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Hemodynamic Determinants of Urine Output During Spinal Anesthesia

Hemodynamic Determinants of Urine Output During Spinal Anesthesia

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT06814561
Enrollment
30
Registered
2025-02-07
Start date
2025-01-30
Completion date
2025-10-30
Last updated
2025-11-28

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Urine Output Decreased

Keywords

urine output, spinal anesthesia, mean arterial pressure

Brief summary

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.

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.

Interventions

DRUGMarcaine 0.5% Solution for Injection

The study involves the administration of 0.5% Marcaine heavy for spinal anesthesia in patients undergoing vascular surgery. The aim is to assess how this anesthesia affects urine output relative to mean arterial pressure.

Sponsors

Institutul de Urgenţă pentru Boli Cardiovasculare Prof.Dr. C.C. Iliescu
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

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.

Design outcomes

Primary

MeasureTime frameDescription
Catheter-Assisted Urine Output Measurement Post-Spinal Anesthesia10, 20, 30, 40, 50, and 60 minutes post-surgical intervention.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

Countries

Romania

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026