Psych, Substance Abuse, Poisoning

Question 1

Antidotes for cyanide poisoning include […] (preferred) or […]; alternatively nitrites may be used to induce methemoglobinemia.

Answer 1

Antidotes for cyanide poisoning include hydroxycobalamin (preferred) or sodium thiosulphate; alternatively nitrites may be used to induce methemoglobinemia.

Question 2

Antidotes for cyanide poisoning include hydroxycobalamin (preferred) or sodium thiosulphate; alternatively […] may be used to induce methemoglobinemia.

Answer 2

Antidotes for cyanide poisoning include hydroxycobalamin (preferred) or sodium thiosulphate; alternatively nitrites may be used to induce methemoglobinemia.

Question 3

Exertional heat stroke occurs in healthy individuals undergoing conditioning in extreme heat/humidity due to […].

Answer 3

Exertional heat stroke occurs in healthy individuals undergoing conditioning in extreme heat/humidity due to thermoregulation failure.

vs heat exhaustion, which is due to inadequate fluid and salt replacement

Question 4

Sodium bicarbonate alleviates the cardiotoxicity associated with TCA overdose by decreasing the drugs affinity for […].

Answer 4

Sodium bicarbonate alleviates the cardiotoxicity associated with TCA overdose by decreasing the drugs affinity for fast-acting Na+ channels.

NaHCO3 increases serum pH and extracellular sodium, which alleviates the cardio-depressant action of TCAs on sodium channels

Question 5

Treatment of salicylate intoxication includes alkalinization of the urine with […].

Answer 5

Treatment of salicylate intoxication includes alkalinization of the urine with sodium bicarbonate.

improves renal excretion

Question 6

What acid-base disturbance is associated with cyanide poisoning?

Answer 6

Metabolic acidosis

cyanide blocks cytochrome oxidase a3 in the mitochondrial ETC, thus promoting anaerobic metabolism and causing lactic acidosis

Question 7

What anti-emetic agents may cause extraparkinsonian symptoms (e.g. acute dystonia) as a possible side effect?

Answer 7

metoclopramide and prochlorperazine

other EPS include akathisia and parkinsonism; due to dopamine receptor blockade

Question 8

What antidote is frequently used to treat methanol and/or ethylene glycol poisoning?

Answer 8

Fomepizole

inhibits alcohol dehydrogenase; ethanol may be used as well

Question 9

What is the likely diagnosis in a farmer that presents to the hospital with agitation, vomiting, and watery eyes? Physical exam reveals 1 mm pupils bilaterally and increased bowel sounds.

Answer 9

Organophosphate (acetylcholinesterase inhibitor) poisoning

Question 10

What is the likely diagnosis in a group of individuals that present with headache, nausea/vomiting, and confusion after eating at an indoor barbecue? Physical examination of one patient reveals tachycardia, tachypnea, and pinkish-skin hue.

Answer 10

Carbon monoxide poisoning

diagnosis is confirmed by measuring carboxyhemoglobin levels (> 3% in non-smokers; > 10% in smokers)

Question 11

What is the likely diagnosis in a homeless patient that presents with confusion, epigastric pain, and blurred vision? Laboratory studies reveal anion gap metabolic acidosis.

Answer 11

Methanol poisoning

methanol intoxication effects the eyes (vs ethylene glycol, which effects the kidneys)

Question 12

What is the likely diagnosis in a homeless patient that presents with confusion, flank pain, and hematuria? Laboratory studies show anion gap metabolic acidosis and urine microscopy reveals calcium oxalate crystals.

Answer 12

Ethylene glycol poisoning

ethylene glycol doesn’t typically affect the eyes (vs methanol)

Question 13

What is the likely diagnosis in a middle-aged man with a history of poorly controlled HIV that presents with changes in personality and bizarre behavior? The patient also appears to have impaired attention and calculation. Brain MRI reveals a diffuse increase in intensity in the white matter.

Answer 13

HIV-associated neurocognitive dysfunction

Question 14

What is the likely diagnosis in a military recruit that collapses during training exercises on a hot, humid day? The patient is disoriented and has a fever of 105.8 F.

Answer 14

Exertional heat stroke

vs heat exhaustion, which typically presents with lower-grade fever (< 104 F) and no altered mental status

Question 15

What is the likely diagnosis in a patient brought to the ED with severe agitation and combativeness? Urine toxicology is negative. The patient is admitted and remained psychotic for one week before symptoms subsided.

Answer 15

Bath salts intoxication

PCP and cocaine intoxication may present similarly but with shorter durations of effect; additionally, PCP and cocaine are typically included in hospital urine toxicology screens

Question 16

What is the likely diagnosis in a patient that develops confusion, agitation, diaphoresis, and tremors three days after being admitted to the hospital following a motor vehicle accident? Physical exam reveals tachycardia, tachypnea, and hypertension.

Answer 16

Delirium tremens

defined by autonomic excitation, agitation, tremor, and altered sensorium 48 - 96 hours after the last drink

Question 17

What is the likely diagnosis in a patient that experiences sleep difficulties with “normal” bed times? The patient has no difficulty going to bed and waking up late (e.g. sleeping from 4 am to 12 pm).

