Lidocaine hydrochloride
Brand Name: lidocaine HCl in 5% dextrose
Pregnancy Category B
Drug classes: Antiarrhythmic, Local anesthetic
Therapeutic actions
Type 1 antiarrhythmic: decreases diastolic depolarization, decreasing automaticity of ventricular cells; increases ventricular fibrillation threshold.
Local anesthetic: blocks the generation and conduction of action potentials in sensory nerves by reducing sodium permeability, reducing height and rate of rise of the action potential, increasing excitation threshold, and slowing conduction velocity.
Indications
· As antiarrhythmic: Management of acute ventricular arrhythmias during cardiac surgery and MI (IV use). Use IM when IV administration is not possible or when ECG monitoring is not available and the danger of ventricular arrhythmias is great (single-dose IM use, for example, by paramedics in a mobile coronary care unit)
· As anesthetic: Infiltration anesthesia, peripheral and sympathetic nerve blocks, central nerve blocks, spinal and caudal anesthesia, retrobulbar and transtracheal injection; topical anesthetic for skin disorders and accessible mucous membranes
Contraindications
· Contraindicated with allergy to lidocaine or amide-type local anesthetics, CHF, cardiogenic shock, second- or third-degree heart block (if no artificial pacemaker), Wolff-Parkinson-White syndrome, Stokes-Adams syndrome.
Adverse effects
Antiarrhythmic with systemic administration
Dizziness/light-headedness, fatigue, drowsiness, unconsciousness, tremors, twitching, vision changes; may progress to seizures, convulsions
Cardiac arrhythmias, cardiac arrest, vasodilation, hypotension
Nausea, vomiting
Rash, anaphylactoid reactions
Respiratory depression and arrest
Malignant hyperthermia, fever, local injection-site reaction
Injectable local anesthetic for epidural or caudal anesthesia
Headache, backache, septic meningitis, persistent sensory, motor, or autonomic deficit of lower spinal segments, sometimes with incomplete recovery
Hypotension due to sympathetic block
Urticaria, pruritus, erythema, edema
Urinary retention, urinary or fecal incontinence
Drug Interaction:
· Increased lidocaine levels with beta-blockers (propranolol, metoprolol, nadolol, pindolol, atenolol), cimetidine, ranitidine
· Prolonged apnea with succinylcholine
Nursing considerations
· Check drug concentration carefully; many concentrations are available.
· Reduce dosage with hepatic or renal failure.
· Continuously monitor response when used as antiarrhythmic or injected as local anesthetic.
· Maintain life-support equipment, and have vasopressors on standby if severe adverse reaction (CNS, CV, or respiratory) occurs when lidocaine is injected.
· Establish safety precautions if CNS changes occur; have IV diazepam or short-acting barbiturate (thiopental, thiamylal) on standby in case of convulsions.
· Monitor for malignant hyperthermia (jaw muscle spasm, rigidity); have life-support equipment and IV dantrolene on standby.
· Titrate dose to minimum needed for cardiac stability, when using lidocaine as antiarrhythmic.
· Reduce dosage when treating arrhythmias in CHF, digitalis toxicity with AV block, and geriatric patients.
· Monitor fluid load carefully; more concentrated solutions can be used to treat arrhythmias in patients on fluid restrictions.
· Have patients who have received lidocaine as a spinal anesthetic remain lying flat for 6–12 hr afterward, and ensure that they are adequately hydrated to minimize risk of headache.
· Check lidocaine preparation carefully; epinephrine is added to solutions of lidocaine to retard the absorption of the local anesthetic from the injection site. Be sure that such solutions are used only to produce local anesthesia. These solutions should be injected cautiously in body areas supplied by end arteries and used cautiously in patients with peripheral vascular disease, hypertension, thyrotoxicosis, or diabetes.
· Use caution to prevent choking. Patient may have difficulty swallowing following use of oral topical anesthetic. Do not give food or drink for 1 hr after use of oral anesthetic.
· Treat methemoglobinemia with 1% methylene blue, 0.1 mg/kg, IV over 10 min.
· Apply lidocaine ointments or creams to a gauze or bandage before applying to the skin.
· Monitor for safe and effective serum drug concentrations (antiarrhythmic use: 1–5 mcg/mL). Doses > 6–10 mcg/mL are usually toxic.
1 comments:
Good
Post a Comment