Anesthesia is a set of techniques for performing a surgical, medical or obstetrical eliminating or reducing pain.

Definition

General anesthesia is a state of narcosis accompanied by a reduction reactions and impaired autonomic transient respiratory and cardiovascular functions. Its objectives are loss of consciousness, absence of pain and muscle relaxation.

Achievement of general anesthesia

General anesthesia consists of three steps:

• Induction: sleep:

• Performed intravenously or by inhalation.

• Control of the patient’s airway due to a decrease or even stop the patient’s ventilation caused by induction.

• The interview:

• Achieved using gaseous agents (halogenated) and / or agents administered intravenously intermittently or continuously. The quality of anesthesia is assessed primarily by observing changes in blood pressure and heart rate.

• Warming of the patient is to keep it in normothermic (body temperature) and to minimize heat losses.

• Compensation of electrolyte loss and blood loss, if they exist.

• The awakening:

• This is the result of the partial or total elimination of anesthetics administered.

• Transfer the patient room Interventional Monitoring Post (SSPI) for monitoring risk of post-operative and post-anesthetic patient:

• Monitoring and maintenance of vital functions.

• Prevention and treatment of any complications.

• Assessment and management of pain.

Definition

The regional anesthesia is a transient abolition of nerve conduction in a predefined territory body. It can be spinal (spinal anesthesia, epidural anesthesia), peripheral (plexus block, …) or local.

Anesthesia techniques is therefore to temporarily interrupt the transmission of pain messages along nerve structures, while preserving the state of consciousness of the patient.

Local anesthetics cause a reversible non-selective blocking of nerve fibers: they interrupt nerve conduction not only sensory fibers, but also the motor fibers. This results in a locking bearing both on the sensitivity and on the motor, to varying degrees depending on the site of injection, the amount administered and the nature of the anesthetic agent used.

Different regional anesthesia

• Regional anesthesia peri-spinal cord:

• Spinal anesthesia.

• Epidural anesthesia.

• Regional anesthesia devices:

• Blocks the upper limbs.

• Block legs.

Definition

Spinal anesthesia is a regional anesthesia peri-spinal. It is injected into the spinal canal, more precisely, in the subarachnoid space of a local anesthetic that is diffusing into the cerebrospinal fluid (CSF), anesthesia of the lower abdomen and lower limbs.

Anatomy

Spinal anesthesia is performed by inserting through the interspinous space a needle into the subarachnoid space. At lumbar interspinous space can be significantly expanded by bending the back: the puncture can be made L4 L5.

Realization of spinal anesthesia

• Position of patient:

• Sitting with knees raised and feet on a stool for a maximum flexion of the spine.

• Anatomical landmarks:

• Puncture can be made L4 L5 (horizontal connecting the two iliac crests).

• After surgical disinfection, a button is formed with a dermal needle of 2.5 to 3 cm long, followed by a deeper penetration.

• Insertion of the needle:

• Through an introducer, is inserted into the interspinous space gauge needle 25 to 26G.

• The needle is directed in the same axis as the spinous process at an angle of 10 to 30 ° upwards.

• Identification of the subarachnoid space:

• The needle is advanced until an increase in resistance translates crossing the ligamentum flavum, and a sudden loss of resistance is felt, indicating the puncture of the dura mater.

• The outcome of CSF withdrawal of the mandrel is the best proof of the correct position of the needle.

• Test:

• After a test suction needle, is held tightly, which is connected to the syringe pre-filled with the intended dose of the anesthetic solution. The solution is injected slowly to avoid turbulence. Introducer needle and then are removed simultaneously.

• Reinstalling the patient:

• The patient is given on the back and the table is positioned to control the ascent of anesthesia. Sensory level is tested by the method picnic button or the sensation of cold alcohol.

Determining the desired level of anesthesia

Knowledge of cutaneous innervation metameric and vegetative innervation of different organs facilitates the determination of the blocking level necessary for each intervention.

Definition

Epidural anesthesia is a regional anesthesia peri-spinal. It is performed by the administration of a local anesthetic into the epidural space, a single injection needle or by repeated injections through a catheter.

The installation is slower and the motor and sensory blockade less powerful than in the spinal anesthesia, despite the injection of a larger volume of local anesthetics. By this slower onset, cardiovascular effects are much less brutal. Headaches occur in case of accidental dural breach.

Anatomy

Epidural anesthesia can be performed at any level of the spine, epidural anesthesia is usually done between L2 and L5, because of the absence of risk of spinal cord injury.

