Ultrasound Blocks for the Anterior Abdominal Wall

2. Ultrasound and Regional Anesthesia | 33
performance of extraepineurial needle tip positioning and
administration of local anesthetic, avoiding intraepineurial
injection. Finally, there may be a reduced need for general
anesthesia and reduced inpatient stay.
The performance of peripheral nerve blocks is clearly
dependent on technique, and expertise and the use of
ultrasounds requires additional skills. Some of the prerequisites
for the implementation of ultrasounds in regional anesthesia
include excellent understanding and knowledge of human
anatomy, understanding of the principles related to
ultrasound-guided blocks, having good hand skills and hand–eye
coordination (Gonano 2009).
Most ultrasound novices have problems with exact
coordination between ultrasound transducer position and needle
tip visualization during advancement. The American and
European Societies of Regional Anesthesia (ASRA and ESRA) have
recently published guidelines for training in ultrasound-guided
regional anesthesia, highlighting the encouragement of
individual institutions to support a quality-improvement process
(Sites 2007, Sites 2009).
Recently a Cochrane review reported that in experienced
hands, ultrasound guidance for peripheral nerve blocks has
success rates at least as peripheral nerve stimulation. The
incidence of vascular puncture or hematoma formation was
reduced in some studies. Ultrasounds may improve the quality of
sensory and motor block. Many studies assessed block
performance time and found a significant reduction with
ultrasounds use. No study has assessed trunk blocks and
statistical analysis was not possible due to the heterogeneity of
the studies. However, the findings are likely to reflect the use of
ultrasounds in experienced hands and may not be reproducible
by less skilled practitioners (Walker 2009).
In conclusion, the use of ultrasounds may provide a potential
standard in regional anesthesia if a responsible, scientific,