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Completed

NCT Number: NCT06869434

Thoraco Lumbar Vertebral Length and Bupivacaine Dosage in C-Section

Our hypothesis is that the bupivacaine dose determined according to the thoracolumbar vertebral body length (VBL) is more effective in achieving a lower hypotension rate during spinal anesthesia for cesarean delivery than the dose usually adjusted based on height and weight. The VBL measurements were determined from the midpoint of C7 to the tuffier line L4 spinous process.

Method: Patients ranging in height from 150 to 170 were randomly assigned to either Group 1 (0.2 mg of 0.5% hyperbaric bupivacaine per cm VBL or Group 2 (height-adjusted dose of 0.5% hyperbaric bupivacaine based on a minimum dose of 0.065 mg/cm according to height) or Group 3 (height-adjusted dose of 0.5% hyperbaric bupivacaine based on a minimum height-adjusted dose of 0.065 mg/cm).

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Key information

Age range

18 year–45 year

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

Primary location

Kudret Doğru

Kayseri, Melikgazi, 38050, Turkey (Türkiye)

About this study

The study followed a parallel study strategy. Patients provided informed permission before the procedure. The study was randomly assigned and blinded. The study was conducted from April 2025 to December 2025. Patients with pre-existing or pregnancy-induced hypertension, cardiovascular or cerebrovascular disease, contraindications to spinal anesthesia, weighing < 50 kg or > 110 kg, and heights higher than 170 cm or shorter than 150 cm were eliminated. Informed written consent was acquired from all patients participating in the trial. Each patient was evaluated for vital parameters and possible complications at 3-minute intervals before and after the spinal anesthesia application, treated if necessary, and recorded. The study was concluded at the end of the cesarean section.

There was no premeditation among the patients. The patient had standard monitoring, including non-invasive blood pressure, ECG, and pulse oximetry, with recorded baseline blood pressure and heart rate measurements. We inserted two 20-gauge intravenous cannulas and administered an IV-balanced solution using these routes. The patients' age, height, weight, ASA class, and VBL (C7-L4 Tuffier line cm) were recorded. The Tuffier's line (TL), which is made by drawing a horizontal line across the tops of the iliac crests, is the most common anatomical landmark right now. It has been shown to match up with the L4-L5 interspace or the L4 spinous process.

After skin infiltration with 2% lidocaine, a 25-gauge short-bevel Quincke spinal needle was placed at the L3-4 vertebral interspace with the patient in a sitting position. After aspiration of cerebrospinal fluid, the following anesthetic solutions were delivered over 5 seconds. Randomization was used to divide the patients into three groups. The trial was double-blind, with the patient and assessor unconscious of their group allocation. Only the practitioner delivering the spinal anesthesia was aware of the group allocation. Systolic, diastolic, and mean arterial blood pressure and heart rate were documented at baseline and assessed at 3-minute intervals, commencing 3 minutes post-spinal injection and persisting until the initiation of surgical procedures, after which measurements were conducted at 3-minute intervals.

Patients in Group VBL (Vertebral Body Length) received 0.2 mg x VBL cm of 0.5% hyperbaric bupivacaine. In contrast, Group FD (fixed dose) received a 0.5% hyperbaric bupivacaine volume based on a dose calculated according to the patient's height of 0.065 mg/cm. Group AD (adjusted dosage) got intrathecal heavy bupivacaine (0.5%) tailored to the patient's height and weight. A dosage was derived using Harten's dose chart formulated for Caucasian parturients

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • American Society of Anesthesiologists (ASA) Class II
  • Having regular antenatal visits
  • Singleton pregnancy at ≥37 weeks of gestation
  • Pregnant women aged 18-45 -

Exclusion criteria

  • Those with eclampsia, those with preeclampsia
  • Undergoing an emergency cesarean section
  • Those with bleeding diathesis and those receiving anticoagulant therapy
  • With a history of carotid artery stenosis,
  • Cardiovascular disease,
  • Hypertension,
  • Chronic obstructive pulmonary disease,
  • Heart rhythm outside of sinus
  • Patients with a history of cerebrovascular disease
  • Alcoholism or psychiatric illness
  • Placenta previa, accreta, and percreta

Treatment and study plan

Group VBL (Thoracolumbal vertebral body length) received 0.2 mg x VBL cm of %0.5 hyperbaric bupivacaine

Procedure

intrathecal heavy bupivacaine (0.5%) tailored to the patient's height and weight. A dosage was derived using Harten's dose chart formulated for Caucasian parturients

Other names: Group FD (fixed dose) received a volume of 0.5% hyperbaric bupivacaine based on a dose calculated according to the patient's height 0.065 mg/cm

Group FD (fixed dose) received a volume of 0.5% hyperbaric bupivacaine based on a dose calculated according to the patient's height 0.065 mg/cm

Procedure

Group FD (fixed dose) received a volume of 0.5% hyperbaric bupivacaine based on a dose calculated according to the patient's height 0.065 mg/cm

Group AD (adjusted dosage) got intrathecal heavy bupivacaine (0.5%) tailored to the patient's height and weight.

Procedure

Group AD (adjusted dosage) got intrathecal heavy bupivacaine (0.5%) tailored to the patient's height and weight.

Primary outcomes

  1. Hypotension Rate Among the Groups

    Time frame: From initiation of spinal anesthesia to completion of surgery, during the intraoperative period (mean duration approximately 60-90 minutes)

    Maternal hypotension was defined as a decrease in systolic blood pressure of more than 20% from baseline or a systolic blood pressure <90 mmHg. The incidence of hypotension was recorded intraoperatively for each participant.

Sponsors and collaborators

Lead sponsor

TC Erciyes University

Other

Registry information

Official study title

In Cesarean Sections, is the Length of the Thoracolumbar Vertebral Column Applicable for Determining the Dosage of Bupivacaine in Spinal Anesthesia?

Acronym: bupivacaine

Important dates

Study start
2025
Primary completion
2025
Study completion
2025
First posted
Mar 11, 2025
Registry last updated
Apr 24, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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