A 26-year-old man comes to the emergency department with a 4-day history of fever and chills. He has no chronic medical problems and takes no prescription medications. He drinks alcohol daily. Temperature is 38.3 C (101 F), blood pressure is 110/70 mm Hg, pulse is 95/min, and respirations are 14/min. Examination reveals clear lung fields and a pansystolic murmur at the lower sternal border that increases with inspiration. Multiple needle marks are present on both upper extremities. Laboratory evaluation shows leukocytosis and an elevated erythrocyte sedimentation rate. Chest x-ray reveals no airspace disease. Blood cultures are drawn and empiric antibiotics and supportive treatment are begun. An echocardiogram is ordered. A day later, the nurse reports an acute change in mentation. The patient had been conversing normally with a visitor shortly before the onset of somnolence. He is responsive only to noxious stimuli. Blood pressure is 95/65 mm Hg, pulse is 70/min, and respirations are 10/min. Pupils are equal and 1 mm bilaterally. The neck is supple and no jugular venous distension is seen. He can move all extremities. Which of the following is the most likely etiology for the acute clinical change in this patient?

Question

A 26-year-old man comes to the emergency department with a 4-day history of fever and chills.  He has no chronic medical problems and takes no prescription medications.  He drinks alcohol daily.  Temperature is 38.3 C (101 F), blood pressure is 110/70 mm Hg, pulse is 95/min, and respirations are 14/min.  Examination reveals clear lung fields and a pansystolic murmur at the lower sternal border that increases with inspiration.  Multiple needle marks are present on both upper extremities.  Laboratory evaluation shows leukocytosis and an elevated erythrocyte sedimentation rate.  Chest x-ray reveals no airspace disease.  Blood cultures are drawn and empiric antibiotics and supportive treatment are begun.  An echocardiogram is ordered.  A day later, the nurse reports an acute change in mentation.  The patient had been conversing normally with a visitor shortly before the onset of somnolence.  He is responsive only to noxious stimuli.  Blood pressure is 95/65 mm Hg, pulse is 70/min, and respirations are 10/min.  Pupils are equal and 1 mm bilaterally.  The neck is supple and no jugular venous distension is seen.  He can move all extremities.  Which of the following is the most likely etiology for the acute clinical change in this patient?

Quizplus · Accepted Answer

11ec25c8_d1d8_8f21_bc81_e1ba3ff04207_MD0003_00 This patient with fever, a pansystolic murmur at the lower sternal border, and evidence of intravenous drug use (eg, needle marks) likely has infective tricuspid valve endocarditis. His subsequent acute change in mental status, respiratory depression, and miosis suggest opioid intoxication (OI). The most reliable and predictive sign of OI is decreased respiratory rate. Other evidence includes hypotension and bradycardia. These findings in the setting of an acute change after a visitor suggest occult opioid use during the hospitalization. Other common findings include hypothermia and hypoactive bowel sounds. Neurologic examination is typically nonfocal. Evaluation should include measurement of blood glucose, tests for other illicit substances, and consideration of arterial blood gas analysis and ECG. Management focuses on protecting the airway and improving ventilation. The prompt administration of naloxone can result in rapid improvements. This drug should be titrated to improve the respiratory rate but not to achieve normal mental status. (Choices A and B) Cerebral abscess and embolic cerebral vascular accidents are important considerations in patients with infective endocarditis and abnormal neurologic findings. However, patients typically have focal findings on examination, and neither condition is commonly associated with miosis or respiratory depression. (Choices C and D) Acute hypocalcemia commonly presents with symptoms of tetany such as paresthesias, muscle spasm, and diaphoresis, whereas acute hyponatremia presents with nausea and malaise. Seizures can occur due to hypocalcemia, but the patient lacks other associated findings such as convulsions or loss of bowel or bladder function. Patients who have hyponatremia can develop obtundation, but it does not usually present until a markedly lower level of sodium occurs (ie, <120 mEq/L). Neither hypocalcemia nor hyponatremia would explain this patient's respiratory depression or miosis. < (Choice F) Subarachnoid hemorrhage almost universally presents with a sudden, severe headache, which this patient lacks. Patients may also demonstrate signs of meningismus. Loss of consciousness, if present, is typically brief. (Choice G) Wernicke encephalopathy is characterized by disorientation, inattentiveness, and nystagmus (not miosis) on examination. Acute obtundation and respiratory depression are not common. Educational objective: Opioid intoxication is commonly characterized by mental status changes, respiratory depression, and miosis. Hypotension, bradycardia, hypothermia, and decreased bowel sounds may also be present. References: Illicit opioid intoxication: diagnosis and treatment. (http://www.ncbi.nlm.nih.gov/pubmed/22879747)

A 26-Year-Old Man Comes to the Emergency Department with a 4-Day