Wednesday, May 24, 2017

NBME 7 question on intoxication

Disclaimer: This is an NBME form 7 question for step 2 CK. If you are planning to take USMLE step 2 CK in the future, I would recommend that you DO NOT read this post because it will bias your assessments.

A 19-year-old man is brought to the emergency department by police for evaluation after he was found standing in his neighbor's living room during the middle of the night. He is conscious but remains mute during questioning. His temperature is 37°C (98.6°F), pulse is 98/min, respirations are 18/min, and blood pressure is 160/95 mm Hg. Physical examination shows bilateral nystagmus, constricted pupils, hypertonia, and decreased sensation to pinprick. Which of the following is the most likely substance taken?

A. Alcohol
B. Amphetamine
C. Hallucinogen
D. Inhalant
E. Opioid

Classic toxidrome of PCP intoxication: violent behavior, nystagmus, tachycardia, hypertension, anesthesia, and analgesia.

The clinical picture may wax and wane between extreme agitation and sedation, because PCP can produce CNS stimulation and depression through its different clinical effects in the CNS.

Sedation and loss of inhibition tend to occur with ingestions of 1 to 5 mg, with the CNS findings of slurred speech, violent behavior and blank staring, horizontal, vertical, or rotatory nystagmus, ataxia, hyperthermia, and seizures at these doses.

It produces sympathomimetic signs such as hypertension, tachycardia, and diaphoresis similar to cocaine, and cholinergic signs like bronchospasm, salivation, urinary retention, flushing, and miosis, similar to opiates. The most common of these are tachycardia and hypertension.

Decreased but intact pain perception, midpoint pupils, nystagmus, ataxia differentiates PCP from stimulants.

Most deaths in PCP-intoxicated patients, however, result from patients’ violent behavior, rather than direct effects of the drug.

Patients recovering from PCP exposure may undergo an emergence reaction as the drug is eliminated, consisting of psychosis, bizarre behavior, or depression that may last from days to weeks. Prolonged psychosis is more commonly seen in chronic abusers, and is a poor prognostic sign, as the patient may go on to develop true schizophrenia. Depression, anxiety, irritability, restlessness, anergia, and disturbances of thought and sleep have been described in as little as a day of abstinence in chronic abusers.


1 comment:

This is express yourself space. Where you type create something beautiful! <3
Wondering what do I write? Well...
Tell us something you know better. You are a brilliant mind. Yes, you are! ^__^
Ask about something you don't understand @_@?
Compliment... Say something nice! =D
Be a good critic and correct us if something went wrong :|
Go ahead. Comment all you like here! (:

PS: We have moderated comments to reduce spam. ALL comments that are not spam will be published on the website.