Abstract
The Regional anesthesia is evolving rapidly and becoming increasingly popular. The reason is that conductive anesthesia is widely integrated in the treatment of pain, during the pre, intra and postoperative period. Nerve blocks are available for the management of sports related injuries and injection of local anesthetics in the vicinity of nerve is used for both diagnostic and therapeutic purpose in sports medicine. However, regional anesthesia carries certain risk from nerve injury, caused by intraneural injection. For their prevention today are in use few different methods, but the nerve injury can still occur. The purpose of this work is to determine the values of pressures which appear during intraneural and perineural application of local anesthetic, and to compare those values in order to avoid cases of intraneural injections in clinical practice with consequential complications. In this experimental study there have been used 12 Wistar rats. After general anesthesia, the sciatic nerves (n=24) were exposed bilaterally. Under the direct visual control, the needle was placed intraneural or perineural and 3 ml of lidocaine 2% was injected using an automated infusion pump (3 ml/min). Injection pressure data were acquired using a manometer coupled to a computer. After application and awakening from general anesthesia, the animals were subjected to neurological examination during the next 7 days. Even though all perineural injections resulted with the pressure 27,92 kPa, the majority of intraneural injections were combined with the injection pressure ě 69,8 kPa. The difference between average values of intra and perineural injections (with 95% safe interval) was significant (t=3,14; df=6; P=0,02). Also, residual neurologic impairment was present only in those hind limb after intraneural injections which was associated with injection pressures > 69,8 kPa. Injection application in different tissues results in different values of injection pressures, which depends on structure, compactness and elasticity of tissue. As long as the injection pressure is low, injection into poorly compliant tissue can be avoided and the neurological damage can be prevented.
