All practice questions

An infectious diseases consultation is requested for a $59$-year-old male inpatient. He was admitted $4$ days ago with severe back pain and fever, leading to a diagnosis of $\text{T10}-\text{T11}$ vertebral osteomyelitis and an associated epidural abscess. Urgent surgical decompression and debridement were performed on the day of admission. Blood cultures obtained prior to antibiotic administration, as well as intraoperative tissue specimens, have both grown Staphylococcus aureus. Susceptibility testing confirms the isolate is susceptible to oxacillin, cefazolin, vancomycin, and daptomycin. The patient has been receiving empiric intravenous vancomycin therapy since presentation. His medical history includes type $2$ diabetes mellitus and hypertension. $3$ years ago, he experienced a severe allergic reaction following a dose of oral amoxicillin; he rapidly developed diffuse urticaria, wheezing, and facial angioedema, which necessitated emergency administration of intramuscular epinephrine. He has no prior exposure to cephalosporin antibiotics. Currently, his vital signs are stable, and his serum creatinine is $0.9 \text{ mg/dL}$. Based on current guidelines, which of the following is the most appropriate next step in the pharmacologic management of this infection?

A 68-year-old woman is evaluated in the hospital for new-onset skin lesions. Six days ago, she was admitted for a right lower extremity deep vein thrombosis and started on a continuous intravenous unfractionated heparin infusion and oral warfarin. Two days ago, her platelet count was noted to have decreased from $260,000/\text{mm}^3$ on admission to $105,000/\text{mm}^3$. Heparin was immediately discontinued, a serotonin release assay was sent, and an intravenous argatroban infusion was started. Warfarin was continued. Today, she complains of significant pain over her abdomen and both thighs. Physical examination reveals well-demarcated, erythematous, and purpuric lesions with central areas of black necrosis in these regions. Vital signs are stable.

Laboratory results today:
Hemoglobin: $11.2\text{ g/dL}$
Platelet count: $110,000/\text{mm}^3$
Prothrombin time (PT): $25\text{ sec}$
Activated partial thromboplastin time (aPTT): $68\text{ sec}$
INR: $2.4$

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

A 4-year-old girl is brought to the office by her father for a well-child examination. The father is worried about her overall development. He states that since she started attending a new preschool three months ago, she has frequently engaged in conversations with an "imaginary friend" in her bedroom. Furthermore, she intermittently repeats syllables when she is very eager to talk about her day. The father is also concerned because she is unable to draw a square or ride a two-wheeled bicycle, milestones that her older sibling had already achieved by age 5. Her medical history is unremarkable. On examination, the patient appears well-nourished and cooperative. She is able to hop on one foot and catch a bounced ball. When given paper and crayons, she successfully draws a person with four body parts and copies a cross, but she cannot draw a square or a triangle. During the visit, her speech is entirely understandable to the physician, and she exhibits no facial grimacing, jaw jerking, or eye blinking when repeating syllables. Which of the following is the most appropriate next step in management?

Match each pediatric patient presenting for a routine well-child visit with the corresponding age-appropriate universal screening test recommended by the American Academy of Pediatrics.

A pediatric clinic is reviewing its protocols for routine health maintenance and immunization delivery. The clinical educator asks the medical students to outline the chronological progression of vaccinations. Arrange the following immunization milestones in chronological order based on the age at which they are routinely indicated for a healthy, full-term child in the United States, starting from the earliest intervention.

Match the following clinical scenarios of patients presenting with thrombocytopenia to the most likely underlying diagnosis.

Match the following classic infectious disease clinical presentations with the most appropriate first-line antimicrobial therapy.

A 45-year-old man presents to the outpatient clinic with a 2-day history of right calf pain and swelling. He recently returned from a 14-hour international flight. He has no chest pain, shortness of breath, or hemoptysis. His medical history is unremarkable, and he takes no medications.

Vital signs are:
Temperature: 37.0°C (98.6°F)
Heart rate: 78/min
Blood pressure: 125/80 mmHg
Respiratory rate: 14/min
Oxygen saturation: 98% on room air

Physical examination reveals a 4 cm increase in the circumference of the right calf compared to the left. The right calf is warm, tender to palpation, and exhibits mild erythema.

