Ultrasound guided regional anesthesia

Conventional peripheral nerve block techniques that are performed without visual guidance are highly dependent on surface anatomical landmarks for localization of the target nerve. It is therefore not surprising that regional anesthetic techniques are associated with a reported failure rate of up to 20% presumably because of incorrect needle and/or local anesthetic placement. Multiple trial-and-error attempts to locate the target nerve can lead to operator frustration, unwarranted patient pain, and time delay in the operating room, especially in patients with difficult anatomical landmark. The use of ultrasound in regional anesthesia has many advantages, which include,

Advantages of Ultrasound
  1. Reveals the nerve location and the surrounding vascular, muscular, bony, and visceral structures.
  2. Provides real-time imaging guidance during needle advancement allowing for purposeful needle movement and proper adjustments in direction and depth.
  3. Images the local anesthetic spread pattern during injection.
  4. Improves the quality of sensory block, the onset time, and the success rate compared to nerve stimulator techniques (as shown in some clinical studies).
  5. Reduces the number of needle attempts for nerve localization which may prove to reduce the risk of nerve injury.
  6. Differentiates extravascular injection from unintentional intravascular injection.
  7. Differentiates extraneural injection from unintentional intraneural injection.

At our institute we do lot of USG guided upper limb and lower limb nerve blocks. Major physiologic alterations brought about by general anesthesia can be avoided by the use of regional anesthetic techniques, and perioperative risk can be favorably influenced. Sick patients with multiple co-morbid conditions can undergo procedures under regional nerve blockade, thereby avoiding risk associated with general anesthesia. Many of our blocks are performed with long acting agents that provide not only intraoperative anesthesia, but postoperative analgesia as well. The placement of perineural catheters (upper and lower extremity) and the use of continuous regional analgesia techniques are utilized to provide postoperative analgesia for an extended period of time.