Aspirin

Aspirin

Aspirin , also known as acetylsalicylic acid , is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. It was discovered by Arthur Eichengrun, a chemist with the German company Bayer...

 poisoning or salicylism can be acute or chronic. A single overdose may cause acute poisoning; continuous usage of an elevated dosage over long periods of time may cause chronic poisoning. Acute overdose has a mortality rate

Mortality rate

Mortality rate is a measure of the number of deaths in a population, scaled to the size of that population, per unit time...

 of 2%. Chronic overdose is more commonly lethal with a mortality rate of 25%; chronic overdose may be especially severe in children. Symptoms may range from mild nausea

Nausea

Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...

 and vomiting

Vomiting

Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...

, abdominal pain, lethargy, tinnitus

Tinnitus

Tinnitus |ringing]]") is the perception of sound within the human ear in the absence of corresponding external sound.Tinnitus is not a disease, but a symptom that can result from a wide range of underlying causes: abnormally loud sounds in the ear canal for even the briefest period , ear...

, and dizziness

Dizziness

Dizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....

 to severe such as seizure

Seizure

An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...

 or cerebral edema

Cerebral edema

Cerebral edema or cerebral œdema is an excess accumulation of water in the intracellular or extracellular spaces of the brain.-Vasogenic:Due to a breakdown of tight endothelial junctions which make up the blood-brain barrier...

 depending on the dose consumed.

Toxicity is managed with a number of potential treatments including: activated charcoal, intravenous dextrose and normal saline, sodium bicarbonate

Sodium bicarbonate

Sodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula Na HCO3. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda . The natural mineral form is...

, and dialysis.

Symptoms

Aspirin overdose has potentially serious consequences, sometimes leading to significant morbidity and death

Death

Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....

. Patients with mild intoxication frequently have nausea

Nausea

Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...

 and vomiting

Vomiting

Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...

, abdominal pain, lethargy, tinnitus

Tinnitus

Tinnitus |ringing]]") is the perception of sound within the human ear in the absence of corresponding external sound.Tinnitus is not a disease, but a symptom that can result from a wide range of underlying causes: abnormally loud sounds in the ear canal for even the briefest period , ear...

, and dizziness

Dizziness

Dizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....

. More significant symptoms occur in more severe poisonings and include hyperthermia

Hyperthermia

Hyperthermia is an elevated body temperature due to failed thermoregulation. Hyperthermia occurs when the body produces or absorbs more heat than it can dissipate...

, tachypnea

Tachypnea

Tachypnea means rapid breathing. Any rate between 12-20 breaths per minute is normal. Tachypnea is a respiration rate greater than 20 breaths per minute. - Distinction from other breathing terms :...

, respiratory alkalosis

Respiratory alkalosis

Respiratory alkalosis is a medical condition in which increased respiration elevates the blood pH...

, metabolic acidosis

Metabolic acidosis

In medicine, metabolic acidosis is a condition that occurs when the body produces too much acid or when the kidneys are not removing enough acid from the body. If unchecked, metabolic acidosis leads to acidemia, i.e., blood pH is low due to increased production of hydrogen by the body or the...

, hypokalemia

Hypokalemia

Hypokalemia or hypokalaemia , also hypopotassemia or hypopotassaemia , refers to the condition in which the concentration of potassium in the blood is low...

, hypoglycemia

Hypoglycemia

Hypoglycemia or hypoglycæmia is the medical term for a state produced by a lower than normal level of blood glucose. The term literally means "under-sweet blood"...

, hallucinations, confusion

Mental confusion

Confusion of a pathological degree usually refers to loss of orientation sometimes accompanied by disordered consciousness and often memory Confusion (from Latin confusĭo, -ōnis, noun of action from confundere "to pour together", also "to confuse") of a pathological degree usually refers to loss...

, seizure

Seizure

An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...

, cerebral edema

Cerebral edema

Cerebral edema or cerebral œdema is an excess accumulation of water in the intracellular or extracellular spaces of the brain.-Vasogenic:Due to a breakdown of tight endothelial junctions which make up the blood-brain barrier...

, and coma

Coma

In medicine, a coma is a state of unconsciousness, lasting more than 6 hours in which a person cannot be awakened, fails to respond normally to painful stimuli, light or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions. A person in a state of coma is described as...

. The most common cause of death following an aspirin overdose is cardiopulmonary arrest usually due to pulmonary edema

Pulmonary edema

Pulmonary edema , or oedema , is fluid accumulation in the air spaces and parenchyma of the lungs. It leads to impaired gas exchange and may cause respiratory failure...

.

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 to 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.

Monitoring of biochemical parameters such as electrolytes, liver and kidney function, urinalysis

Urinalysis

A urinalysis , also known as Routine and Microscopy , is an array of tests performed on urine, and one of the most common methods of medical diagnosis...

