Question Of The Day #74

January 28, 2022December 27, 2021 ~ Joseph Ciano, USA ~ Leave a comment

Which of the following is the most appropriate next step in management for this patient’s condition?

Explanation

This patient presents to the Emergency Department with altered mental status, difficulty breathing, vomiting, and hypersalivation after an unknown ingestion. His exam shows an ill patient with constricted pupils (miosis), wet skin (diaphoresis), bradycardia, and tachypnea. Altered mental status has a broad differential diagnosis, including intracranial bleeding, stroke, post-ictal state, hypoglycemia, electrolyte abnormalities, other metabolic causes, infectious etiologies, toxicological causes, and many other conditions. This patient’s constellation of signs and symptoms support the presence of a cholinergic toxidrome due to organophosphate poisoning. See the chart below for a review of the most common toxidromes (toxic syndromes).

*Treatment of all toxic ingestions should include general supportive care and management of the airway, breathing, and circulation of the patient. Examples include administration of supplemental oxygen in hypoxia, IV fluids in hypotension, cooling measures in hyperthermia, etc.
**Flumazenil is the antidote for benzodiazepine overdose, but it is rarely used clinically as it can trigger benzodiazepine-refractory seizures.

Cholinergic toxidromes can be caused by organophosphate or carbamate pesticides, as well as nerve gas agents (i.e., sarin gas). These agents cause poisoning by increasing the amount of acetylcholine at the neuromuscular junction, causing stimulation at muscarinic and nicotinic acetylcholine receptors. This causes a dramatic increase in bodily secretions with increased respiratory secretions and airway compromise as the most common cause of death in this population. The cholinergic toxidrome can be remembered with the mnemonic “DUMBBELLS” (diarrhea/diaphoresis, urination, miosis, bradycardia, bronchorrhea, emesis, lacrimation, low BP, salivation).

The first step in treating any patient who has the potential cause to harm or expose staff members to the poisoning agent is patient decontamination (Choice C). This patient should be undressed and adequately decontaminated by staff members who are wearing personal protective equipment (PPE). Once the patient is decontaminated, the airway should be established with endotracheal tube placement (Choice A) and IV atropine (Choice B) should be given to reverse the toxidrome. Atropine can be started at 2-4mg IV and repeated every 5-10 minutes until respiratory secretions are cleared. Pralidoxime (Choice D) should also be given as soon as possible to prevent irreversible changes (“aging”) to the acetylcholinesterase at the neuromuscular junction. This timeframe varies from minutes to hours after exposure, depending on the agent. All choices provided in this question are important actions to take, but patient decontamination (Choice C) is the most important initial next step. Correct Answer: C

References

Kitchen, L. (2015). The Approach to the Poisoned Patient. EMDocs. http://www.emdocs.net/the-approach-to-the-poisoned-patient/
Sahi, N. (2018). TOXCard: Nerve agents. EM Docs. http://www.emdocs.net/toxcard-nerve-agents/

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Question Of The Day #73

January 21, 2022December 27, 2021 ~ Joseph Ciano, USA ~ Leave a comment

Which of the following is the most likely cause of this patient’s condition?

Explanation

This patient presents to the Emergency Department with a depressed mental status and normal sized pupils after an unknown toxic ingestion. Many different agents can act as Central Nervous System depressants and cause this clinical presentation. Some examples include ethanol, toxic alcohols (methanol, ethylene glycol, isopropyl alcohol), benzodiazepines, barbiturates, opioids, and muscle relaxants.

Of the choices listed, Heroin (Choice A) and Alprazolam (Choice B) are the most likely. Heroin is an opioid, and Alprazolam is a benzodiazepine (a sedative-hypnotic agent). The clinical presentation caused by overdoses of opioids versus sedative-hypnotic agents overlaps in many areas, but the pupillary exam can help the most in differentiating the type of ingestion. Opioids will can constricted, pinpoint pupils, while benzodiazepines should not cause change in pupillary size. See the chart below for a review of the most common toxidromes (toxic syndromes).

Cocaine (Choice C) is a sympathomimetic with a CNS excitatory effect, not a CNS depressant effect as in this patient. A large ingestion of paracetamol (Choice D) is often accompanied with little to no symptoms in the first 24hours. Later in the ingestion timeline, liver failure and its associated sequalae can occur if no antidote is given. Correct Answer: B

References

Kitchen, L. (2015). The Approach to the Poisoned Patient. EMDocs. http://www.emdocs.net/the-approach-to-the-poisoned-patient/

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Question Of The Day #72

January 14, 2022December 27, 2021 ~ Joseph Ciano, USA ~ Leave a comment

Which of the following is the most likely cause of this patient’s condition?

