Ultrasound Spinal Anesthesia
Conditions
Keywords
Spinal anesthesia, ultrasound, real-time
Brief summary
The traditional landmarks to locate the injection site and orientation of the spinal needle for spinal anesthesia are based on palpation of surface bony landmarks. However the actual injection target into the CSF is located at an unknown depth inside the patients 3 dimensional spinal anatomy which can itself vary in its orientation relative to these surface markers.Also bony surface markers may not be palpable in some patients or the patient may have altered spinal alignment. Thus an already blind procedure can become even more misguided involving multiple trial and error needle insertions. On the other hand ultrasound allows visualisation of deep target structures which are impalpable, it allows assessment of spinal alignment and thus directs the orientation of the seeking needle more accurately. Performing US in real-time during needle insertion gives continuous feedback about the correct needle approach path which should reduce the number of blind needle passes.
Interventions
The neuraxial US scan will be performed with the patient in the sitting or lateral position with the hip and knees slightly flexed using full aseptic technique. The spinal needle will be inserted in real-time under direct ultrasound guidance to administer the spinal anesthetic.
Sponsors
Sunnybrook Health Sciences Centre
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Consenting patients of at least 18 years of age undergoing spinal anesthesia for elective lower limb surgery
Exclusion criteria
(are as for Spinal anesthesia generally) * Patient refusal * Sepsis or local infection at the site of injection * Hypovolemia * Coagulopathy (INR ≥1.5, Platelets \< 75X 109 /L, anticoagulant therapy) * Indeterminate neurologic disease * Increased intracranial pressure * Local anesthetic allergy * Infection distinct from the site of injection * Unknown duration of surgery
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Number of ventral passes of the spinal needle into the patient | Assessed at time of spinal anesthetic injection (baseline) |
| Rate of successful performance of real-time ultrasound guided spinal needle insertion | Assessed at time of spinal anesthetic injection (baseline) |
Secondary
| Measure | Time frame |
|---|---|
| Time for the procedure from first needle contact to the skin to injection of the medication into the spinal canal | Assessed at time of spinal anesthetic injection (baseline) |
Countries
Canada
Outcome results
None listed