MCQs In posioning

Q 1:

A 1-year-old boy has a blood lead level of ِ1.9 mcmol/L (40 mcg/dL). His parents have been renovating their 60-year-old home. There is no history of pica.

Of the following, the MOST likely source of this child's lead poisoning is:

A.  folk remedies

B.  household dust

C.  lead-glazed pottery

D.  lead plumbing

E.  soil

Answer

B

Lead often is absorbed by children through the respiratory and gastrointestinal tracts. It also can be absorbed transplacentally by the fetus. 

Because lead is a toxic substance, efforts have been made to reduce the lead content in air, water, and food. 

In older homes that have not be inspected for lead, household dust has been found to contain high concentrations of lead in heavily contaminated areas. In older homes that are being renovated or that have peeling or chipping paint, children can ingest contaminated household dust through normal hand-to-mouth activity. Lead risk assessment questionnaires can be used to help determine whether a child is at risk for lead poisoning.

            A thorough history should be able to elicit other, less frequent causes of lead poisoning. Lead plumbing has been nearly eliminated, but lead-soldered plumbing may transfer small amounts of lead to water. Soil near roads and interstate highways can have high levels of lead from exhaust fumes. Children who eat this soil are at risk for lead poisoning. The lead in lead-glazed pottery can leach into liquids and foods, especially if acidic items are stored in such containers. Certain folk remedies (eg, amarcon and greta) that are used to treat colic contain lead that could result in lead poisoning.

            There is evidence that blood lead levels as low as 0.48 mcmol/L (10 mcg/dL) can cause impaired cognitive function. The child in the vignette, who has a blood lead level of 1.9 mcmol/L (40 mcg/dL), is at risk for central nervous system damage. Appropriate management includes chelation therapy and removal from the contaminated home until lead decontamination has been achieved.

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Q 2
:

A 12-year-old boy is brought to the emergency department by friends. He is agitated and disoriented. Vital signs include a blood pressure of 170/100 mm Hg, heart rate of 120 beats/min, and a temperature of 100.5°F (38°C). Shortly after arrival, he experiences a generalized seizure. You suspect a cocaine overdose.

Of the following, the MOST appropriate medication to administer is:

A.         diazepam

B.         haloperidol

C.         nifedipine

D.         nitroprusside

E.         phenytoin

Answer

A

Symptoms and signs of acute cocaine overdose include agitation, fever, tachycardia, hypertension, and seizures. This potent central nervous system (CNS) and cardiac stimulant usually is administered by insufflating (“snorting”), although it may be injected intravenously or smoked (“free-based”). Cocaine inhibits neuronal uptake of dopamine, norepinephrine, and serotonin and stimulates pleasure centers in the brain. Its use is potentially addictive, with the mode of administration possibly influencing this potential. For example, “free-basing” appears to create more drug craving than intravenous injection or insufflation.

            Cocaine produces a continuum of dose-related effects ranging from mild intoxication to overdose. At lower doses, for example, the individual experiences euphoria and overconfidence; at higher doses, there may be aggressive or violent behavior with paranoia or psychosis. Although a relationship between dose and clinical effect has been observed, it should be recognized that death due to cocaine ingestion may occur regardless of the dose ingested, the blood level of cocaine, or the route of administration.

            An acute cocaine overdose, such as that experienced by the boy presented in the vignette, may produce a number of life-threatening complications involving the CNS, cardiovascular, and pulmonary systems that require careful patient monitoring and supportive care. Seizures are managed best with a benzodiazepine (eg, diazepam); if seizures persist, phenobarbital followed by phenytoin may be administered. Cocaine-induced hypertension has been associated with little morbidity or mortality, usually is short-lived, and may be followed by significant hypotension. For these reasons, pharmacologic treatment, usually with nitroprusside rather than nifedipine, is reserved for those patients