Distribution, Pharmacokinetics and Extent of Sensory Blockade in ESP Blocks

A Volunteer Study to Determine the Anatomical Distribution of Injectate, the Extent of Sensory Block, and the Pharmacokinetics of Ropivacaine Following Erector Spinae Plane (ESP) Blocks.

The primary objectives of this study are to define the extent of dermatomal anesthesia and anatomical spread of injectate (as defined by MRI imaging) that is provided by an ESP block at the T5 level, using twenty milliliters of 0.5% ropivacaine.

The secondary objectives include: 1) the measurement of changes in hemodynamic parameters associated with the ESP block, 2) the duration of sensory effects provided by ropivacaine with or without epinephrine, 3) the venous plasma concentration of ropivacaine associated at various time intervals after completion of the ESP block.

Inclusion Criteria:

• Healthy adults aged 18 to 60 inclusive
• Weight between 60 and 100 kg inclusive
• Height 160 to190 cm inclusive

Exclusion Criteria:

• Pregnant females
• Chronic medical condition requiring medication
• History of previous major spinal, abdominal or thoracic surgery
• Congenital abnormalities of the spine, back, thorax or abdomen
• History of major trauma to the thorax or abdomen;
• Allergy to ropivacaine or other amide local anesthetics
• The presence of any metallic implant in their body
• Any contraindication to magnetic resonance imaging as determined by completion of a standard questionnaire administered to all patients undergoing magnetic resonance imaging.
• Allergy to Gadolinium radiological contrast agent.