The Impact of Ultrasound-Guided Spinal Anesthesia

Impact of Ultrasound Guidance on the Performance of Spinal Anesthesia

Neuraxial anesthesia is a commonly employed technique for subumbilical surgical procedures due to its effectiveness and safety profile. The advent of ultrasound technology has introduced the possibility of visualizing anatomical landmarks in real time, thereby facilitating more accurate and potentially safer subarachnoid punctures. This study aims to compare conventional spinal anesthesia, based on palpation, with ultrasound-guided spinal anesthesia, focusing on procedural ease and overall facilitation.

it's a prospective, single-center, randomized, single-blind study. We included patients aged 18 years or older, classified as ASA I or II, scheduled for elective surgery, and who provided written informed consent. Exclusion criteria included failed subarachnoid puncture, conversion to general anesthesia, or the occurrence of major intraoperative complications such as vasovagal episodes or cardiac rhythm disturbances. Participants were randomly assigned, based on a randomization table, into two groups: Group1 (traditional technique), in which spinal anesthesia was performed using the conventional palpation-based method for space localization; and Group2 (ultrasound-guided technique), in which spinal anesthesia was performed under real-time ultrasound guidance. The primary outcome was the total procedure time, measured in seconds from the end of skin antisepsis to the initiation of subarachnoid injection. Secondary outcomes included the number of puncture attempts, the number of needle redirections within the same interspace, the occurrence of procedural incidents, and postoperative complaints such as radicular pain, osseous contact pain, intraoperative paresthesias, and traumatic punctures.

Study Overview

• Status: Completed
• Conditions: Spinal Anesthesia; Ultrasound Guidance; Procedural Performance; Conventional Palpation Technique
• Intervention / Treatment: Device: Conventional spinal anesthesia; Device: Ultrasound-guided spinal anesthesia

• Study Type: Interventional
• Enrollment (Actual): 136
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Tunisia
  • Tunis, Tunisia
    • Military Hospital of Tunis

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Patients aged 18 years or older.
• Classified as American Society of Anesthesiologists (ASA) physical status I or II.
• Scheduled for elective surgery under spinal anesthesia.
• Provided written informed consent.

Exclusion Criteria:

• Failed subarachnoid puncture.
• Conversion to general anesthesia.
• Occurrence of major intraoperative complications (e.g., vasovagal episodes, cardiac rhythm disturbances).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Conventional spinal anesthesia; The operator began by palpating the posterior superior iliac spines to mentally determine the Tuffier's line, which roughly corresponds to the L4-L5 intervertebral space. The spinous processes were then palpated to precisely locate the targeted intervertebral space. The needle was subsequently inserted until cerebrospinal fluid return was obtained, and the anesthetic agent was administered slowly	Device: Conventional spinal anesthesia; The spinous processes were then palpated to precisely locate the targeted intervertebral space
Active Comparator: Ultrasound-guided spinal anesthesia; The operator set up the sterile equipment, which included an ultrasound machine equipped with a low-frequency convex probe (2-5 MHz). The probe, previously disinfected, was covered with a sterile sheath containing sterile coupling gel. First, the transducer was positioned in a paramedian sagittal plane, placed 1-2 cm lateral to the spinous processes. The sacrum was identified as a flat, hyperechoic structure producing a marked acoustic shadow, serving as the starting landmark for identifying successive lumbar intervertebral spaces. By gradually sliding the transducer cephalad, the vertebral laminae appeared as hyperechoic lines alternating with their posterior acoustic shadows. The interlaminar spaces, located between two adjacent laminae, form true acoustic windows that allow visualization of the underlying neuraxial structures. The exploration continued until the intervertebral space deemed optimal for puncture was identified. The probe was then switched to a midline posit	Device: Ultrasound-guided spinal anesthesia; A combined sequence was used, beginning with a longitudinal paramedian scan, followed by a 90-degree rotation to obtain a transverse interspinous view. This allowed for the identification of the spinal canal, after which the puncture was performed using dynamic, out-of-plane guidance

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
procedure time	60sec

Collaborators and Investigators

• Sponsor: Military Hospital of Tunis

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2025
• Primary Completion (Actual): May 31, 2025
• Study Completion (Actual): July 30, 2025

Study Registration Dates

• First Submitted: December 25, 2025
• First Submitted That Met QC Criteria: December 25, 2025
• First Posted (Actual): January 8, 2026

Study Record Updates

• Last Update Posted (Actual): January 8, 2026
• Last Update Submitted That Met QC Criteria: December 25, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Other Study ID Numbers: 54/2024/clpp/militaryhosptunis

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No