Laboratory panels reveal:
Hemoglobin: 14.8 g/dL
Mean corpuscular volume (MCV): 88 fL
Platelet count: 260,000/mm³
White blood cell count: 8,100/mm³
Serum creatinine: 0.9 mg/dL
Prothrombin time (PT): 12 seconds
Activated partial thromboplastin time (aPTT): 30 seconds

A comprehensive duplex ultrasonography of the right lower extremity demonstrates a non-compressible segment in the right popliteal vein.

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

A $65$-year-old man visits the clinic reporting a $3$-week history of profound fatigue, subjective fevers, and widespread joint pain. He notes that his wrists, knees, and ankles feel stiff and swollen. His past medical history is significant for ischemic cardiomyopathy with a reduced ejection fraction and chronic obstructive pulmonary disease. His daily medications include carvedilol, lisinopril, furosemide, hydralazine, and a tiotropium inhaler. Vital signs show a temperature of $37.9^\circ\text{C}$ ($100.2^\circ\text{F}$), blood pressure of $128/78\text{ mmHg}$, and heart rate of $76/\text{min}$. Physical examination reveals mild symmetric effusions in the knees and wrists without overlying erythema. Cardiopulmonary examination reveals normal heart sounds without murmurs, and clear lung fields bilaterally.

Laboratory investigations reveal the following:

Based on the patient's clinical presentation and laboratory findings, which of the following is the most appropriate next step in management?

Match each neonatal clinical vignette with its primary underlying pathophysiology.

A 52-year-old man presents to the urgent care clinic due to severe pain, redness, and swelling in his left big toe. The symptoms started abruptly early this morning and have progressively worsened, making it difficult for him to walk. He has a medical history of hypertension, for which he takes hydrochlorothiazide. His temperature is 37.2°C (99.0°F), blood pressure is 135/85 mm Hg, and pulse is 88/min. Physical examination reveals a remarkably tender, erythematous, and warm left first metatarsophalangeal joint with significant swelling. An arthrocentesis is performed, and synovial fluid analysis demonstrates a leukocyte count of 25,000/mm³ with negatively birefringent, needle-shaped crystals under polarized light microscopy. Gram stain of the fluid shows no organisms, and his serum creatinine is 0.9 mg/dL. Which of the following is the most appropriate next step in the management of this patient?

A 72-year-old man with a history of a bioprosthetic aortic valve replacement three years ago is hospitalized due to a 4-week history of low-grade fever, progressive fatigue, and night sweats. On physical examination, his temperature is $38.2^\circ\text{C}$ ($100.8^\circ\text{F}$), blood pressure is $118/76\text{ mmHg}$, and heart rate is $92/\text{min}$. A new grade 2/6 diastolic decrescendo murmur is heard at the right upper sternal border. Laboratory evaluation shows a leukocyte count of $14,500/\text{mm}^3$ and a serum creatinine of $1.1\text{ mg/dL}$. Transesophageal echocardiography reveals a $1.4\text{ cm}$ vegetation on the prosthetic valve. Three sets of blood cultures obtained prior to antibiotic administration are all positive for *Enterococcus faecalis*. The patient is empirically started on intravenous vancomycin and gentamicin.

Antimicrobial susceptibility testing for the isolate demonstrates the following:
* Ampicillin: Susceptible
* Penicillin: Susceptible
* Vancomycin: Susceptible
* Gentamicin: High-level resistance

Which of the following is the most appropriate antimicrobial regimen for this patient?

Match each clinical scenario describing a patient undergoing pharmacotherapy for a rheumatologic condition to the critical screening, prophylaxis, or adverse effect monitoring mandated by their specific medication.

Match each clinical presentation of a severe electrolyte abnormality to the most appropriate initial therapeutic intervention.

