All practice questions

Identify the appropriate ethical doctrine or legal standard that dictates medical decision-making for the following incapacitated individuals.

A public health task force is funding a randomized, non-inferiority clinical trial comparing a novel 3-day oral antibiotic regimen to the standard 7-day oral regimen for uncomplicated urinary tract infections in pregnant patients. The non-inferiority margin ($\Delta$) is set at a 5% difference in clinical cure rates. The researchers calculated that a sample size of 800 patients (400 per group) is required to achieve 80% statistical power at a one-sided $\alpha$ level of 0.025, anticipating a maximum 10% dropout rate. Midway through the trial, an independent data monitoring committee notes that the actual dropout rate has exceeded 30% due to patients relocating and missing follow-up appointments. If the researchers continue the trial without modifying the initial enrollment target, which of the following statistical consequences is most likely to occur?

An armed forces medical induction center is initiating a screening protocol for latent tuberculosis infection among incoming personnel. The protocol utilizes a highly standardized interferon-gamma release assay. Epidemiological surveillance indicates that the true prevalence of latent tuberculosis in this incoming cohort of $5,000$ recruits is exactly $4\%$. The laboratory parameters for this specific assay demonstrate a sensitivity of $90\%$ and a specificity of $98\%$.

If a recruit from this cohort receives a positive result on this assay, what is the probability that the individual actually has a latent tuberculosis infection? (Enter the value as a percentage rounded to the nearest whole number).

A prospective cohort study is conducted to evaluate the association between the initiation of a new selective serotonin reuptake inhibitor (SSRI) and the incidence of gastrointestinal (GI) bleeding in older adults. The researchers calculate an unadjusted (crude) Relative Risk (RR) of $1.65$ ($95\%$ CI: $1.20 - 2.25$, $p < 0.01$).

To further investigate the relationship, the investigators stratify the analysis based on the concurrent use of nonsteroidal anti-inflammatory drugs (NSAIDs). The stratum-specific results are presented below:

Based on these findings, which of the following best describes the role of concurrent NSAID use in this study?

A 52-year-old woman with advanced cervical cancer complicated by bilateral hydronephrosis is admitted to the hospital with intractable pelvic pain and rapidly progressing altered mental status. Over the past three days, her pain became increasingly difficult to control at home, prompting her outpatient physician to double her dose of sustained-release oral morphine. On evaluation, the patient is agitated, picking at her bedsheets, and disoriented to time and place. She exhibits sudden, involuntary jerking movements of her upper and lower extremities. When the physician gently palpates her arm to check her pulse, she screams, complaining that her skin "feels like it is on fire." Vital signs are temperature 37.2°C (99.0°F), pulse 110/min, respirations 16/min, and blood pressure 138/85 mm Hg. Oxygen saturation is 96% on room air. Neurologic examination reveals diffuse hyperalgesia, hyperreflexia, and multifocal myoclonus. Laboratory studies show a serum creatinine level of 3.4 mg/dL (baseline 1.1 mg/dL one month ago). Which of the following is the most appropriate next step in the management of this patient?

An ambulatory surgery center has noted a steady increase in same-day procedure cancellations over the past six months, primarily due to incomplete preoperative medical clearances. The medical director convenes a multidisciplinary quality improvement team to address this issue using the Lean Six Sigma DMAIC (Define, Measure, Analyze, Improve, Control) framework. Arrange the following actions in the correct chronological sequence according to this methodology.

A medical epidemiologist at a national occupational health authority is investigating a suspected etiological link between prolonged exposure to a specific aerosolized solvent used in synthetic rubber manufacturing and the development of hepatic angiosarcoma. Hepatic angiosarcoma is an exceptionally rare malignancy, with an estimated incidence of less than 1 case per million person-years. Because a prospective cohort study would be economically and logistically impractical, the epidemiologist searches a national cancer registry and identifies 38 patients who received a confirmed diagnosis of hepatic angiosarcoma between 2015 and 2025. Which of the following study designs and analytical strategies is most appropriate to establish an association in this context?

