthesia	Urine volume is accurately measured using a catheter connected to a graduated collection bag. This method tracks the accumulated volume at specific intervals, providing a precise assessment of renal function and fluid management efficacy following spinal anesthesia	10, 20, 30, 40, 50, and 60 minutes post-surgical intervention.

Collaborators and Investigators

• Sponsor: Institutul de Urgenţă pentru Boli Cardiovasculare Prof.Dr. C.C. Iliescu
• Investigators: Study Chair: Robert Hahn, Professor, Karolinska Institutet: Stockholm, SE (Department of Clinical Sciences, Danderyd Hospital) Employment; Study Director: Serban-Ion Bubenek-Turconi, Professor, CC Iliescu Cardiovascular Institute

Study record dates

Study Major Dates

• Study Start (Actual): January 30, 2025
• Primary Completion (Actual): September 1, 2025
• Study Completion (Actual): October 30, 2025

Study Registration Dates

• First Submitted: February 1, 2025
• First Submitted That Met QC Criteria: February 5, 2025
• First Posted (Actual): February 7, 2025

Study Record Updates

• Last Update Posted (Actual): November 28, 2025
• Last Update Submitted That Met QC Criteria: November 23, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: spinal anesthesia; mean arterial pressure; urine output
• Additional Relevant MeSH Terms: Urogenital Diseases; Male Urogenital Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urination Disorders; Urological Manifestations; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Oliguria; Organic Chemicals; Pharmaceutical Preparations; Therapeutics; Drug Administration Routes; Drug Therapy; Anilides; Amides; Aniline Compounds; Amines; Bupivacaine; Injections; Solutions
• Other Study ID Numbers: 2511

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No