Skip to main content
OpenTrials
Not Yet Recruiting

NCT Number: NCT07376798

Effect of Patient Position on Bupivacaine Dose Requirement and Hemodynamic Stability in Spinal Anesthesia

This study compares different combinations of local anesthetic doses and patient positions during spinal anesthesia for urogenital surgery. Spinal anesthesia is a common and safe technique where medication is injected into the lower back to numb the body during surgery.

The study will test two different doses of bupivacaine (a numbing medication): a lower dose (8 mg) and a standard dose (12 mg). It will also test two different patient positions after the spinal injection: lying flat (neutral position) and lying with the head slightly lower than the feet (Trendelenburg position).

Participants will be randomly assigned to one of four groups:

* Group 1: Lower dose + lying flat * Group 2: Lower dose + head-down position * Group 3: Standard dose + lying flat * Group 4: Standard dose + head-down position

The study will measure how well the anesthesia works, how high the numbness spreads in the body, and how it affects blood pressure and heart rate. The goal is to find the best combination of dose and position that provides good anesthesia while keeping blood pressure stable.

This research may help doctors choose the safest and most effective anesthesia approach for each patient based on their individual needs.

Not Yet Recruiting

Trial opening soon.

Get Notified

Key information

Conditions

Spinal Anesthesia Bupivacaine Hemodynamic Changes Patient Positions

Age range

18 year–70 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Age 18-70 years
  • American Society of Anesthesiologists (ASA) physical status classification I-II
  • Scheduled for elective urogenital surgery
  • Suitable candidate for spinal anesthesia
  • Able to read, understand, and provide written informed consent
  • Body Mass Index (BMI) less than 35 kg/m²
  • Willing to participate in the study

Exclusion criteria

  • Contraindications to spinal anesthesia (coagulopathy, infection at injection site, patient refusal)
  • History of neurological disease
  • Spinal deformity or previous spinal surgery
  • History of allergic reaction to local anesthetics (amide-type)
  • ASA physical status classification III or higher
  • Emergency surgery
  • Pregnancy
  • Psychiatric illness preventing effective communication
  • Refusal to participate in the study
  • Unable to understand or provide informed consent

Treatment and study plan

Bupivacaine %0.5 (hyperbaric)

Drug

8 mg or 12 mg 0.5% hyperbaric bupivacaine administered intrathecally via spinal anesthesia at L3-4 or L4-5 interspace.

Primary outcomes

  1. Maximum Sensory Block Level

    Time frame: From injection to 30 minutes post-spinal anesthesia

    The highest dermatomal level of sensory blockade achieved, assessed using pin-prick test (sharp/dull discrimination). Measured as the specific dermatome level (e.g., T4, T6, T8).

  2. Incidence of Hypotension

    Time frame: From spinal injection through end of surgery

    Proportion of participants experiencing hypotension, defined as mean arterial pressure (MAP) decrease ≥20% from baseline

  3. Sensory Block Onset Time

    Time frame: From spinal injection through end of surgery

    Time required to achieve T10 dermatomal sensory block level, measured from completion of intrathecal injection to confirmation of T10 level by pin-prick test.

Secondary outcomes

  1. Motor Block Degree

    Time frame: From spinal injection through end of surgery

    Degree of motor blockade assessed using modified Bromage scale (0=no motor block, able to raise extended leg; 1=unable to raise extended leg, able to flex knee; 2=unable to flex knee, able to flex ankle; 3=complete motor block, unable to move).

  2. Surgical Adequacy

    Time frame: Throughout surgery

    Proportion of participants with adequate anesthesia for surgical procedure completion, assessed as adequate (surgery completed without supplemental analgesia/sedation) or inadequate (requiring supplemental intervention).

  3. Incidence of Bradycardia

    Time frame: From spinal injection through end of surgery

    Proportion of participants experiencing bradycardia, defined as heart rate <50 beats per minute requiring treatment.

  4. Incidence of Nausea and Vomiting

    Time frame: From spinal injection through end of surgery

    Proportion of participants experiencing nausea and/or vomiting during the intraoperative and immediate postoperative period.

Study contacts

Contact information is provided by the study sponsor or research team.

Hasan Duman, M.D.

CONTACT

[email protected]

+905547317716

Sponsors and collaborators

Lead sponsor

University of Health Sciences Balikesir Hospital Eduation and Research

Other Gov

Registry information

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Jan 29, 2026
Registry last updated
Jan 29, 2026

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

View the official ClinicalTrials.gov record (opens in a new tab)

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.

Related clinical trials

Published trials that share one or more normalized conditions with this study.