A 38-year-old woman is brought to the emergency department due to confusion. Her husband says she has had a headache and acted strangely for the past 24 hours. He had difficulty awakening her this morning and observed 2 short episodes of rhythmic jerking of her right arm. The patient has no known medical problems and takes no medications. Family and social history are unremarkable.
Temperature is 39.1 C (102.4 F) , blood pressure is 116/62 mm Hg, pulse is 105/min, and respirations are 18/min. BMI is 25 kg/m². The patient is lethargic and her clothes are soiled with urine. Mucous membranes are moist. Funduscopic examination is normal. The patient responds to verbal stimulation and follows simple commands but is oriented to person only. There is no neck stiffness, and the remainder of the physical examination is normal.
Serum chemistry, complete blood count, and coagulation studies are remarkable only for a leukocyte count of 14,000/mm³ with 88% neutrophils. Chest x-ray and urinalysis are normal. ECG shows sinus tachycardia. Noncontrast CT scan of the head shows no acute intracranial findings. Lumbar puncture results are as follows:
Cerebrospinal fluid culture and herpes simplex virus PCR are sent, and intravenous acyclovir is ordered. Which of the following additional interventions is most appropriate for this patient?

Question

A 38-year-old woman is brought to the emergency department due to confusion. Her husband says she has had a headache and acted strangely for the past 24 hours. He had difficulty awakening her this morning and observed 2 short episodes of rhythmic jerking of her right arm. The patient has no known medical problems and takes no medications. Family and social history are unremarkable.
Temperature is 39.1 C (102.4 F) , blood pressure is 116/62 mm Hg, pulse is 105/min, and respirations are 18/min. BMI is 25 kg/m². The patient is lethargic and her clothes are soiled with urine. Mucous membranes are moist. Funduscopic examination is normal. The patient responds to verbal stimulation and follows simple commands but is oriented to person only. There is no neck stiffness, and the remainder of the physical examination is normal.
Serum chemistry, complete blood count, and coagulation studies are remarkable only for a leukocyte count of 14,000/mm³ with 88% neutrophils. Chest x-ray and urinalysis are normal. ECG shows sinus tachycardia. Noncontrast CT scan of the head shows no acute intracranial findings. Lumbar puncture results are as follows:

Cerebrospinal fluid culture and herpes simplex virus PCR are sent, and intravenous acyclovir is ordered. Which of the following additional interventions is most appropriate for this patient?

Quizplus · Accepted Answer

This patient has evidence of viral encephalitis (eg, fever, confusion) and has been appropriately started on empiric acyclovir. Acyclovir is relatively insoluble in urine and when given intravenously can precipitate within the renal tubules, leading to urinary obstruction and acute kidney injury. Acute kidney injury typically develops within 48 hours of drug initiation; patients may present with colicky flank or abdominal pain. Hematuria, pyuria, and birefringent needle-shaped crystals may be noted on urinalysis. Oral acyclovir has lower bioavailability and therefore has minimal risk of crystalline nephropathy. Intravenous acyclovir should be given with normal saline hydration of at least 2 L/day, with a goal urine output of 75 mL/hr to reduce renal tubule drug concentration and crystal formation. If renal failure develops, treatment is supportive and consists of drug withdrawal (if possible), aggressive hydration, and administration of a loop diuretic to flush the crystals from the renal tubules. Hemodialysis is occasionally necessary for severe toxicity. This patient should also receive intravenous fluids for possible sepsis. (Choice A) Telemetry monitoring is indicated for active cardiac disease (eg, recent myocardial infarction, angina, arrhythmias) and critical illness (eg, hypotension). Although this patient has encephalitis, she is hemodynamically stable and does not have active cardiac disease. (Choice B) Droplet precautions are indicated when there is concern for bacterial meningitis (eg, Neisseria meningitidis, Haemophilus influenzae). Cerebrospinal fluid analysis in bacterial meningitis would typically show very low glucose (<45 mg/dL), high protein (>250 mg/dL), and a more elevated leukocyte count (>1,000/mm³) than seen in this patient. ³ (Choice D) Proton pump inhibitors are typically indicated as prophylaxis for critically ill patients with coagulopathies (platelets <50,000/mm³, INR >1.5), mechanical ventilation >48 hours, or head trauma. However, proton pump inhibitors are associated with increased risk of Clostridium difficile infection and pneumonia. ³ (Choice E) Physical restraints have significant risks-including worsening agitation, prolonged delirium, and pressure sores-and should be reserved for patients who are at risk for harm to themselves or others. Educational objective: Intravenous acyclovir is relatively insoluble in urine and can precipitate within the renal tubules, leading to urinary obstruction and acute kidney injury. Normal saline infusion during acyclovir administration with a goal urine output of 75 mL/hr is recommended to prevent crystal formation. __________ References: Comparison of renal function indicators according to hydration volume in patients receiving intravenous acyclovir with CNS infection. (http://www.ncbi.nlm.nih.gov/pubmed/25504951)

A 38-Year-Old Woman Is Brought to the Emergency Department Due