Local Anesthetic and Spinal Needles Overview

Local Anesthetic Needles

• Designed to deliver anesthetic agents to specific areas, numbing the target region without affecting consciousness.

Spinal Needles

• Essential tools for spinal anesthesia.
• Available in various types, each designed for specific purposes and patient needs.
• Types are categorized by tip design:
  • Cutting (Quincke): Easier to insert but cause more tissue damage. Higher risk of post-dural puncture headache (PDPH) due to larger hole created.
  • Non-cutting (Whitacre, Sprotte): More challenging to insert but cause less tissue damage. Lower risk of PDPH.

Quincke Needle

• Description: Features a cutting bevel tip.
• Advantages: Easier insertion due to the cutting tip.
• Disadvantages: Higher risk of PDPH (post-dural puncture headache) due to a larger hole created.

Whitacre Needle

• Description: Atraumatic, pencil-point needle with a side hole.
• Advantages: Lower risk of PDPH, less tissue damage.
• Disadvantages: Slightly more challenging to insert compared to a Quincke needle.

Sprotte Needle

• Description: Similar to a Whitacre needle but with a longer side hole.
• Advantages: Lower risk of PDPH, better cerebrospinal fluid (CSF) flow.
• Disadvantages: Can be more difficult to handle due to the longer side hole.

Spinal Needle Sizes and Color Coding

• Measured by gauge (G), which indicates diameter.
• Larger gauge number indicates a thinner needle.
• 18-gauge needle has a larger diameter than a 25-gauge needle.
• Thinner needles cause less post-spinal headache and pain, but are more delicate and require precise administration.
• Color-coding helps quickly identify the gauge of the needle.

Spinal Needle Lengths

• Short needles: Often used for pediatric patients.
• Standard length needles (about 90mm): Suitable for most adult patients.
• Long needles: Used for obese patients or when a deeper reach is necessary.

Epidural Anesthesia Needle

• Designed to deliver anesthetic into the epidural space (area outside the dural sac containing the spinal cord and CSF).
• Key features:
  • Size/Gauge: Typically larger than spinal needles (often 16G to 18G).
  • Length: Around 8-9 cm to reach the epidural space.
  • Tip design: Most common is the Tuohy needle with a curved, blunt tip to prevent dural puncture.
  • Catheter: Often used to insert a catheter into the epidural space to allow continuous or intermittent administration of anesthetic.

Combined Spinal-Epidural (CSE) Needles

• Needle-Through-Needle (NTN) technique used.

Standard Local Anesthesia Needles

• Gauge: Typically range from 25G to 30G.
• Length: Varies from short (20mm) to long (32mm).
• Use: Commonly used in dental procedures, minor surgical interventions, and regional blocks.
• Design: Includes a bevel, shaft, hub, syringe adapter, and cartridge penetration end.

Ultrasound-Guided Needles

• Gauge: Often 22G to 25G.
• Length: Longer needles (up to 100mm) for deeper tissue access.
• Use: Used in procedures requiring precise placement of anesthetic, such as nerve blocks.
• Design: Features echogenic markings or coatings to enhance visibility under ultrasound.