Blocking the more intense and faster depuncturing is obtained in point, from which it extends upwardly and downwardly. It can therefore be a blockage segmental sensations persist leaving side segments blocked.

Realization of epidural anesthesia

• Position of patient:

• Sitting with knees raised and feet on a stool for a maximum flexion of the spine.

• Anatomical landmarks

• Epidural anesthesia can be performed at any level of the spine, epidural anesthesia is usually done between L2 and L5.

• Must carefully place the epidural needle in the space between the ligamentum flavum and the dura mater, without puncturing.

• Insertion of the needle:

• The median first used to introduce the needle in the widest portion of the epidural space.

• A Tuohy needle with its mandrel is inserted through a button dermal anesthesia. After growth of 1.5 to 3 cm in the interspinous ligament mandrel is removed.

• Identification of the epidural space:

• The body of a syringe (glass most often) is lubricated with a few drops of local anesthetic so that the piston slides more easily.

• The syringe, containing approximately 3 ml of air, is firmly connected to the needle and a constant pressure is applied to the piston during the progress of the needle prudent.

• A sudden loss of resistance to the piston translates the input bevel into the epidural space. Less than 1 ml of air should return in the syringe after injection of 3 ml.

• Test dose:

• The syringe is detached from the needle and a reflux spontaneous blood or CSF is sought.

• A test dose of 3 mL of local anesthetic with adrenaline 1/200 000 should not cause significant anesthetic effect if the needle is well into the epidural space. If the dura has been punctured, blocking suggestive of spinal anesthesia will appear in 3 min. If the adrenaline solution is injected into a vein epidural, there will be an increase of 20 to 50% of heart rate.

• Implementation of the continuous block catheter for:

• Introduiction of a catheter into the epidural space to facilitate reinjection: catheter 18 or 20 gauge G, radiopaque, whose end is graduated in cm.

• The catheter is introduced into the needle until resistance translates his arrival at the bevel (normally upwardly), then it is introduced at a distance of 2 to 3 cm in the space epidural.

When the catheter is in place, the needle is carefully withdrawn out of the catheter which must be held firmly to prevent its accidental removal with the needle. After the establishment of the connection and a new test suction catheter is attached to the skin and the injection of a local anesthetic is performed.

Determining the desired level of anesthesia

Knowledge of cutaneous innervation metameric and vegetative innervation of different organs facilitates the determination of the blocking level necessary for each intervention.

Surgical site Suggested minimum level skin for epidural anesthesia

Nerve block is the injection of a local anesthetic into the nerve blocks, at the duct, through stimulation of anatomical landmarks and to find nerves to numb and block nerve impulses.

Local anesthetics can be injected at or plexus nerve trunks, or more distal nerve infiltration ramifications.

Block upper limb

The puncture is made in the neck and / or arm, with a tracking electrical stimulation.

It is important to know that the removal of the block, the recurrence of pain may be sharp and must, therefore, administer analgesics before the recurrence of pain.

• Inter scalene block (for surgery of the shoulder and arm).

• Humeral block (for elbow surgery and hand).

Block of the lower limbs

• Sciatic block (for foot surgery) puncture at the bottom or above the knee.

• Femoral block (femoral) for surgery of the knee, femur fracture, amputation of foot or toe).

Definition

The brachial plexus is formed by a single injection in the fiber space which contains the brachial plexus and axillary artery.

The plexus is responsible for all motor innervation and almost all sensory innervation of the upper limb, the sensitivity of the medial aspect of the arm being provided by the intercostobrachial nerve and the shoulder of the cervical plexus .

Anatomy

The space that contains the fibrous brachial plexus and axillary artery, its origin is formed by an extension of the pre-vertebral fascia that extends from the scalene muscles to the end of the arm where it becomes the sheath axilla.

The brachial plexus is formed by the union of the anterior roots from C5 to C8 and D1. 5 roots merge to form three trunks divide primary branches secondarily, then terminal nerves. There are close anatomical relationship between the secondary trunks and the axillary artery.

Completion of the block

Nerve block is carried out by injecting a local anesthetic into the nerve blocks, in ducts, through stimulation and anatomical landmarks to locate the nerves to be anesthetized and block nerve impulses.

The withers is the injection of a local anesthetic intravenously impregnating a segment of a single member of the general circulation by a tourniquet artificial, after it has been drained of blood.

Sedation is the removal of what is excessive in the reactions of an organism or organ type. It is a form of appeasement anesthesia with sedation, with preservation of lung function.

Local anesthesia is the attenuation or abolition of pain by blocking the nerve endings.