Regional anesthesia - subarachnoid - in general surgery, urology, orthopedics, gynecology, obstetrics, also in various diagnostic and therapeutic procedures.
Composition:
1 ml of solution contains 50 mg of Lidocaine hydrochloride.
Action:
Lidocaine is a local anesthetic with an amide structure. It inhibits the formation and conduction of stimuli in the nerve fibers. Inhibition of ion inflow Na+ prevents generation and conduction of impulses appearing in response to depolarization. The threshold of excitability of nerve fibers increases until complete conduction is blocked. In the first place, thin fibers are blocked. pain, then thicker - sensory. In order to block the motor fibers (the thickest ones), the highest concentrations of lidocaine are necessary. The preparation is a hyperbaric solution. Following the subarachnoid administration of 100 mg Lidocaine, the maximum plasma concentration reaches only 0.5 μg / ml. After a subarachnoid administration of 25-100 mg lidocaine, the duration of anesthesia is 60-90 min. At concentrations of 1-4 μg / ml, 40-80% of the drug is associated with proteins. Lidocaine crosses the blood-brain barrier and through the placenta. It is metabolized in the liver to several metabolites - N-dealkylated derivatives. It is excreted by the kidneys above all in the form of metabolites, only 10% in unchanged form.
Contraindications:
Hypersensitivity to lidocaine or other local anesthetics with amide structure. Contraindications for subarachnoid anesthesia: acute diseases o.u.n. (eg meningitis, tumors, gray matter of the spinal cord, intracranial hemorrhage). Stenosis of the spinal cord, spinal diseases (eg inflammatory process, tuberculosis of the spine, tumors) or recent spinal injuries (eg fractures). Sepsis. Subacute spinal cord degeneration in the course of pernicious anemia. Skin infection in the place of anesthesia or in its vicinity. Cardiogenic or hypovolemic shock. Coagulation disorders or treatment with anticoagulants.
Precautions:
Do not perform subarachnoid anesthesia in patients with hypovolaemia. Prior to subarachnoid anesthesia, regardless of the anesthetic used, the potential risks and benefits for the patient should be considered. Due to the occurrence of excessive (high) spinal anesthesia in obese patients with intra-abdominal hypertension and in women in advanced pregnancy, the dose of the local anesthetic should be reduced. Carefully use in very low patients with malformed spine, with neurological problems, heart block, severe hypertension, liver failure and in patients with neurological disorders such as multiple sclerosis, hemiplegia, transverse paralysis, neuromuscular disorders. Toxic effects of lidocaine on o.u.n. is manifested by convulsions after exceeding the concentration of 6 μg / ml serum, symptoms of poisoning may aggravate acidosis and the use of drugs that stimulate activity o.u.n.
Pregnancy and lactation:
The preparation can be used during pregnancy only in exceptional cases. Local anesthetics administered during labor easily pass through the placenta and may cause symptoms of intoxication in the fetus' mother. Lidocaine may cause cardiac abnormalities in the fetus and a decrease in blood pressure in the mother. The product is excreted in human milk, therefore its use during breastfeeding requires caution.
Side effects:
During anesthesia, a decrease in blood pressure, nausea, vomiting was observed, and after completion: post-operative headaches, back pain. Direct, damaging effects of lidocaine on the spinal cord and nerve roots that do not have a connective sheath are possible. Transient neurological syndromes such as arachnoiditis and aseptic meningitis may occur.Undesirable effects of lidocaine are usually the result of excessive increase in its concentration in body fluids as a result of too high a dose, disturbances in kinetics or inadequate injection technique. Symptoms of poisoning lidocaine on the part of the central nervous system: a metallic taste in the mouth, feeling of bewilderment, agitation, anxiety, euphoria, tremors, confusion, headache, dizziness, nausea, tinnitus, blurred vision, vomiting, feeling hot, cold or numbness, loss consciousness, convulsions, CNS depression; on the part of the circulatory system: lowering of blood pressure, bradycardia, and in extremely severe cases, cardiac arrest. Hypersensitivity reactions may occur very rarely: skin lesions, urticaria, edema, anaphylactoid symptoms.
Dosage:
A subarachnoid anesthesia. Adults: usually 25-100 mg, the duration of anesthesia is 60-90 min .; Repeating the dose is not recommended. Children over 16 years old, without coexisting diseases and in good physical condition: 25-100 mg. No dose recommendations for younger children, the dose should be adjusted for height and weight (up to 5 mg / kg). In children of high body weight, it is often necessary to reduce the dose to the appropriate amount for normal body weight. In patients with impaired liver function, heart disease, debilitated or elderly, the dose should be reduced. If during anesthesia (place of puncture in intercostal space L3-L4) the patient remains seated, anesthesia includes dermatoses below the Th level7-th10. If anesthesia is performed in a patient lying on the side, and after completing the injection will be laid flat on his back in the upper range can reach dermatomes anesthesia Th4-th7.
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