Sun21November0420PM 19

A 45-year-old man is admitted to the Emergency department with a suspected overdose of enterically coated aspirin.

The patient has been vomiting and complains of tinnitus.

On examination, he is sweating profusely and is clinically dehydrated. His vital signs are as follows: temperature 37.5°C, pulse 110 regular, blood pressure 150/95 mmHg, respiratory rate 25 breaths per minute and oxygen saturation 95% on air.

It is thought that the aspirin was ingested two hours ago.

The biochemistry results are as follows:

pH 7.5 (7.35-7.45)

PaCO2 30 mmHg (38-42)

PaO2 102 mmHg (75-100)

BE +5 (-3 to +3)

Bicarbonate 22 mEq/L (22-28)

SpO2 96% -

Glucose 13 mmol/L (3.5-5.5)

Salicylate levels 610 mg/L -

Which one of the following is the most appropriate initial clinical intervention in this case?

(Please select 1 option)

Activated charcoal This is the correct answer

Alkalinisation of urine Incorrect answer selected

Forced diuresis

Gastric lavage

Haemodialysis

Explanation

The clinical picture of this patient is consistent with a moderate overdose of aspirin.

There is no specific antidote to ingested salicylates.

The management of a poisoning is supportive with measures to prevent further absorption from the gastrointestinal tract and enhance excretion. Ideally activated charcoal should be given within an hour of ingestion but should be considered if enterically coated aspirin is ingested. Patients with salicylate poisoning can be given repeat doses of activated charcoal (four hourly doses of 50 g in adults, 1 g/kg body weight in children) until the salicylate level peaks to minimise delayed absorption of salicylates.

The initial treatment especially of this patient should include the administration of activated charcoal and repeated as bezoars may form resulting in delayed absorption of salicylate. This should continue until salicylate levels have peaked.

Gastric lavage is useful if the ingestion is known to have occurred within one hour but the airway should be protected during the procedure. The patient should then be rehydrated and the urine alkalinised to promote urinary excretion. This is achieved by giving an infusion of 1.25% sodium bicarbonate.

A forced diuresis alone is not recommended as it can lead to severe electrolyte disturbance and pulmonary or cerebral oedema.

Severe cases of salicylate poisoning where plasma levels of salicylate are high >800 mg/L, severe metabolic acidosis, acute kidney injury or where the patient has neurological impairment (coma, hallucinations or seizures) may require early haemodialysis.

Reference:

Dargan PI, et al. An evidence based flowchart to guide the management of acute salicylate (aspirin) overdose. Emerg Med J. 2002;19:206-9.

Answer Statistics

1

38%

2

32%

3

3%

4

8%

5

21%

Times answered: 273