, and complete blood count

Complete blood count

A complete blood count , also known as full blood count or full blood exam or blood panel, is a test panel requested by a doctor or other medical professional that gives information about the cells in a patient's blood...

 is undertaken along with frequent checking of salicylate and blood sugar

Blood sugar

The blood sugar concentration or blood glucose level is the amount of glucose present in the blood of a human or animal. Normally in mammals, the body maintains the blood glucose level at a reference range between about 3.6 and 5.8 mM , or 64.8 and 104.4 mg/dL...

 levels. Arterial blood gas

Arterial blood gas

An arterial blood gas is a blood test that is performed using blood from an artery. It involves puncturing an artery with a thin needle and syringe and drawing a small volume of blood. The most common puncture site is the radial artery at the wrist, but sometimes the femoral artery in the groin or...

 assessments will typically find respiratory alkalosis

Alkalosis

Alkalosis refers to a condition reducing hydrogen ion concentration of arterial blood plasma . Generally, alkalosis is said to occur when pH of the blood exceeds 7.45. The opposite condition is acidosis .-Causes:...

 early in the course of the overdose due to hyperstimulation of the respiratory center, and may be the only finding in a mild overdose. An anion-gapmetabolic acidosis

Metabolic acidosis

In medicine, metabolic acidosis is a condition that occurs when the body produces too much acid or when the kidneys are not removing enough acid from the body. If unchecked, metabolic acidosis leads to acidemia, i.e., blood pH is low due to increased production of hydrogen by the body or the...

 occurs later in the course of the overdose especially if it is a moderate to severe overdose, due to the increase in protons (acidic contents) in the blood.

The diagnosis of poisoning usually involves measurement of plasma salicylate, the active metabolite of aspirin, by automated spectrophotometric methods. Plasma salicylate levels generally range from 30-100 mg/L (3-10 mg/dL) after usual therapeutic doses, 50-300 mg/L in patients taking high doses and 700-1400 mg/L following acute overdose. 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.

Treatment

When aspirin overdose is suspected, immediately contact a medical doctor, or any medical professional if no doctor is available. All overdosed patients should be conveyed to a hospital immediately for assessment. Initial treatment of an acute overdose involves resuscitation followed by gastric decontamination by administering activated charcoal, which absorbs the aspirin in the gastrointestinal tract

Gastrointestinal tract

The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....

. Stomach pumping

Gastric lavage

Gastric lavage, also commonly called stomach pumping or Gastric irrigation, is the process of cleaning out the contents of the stomach. It has been used for over 200 years as a means of eliminating poisons from the stomach. Such devices are normally used on a person who has ingested a poison or...

 is no longer routinely used in the treatment of poisonings but is sometimes considered if the patient has ingested a potentially lethal amount less than one hour before presentation. Inducing vomiting with syrup of ipecac

Syrup of ipecac

Syrup of ipecac , commonly referred to as ipecac, is derived from the dried rhizome and roots of the ipecacuanha plant, and is a well known emetic .-Preparation:...

 is not recommended. Repeated doses of charcoal have been proposed to be beneficial in cases of aspirin overdosing, although one study found that they might not be of significant value. Regardless, most clinical toxicologists will administer additional charcoal if serum salicylate levels are increasing.

Intravenous fluids

Intravenous fluids containing dextrose such as D5W are recommended to keep a urinary output between 2 - 3 ml/kg/hr.

Alkalinization of the urine

Sodium bicarbonate

Sodium bicarbonate

Sodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula Na HCO3. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda . The natural mineral form is...

 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

Hemodialysis

In medicine, hemodialysis is a method for removing waste products such as creatinine and urea, as well as free water from the blood when the kidneys are in renal failure. Hemodialysis is one of three renal replacement therapies .Hemodialysis can be an outpatient or inpatient therapy...

 can be used to enhance the removal of salicylate from the blood. Hemodialysis is usually used in severely poisoned patients; for example, patients with significantly high salicylate blood levels [ 7.25 mmol/L (100 mg/dL) in acute ingestions or 40 mg/dL in chronic ingestions], or significant neurotoxicity (agitation, coma, convulsions), renal failure, pulmonary edema, or cardiovascular instability. Hemodialysis also has the advantage of restoring electrolyte

Electrolyte

In chemistry, an electrolyte is any substance containing free ions that make the substance electrically conductive. The most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible....

 and acid-base abnormalities while removing salicylate

Epidemiology

During the latter part of the 20th century, the number of poisonings from salicylates declined, mainly because of the increased popularity of other over-the-counter analgesics such as paracetamol

Paracetamol

Paracetamol INN , or acetaminophen USAN , is a widely used over-the-counter analgesic and antipyretic . It is commonly used for the relief of headaches and other minor aches and pains and is a major ingredient in numerous cold and flu remedies...

 (acetaminophen). Fifty-two deaths involving single-ingredient aspirin were reported in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

in 2000; however, in all but three of these cases, the reason for the ingestion of lethal doses was intentional -- predominantly suicidal.