Ultrasonographic guidance in pediatric regional anesthesia part 1: theoretical background

Abstract

Recent findings support the use of ultrasonographic guidance in pediatric regional anesthesia. This review article illustrates basic knowledge in physics of ultrasound and ultrasonographic appearance of neuronal structures, which are prerequisites for the safe application of this technique in daily clinical practice. A critical view on education and ethics in science should emphasize future developments in ultrasonography for pediatric regional anesthesia.

Ultrasound-guided proximal and distal sciatic nerve blocks in children

“…For the last three years ultrasonography has been used routinely in the performance of peripheral nerve blocks in children and adults. An excellent two-part study has been published that illustrates the basic physics of ultrasound and the ultrasonographic appearance of the different neuronal structures in children [4,5].…”

Echotexture and Correlated Histologic Analysis of Peripheral Nerves Important in Regional Anesthesia

“…7Y9 In US images, peripheral nerves are subjectively categorized as hypoechogenic, hyperechogenic, or mixed. 6,9 The grayscale image carries the intensity information that can be numerically expressed; consequently, it is possible to objectively grade the intensity using simple image programs. At present, the degree of mixed echogenicity is not characterized systematically or objectively.…”

Design, prototyping, and evaluation of a collapsible device for single-operator sheathing of ultrasound probes

“…Air bubbles are detrimental to image quality because the acoustic impedance and sound velocity of air are very different from that of soft tissue (Marhofer and Frickey, 2006). When considering a medium to better bridge the ultrasound probe and the surface of the body, two requirements must be satisfied: (1) minimize air bubbles within the medium and (2) match impedance and sound velocity to that of human tissues.…”

“…1, requires that the probe first be held upright while a thin layer of an acoustic gel is applied to the transducer head. This medium aids in transmitting ultrasound signals to tissues to preserve image quality by minimizing the difference in acoustic impedance and sound velocity between the transducer and the human tissue (Marhofer and Frickey, 2006). The sheath is then unwrapped and gloves donned by the clinician.…”