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Dural Sac Area-Guided Spinal Anesthesia Dosing for TURP

26 de agosto de 2026 actualizado por: Ezgi Budak Ozyalcın, Istanbul University

Clinical Effects of Individualized Spinal Anesthesia Dosing Based on Ultrasound-Measured Dural Sac Cross-Sectional Area in Patients Undergoing Transurethral Resection of the Prostate: A Prospective, Randomized Controlled Trial

This randomized controlled study will evaluate whether individualizing the dose of spinal anesthesia according to the ultrasound-derived dural sac cross-sectional area (DSCSA) can improve hemodynamic stability in patients undergoing transurethral resection of the prostate (TURP).

Participants aged 40 years or older will be randomly assigned to one of two groups. In the individualized-dose group, the anteroposterior diameter of the dural sac will be measured by ultrasound at the L3-L4 level, and DSCSA will be calculated from this measurement. The dose of intrathecal bupivacaine will then be individualized according to the calculated DSCSA. In the control group, participants will receive a fixed dose of intrathecal bupivacaine. Both groups will also receive intrathecal fentanyl.

The main outcome is the incidence of intraoperative hypotension. The study will also evaluate the number of hypotensive episodes, minimum mean arterial pressure, vasopressor and atropine requirements, sensory and motor block characteristics, respiratory monitoring parameters, cerebral oxygenation, and adverse events.

The study aims to determine whether a DSCSA-guided dosing strategy can reduce excessive spinal block and improve hemodynamic stability while maintaining effective spinal anesthesia.

Descripción general del estudio

Descripción detallada

This prospective, randomized controlled study compares two routinely used approaches to determining the intrathecal bupivacaine dose for spinal anesthesia in patients undergoing transurethral resection of the prostate (TURP). No new drug, new indication, or experimental treatment will be introduced. Both dosing approaches are currently used in routine clinical practice; the study will prospectively and randomly compare their clinical effects.

Participants will be randomly assigned to either a dural sac cross-sectional area (DSCSA)-guided individualized dosing group or a fixed-dose control group.

Before spinal anesthesia, the anteroposterior diameter of the dural sac will be measured by ultrasound at the L3-L4 intervertebral level. DSCSA will be calculated using the formula A = π × (D/2)².

In the individualized-dose group, a DSCSA of 150 mm² will be used as the reference value corresponding to 10 mg of intrathecal bupivacaine. The bupivacaine dose will be adjusted proportionally according to the participant's calculated DSCSA and limited to a minimum of 6 mg and a maximum of 12.5 mg. Fentanyl 25 micrograms will be added intrathecally.

In the fixed-dose group, participants will receive 10 mg (2 mL of 0.5%) intrathecal bupivacaine together with fentanyl 25 micrograms.

Spinal anesthesia will be performed at the L3-L4 intervertebral space using a 27-gauge Quincke needle. Standard intraoperative monitoring will be performed according to the study protocol. Sensory and motor block characteristics and hemodynamic variables will be recorded prospectively for comparison between the two dosing strategies.

Tipo de estudio

Intervencionista

Inscripción (Estimado)

60

Fase

  • No aplica

Contactos y Ubicaciones

Esta sección proporciona los datos de contacto de quienes realizan el estudio e información sobre dónde se lleva a cabo este estudio.

Estudio Contacto

  • Nombre: Ezgi Budak Ozyalcin, MD
  • Número de teléfono: +905056043177
  • Correo electrónico: budakezgi@gmail.com

Ubicaciones de estudio

      • Istanbul, Turquía (Türkiye), 34360
        • Istanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine
        • Contacto:

Criterios de participación

Los investigadores buscan personas que se ajusten a una determinada descripción, denominada criterio de elegibilidad. Algunos ejemplos de estos criterios son el estado de salud general de una persona o tratamientos previos.

Criterio de elegibilidad

Edades elegibles para estudiar

  • Adulto
  • Adulto Mayor

Acepta Voluntarios Saludables

No

Descripción

Inclusion Criteria:

  • Male participants aged 40 years or older
  • American Society of Anesthesiologists (ASA) physical status I-III
  • Scheduled to undergo transurethral resection of the prostate (TURP) for prostate cancer

Exclusion Criteria:

  • Refusal of spinal anesthesia
  • Local infection or wound at the planned puncture site
  • Current anticoagulant therapy
  • Neurological disease, including multiple sclerosis, myelopathy, or peripheral neuropathy
  • Known allergy to any of the study medications
  • Inability to maintain the required position during ultrasound measurement or spinal puncture

Plan de estudios

Esta sección proporciona detalles del plan de estudio, incluido cómo está diseñado el estudio y qué mide el estudio.

¿Cómo está diseñado el estudio?