A 75-year-old man with a history of heart failure and osteoarthritis presents to the emergency department with a 3-day history of fever, productive cough, and acute confusion. Vital signs show a temperature of $38.8^\circ\text{C}$ ($101.8^\circ\text{F}$), blood pressure of $85/50$ mm Hg, heart rate of $115$/min, and respiratory rate of $32$/min. Laboratory studies reveal a blood urea nitrogen (BUN) of $40$ mg/dL. He is diagnosed with severe community-acquired pneumonia. Over the subsequent weeks, his infection is successfully treated, but he experiences profound deconditioning. Prior to admission, he was entirely independent with his activities of daily living. Currently, he requires moderate assistance to transfer from a bed to a chair and tolerates a maximum of $45$ minutes of physical therapy daily. His long-term goal is to return to his baseline level of independent living in the community.

Arrange the following care settings in the most appropriate chronological sequence for this patient's complete transition of care, from initial emergency department disposition to final community recovery, based on standard risk stratification and functional assessment guidelines.

A 16-year-old girl is evaluated in the clinic for heavy menstrual bleeding. She reports that since menarche at age 12, her menstrual periods have consistently lasted 8 to 10 days, frequently requiring her to change pads every 2 hours on the heaviest days. She also recalls an episode of prolonged bleeding following a dental extraction two years ago. The patient takes no daily medications, though she occasionally uses ibuprofen for cramps. Family history is notable for a maternal aunt who required a blood transfusion after childbirth. Physical examination reveals normal vital signs, no joint deformities, and no petechiae or ecchymoses. The physician suspects von Willebrand disease (vWD) and plans to initiate a laboratory workup. Arrange the following tiers of laboratory testing in the most appropriate sequential diagnostic order, from initial screening to definitive disease subtyping.

A 54-year-old woman comes to the clinic due to persistent joint pain and morning stiffness. She was diagnosed with rheumatoid arthritis two years ago and has been taking oral methotrexate, but her symptoms remain poorly controlled. Physical examination shows active synovitis and effusion in the bilateral metacarpophalangeal and proximal interphalangeal joints. The physician plans to initiate a tumor necrosis factor (TNF) alpha inhibitor. Before starting the new medication, an interferon-gamma release assay is obtained and is positive. A chest radiograph shows no abnormalities, and she has no cough, night sweats, or weight loss. The physician decides to delay the biologic therapy and initiates a course of rifampin. The proposed biologic therapy increases the risk of disease reactivation in this patient by directly impairing which of the following immunologic processes?

A $64$-year-old woman is evaluated in the oncology clinic to discuss systemic therapy for newly diagnosed metastatic colorectal cancer. Two weeks ago, she underwent a right hemicolectomy for an obstructing cecal mass. Intraoperative findings and subsequent imaging confirmed the presence of unresectable bilobar hepatic metastases. Pathology of the primary tumor demonstrated moderately differentiated adenocarcinoma. Comprehensive molecular profiling of the tumor tissue reveals a missense mutation in codon $12$ of the KRAS gene. The patient has no other significant past medical history and her Eastern Cooperative Oncology Group (ECOG) performance status is $0$. The medical team plans to initiate a combination cytotoxic chemotherapy regimen. Based on the molecular pathology findings, the addition of a monoclonal antibody directed against which of the following targets is specifically contraindicated due to lack of therapeutic benefit?

An emergency response team brings a 59-year-old male to the trauma bay due to the abrupt onset of excruciating pain between his shoulder blades. The patient describes the pain as a "ripping" sensation that started 45 minutes prior to arrival. His medical history includes long-standing hypertension and a severe allergic reaction to iodinated contrast dye five years ago that resulted in anaphylactic shock and required mechanical ventilation. Current vital signs include a heart rate of 112/min, a respiratory rate of 22/min, and blood pressure readings of 205/115 mm Hg in the right arm and 175/95 mm Hg in the left arm. A bedside electrocardiogram reveals sinus tachycardia with left ventricular hypertrophy but no acute ischemic changes. A portable chest radiograph shows a widened mediastinum. Which of the following is the most appropriate next imaging study to establish the diagnosis?

A $45$-year-old man with a history of HIV infection presents to the emergency department due to a $4$-week history of progressively worsening clumsiness of his right hand and difficulty walking. He admits to discontinuing his antiretroviral therapy two years ago. His vital signs are within normal limits. Neurological examination reveals right-sided hemiparesis, hyperreflexia in the right upper and lower extremities, and an unsteady, broad-based gait. His current CD4 $^+$ lymphocyte count is $60 \text{ cells/mm}^3$. An MRI of the brain with and without gadolinium contrast is performed. The scan reveals several asymmetric, hyperintense lesions on T2-weighted and FLAIR sequences located in the subcortical white matter of the left frontal and parietal lobes. The lesions do not demonstrate contrast enhancement, and there is no evidence of perilesional edema or mass effect.

