BACKGROUND : The ilio-inguinal/iliohypogastric nerve block (INB) is one of
the most common peripheral nerve block techniques in pediatric anesthesia,
which is largely due to the introduction of ultrasound (US) guidance. Despite
the benefits of US guidance, the absence of an US machine should not deter
the provider from performing INB, considering that many institutions, especially
in developing countries, cannot afford to provide ultrasound machines
in their anesthesiology departments. The aim of this study was to revisit the
anatomical position of the ilio-inguinal and iliohypogastric nerves in relation
to the anterior superior iliac spine (ASIS), in a large sample of neonatal
cadavers, and compare the results with a similar group in a previously published
METHODS : With Ethics Committee approval, the ilio-inguinal and iliohypogastric
nerves were carefully dissected in 54 neonatal cadavers.
RESULTS : In the total sample, the ilio-inguinal nerve was found to be
2.2 1.2 mm from the ASIS, on a line connecting the ASIS to the umbilicus.
The iliohypogastric nerve was on average 3.8 1.3 mm from the ASIS. For
the entire sample, the optimal needle insertion site was 3.00 mm from the
ASIS. Although there is a strong correlation between the needle insertion point
and the weight of the neonate, this will only ‘fit’ for 60%of the population.
CONCLUSION : The linear regression formula; needle insertion distance
(mm) = 0.6 9 weight + 1.8 can be used as a guideline for the position of the
ilio-inguinal and iliohypogastric nerves.