The technology and clinical understanding of anatomical sonography has evolved greatly over the past decade. In the Department of Anaesthesia and Intensive Care Medicine at the Medical University of Vienna, ultrasonography has become a routine technique for regional anaesthetic nerve block. Recent studies have shown that direct visualization of the distribution of local anaesthetics with high-frequency probes can improve the quality and avoid the complications of upper/lower extremity nerve blocks and neuroaxial techniques. Ultrasound guidance enables the anaesthetist to secure an accurate needle position and to monitor the distribution of the local anaesthetic in real time. The advantages over conventional guidance techniques, such as nerve stimulation and loss-of-resistance procedures, are significant. This review introduces the reader to the theory and practice of ultrasound-guided anaesthetic techniques in adults and children. Considering their enormous potential, these techniques should have a role in the future training of anaesthetists.

SummaryUltrasonography may offer significant advantages in regional anaesthesia of the upper and lower limbs. It is not known if the same advantages demonstrated in adults also apply to children. We therefore performed a prospective, randomised study comparing ultrasound visualisation to conventional nerve stimulation for infraclavicular brachial plexus anasesthesia in children. Forty children scheduled for arm and forearm surgery underwent infraclavicular brachial plexus blocks with ropivacaine 0.5 ml.kg )1 guided by either nerve stimulation or ultrasound visualisation.Evaluated parameters included sensory block quality, sensory block distribution and motor block. All surgical procedures were performed under brachial plexus anaesthesia alone. Direct ultrasound visualisation was successful in all cases and was associated with significant improvements when compared with the use of nerve stimulation: lower visual analogue scores during puncture (p = 0.03), shorter mean (median) sensory onset times (9 (5-15) min vs. 15 (5-25) min, p < 0.001), longer sensory block durations (384 (280-480) min vs. 310 (210-420) min, p < 0.001), and better sensory and motor block scores 10 min afrter block insertion. Ultrasound visualisation offers faster sensory and motor responses and a longer duration of sensory blockade than nerve stimulation in children undergoing infraclavicular brachial plexus blocks. In addition, the pain associated with nerve stimulation due to muscle contractions at the time of insertion is eliminated.

The use of ultrasound to guide needle placement and monitor the spread of local anesthetic improves the success rate of interscalene brachial plexus block.

Aggressive warming better maintained core temperature (36.5 degrees vs 36.1 degrees C) and slightly decreased intraoperative blood pressure. Aggressive warming also decreased blood loss by approximately 200 mL. Aggressive warming may thus, be beneficial in patients undergoing hip arthroplasty.

Our findings confirm that the GON can be visualized using ultrasound both at the level of the superior nuchal line and C2. This newly described approach superficial to the obliquus capitis inferior muscle has a higher success rate and should allow a more precise blockade of the nerve.