A 5-year-old boy is brought back to the emergency department by his grandmother due to "bizarre behavior" a day after being seen there for a left eye injury sustained while playing flag football. At that time he was diagnosed with traumatic iritis and prescribed cyclopentolate eye drops for symptomatic relief. Two hours ago, he began acting strangely and said there were green men outside his house. Temperature is 37.8 C (100 F), blood pressure is 130/75 mm Hg, pulse is 150/min, and respirations are 24/min. He is agitated and disoriented, and he does not answer questions appropriately. The pupils are 8 mm bilaterally, and visual acuity is decreased. Perilimbal conjunctival injection of the left eye is present. Extraocular movements are intact. Mucous membranes are dry. Heart sounds are regular and rapid without a murmur or rub. The lungs are clear to auscultation. Deep tendon reflexes are normal. Which of the following is the best next step in management of this patient?

Question

A 5-year-old boy is brought back to the emergency department by his grandmother due to "bizarre behavior" a day after being seen there for a left eye injury sustained while playing flag football.  At that time he was diagnosed with traumatic iritis and prescribed cyclopentolate eye drops for symptomatic relief.  Two hours ago, he began acting strangely and said there were green men outside his house.  Temperature is 37.8 C (100 F), blood pressure is 130/75 mm Hg, pulse is 150/min, and respirations are 24/min.  He is agitated and disoriented, and he does not answer questions appropriately.  The pupils are 8 mm bilaterally, and visual acuity is decreased.  Perilimbal conjunctival injection of the left eye is present.  Extraocular movements are intact.  Mucous membranes are dry.  Heart sounds are regular and rapid without a murmur or rub.  The lungs are clear to auscultation.  Deep tendon reflexes are normal.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

This patient who was prescribed cyclopentolate eye drops for traumatic iritis (eg, left perilimbal conjunctival injection) has developed symptoms of anticholinergic toxicity, including confusion and hallucinations, hyperthermia, hypertension, tachycardia, dilated pupils, and dry mucous membranes. Cyclopentolate is an anticholinergic medication that causes paralysis of the ciliary muscle and often improves pain due to traumatic iritis. It is one among many common medications known to cause anticholinergic toxicity, to which children and the elderly are particularly susceptible. anticholinergic toxicity common medications Treatment for anticholinergic toxicity begins with supportive care (eg, stabilization of airway, breathing, circulation), and mild cases often resolve with supportive therapy alone. For patients such as this one, with severe toxicity that is both peripheral (eg, dilated pupils, dry mucous membranes) and central (eg, hallucinations), physostigmine is recommended. Physostigmine reversibly inhibits acetylcholinesterase in both the peripheral nervous system and CNS; this increases the concentration of acetylcholine and overcomes the anticholinergic blockade. When physostigmine is indicated, it is administered slowly and in small doses to avoid sending the patient into cholinergic toxicity. (Choice A) CT scan of head may be indicated if significant traumatic brain injury or intracranial hemorrhage is suspected as the cause of altered mental status. However, neurologic symptoms associated with these injuries typically present within a few hours of the head trauma (vs a day later) and cause depressed consciousness (vs hallucinations). Bilateral pupillary dilation and dry mucous membranes would not be expected. (Choice B) An emergency ophthalmology consult is appropriate when ocular trauma is the suspected cause of decreased visual acuity. However, this patient sustained trauma only to his left eye; his new bilateral ocular findings (eg, decreased visual acuity, dilated pupils, tachycardia), along with other systemic symptoms (eg, confusion, hypertension), are more likely due to a central cause (eg, anticholinergic toxicity). (Choice C) Lumbar puncture can help diagnose encephalitis or meningitis, which can cause fever, tachycardia, and altered mental status. However, hypertension and dilated pupils would not be expected. (Choice D) Mannitol, an osmotic diuretic, may be used to treat acutely increased intracranial pressure (ICP), as can occur after head trauma. However, acute ICP elevation classically causes headache, vomiting, and obtundation (rather than hallucinations). When severe enough to cause abnormal vital signs (eg, Cushing triad in impending herniation), it typically also causes severe neurologic impairment (eg, unconsciousness). Educational objective: Many common medications (eg, cyclopentolate eye drops) can cause anticholinergic toxicity, especially in children or the elderly. Physostigmine, a reversible acetylcholinesterase inhibitor, may be considered to treat severe anticholinergic toxicity. References: Pharmacological management of anticholinergic delirium-theory, evidence and practice. (http://www.ncbi.nlm.nih.gov/pubmed/26589572)

A 5-Year-Old Boy Is Brought Back to the Emergency Department