Anaesthesia

Anaesthesia

Introduction

Local anaesthetic can be defined as a drug which reversibly prevents transmission of the nerve impulse in the region to which it is applied, without affecting consciousness. There are many drugs which exert local anaesthetic activity in addition to their main clinical uses, but this tutorial will focus on those drugs which are principally used for their local anaesthetic properties. Anaesthesia during surgery removes any sense of touch, heat and pain, as well as the motor activity of muscles. Each surgery is now done with the help of anaesthesia, which may be of various types depending on the importance of the operation, ranging from simple local anaesthesia (for example in the case of a tooth extraction), or intra-articular, up to more complex techniques, such as the so-called spinal epidural and the blocking of various peripheral nerves (or truncal block).

Discussion and Analysis

Local anaesthesia involves infiltration of drugs into the skin at the points where the surgeon will operate with its tools, in order to eliminate the pain in the affected area. The intra-articular anaesthesia involves the injection of the anaesthetic into the joint, so as to anesthetize all structures within the joint cavity (membrava synovial, menisci, and ligaments). Anaesthesia or spinal subarachnoid block performs a unilateral that is to anesthetize a single limb or even portions of the same [1]. The technique consists of introducing the anaesthetic in the intrathecal space (i.e. where there is the cerebrospinal fluid that surrounds the brain and spinal cord), in direct contact with the nerve roots. Therefore, it allows a rapid onset of action and excellent muscle relaxation.

On the contrary, the epidural anaesthesia or neuraxial consists of introducing the anaesthetic in an anatomical space said epidural, which runs along the spinal column. In the case of lower limb, anaesthetic is injected at the lumbar spine; the result is a complete anaesthesia of all anatomical structures of the limbs [2]. The onset of action is very slow and cannot be unilateral (i.e. it is not possible to anesthetize a single limb); allows however to prolong the anaesthetic effect with the introduction within the epidural space of a same thin Caterino, in relation to the duration and extent of surgery. The patient can thus perform the first movement of the limb, and physical therapy after surgery in complete analgesia.

It is of fundamental importance to clarify the fact that both techniques epidural and spinal anaesthesia are performed in the lumbar spine where the spinal cord is not present, since the latter end of the last dorsal and first lumbar. These techniques are considered by the international scientific community as the safest and most effective to perform the anaesthesia to the lower limb. The only contraindications for the performance of these two techniques are taking anticoagulant drugs by the patient and the presence of pre-existing neurological disorders [3]. This is to inject the anaesthetic in each of the affected nerve. In particular, it is possible to carry out the block of the sciatic nerve and femoral nerve ...