Axillary block is a partial anesthesia procedure used to numb the upper extremity. In this procedure, the nerve plexuses that supply the arm are anesthetized, blocking the transmission of stimuli. This allows surgical procedures in orthopedics and surgery, as well as very effective pain management.
What is axillary blockade?
Axillary blockade is a partial anesthesia procedure used to numb the upper extremity. To achieve such a block, an anesthetic, called an anesthetic, is injected in the area of the axillary nerve plexus. Axillary blockade is a regional anesthetic procedure also known as plexus anesthesia. By blocking the nerves in the axillary region, it is possible to perform surgical procedures on the upper extremity. To achieve such a block, an anesthetic, known as an anesthetic, is injected in the area of the plexus of nerves in the armpit. This briefly anesthetizes the nerves of the brachial plexus, consisting of the ulnar nerve, radial nerve, median nerve and musculocutaneous nerve. Stimulus transmission is not possible. Sensitivity and especially pain sensation are abolished. In addition, paralysis of the muscles in the arm occurs. Furthermore, it is possible to place a catheter in the area of the brachial plexus in order to continuously inject anesthetic for pain therapy postoperatively. This is a great advantage over other anesthesia methods, as this postoperative pain therapy can be carried out for any length of time through the plexus blockade, depending on the patient’s pain condition.
Function, effect, and goals
Axillary blockade can be used to perform surgical procedures on the distal upper arm, elbow joint, radius/ulnar, wrist, and fingered hand. In addition to its use in the surgical field, axillary blockade is also used for pain therapy. For this purpose, a catheter is placed in the puncture site and anesthetics are continuously injected postoperatively. Such pain treatment is often indicated for chronic pain, CRPS (complex regional pain syndrome), neuralgia and phantom limb pain. Axillary blockade differs in four different techniques. The oldest technique used is the supraclavicular plexus block. Here, the brachial plexus above the clavicle is blocked with anesthetics. The advantage of this method is that virtually all outgoing nerve cords of the brachial plexus are blocked. The standardized and thus most common technique of axillary blockade is the so-called axillary plexus blockade. Here, the anesthetic is injected into the vascular nerve sheath of the brachial plexus. The advantage of this method is the rather easy access via the axilla to the brachial plexus. Therefore, this procedure is also frequently used in children. In case of a surgical intervention in the shoulder joint, the so-called interscalene blockade is performed. Here, the anesthetic is injected at the level of the 6th hemivertebra between the scalenus anterior and scalenus medius muscles. Here, too, the brachial plexus is analgesized. Rarely, the infraclavicular plexus block is performed. Here, the anesthetic is injected between the clavicle, pectoralis muscle, and proc. coracoideus. However, this technique is relatively new and further studies have not yet been done. To locate the brachial plexus, a so-called nerve stimulator is attached to the end of the puncture cannula for this purpose. If the tip of the cannula reaches the area of the brachial plexus, this is manifested by contractions of the forearm muscles. Alternatively, the puncture cannula can also be inserted with the aid of an ultrasound. If the anesthetic is injected with the help of a nerve stimulator at the brachial plexus, about 40ml of anesthetic is introduced. Long-acting local anesthetics, such as ropivacaine, are usually used for this purpose. However, since the effect usually takes 20-30 minutes, another fast-acting and short-acting local anesthetic, such as prilocaine or mepivacaine, can also be administered. If the patient is nervous, restless or stressed by the surgical procedure, a sedative medication can be administered. This causes the patient to enter a twilight state and can be awakened at any time.
Risks, side effects and dangers
Axillary blockade, in terms of alternative forms of anesthesia, is a relatively safe and gentle anesthetic.Side effects such as nausea, vomiting, hoarseness or irritable cough, which can occur with general anesthesia, are not present with local anesthesia. However, typical side effects of an axillary block are present. These can include numbness, muscle tremors and tingling in the operated arm. Sensory disturbances of this kind can be caused by the anesthesia or by the blood stasis cuff. Experience has shown, however, that these complaints subside after a few weeks. In addition, bleeding into the tissue in the area of the puncture site may occur. Rarely, there is damage to the soft tissues or irritation of nerves. This can also lead to sensory disturbances in the form of insensitivity, numbness, pain sensations or even paralysis due to damage to the nerves. Hypersensitivity or an allergic reaction to the injected anesthetic may be manifested by a drop in blood pressure and pulse. If the anesthetic is injected into the bloodstream unintentionally, cardiovascular symptoms, unconsciousness, seizures, and even cessation of breathing may occur. Therefore, axillary blockade should not be performed if such allergy or hypersensitivity is known. In case of a long-lasting blockade of the stimulus transmission by a catheter, symptoms of poisoning may occur. These manifest themselves as dizziness, nervousness, seizures, cardiac arrhythmia or sudden drop in blood pressure. When the puncture needle is inserted, blood vessels may also be damaged, as the plexus runs through the middle of them. Infections and tumors in the area of the arm are considered absolutely contraindicated. Blood clotting disorders and the use of medications should be discussed with the anesthesiologist prior to the surgical procedure. Discontinuation of medications may be necessary to perform the procedure.
