Vulnerability of different nerves to intrafascicular injection by different needle types and at different approach angles: a mathematical model.

Background And Objectives: We assume that intrafascicular spread of a solution can only occur if a large enough portion of the distal needle orifice is placed inside the fascicle. Our aim is to present and evaluate a mathematical model that can calculate the theoretical vulnerability of fascicles, analyzing the degree of occupancy of the needle orifice in fascicular tissue by performing simulations of multiple positions that a needle orifice can take inside a cross-sectional nerve area.

Methods: We superimposed microscopic images of two routinely used nerve block needles (22-gauge, 15° needle and 22-gauge, 30° needle) over the microscopic images of cross-sections of four nerve types photographed at the same magnification.

Functional anatomy of the nerve and optimal placement of the needle for successful (and) safe nerve blocks.

Purpose Of Review: Summarize the current thinking concerning the clinically relevant aspects of nerve anatomy and best injection sites for nerve blocks.

Recent Findings: The widespread use of ultrasound in regional anesthesia has changed the practice of regional anesthesia and created new possibilities. Among them is the ability to identify fascial planes, and this has become the basis for a new group of blocks, the fascial plane blocks.

Treatment of Liver Trauma: Operative or Conservative Management.

Background: The liver is one of the most frequently damaged organs when abdominal trauma occurs. Currently, a conservative management constitutes the treatment of choice in patients with hemodynamic stability. The aim of this study is to evaluate the results of an operative and conservative management of 143 patients with liver injury treated in a single institution.