Acute Systemic Toxicity
Application Markain Spinal Heavy in accordance with the recommendations does not lead to a concentration of the drug in the plasma, at which systemic toxic manifestations may occur. However, when using Markain Spinal Heavy in combination with other local anesthetics, acute systemic toxicity can develop through the addition of toxic effects.
Like other local anesthetics, bupivacaine can cause acute toxic reactions from the central nervous and cardiovascular systems, if its use for local anesthesia leads to a high concentration of the drug in the blood. Especially it can be manifested in the case of unintentional intravascular injection. Against the background of a high concentration of bupivacaine in the plasma, cases of ventricular arrhythmia, ventricular fibrillation, sudden cardiovascular collapse and death were documented.However, the doses normally used for intrathecal anesthesia do not result in a high systemic concentration of the drug.
From the central nervous system
With the use of bupivacaine, intoxication manifests itself gradually as signs and symptoms of impaired central nervous system function with an increasing degree of severity. Initial manifestations of intoxication are: paresthesia around the mouth, dizziness, numbness of the tongue, pathologically increased perception of ordinary sounds and tinnitus. Impaired vision and tremor are more serious signs and precede the development of generalized seizures. These phenomena should not be mistakenly regarded as neurotic behavior. Following them, loss of consciousness and the development of large seizures can occur, which can last from a few seconds to several minutes. Due to increased muscular activity, disruption of the normal breathing process after the onset of seizures, hypoxia and hypercapnia quickly appear. In severe cases, apnea may develop. Acidosis increases the toxic effect of local anesthetics.
These phenomena are due to the redistribution of local anesthetic from the central nervous system and the metabolism of the drug. Coping toxic effects can occur quickly, unless anesthetic has been introduced in a very large amount.
Acute Systemic Toxicity Treatment
When the first signs of acute systemic toxicity or the total spinal block appear, discontinue the drug immediately and conduct symptomatic therapy of cardiovascular and neurological (seizures, CNS depression) disorders. In the event of cardiac arrest, cardiopulmonary resuscitation should immediately be used. It is vital to maintain lung ventilation, blood circulation and adequate oxygenation, and also to correct acidosis. When oppressing the activity of the cardiovascular system (arterial hypotension, bradycardia), intravenous injection of 5-10 mg of ephedrine is necessary, which, if necessary, can be repeated after 2-3 minutes. Children should be given a dose of ephedrine in accordance with their age and weight.
When seizures occur, therapy should be provided to maintain the cardiovascular system, provide adequate oxygenation and arrest seizures.If necessary, provide oxygen supply and artificial ventilation of the lungs (using an Ambu bag or intubation of the trachea). If convulsions do not stop on their own within 15-20 seconds, anticonvulsants should be used: thiopental sodium 1-3 mg / kg IV provides rapid arrest of seizures; you can use 0.1 mg / kg diazepam IV (the effect develops more slowly compared with the action of thiopental). Prolonged convulsions can interfere with ventilation and oxygenation. In such cases, for rapid arrest of seizures, intubation of the trachea and administration of a muscle relaxant (eg, succinylcholine 1 mg / kg) can be used.