Salicylate poisoning

Salicylate toxicity has potentially serious consequences, sometimes leading to significant morbidity and death. Patients with mild intoxication frequently have nausea and vomiting, abdominal pain, lethargy, ringing in the ears, and dizziness. More significant signs and symptoms occur in more severe poisonings and include high body temperature, fast breathing rate, respiratory alkalosis, metabolic acidosis, low blood potassium, low blood glucose, hallucinations, confusion, seizure, cerebral edema, and coma. The most common cause of death following an aspirin overdose is cardiopulmonary arrest usually due to pulmonary edema. High doses of salicylate can cause salicylate-induced tinnitus. Severity The severity of toxicity depends on the amount of aspirin taken. ==Pathophysiology==

High levels of salicylates stimulate peripheral chemoreceptors and the central respiratory centers in the medulla causing increased ventilation and respiratory alkalosis. • Phase II is characterized by paradoxic aciduria in the presence of continued respiratory alkalosis occurs when sufficient potassium has been lost from the kidneys. This phase may begin within hours and may last 12–24 hours. or 24 hours or more after ingestion in an adolescent or adult. ==Diagnosis==

The acutely toxic dose of aspirin is generally considered greater than 150 mg per kg of body mass. Moderate toxicity occurs at doses up to 300 mg/kg, severe toxicity occurs between 300 and 500 mg/kg, and a potentially lethal dose is greater than 500 mg/kg. Chronic toxicity may occur following doses of 100 mg/kg per day for two or more days. Patients may undergo repeated testing until their peak plasma salicylate level can be estimated. Optimally, plasma levels should be assessed four hours after ingestion and then every two hours after that to allow calculation of the maximum level, which can then be used as a guide to the degree of toxicity expected. Patients may also be treated according to their individual symptoms. ==Prevention==

Efforts to prevent poisoning include child-resistant packaging and a lower number of pills per package. ==Treatment==

There is no antidote for salicylate poisoning. Inducing vomiting with syrup of ipecac is not recommended. especially in ingestion of enteric coated and extended release salicylic acid formulations which are able to remain in the gastrointestinal (GI) tract for longer periods of time. Sodium bicarbonate is given in a significant aspirin overdose (salicylate level greater than 35 mg/dL 6 hours after ingestion) regardless of the serum pH, as it enhances elimination of aspirin in the urine. It is given until a urine pH between 7.5 and 8.0 is achieved. Dialysis Hemodialysis can be used to enhance the removal of salicylate from the blood, usually in those who are severely poisoned. Examples of severe poisoning include people with high salicylate blood levels: 7.25 mmol/L (100 mg/dL) in acute ingestions or 40 mg/dL in chronic ingestions, Salicylic acid has a small size (low molecular mass), has a low volume of distribution (is more water soluble), has low tissue binding and is largely free (and not protein bound) at toxic levels in the body; all of which make it easily removable from the body by hemodialysis. Indication for dialysis: • Salicylate level higher than 90 mg/dL (6.5 mmol/L) • Severe acid–base imbalance • Severe cardiac toxicity • Acute respiratory distress syndrome • Cerebral involvement / neurological signs and symptoms • Rising serum salicylate level despite alkalinization/multidose activated charcoal, or people in which standard approaches to treatment have failed • Unable to tolerate fluids with fluid overload ==Epidemiology==

Acute salicylate toxicity usually occurs after an intentional ingestion by younger adults, often with a history of psychiatric disease or previous overdose, whereas chronic toxicity usually occurs in older adults who experience inadvertent overdose while ingesting salicylates therapeutically over longer periods of time. ==History==

Aspirin poisoning has been cited as a possible driver of the high mortality rate during the 1918 flu pandemic, which killed 50 to 100 million people. ==See also==