Which of the following is the most likely diagnosis based on these imaging findings?

An infectious disease specialist is reviewing the laboratory data of five adult patients referred to an ambulatory clinic for evaluation of potential liver disease. Vital signs are within normal limits for all patients. Reference ranges for the hepatic panel are as follows: AST $8-40$ U/L, ALT $7-56$ U/L, Total Bilirubin $0.1-1.2$ mg/dL. Match each patient's comprehensive biochemical and serological laboratory profile to the most accurate diagnostic interpretation.

A $54$-year-old woman is brought to the emergency department for severe shortness of breath, dizziness, and chest tightness that has progressively worsened over the past $48$ hours. She was treated for a severe viral upper respiratory tract infection three weeks ago. On presentation, she appears anxious, diaphoretic, and pale. Vital signs show a temperature of $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure of $86/66$ mmHg, heart rate of $122$/min, and respiratory rate of $24$/min. The physician suspects cardiac tamponade as the primary cause of her hemodynamic instability. Based on this suspected diagnosis, which of the following physical examination findings are highly indicative of this specific condition? (Select all that apply)

A 62-year-old man is evaluated in the emergency department for persistent bleeding from a minor forearm laceration sustained 3 hours ago. He also reports recent episodes of epistaxis and easy bruising over the past week. He has a 30-year history of severe alcohol use disorder. Vital signs are within normal limits. Physical examination reveals scleral icterus, palmar erythema, shifting dullness on abdominal exam, and several ecchymoses on the lower extremities.

Laboratory results are as follows:

Which of the following is the most likely etiology of this patient's bleeding diathesis?

A 31-year-old man presents to the outpatient clinic reporting a 4-month history of frequent, bulky, foul-smelling bowel movements, significant flatulence, and a 4-kg (8.8-lb) weight loss. He notes that the diarrhea does not resolve with fasting. He also complains of an intensely pruritic, blistering rash on his forearms and knees that has worsened over the past few weeks. His medical history is notable for recurrent sinusitis since childhood. Vital signs are within normal limits. Physical examination reveals conjunctival pallor and excoriated papules with occasional intact vesicles on the extensor surfaces of the upper and lower extremities.

Laboratory testing reveals:

Which of the following is the most appropriate next step in laboratory evaluation for this patient's underlying condition?

A 58-year-old man presents to the clinic for evaluation of progressive, diffuse muscle weakness and a dull, aching pain in his lower back, pelvis, and thighs that has worsened over the past six months. He reports difficulty climbing stairs and rising from low chairs. He was diagnosed with celiac disease three years ago but admits to frequently consuming gluten-containing foods due to lifestyle constraints. He has no history of fractures or significant trauma. Vital signs are within normal limits. Physical examination reveals mild tenderness to palpation over the lumbar spine and bilateral proximal muscle weakness in the lower extremities (4/5 strength).

Laboratory results are as follows:

Which of the following is the most likely diagnosis based on these clinical and laboratory findings?

During the evaluation of complex, undifferentiated clinical presentations, acquiring a targeted and nuanced social, dietary, and recreational history is paramount. Match each specific historical finding elicited during patient interviewing with the corresponding clinical diagnosis or syndrome it most strongly suggests.

A 28-year-old woman, G2P1, at 26 weeks gestation presents to the emergency department complaining of sudden-onset right-sided pleuritic chest pain, dyspnea, and a swollen right calf that began 6 hours ago. Her temperature is $37.1^\circ$ C ($98.8^\circ$ F), blood pressure is $118/76$ mmHg, heart rate is $112$/min, and respiratory rate is $22$/min. Oxygen saturation is $96\%$ on room air. Physical examination reveals an enlarged, tender right calf with pitting edema. The physician highly suspects a pulmonary embolism. Assume that for each sequential imaging study performed, the results return as negative or indeterminate, necessitating progression to the next appropriate imaging modality to definitively evaluate for pulmonary embolism.

Arrange the following imaging modalities in the most appropriate step-wise sequence according to evidence-based diagnostic algorithms for pregnant patients.