Ultrasound guided regional anesthesia is one of the most important developments in the field of anesthesiology. The technique has many advantages, and is recognized as one of the best methods of administering local anesthesia to targeted areas with both improved efficacy and safety.

History

Ultrasonography was first used as a method of guided peripheral nerve blockade (PNB) at the University of Vienna in the 1990s. Before that point, radiologists had only ever used ultrasound to guide needles during biopsies. The idea of ultrasound guided regional anesthesia has transformed the field of anesthesiology.  Anesthesiologists starting using the technique in the brachial plexus and femoral nerves, but have since expanded the use of ultrasound guided peripheral nerve blocks to include many other sites throughout the body.

The University of Toronto began to expand techniques further and demonstrate the even greater utility of ultrasonography. The last decade has seen the development of smaller ultrasound platforms that are more mobile, facilitating use across multiple operating rooms, as well as the creation of needle recognition software. These innovations have led to the technology used today by anesthesiologists around the world.

How It Works

Ultrasound guided regional anesthesia consists of two parts. The first of these is imaging structures in the plane of section, which includes the target nerve. The second is the process of actually guiding the needle. To use the equipment, anesthesiologists need to understand the technology and receive training in sonoanatomy pattern recognition. They also need to have studied the physical 3D anatomy of the patient.

Advantages

Ultrasound guided regional anesthesia has many advantages for nerve blockade. Traditional surface techniques were not  able to monitor the local anesthetic injectate. Ultrasound techniques, however, allow medical professionals to visualize the anatomy of the area of importance including the actual nerve(s), the surrounding tissue and other structures.

With ultrasound guided techniques, anesthesiologists have a better ability to meet the needle’s target without any unintentional damage. One can see the tip of the needle as it passes through the patient’s tissues and ensure that the needle is following the proper path, including avoiding unintentional vascular injection. An unrecognized intravascular injection can result in local anesthetic toxicity with grave consequences.

One of the most important advantages of ultrasound guided regional anesthesia is that it offers a real time image. This allows anesthesiologists to actually see the spread of the solution and thus monitor local anesthetic delivery and distribution as it is happening. Then they can make any necessary adjustments to the tip of the needle immediately.

Ultrasound guidance in regional anesthesia has also led to improvements in other nerve block techniques and the expanded use of PNB. Ultrasound guidance in regional anesthesia is now widely accepted by the majority of surgeons as one of the best methods of caring for their patients. It has become especially popular in orthopedic surgery, including many outpatient procedures which previously might have required hospitalization for pain control. Patients are able to go home the same day as their surgery essentially pain free.

Ultrasound guidance is also gaining popularity in the field of chronic pain. There are many who wish to use ultrasound guidance in place of fluoroscopy for many chronic pain procedures involving the spine. While this may be controversial, the major benefit of using ultrasound over fluoroscopy would obviously be the avoidance of any X-ray radiation exposure for both the patient and the anesthesiologist.

Thanks to these unique advantages, ultrasound guided regional anesthesia is widely used today and I would encourage all patients to ask their anesthesiologist whether they are a candidate for the benefits of a peripheral nerve block or other regional anesthetic technique.