Detalles de diseño

  • Propósito principal: Cuidados de apoyo
  • Asignación: Aleatorizado
  • Modelo Intervencionista: Asignación paralela
  • Enmascaramiento: Doble

Armas e Intervenciones

Grupo de participantes/brazo
Intervención / Tratamiento
Experimental: DSCSA-Guided Individualized Dose
The dural sac cross-sectional area (DSCSA) will be estimated from the ultrasound-measured anteroposterior dural sac diameter at the L3-L4 level. The intrathecal bupivacaine dose will be individualized according to the DSCSA, using 150 mm² as the reference area corresponding to 10 mg bupivacaine. The calculated bupivacaine dose will be limited to 6-12.5 mg. Fentanyl 25 micrograms will also be administered intrathecally.
The dural sac cross-sectional area (DSCSA) is calculated from the ultrasound-measured anteroposterior dural sac diameter at the L3-L4 level. The intrathecal bupivacaine dose is individualized according to DSCSA.
Hyperbaric bupivacaine is administered intrathecally in both study groups. In the DSCSA-guided group, the dose is individualized according to DSCSA, using 150 mm² as the reference corresponding to 10 mg, with a permitted dose range of 6 to 12.5 mg. In the fixed-dose group, 10 mg (2 mL of 0.5% bupivacaine) is administered.
Fentanyl 25 micrograms is administered intrathecally together with bupivacaine in both study groups.
Comparador activo: Fixed Dose
Participants will receive a fixed intrathecal dose of 10 mg (2 mL of 0.5%) bupivacaine together with fentanyl 25 micrograms.
Hyperbaric bupivacaine is administered intrathecally in both study groups. In the DSCSA-guided group, the dose is individualized according to DSCSA, using 150 mm² as the reference corresponding to 10 mg, with a permitted dose range of 6 to 12.5 mg. In the fixed-dose group, 10 mg (2 mL of 0.5% bupivacaine) is administered.
Fentanyl 25 micrograms is administered intrathecally together with bupivacaine in both study groups.

¿Qué mide el estudio?

Medidas de resultado primarias

Medida de resultado
Medida Descripción
Periodo de tiempo
Incidence of Intraoperative Hypotension
Periodo de tiempo: During surgery (from completion of spinal anesthesia until the end of surgery)
Intraoperative hypotension is defined as a decrease in mean arterial pressure (MAP) of ≥20% from baseline or an MAP <65 mmHg. Participants meeting either criterion at least once during surgery will be classified as having intraoperative hypotension. The outcome will be reported as the percentage of participants with intraoperative hypotension.
During surgery (from completion of spinal anesthesia until the end of surgery)

Medidas de resultado secundarias

Medida de resultado
Medida Descripción
Periodo de tiempo
Number of Intraoperative Hypotension Episodes
Periodo de tiempo: During surgery (from completion of spinal anesthesia until the end of surgery)
Number of intraoperative hypotension episodes recorded for each participant. Hypotension is defined as a decrease in mean arterial pressure (MAP) of ≥20% from baseline or an MAP <65 mmHg.
During surgery (from completion of spinal anesthesia until the end of surgery)
Minimum Intraoperative Mean Arterial Pressure
Periodo de tiempo: During surgery (from completion of spinal anesthesia until the end of surgery)
Lowest mean arterial pressure (MAP), measured in mmHg, recorded during the intraoperative period.
During surgery (from completion of spinal anesthesia until the end of surgery)
Percentage of Participants With a ≥30% Decrease in Mean Arterial Pressure
Periodo de tiempo: During surgery (from completion of spinal anesthesia until the end of surgery)
Percentage of participants experiencing at least one decrease in mean arterial pressure (MAP) of ≥30% from baseline during surgery.
During surgery (from completion of spinal anesthesia until the end of surgery)
Percentage of Participants Requiring Ephedrine
Periodo de tiempo: During surgery (from completion of spinal anesthesia until the end of surgery)
Percentage of participants receiving at least one intravenous dose of ephedrine for treatment of intraoperative hypotension.
During surgery (from completion of spinal anesthesia until the end of surgery)
Total Ephedrine Dose
Periodo de tiempo: During surgery (from completion of spinal anesthesia until the end of surgery)
Total intravenous ephedrine dose, measured in milligrams (mg), administered to each participant during surgery.
During surgery (from completion of spinal anesthesia until the end of surgery)
Percentage of Participants Requiring Atropine
Periodo de tiempo: During surgery (from completion of spinal anesthesia until the end of surgery)
Percentage of participants receiving intravenous atropine for treatment of intraoperative bradycardia.
During surgery (from completion of spinal anesthesia until the end of surgery)
Total Atropine Dose
Periodo de tiempo: During surgery (from completion of spinal anesthesia until the end of surgery)
Total intravenous atropine dose, measured in milligrams (mg), administered to each participant during surgery.
During surgery (from completion of spinal anesthesia until the end of surgery)
Maximum Sensory Block Level
Periodo de tiempo: During surgery (from completion of spinal anesthesia until the end of surgery)
Highest cephalad sensory block level achieved after spinal anesthesia, assessed by the pin-prick test and recorded as the corresponding dermatomal level.
During surgery (from completion of spinal anesthesia until the end of surgery)
Time to Achieve T10 Sensory Block
Periodo de tiempo: Up to 30 minutes after spinal anesthesia
Time, measured in minutes, from completion of intrathecal injection to achievement of a T10 sensory block, assessed using the pin-prick test.
Up to 30 minutes after spinal anesthesia
Time to Two-Dermatome Sensory Regression
Periodo de tiempo: From maximum sensory block until two-dermatome regression, assessed up to 3 hours after spinal anesthesia
Time, measured in minutes, from the maximum sensory block level to regression of the sensory block by two dermatomes, assessed using the pin-prick test.
From maximum sensory block until two-dermatome regression, assessed up to 3 hours after spinal anesthesia
Time to Recovery to Modified Bromage Score 0
Periodo de tiempo: From completion of spinal anesthesia until recovery to Modified Bromage score 0, assessed up to 3 hours after spinal anesthesia
Time, measured in minutes, from completion of intrathecal injection until recovery to a Modified Bromage score of 0, indicating complete recovery of lower-extremity motor function.
From completion of spinal anesthesia until recovery to Modified Bromage score 0, assessed up to 3 hours after spinal anesthesia
Number of Integrated Pulmonary Index ≤4 Episodes
Periodo de tiempo: During surgery (from completion of spinal anesthesia until the end of surgery)
Number of episodes in which the Integrated Pulmonary Index (IPI) is ≤4. The IPI is a composite score ranging from 1 to 10 based on end-tidal carbon dioxide, respiratory rate, oxygen saturation, and pulse rate; lower scores indicate greater respiratory compromise.
During surgery (from completion of spinal anesthesia until the end of surgery)
Incidence of Adverse Events
Periodo de tiempo: During surgery (from completion of spinal anesthesia until the end of surgery)
Percentage of participants experiencing at least one adverse event recorded during the intraoperative study period.
During surgery (from completion of spinal anesthesia until the end of surgery)

