Xylocaine Pump Spray Overdosage

Symptoms: Acute Systemic Toxicity: Toxic reactions originate mainly in the central nervous and the cardiovascular systems.
Central nervous system toxicity is a graded response with signs and symptoms of escalating severity. The first symptoms are circumoral paraesthesia, numbness of the tongue, lightheadedness, hyperacusis and tinnitus. Visual disturbances and muscular tremors are more serious and precede the onset of generalized convulsions. Unconsciousness and grand mal convulsions may follow, which may last from a few seconds to several minutes. Hypoxia and hypercarbia occur rapidly following convulsions due to the increased muscular activity, together with the interference with normal respiration. In severe cases, apnoea may occur. Acidosis increases the toxic effects of local anaesthetics.
Recovery is due to redistribution and metabolism of the local anaesthetic drug from the central nervous system. Recovery may be rapid unless large amounts of the drug have been administered.
Cardiovascular effects are only seen in cases with high systemic concentrations. Severe hypotension, bradycardia, arrhythmia and cardiovascular collapse may be the result in such cases.
Cardiovascular toxic effects are generally preceded by signs of toxicity in the central nervous system, unless the patient is receiving a general anaesthetic or is heavily sedated with drugs eg, benzodiazepine or barbiturate.
Treatment: Acute Toxicity: Treatment of acute toxicity should be instituted at the latest when twitches occur. The necessary drugs and equipment should be immediately available. The objectives of treatment are to maintain oxygenation, stop the convulsions and support the circulation.
Oxygen must be given and, if necessary, assisted ventilation (mask and bag). An anticonvulsant should be given IV if the convulsions do not stop spontaneously in 15-20 sec. Thiopentone sodium 1-3 mg/kg IV will abort the convulsions rapidly. Alternatively, diazepam 0.1 mg/kg bodyweight IV may be used although its action is slower.
Prolonged convulsions may jeopardise the patient's ventilation and oxygenation. If so, injection of muscle relaxant (eg, succinylcholine 1 mg/kg bodyweight) will facilitate ventilation, and oxygentation can be controlled. Early endotracheal intubation must be considered in such situations.
Suxamethonium will stop the muscle convulsions rapidly, but will require tracheal intubation and artificial ventilation, and should only be used by those familiar with these procedures. If cardiovascular depression is evident (hypotension, bradycardia), ephedrine 5-10 mg IV should be given and repeated, if necessary, after 2-3 min.
Should circulatory arrest occur, immediate cardiopulmonary resuscitation should be instituted. Optimal oxygenation and ventilation and circulatory support, as well as treatment of acidosis are of vital importance, since hypoxia and acidosis will increase the systemic toxicity of local anaesthetics. Adrenaline (0.1-0.2 mg as IV or intracardiac injections) should be given as soon as possible and repeated, if necessary.
Children should be given doses commensurate with their age and weight.