A 6-year-old girl is brought to the emergency department by her parents after they found her unresponsive in the basement. They report that her younger sister sprayed the patient with a bottle that had been filled with pesticide to help rid the house of insects. Temperature is 36.6 C (98 F), blood pressure is 110/60 mm Hg, pulse is 58/min, and respirations are 42/min. On examination, the patient is lethargic and salivating. Which of the following medications should be administered first during treatment of this patient's current condition?

Question

A 6-year-old girl is brought to the emergency department by her parents after they found her unresponsive in the basement.  They report that her younger sister sprayed the patient with a bottle that had been filled with pesticide to help rid the house of insects.  Temperature is 36.6 C (98 F), blood pressure is 110/60 mm Hg, pulse is 58/min, and respirations are 42/min.  On examination, the patient is lethargic and salivating.  Which of the following medications should be administered first during treatment of this patient's current condition?

Quizplus · Accepted Answer

11ec160b_3c42_baa3_9249_b53c54b6d044_MD0001_00 This patient developed bradycardia, tachypnea, and excessive salivation after being exposed to a pesticide, suggesting acute organophosphate toxicity. Organophosphates are acetylcholinesterase inhibitors that produce signs of cholinergic excess due to hyperstimulation of the muscarinic (mnemonic: DUMBELS-see table) and nicotinic (ie, muscle weakness, fasciculations, paralysis) receptors. Most exposures occur with commercial pesticides, typically in farmers/field workers or in children with access to stored chemicals. Initial management of organophosphate toxicity includes the administration of atropine, a competitive inhibitor of acetylcholine at the muscarinic receptor, which leads to the resolution of muscarinic symptoms (eg, bradycardia, salivation). Patients who exhibit signs of nicotinic hyperstimulation (eg, weakness) should then receive pralidoxime, a cholinesterase-reactivating agent that treats both the muscarinic and nicotinic effects of organophosphates. However, pralidoxime should be given only after atropine because it can cause transient acetylcholinesterase inhibition, which can momentarily worsen symptoms (Choice E). (Choice B) Flumazenil is indicated to treat benzodiazepine overdose, which presents with sedation but would not be expected to cause bradycardia, tachypnea, or hypersalivation. (Choice C) Naloxone is indicated for treatment of opioid intoxication, which can cause sedation and miosis but suppresses (not increases) the respiratory rate. Opioid intoxication usually occurs via injection or ingestion, rather than external contact with aerosolized agents. (Choice D) Neostigmine is another acetylcholinesterase inhibitor that is sometimes used to treat myasthenia gravis; its use would worsen this patient's cholinergic symptoms. (Choice F) Sodium bicarbonate is indicated to treat patients with tricyclic antidepressant (TCA) overdose who are at risk for ventricular arrhythmias. However, TCA poisoning presents with altered mental status and anticholinergic signs (ie, flushed skin, mydriasis). Educational objective: Organophosphates are acetylcholinesterase inhibitors that are commonly used as agricultural pesticides. Toxicity is characterized by signs of cholinergic excess (eg, miosis, bronchospasm, muscle fasciculations/weakness, diarrhea, vomiting, lacrimation). First-line therapy is atropine, a competitive inhibitor of acetylcholine at the muscarinic receptor.

A 6-Year-Old Girl Is Brought to the Emergency Department by Her