Paediatric regional anaesthesia : a clinical anatomical study

Abstract

In 1973, Winnie and co-workers stated that no technique could truly be called simple, safe and consistent until the anatomy has been closely examined. This is evident when looking at the literature where many anatomically based studies regarding regional techniques in adults have resulted in the improvement of known techniques, as well as the creation of safer and more efficient methods. Anaesthesiologists performing these procedures should have a clear understanding of the anatomy, the influence of age and size, and the potential complications and hazards of each procedure to achieve good results and avoid morbidity. A thorough knowledge of the anatomy of paediatric patients is also essential for successful nerve blocks, which cannot be substituted by probing the patient with a needle attached to a nerve stimulator. The anatomy described in adults is also not always applicable to children, as anatomical landmarks in children vary with growth. Bony landmarks are poorly developed in infants prior to weight bearing, and muscular and tendinous landmarks, commonly used in adults, tend to lack definition in young children. The aim of this research was therefore to study a sample of neonatal cadavers, as well as magnetic resonance images in order to describe the relevant anatomy associated with essential regional nerve blocks, commonly performed by anaesthesiologists in South African hospitals. This research has brought to light the differences between neonatal and adult anatomy, which is relevant since the majority of paediatric regional anaesthetic techniques were developed from studies originally conducted on adult patients. Current techniques were also analysed and where necessary new improvements, using easily identifiable and constant bony landmarks, are described for the safe and successful performance of these regional nerve blocks in paediatric patients. In conclusion a sound knowledge and understanding of anatomy is important for the success of any nerve blocks. This study showed that extrapolation of anatomical findings from adult studies and simply downscaling these findings in order to apply them to infants and children is inappropriate and could lead to failed blocks or severe complications. It would therefore be more beneficial to use the data obtained from dissection of neonatal cadavers.