Answer 17

Delayed sleep phase syndrome

circadian rhythm disorder characterized by inability to fall asleep at “normal” bedtimes (“night owls”);

vs.

advanced sleep phase syndrome, where patients cannot stay up late and have early morning insomnia (“early birds”)

Question 18

What is the likely diagnosis in a patient that presents with confusion and blurry vision after overdosing on an unknown medication? Physical examination reveals dry mucous membranes, decreased bowel sounds, and 8 mm pupils bilaterally.

Answer 18

Anticholinergic toxicity

“mad as a hatter, blind as a bat, dry as a bone, full as a flask, red as a beet”; may be reversed with physostigmine (cholinesterase inhibitor)

Question 19

What is the likely diagnosis in a patient that presents with heavy drooling, dysphagia, and a white tongue after being found next to an empty bottle of an unknown substance?

Answer 19

Caustic ingestion

in severe cases, perforation of the esophagus or stomach can occur, resulting in mediastinitis or peritonitis

Question 20

What is the likely diagnosis in a patient that presents with progressive worsening peripheral neuropathy? Physical exam reveals areas of hyper- and hypopigmentation, as well as hyperkeratosis. The patient restores antique furniture as a hobby.

Answer 20

Arsenic poisoning (chronic)

arsenic may be found in pressure-treated wood and insecticides; diagnosis is confirmed with elevated urine arsenic levels. Mees lines are a characteristic finding

Question 21

What is the likely diagnosis in an automobile mechanic that presents with constipation, increased forgetfulness, and peripheral neuropathy? Laboratory studies reveal microcytic anemia.

Answer 21

Lead poisoning

triad of GI, neurologic, and hematologic symptoms is classic for lead poisoning; peripheraly blood smear may reveal basophilic stippling, though this finding is not specific for lead poisoning

Question 22

What is the likely drug intoxication in a patient that presents with slurred speech, lethargy, and difficulty walking? Pupils are 5 mm and respiratory rate is 8/min.

Answer 22

benzodiazepine or alcohol overdose

lack of pupillary constriction and severe respiratory depression distinguishes benzodiazepine overdose from opioid overdose

Question 23

What is the most common cause of death in patients with TCA overdose?

Answer 23

Cardiac toxicity (e.g. ventricular arrhythmias)

Question 24

What is the next step in management for a patient that presents after ingesting twenty acetaminophen tablets two hours ago? Physical exam and laboratory studies, including LFTs, are normal.

Answer 24

administer activated charcoal and measure serum acetaminophen levels

if a single dose of > 7.5g of acetaminophen is ingested and it’s been < 4hrs since ingestion, activated charcoal should be administered

Question 25

What is the next step in management for a patient that presents with drooling and retrosternal/epigastric pain after ingesting sodium hydroxide (lye)? The patient has been decontaminated and is hemodynamically stable with a normal CXR.

Answer 25

Endoscopy

endoscopy is recommended within the first 12-24 hours to assess the severity of damage and guide further therapy

Question 26

What is the next step in management for an unresponsive patient that presents with respiratory depression and decreased bowel sounds? The patient smells of alcohol. Physical examination reveals 3 mm pupils bilaterally and a respiratory rate of 5/minute.

Answer 26

Naloxone

this patient likely has opioid intoxication (decreased respiratory rate is the most reliable and predictive sign of OI); miosis may be absent!

Question 27

What is the recommended initial management of frostbite?

Answer 27

Rapid rewarming with warm water

however, rewarming should not be attempted if there is a possibility of refreezing before definitive care can be provided

Question 28

What is the recommended treatment for anticholinergic poisoning?

Answer 28

physostigmine (cholinesterase inhibitor)

Question 29

What is the recommended treatment for carbon monoxide poisoning?

Answer 29

100% O2 or hyperbaric O2

Question 30

What is the recommended treatment for organophosphate or acetylcholinesterase inhibitor poisoning?

Answer 30

atropine +/- pralidoxime

equally important is the removal of any clothes, which may be contaminated with pesticides, and washing of skin to prevent further cutaneous absorption

Question 31

What is the treatment for arsenic toxicity?

Answer 31

Chelating agents, such as dimercaprol or DMSA

Question 32

What is the treatment of choice for acute opioid withdrawal?

Answer 32

low-dose methadone + adjunctive medications for symptoms

e.g. loperamide for diarrhea, ibuprofen for myalgias, etc…

Question 33

What is the treatment of choice for patients with alcohol withdrawal?

Answer 33

Benzodiazepines (e.g. lorazepam)

Question 34

What medication is administered to patients with suspected TCA toxicity to improve the effects of cardiac toxicity (e.g. hypotension, prolonged QRS interval, arrhythmia)?

Answer 34

Sodium bicarbonate

indicated if QRS > 100 ms or presence of arrhythmia

Question 35

What medication is administered to treat seizures in patients with suspected TCA toxicity?

Answer 35

Benzodiazepines