A $72$-year-old woman is evaluated on hospital day $3$ for ongoing medication management. She was initially admitted for a severe diabetic foot infection complicated by septic shock. On admission, her blood pressure was $85/50 \text{ mmHg}$, which responded to aggressive intravenous fluid resuscitation. She was empirically started on broad-spectrum intravenous vancomycin and piperacillin-tazobactam. Due to initial profound lethargy and confusion in the emergency department, a comprehensive laboratory workup, including thyroid function tests, was obtained.

Today, the patient is alert, afebrile, and hemodynamically stable. Blood cultures and deep wound cultures from admission both exclusively grow methicillin-susceptible *Staphylococcus aureus* (MSSA). Laboratory results from the admission draw are now available and shown below:

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

An evaluation is requested for a 67-year-old male patient who reports a persistent sore on the bottom of his right foot for the past two months. He has a 15-year history of type 2 diabetes mellitus complicated by peripheral neuropathy. His vital signs include a blood pressure of 135/85 mm Hg, a heart rate of 76/min, and a temperature of 37.0°C (98.6°F). On physical examination, there is a 2.5-cm, painless ulcer on the plantar aspect of the right first metatarsal head. There is no significant surrounding erythema, warmth, or fluctuance. During exploration of the wound, a sterile metallic probe easily contacts hard, gritty tissue at the base of the ulcer. Laboratory testing reveals a leukocyte count of 8,200/mm³ and an erythrocyte sedimentation rate of 95 mm/h. Radiography of the right foot demonstrates focal periosteal elevation and frank cortical erosion of the underlying metatarsal head. Which of the following is the most appropriate next step in the management of this patient?

A hematology consultation service is reviewing the coagulation profiles of four adult patients, all of whom present with unexplained prolonged coagulation times on routine preoperative screening. Based on the specific specialized laboratory testing kinetics provided, match each patient's coagulation profile to the most accurate underlying pathophysiologic mechanism.

An infant girl born at 38 weeks gestation is assessed in the nursery at 30 hours of life due to new-onset temperature instability and increased work of breathing. Her mother received limited prenatal care. The infant was previously vigorous but has become progressively lethargic over the past 4 hours. Current vital signs include a temperature of 38.7°C (101.7°F), heart rate of 185/min, and respiratory rate of 76/min. On physical examination, she demonstrates nasal flaring, marked intercostal retractions, and hypotonia. Dermatologic examination reveals a diffuse eruption of 1- to 3-mm pustules surrounded by erythematous macules on her chest and abdomen; the palms and soles are clear. Following the collection of blood, urine, and cerebrospinal fluid for culture, which of the following is the most appropriate empiric pharmacologic intervention for this patient?

A $35$-year-old man presents to the clinic with an $8$-day history of a persistent cough. He states that the cough is productive of yellowish sputum and is occasionally accompanied by mild retrosternal chest soreness. He reports having a runny nose and a low-grade fever that resolved $3$ days ago. He has no significant past medical history and does not smoke. Vital signs are temperature $37.2^\circ \text{C}$ ($99.0^\circ \text{F}$), blood pressure $122/78 \, \text{mmHg}$, pulse $78/\text{min}$, and respiratory rate $16/\text{min}$. Pulse oximetry is $98\%$ on room air. Physical examination reveals normal tympanic membranes, mild pharyngeal erythema without exudate, and clear lung fields bilaterally without wheezes, rhonchi, or crackles. Which of the following is the most appropriate next step in management?

A couple brings their 8-month-old son to the pediatric clinic for a pre-travel consultation. They are scheduled to relocate temporarily to a rural region in Sub-Saharan Africa in two weeks. This region currently has high endemic rates of both measles and hepatitis A. The boy was born prematurely at 32 weeks gestation following an uncomplicated pregnancy and neonatal course. His routine immunizations are up to date according to his chronological age. The parents report that he has had mild nasal congestion and a clear nasal discharge for the past two days. On examination, his temperature is 37.6°C (99.7°F). He is playful, well-appearing, and in no respiratory distress. Neurologic examination reveals that he is able to roll from back to front and sits leaning forward on his hands, but he falls over when his hands are removed. Which of the following is the most appropriate management plan for this patient today?