Review of essential understanding of ultrasound physics and equipment operation

Table 1 Several potential advantages over the nerve stimulation methods

Advantages of ultrasound nerve localisation in regional anesthesia[4]

Real time imaging-helps to modify the technique based on individual differences in anatomy

Actual visualisation of neural structures

Guides approximate needle positioning (not too near or too far)

Lesser patient discomfort-motor confirmation/muscle twitches may not be necessary

Can visualise vascular structures-helps to avoid intravascular injections

Visualisation of local anesthetic spread-less volume block-decreases the chances of toxicity

Can visualise important organs and avoid injury-lung shadows in supraclavicular block, paravertebral block

Other advantages of ultrasound as compared to fluoroscopy or computed tomography scan

Easy to use-less bulky

Does not need a separate environment-such as radiation shielded walls

No radiation exposure-safe

Cheaper

Produces tomographic images

Does not need a technician to operate