Ultrasound-assisted Versus Conventional Landmark-guided Spinal Anesthesia in Patients With Abnormal Spinal Anatomy

Study Overview
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Brief Summary
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Spinal anesthesia can be challenging in patients with lumbar scoliosis or previous lumbar spine surgery. This study aims to evaluate whether the use of the ultrasound-assisted spinal anesthesia reduces the number of passes required to successful dural puncture compared with the conventional surface landmark-guided technique in patients with abnormal spinal anatomy.

Official Title
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Ultrasound-assisted Versus Conventional Landmark-guided Spinal Anesthesia in Patients With Abnormal Spinal Anatomy

Conditions
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Anesthesia, Spinal, Ultrasonography, Scoliosis

Intervention / Treatment
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* Procedure: Ultrasound-assisted paramedian spinal anesthesia
* Procedure: Landmark-guided spinal anesthesia
* Drug: 0.5% heavy bupivacaine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients scheduled to undergoing elective orthopedic surgery under spinal anesthesia, with ASA physical status classification I, II, III, and with (1) or (2) documented scoliosis in preoperative L-S-Spine X-ray (Cobb abgle > 10 degree) previous history of lumbar spinal surgery Exclusion Criteria: Patients with contraindication to spinal anesthesia (coagulopathy, local infection, allergy to local anesthetic) Patients with morbid cardiac diseases Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Ultrasound-assisted<br>Preprocedural ultrasound-assisted paramedian spinal anesthesia will be performed. 0.5% heavy bupivacaine will be injected to intrathecal space for spinal anesthesia. | Procedure: Ultrasound-assisted paramedian spinal anesthesia<br>* A preprocedural ultrasound scanning will be done, and skin marking will be made. The needle entry point and insertion angle will be determined based on ultrasound scanning. Spinal anesthesia will be performed via paramedian approach.<br>* Other names: sono-assisted;Drug: 0.5% heavy bupivacaine<br>* 0.5% heavy bupivacaine will be administered into intrathecal space. The dose of local anesthetic injected for spinal anesthesia will be at the discretion of the attending anesthesiologist. The dose range of intrathecal bupivacaine will be between 12 and 16 mg.<br>* Other names: bupivacaine;|
| Active Comparator: Landmark-guided<br>Landmark-guided spinal anesthesia will be performed, via either midline or paramedian approach. 0.5% heavy bupivacaine will be injected to intrathecal space for spinal anesthesia. | Procedure: Landmark-guided spinal anesthesia<br>* Spinal anesthesia will be done using conventional landmark-guided technique.<br>* Other names: conventional;Drug: 0.5% heavy bupivacaine<br>* 0.5% heavy bupivacaine will be administered into intrathecal space. The dose of local anesthetic injected for spinal anesthesia will be at the discretion of the attending anesthesiologist. The dose range of intrathecal bupivacaine will be between 12 and 16 mg.<br>* Other names: bupivacaine;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the number of needle passes | the number of forward advancements of the spinal needle in a given interspinous space, i.e., withdrawal and redirection of spinal needle without exiting the skin | Intraoperative (from the first insertion of needle to patient's skin, until the completion of spinal anesthetic injection) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of spinal needle insertion attempts | the number of times the spinal needle was withdrawn from the skin and reinserted | Intraoperative (from the first insertion of needle to patient's skin, until the completion of spinal anesthetic injection) | 
| Time for identifying landmarks | In group L, time from start of palpation to completion of the process, as declared by the anesthesiologist. In group U, time from placement of the ultrasound probe on the skin to the completion of markings. | 1 day (time taken for establish the landmark, from start of palpation/US scanning to completion of palpation/scanning) | 
| Time taken for performing spinal anesthetic | time from needle insertion to the completion of injection | Intraoperative (from insertion of the needle to the completion of injection) | 
| dermatome level of sensory block | thoracic dermatome level of sensory block assessed by loss of cold sensation tested with 2% chlorhexidine swab | 5, 10, 15 minutes after the completion of spinal anesthetic injection | 
| Incidence of radicular pain, paraesthesia, and blood tapping in the spinal needle | Incidence of radicular pain, paraesthesia, and blood tapping in the spinal needle during the spinal anesthesia procedure | Intraoperative (from the first insertion of needle, until the completion of spinal anesthetic injection) | 
| Periprocedural pain | 11-point verbal rating scale (0=no pain, 10=most pain imaginable) | Patients will be asked immediately after the completion of spinal anesthesia | 
| Periprocedural discomfort score | 11-point verbal rating scale (0=no discomfort, 10=most discomfort imaginable) | Patients will be asked immediately after the completion of spinal anesthesia |