Otras medidas de resultado

Medida de resultado
Medida Descripción
Periodo de tiempo
Mean Left Regional Cerebral Oxygen Saturation During the First 60 Minutes
Periodo de tiempo: During the first 60 minutes after spinal anesthesia
Mean left regional cerebral oxygen saturation (rSO₂), measured continuously by frontal near-infrared spectroscopy (NIRS) during the first 60 minutes after spinal anesthesia. The outcome will be reported as the mean rSO₂ value.
During the first 60 minutes after spinal anesthesia
Minimum Regional Cerebral Oxygen Saturation
Periodo de tiempo: During the first 60 minutes after spinal anesthesia
Lowest regional cerebral oxygen saturation (rSO₂) value recorded by frontal near-infrared spectroscopy (NIRS) during the first 60 minutes after spinal anesthesia.
During the first 60 minutes after spinal anesthesia
Maximum Relative Decrease in Regional Cerebral Oxygen Saturation
Periodo de tiempo: During the first 60 minutes after spinal anesthesia
Maximum relative decrease in regional cerebral oxygen saturation (ΔrSO₂max) from the baseline value during the first 60 minutes after spinal anesthesia, measured by frontal near-infrared spectroscopy (NIRS).
During the first 60 minutes after spinal anesthesia

Colaboradores e Investigadores

Aquí es donde encontrará personas y organizaciones involucradas en este estudio.

Patrocinador

Investigadores

  • Investigador principal: Ezgi Budak Özyalçın, MD, Istanbul University - Cerrahpasa

Fechas de registro del estudio

Estas fechas rastrean el progreso del registro del estudio y los envíos de resultados resumidos a ClinicalTrials.gov. Los registros del estudio y los resultados informados son revisados ​​por la Biblioteca Nacional de Medicina (NLM) para asegurarse de que cumplan con los estándares de control de calidad específicos antes de publicarlos en el sitio web público.

Fechas importantes del estudio

Inicio del estudio (Estimado)

24 de agosto de 2026

Finalización primaria (Estimado)

24 de noviembre de 2026

Finalización del estudio (Estimado)

10 de diciembre de 2026

Fechas de registro del estudio

Enviado por primera vez

23 de agosto de 2026

Primero enviado que cumplió con los criterios de control de calidad

26 de agosto de 2026

Publicado por primera vez (Actual)

31 de agosto de 2026

Actualizaciones de registros de estudio

Última actualización publicada (Actual)

31 de agosto de 2026

Última actualización enviada que cumplió con los criterios de control de calidad

26 de agosto de 2026

Última verificación

1 de agosto de 2026

Más información

Términos relacionados con este estudio

Plan de datos de participantes individuales (IPD)

¿Planea compartir datos de participantes individuales (IPD)?

NO

Información sobre medicamentos y dispositivos, documentos del estudio

Estudia un producto farmacéutico regulado por la FDA de EE. UU.

No

Estudia un producto de dispositivo regulado por la FDA de EE. UU.

No

Esta información se obtuvo directamente del sitio web clinicaltrials.gov sin cambios. Si tiene alguna solicitud para cambiar, eliminar o actualizar los detalles de su estudio, comuníquese con register@clinicaltrials.gov. Tan pronto como se implemente un cambio en clinicaltrials.gov, también se actualizará automáticamente en nuestro sitio web. .

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