Lidocaine Toxicity Tips For Your Family's Health

Lidocaine Toxicity

November 7th, 2011 Gabrielle Denehy Leave a comment Go to comments

One of the most commonly used local anesthetic for medical procedures is lidocaine. This anesthetic agent is marketed under the trade name, “Xylocaine”. It is the first anesthetic belonging to the amino-amide class. Overdose of any drug leads to toxicity. Same is true for lidocaine. Lidocaine toxicity can develop in adults and children due to its overdose via parenteral or topical administration, accidental ingestion or long-term use. Lidocaine is administered with or without epinephrine. Maximum dose of lidocaine that can be administered with epinephirine is 7 mg/kg whereas, without epinephrine it is 3-5 mg/kg. Anything more than this recommended dose is dangerous and can produce toxic effects in a person. Symptoms of Toxicity Toxicity symptoms of lidocaine usually appear in a progressive manner. Given below are the various symptoms that can be observed one after the other in an affected person.

Numbness and tingling of the tongue
Dizziness and lightheadedness
Disturbances in vision
Headache
Muscle twitching
Unconsciousness
Seizures
Coma
Respiratory arrest
Depression of cardiovascular system

Treatment Provided

As soon as lidocaine toxicity is identified, its administration, be it topical or parenteral, is stopped.
The person is provided with adequate oxygen supply through a face mask or a tube that is inserted in an external orifice of the body (intubation).
Cardiovascular system of the person is monitored carefully. Small doses of epinephrine are administered to the patient. Intravenous fluids and vasopressor drugs causing constriction of the blood vessels are used to support the patient’s health.
Seizures are controlled by the use of benzodiazepines, which are the drug of choice for this condition. Succinylcholine, along with intubation, is used in some cases to control unwanted neuromuscular effects of seizures. Another short-acting hypnotic agent, known as Propofol, can also be used for seizure control. However, its use is restricted because it can potentially increase toxic effects in the cardiovascular system.
Physicians administer sodium bicarbonate to patients for severe metabolic acidosis because acidosis is known to potentiate the toxic effects that lidocaine has on the cardiovascular system.
In rare cases, when overdose of lidocaine is excessively large, complications like cardiac arrest can come into picture. This serious complication is treated with cardiopulmonary bypass.

Prevention of Toxicity

Patient education is extremely important so that they are well aware of toxicity symptoms associated with lidocaine. Instructions to contact the doctor immediately must be given to patients, in case toxicity symptoms are visible, so that immediate treatment can be provided.
Administration of large doses of lidocaine must be done in a slow manner. For instance, any dose more than 5 ml must be injected in increments of 3 ml, so that, the body can gradually come under the anesthetic effect of the drug.
Anesthesiologists must be clear about the recommended doses of lidocaine. Lack of knowledge and carelessness can endanger a patient’s life due to administration of toxic doses of the anesthetic.
Maintaining communication with the patient when lidocaine is administered, helps in identifying serious symptoms of toxicity like, variation in mental status etc. This helps in immediately stopping further administration of the anesthetic agent.

Lidocaine toxicity not only depends on the dose of anesthetic used, but also on the speed with which it is administered, vascularity at the site of injection, acidosis and low protein in the body. Drug interactions can also lead to toxicity. Propranolol, cimetidine, phenytoin, clonidine and ciprofloxacin are some of the medications which affect lidocaine level in the body. Patients with liver dysfunction are more susceptible to develop toxic effects of lidocaine because its metabolism occurs in the liver. Impaired liver function fails to metabolize the anesthetic, thereby, gradually increasing its level in the body. Report published by the American Association of Poison Control Centers’ National Poison Data System, in the year 2007 states that, 670 children below 6 years of age were found to be affected by lidocaine exposure. In the same report, it was stated that, out of total lidocaine exposures, 229 cases developed minor effects, 83 developed moderate effects and 16 of them suffered from major toxicity effects. However, no deaths were reported in the study. This brings us to the conclusion that, if, lidocaine toxicity is identified at an early stage, the risk of developing serious toxicity outcomes can be reduced to a large extent.

Tips For Your Family's Health