Ultrasound-assisted Spinal Anaesthesia in Patients With Difficult Anatomical Landmarks

University Health Network, Toronto

Status: Completed

Conditions: Spinal Anesthesia

Treatments: Procedure: Manual palpation; Procedure: Ultrasound guidance

Study type: Interventional

Funder types: Other

Identifiers

NCT00956137

09-0190-AE

Details and patient eligibility

About

Spinal anesthesia is the technique of choice in patients undergoing total joint arthroplasty at Toronto Western Hospital (UHN). The most significant predictor of the ease of performance of spinal anesthesia is the quality of palpable surface landmarks (the spinous processes of the lumbar vertebrae). These surface landmarks may be absent, indistinct or distorted in many of the patients presenting for total joint arthroplasty. This is because of obesity, previous spinal surgery, scoliosis and degenerative changes of aging. The investigators have shown in a previous study that a pre-procedural ultrasound scan of the spine can reliably identify an appropriate site for needle insertion in spinal anesthesia, and that this results in a high success rate on the first needle insertion attempt (84% vs 61-64% in published studies). The investigators therefore believe that this ultrasound-assisted technique of spinal anesthesia is extremely useful, especially in patients with poor-quality surface landmarks. However there are no published randomized controlled trials to date that compare the efficacy of the ultrasound-assisted technique with the traditional surface landmark-guided technique of spinal anesthesia.

Enrollment: 180 patients

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Planned spinal anesthesia for elective lower limb surgery; and one or more of the following:

  1. Body mass index ≥ 35 kgm-2
  2. Scoliosis or other spinal deformity
  3. Poorly palpable or impalpable spinous processes

Exclusion criteria

• Patient refusal
• Contra-indications to regional anesthesia
• Known allergy to local anesthetics
• Bleeding diathesis
• Inability to provide informed consent

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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180 participants in 2 patient groups

Ultrasound

Experimental group

Description:

Use of ultrasound to identify vertebral interspaces for needle insertion.

Treatment:

Procedure: Ultrasound guidance

Palpation

Active Comparator group

Description:

Use of manual palpation to identify vertebral landmarks and vertebral interspaces for needle insertion.

Treatment:

Procedure: Manual palpation