A 64-year-old man is brought to the emergency department.  The patient was found unconscious on the floor at the scene of a fire at a local bar.  He was placed on oxygen and transported to the emergency department.  Medical history is unknown.  On arrival, the patient is unresponsive.  Black soot is present near the nares and mouth.  His beard is singed.  The lungs are clear to auscultation bilaterally.  The skin is reddish and capillary refill time is delayed.  No cutaneous burns are present.  Temperature is 37.2 C (99 F), blood pressure is 110/60 mm Hg, pulse is 140/min and regular, and respirations are 28/min.  Oxygen saturation is 100% on a nonrebreather mask.  Finger-stick glucose is 90 mg/dL.  Laboratory results are as follows:

What is the primary cause of this patient’s metabolic acidosis?

A 67-year-old man with advanced multiple myeloma is brought to the office due to progressively increasing generalized weakness and altered mental status for 5 days.  He currently takes acetaminophen, naproxen, and a fentanyl patch for pain.  Temperature is 36.5 C (97.7 F), blood pressure is 120/70 mm Hg, and pulse is 68/min.  Examination shows no focal findings.  Laboratory results are as follows:

Which of the following is the most likely explanation for this patient’s altered mental status?

An older-appearing man of unknown age is brought to the emergency department by paramedics on New Year’s Eve.  They found him minimally responsive and lying on the side of a street.  In the emergency department, the patient’s core body temperature is 29 C (84.2 F), blood pressure is 70/30 mm Hg, heart rate is 40/min, and respirations are 6/min and shallow.  His oxygen saturation is 90% on 5 L oxygen.  On examination, the patient remains unresponsive to verbal stimuli and his breath smells of alcohol.  His pupils are normal and symmetric but have a sluggish reaction to light.  Lung examination reveals crackles bilaterally.  Cardiovascular examination reveals bradycardia with an irregular pulse.  Neurologic examination is difficult to perform but shows marked hyporeflexia throughout.  An initial ECG shows sinus bradycardia with frequent premature ventricular complexes.  Capillary blood glucose is 315 mg/dL.  Paramedics have started an infusion of warmed normal saline via 16-g peripheral access.  The patient has also received one dose of intravenous thiamine.

Item 1 of 2

Which of the following is the most appropriate next step in management of this patient?

Item 2 of 2

Appropriate measures are initiated, and in 3 hours the patient’s core temperature is 33.2 C (91.8 F).  Blood pressure is 82/42 mm Hg and heart rate is 42/min.  The patient remains lethargic.  His initial laboratory results are as follows:

The cardiac monitor shows persistent sinus bradycardia with frequent premature ventricular contractions.  Which of the following is the most appropriate next step in management of this patient?

A 30-year-old man is brought to the emergency department by an ambulance after a gas station attendant noticed the patient disoriented and wandering aimlessly.  The patient has had nausea, vomiting, and dizziness.  Emergency department records indicate that the patient has a history of schizophrenia, but he cannot remember the names of his medications.  He also has limited memory of the previous day.  The patient smokes cigarettes occasionally and does not use alcohol or illicit drugs.  Temperature is 41.1 C (106 F), blood pressure is 90/60 mm Hg, pulse is 128/min, and respirations are 26/min.  The patient is lethargic and appears disheveled and sunburned; he is oriented to person only.  The skin and oral mucous membranes are dry.  The lungs are clear to auscultation.  The heart rhythm is regular with no murmurs.  Muscle tone is moderately decreased and reflexes are normal.  He moves all extremities to command.  Laboratory results are as follows:

Urine drug screen is positive for methamphetamines.  Chest x-ray is clear.  CT scan of the head without contrast shows no acute intracranial abnormalities.  Which of the following is the most appropriate immediate step in management of this patient?

A 2-year-old boy is brought to the emergency department by his grandmother due to altered mental status.  He was playing in the garage, where chemicals are stored, for a long time earlier in the day.  The patient has had multiple episodes of emesis over the past several hours.  Temperature is 36.9 C (98.4 F), blood pressure is 78/45 mm Hg, pulse is 130/min, and respirations are 45/min.  Oxygen saturation by pulse oximetry is 98% on room air.  Physical examination reveals the patient to be somnolent; pupils are 3 mm and reactive.  Lungs are clear to auscultation.  Abdomen is soft and bowel sounds are normal.  During examination, he develops a generalized tonic-clonic seizure.

Item 1 of 2
Exposure to which of the following is the most likely cause of this patient’s symptoms?

Item 2 of 2

The patient’s airway is secured via endotracheal intubation.  Laboratory results are as follows:

Which of the following is the best next step in management?