Explanation

This patient presents to the Emergency Department with severe agitation and altered mental status. His exam demonstrates hypertension, tachycardia, elevated temperature, restlessness, dilated pupils, and wet diaphoretic skin. Altered mental status has a broad differential diagnosis, including intracranial bleeding, stroke, post-ictal state, hypoglycemia, electrolyte abnormalities, other metabolic causes, infectious etiologies, toxicological causes, and many other conditions. This patient’s history and exam support the presence of a toxidrome. See the chart below for a review of the most common toxidromes (toxic syndromes).

This patient has a sympathomimetic toxidrome (Choice C), which can be caused from cocaine, MDMA (ecstasy), methamphetamine, and other drugs. The anticholinergic toxidrome (Choice A) has many overlapping features with the sympathomimetic toxidrome, such as elevated blood pressure and heart rate, elevated temperature, agitation, and dilated pupils. One feature that can be used to differentiate these toxidromes is the skin exam. Sympathomimetic agents commonly cause wet diaphoretic skin, while anticholinergic agents cause dry skin. The cholinergic toxidrome (Choice B) presents with increased secretions (wet skin, diarrhea, vomiting, hypersalivation, bronchorrhea, etc.). One cause of this toxidrome is exposure to organophosphates. This patient is diaphoretic, but otherwise does not possess the other features of the cholinergic toxidrome. The opioid toxidrome (Choice D) would present with somnolence, as opposed to the CNS excitation seen in this patient. Correct Answer: C

References

Christy, G. (2019). EM@3AM: Overdose. EMDocs. http://www.emdocs.net/em3am-overdose/

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Question Of The Day #71

January 7, 2022December 27, 2021 ~ Joseph Ciano, USA ~ Leave a comment

Which of the following is the most appropriate next step in management for this patient’s condition?

Explanation

This patient arrives to the Emergency Department with lethargy, decreased respiratory rate, hypoxemia, pinpoint pupils, and a normal glucose level. The initial evaluation and treatment of this patient should be focused on management of the patient’s airway, breathing, and circulation (ABCs, also known as the ‘primary survey’). The airway should be repositioned to minimize obstructions to breathing, such as the tongue. Vomitus in the airway can also be removed manually or via suction to prevent obstruction of the airway or aspiration. Next, supplemental oxygen should be provided to treat the patient’s hypoxemia.

Altered mental status has a broad differential diagnosis, including intracranial bleeding, stroke, post-ictal state, hypoglycemia, electrolyte abnormalities, other metabolic causes, infectious etiologies, toxicological causes, and many other conditions. This patient’s history and exam support the presence of an opioid toxidrome. See the chart below for a review of the most common toxidromes (toxic syndromes).

toxidromes — *Treatment of all toxic ingestions should include general supportive care and management of the airway, breathing, and circulation of the patient. Examples include administration of supplemental oxygen in hypoxia, IV fluids in hypotension, cooling measures in hyperthermia, etc.
**Flumazenil is the antidote for benzodiazepine overdose, but it is rarely used clinically as it can trigger benzodiazepine-refractory seizures.

In addition to supportive treatments, like airway repositioning and supplemental oxygen, the antidote to opioid overdose should be promptly administered. Naloxone (Choice C) is the antidote to opioid overdose. Naloxone can be administered intravenously, intramuscularly, and intranasally. Naloxone should be started at a dose of 0.04mg and can be administered every 2-3 minutes at incrementally higher doses to a maximum total dose of 10mg. The goal of Naloxone administration is to achieve independent ventilations. Administering a larger initial dose of 0.4mg or 1mg can precipitate acute opioid withdrawal in a chronic opioid user.

IV Lorazepam (Choice A) is a benzodiazepine and would make the patient more sedated. Benzodiazepines are helpful in patients with an active seizure, severe agitation, or anxiety. Anticholinergic overdose (atropine, scopolamine) or sympathomimetic overdose (cocaine, methamphetamines, MDMA) are also responsive to benzodiazepines. IV Atropine (Choice C) is an anticholinergic agent. Atropine would worsen this patient’s borderline hypotension and mild bradycardia. IV Dextrose (Choice D) would be a reasonable medication to give if the glucose was unknown. The question stem provides a normal glucose level. Correct Answer: B