A 23-year-old man is brought to the emergency department by his mother due to intentional drug overdose and rapid breathing.  The patient’s mother found him actively vomiting when she returned home from work.  The patient told her that he felt depressed after his girlfriend broke up with him earlier today and that he ingested the entire contents of a bottle of pills from the medicine cabinet.  The patient reports nausea and dizziness and has vomited 3 times since arriving at the emergency department.  Temperature is 38.1 C (100.6 F), blood pressure is 100/55 mm Hg, pulse is 110/min, and respirations are 34/min.  Pulse oximetry is 99% on room air.  On physical examination, the patient is alert and anxious-appearing.  He has no retractions, nasal flaring, or cough.  The lungs are clear to auscultation.  The pupils are normal sized and reactive.  The abdomen is soft and nontender; bowel sounds are normoactive.  Neurologic examination, including deep tendon reflexes, reveals no abnormalities.  ECG shows sinus tachycardia.  Chest x-ray reveals no abnormalities.

Item 1 of 2

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

Item 2 of 2

Laboratory results are as follows:

Item 2 of 2

Which of the following is the most appropriate next step in management of this patient?

A 54-year-old woman is evaluated for abdominal discomfort.  She has been feeling weak for the past 7 days.  The patient is not eating well due to nausea and has noticed that her urine has become darker.  She has a history of hypertension and generalized anxiety disorder.  Her medications include amlodipine and chlorthalidone.  For the past 4 months she has also been using ginseng as an energy booster and kava kava to control her anxiety.  Two months ago, the patient started using Gingko biloba in an attempt to improve her memory.  She states that she had been feeling better, less anxious, and more alert until last week.  The patient does not use tobacco, alcohol, or illicit drugs.  Examination shows mild jaundice.  Heart sounds are normal and lung sounds are clear.  The liver is palpable 2 cm below the costal margin and tender.  Neurologic examination reveals no abnormalities.  Her laboratory tests are as follows:

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

A 44-year-old man is rescued from a house fire and brought to the emergency department with nausea, headache, and altered mental status.  The fire likely began due to the stove accidently being left on overnight.  He has no chronic medical problems and takes no medications.  The patient had smoked a pack of cigarettes a day for 10 years but quit several years ago.  He does not use illicit drugs.  Temperature is 36.7 C (98 F), blood pressure is 110/70 mm Hg, pulse is 112/min, and respirations are 28/min.  Pulse oximetry is 97% on room air.  The patient has soot around the mouth and oropharynx, flushed cheeks, pink palmar skin, and breath that smells strongly of smoke.  He is lethargic but has spontaneous movement in all extremities.  Cardiopulmonary auscultation reveals clear lung fields and normal heart sounds with occasional ectopic beats.  Laboratory results are as follows:

Chest-x ray reveals no infiltrates.  ECG shows T-wave inversions in leads I, aVL, V5, and V6 that were not present on previous ECGs.  Which of the following is most likely to confirm the underlying diagnosis?

A 48-year-old woman with no past medical history is brought to the emergency department by an ambulance after being rescued from a burning apartment building.  The woman was trapped in a smoke-filled back bedroom of the apartment.  On physical examination, her vital signs are stable, and while there is some singeing of her facial hair, there is no visible evidence of burns.  An arterial blood gas is obtained, and the values are as follows:

What potential development is of most concern in this woman over the next 24 hours?

A 52-year-old woman comes to the office for follow-up of hypertension.  The patient’s blood pressure has been stable over the past 8 years on treatment with hydrochlorothiazide and amlodipine.  However, recent home blood pressure readings have been higher than usual.  The patient has had no changes in sleep quality, caffeine intake, or dietary sodium, but she has been drinking an herbal tea, which her son brought back from a trip to Asia, several times a day.  She also takes black cohosh for occasional menopausal hot flashes.  The patient does not use tobacco, alcohol, or illicit drugs.  Temperature is 36.5 C (97.7 F), blood pressure is 152/88 mm Hg, pulse is 70/min, and respirations are 14/min.  Physical examination reveals normal jugular venous pressure, clear lung fields, and normal S1 and S2.  Femoral pulses are 2+ bilaterally, and no abdominal bruits are noted.  Laboratory results are as follows:

Additional testing shows a supine morning plasma renin activity of 0.15 ng/mL per hour (normal: 0.3-1.9) and a serum aldosterone level of 0.9 ng/dL (normal: 2-5).  Which of the following is the most likely cause of this patient’s uncontrolled hypertension?