All practice questions

A 48-year-old man who underwent a deceased-donor renal transplantation 7 months ago is evaluated during a routine follow-up visit. He feels well and reports no fever, dysuria, or decreased urine output. His current medications include tacrolimus, mycophenolate mofetil, and prednisone. His blood pressure is 138/86 mmHg, and his temperature is 37.1°C (98.8°F). Physical examination of the allograft reveals no tenderness. Laboratory studies show a serum creatinine level of 2.6 mg/dL, which has increased from a baseline of 1.3 mg/dL three months ago. A renal ultrasound demonstrates normal graft size, no hydronephrosis, and normal resistive indices. An ultrasound-guided percutaneous needle biopsy of the allograft is performed. Light microscopy reveals a dense interstitial infiltrate predominantly composed of lymphocytes and macrophages, with greater than 10 mononuclear cells per tubular cross-section (severe tubulitis). Several small arteries exhibit subendothelial mononuclear inflammatory cells with lifting of the endothelial layer (intimal arteritis). Immunohistochemical staining for C4d is negative in the peritubular capillaries. Staining for SV40 T antigen is also negative. Based on the histopathologic findings, which of the following is the most likely diagnosis?

A 42-year-old woman is brought to the emergency department after falling from a 15-foot ladder. She is confused, pale, and diaphoretic. Vital signs show a blood pressure of 85/50 mm Hg, heart rate of 122/min, respiratory rate of 26/min, and oxygen saturation of 91% on room air. She has evident facial swelling, a visibly deformed mandible, and blood pooling in her oropharynx causing stridorous breathing. Arrange the following initial management steps in the most appropriate chronological order according to standard trauma resuscitation protocols.

A 24-year-old female is rushed to the resuscitation bay by her college roommate, who discovered her in a highly lethargic state in their dormitory. An empty bottle of amitriptyline was found on her bedside table. Upon evaluation, the patient is somnolent and disoriented but spontaneously maintains a patent airway and localizes to painful stimuli. Her past medical history is notable for recurrent major depressive disorder and generalized anxiety. Current vital signs show a temperature of 38.2°C (100.8°F), heart rate of 138/min, blood pressure of 78/48 mm Hg, respirations of 14/min, and pulse oximetry of 96% on ambient air. Physical examination reveals mydriasis, dry oral mucosa, and a complete absence of bowel sounds. A stat electrocardiogram displays a wide-complex sinus tachycardia with a QRS duration of 145 ms and a prominent terminal R wave in lead aVR. Which of the following represents the most urgent initial step in the stabilization of this patient?

In her third trimester (28 weeks gestation), a 31-year-old pregnant patient arrives at the acute care unit complaining of abrupt-onset shortness of breath accompanied by right-sided pleuritic chest pain. Upon evaluation, her vital signs reveal a heart rate of 118/min, respiratory rate of 24/min, and an oxygen saturation of 94% on ambient air. Physical examination demonstrates a swollen, tender right calf, though her lung fields are clear to auscultation. Given the high clinical suspicion for a pulmonary embolism, arrange the following imaging modalities in the chronological sequence they should be ordered and interpreted to establish a definitive diagnosis while optimally minimizing maternal and fetal radiation exposure.

A 68-year-old woman presents to the emergency department with sudden-onset, severe pain in her right lower extremity that began 2 hours ago. On physical examination, the right foot is pale, cold, and pulseless. She is unable to wiggle her toes, and sensation to light touch is absent over the dorsum of the foot. Her blood pressure is 145/90 mmHg, and her heart rate is 110/min with an irregularly irregular rhythm. Which of the following are the most appropriate immediate steps in the management of this patient? (Select all that apply)

A 58-year-old man with a 30-pack-year smoking history undergoes a routine preoperative chest radiograph prior to an elective inguinal hernia repair. The radiograph reveals a newly noted 1.4-cm circumscribed opacity in the periphery of the right upper lobe. He has no cough, hemoptysis, shortness of breath, or weight loss. Physical examination is unremarkable. Vital signs are within normal limits.

Arrange the following diagnostic and management steps in the most appropriate, evidence-based chronological sequence for evaluating this pulmonary finding.

A 28-year-old man is brought to the emergency department by ambulance after sustaining a self-inflicted gunshot wound to the abdomen. On arrival, he is pale, diaphoretic, and in obvious distress. His blood pressure is 75/40 mmHg, pulse is 142/min, and respiratory rate is 24/min. The trauma surgery team is activated, and an operating room is prepared.

The patient is awake, alert, and oriented to person, place, and time. When the nursing staff attempts to establish intravenous access for aggressive fluid and blood resuscitation, the patient physically resists and removes the tourniquet. He calmly states, "I know that I am bleeding internally. I understand that if you do not perform surgery, I will die. But the archangel Gabriel spoke to me this morning and explained that my blood must return to the earth to prevent the apocalypse. I am refusing all medical treatment."

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

Match each clinical scenario to its correct patient safety classification.

Match each clinical scenario or hospital intervention with the correct patient safety concept or level of the hierarchy of safety controls.

Review the following complex clinical presentations involving requests to withhold information. Pair each patient presentation with the legally and ethically mandated physician action regarding disclosure.

Medical malpractice is a specific type of tort law that requires the plaintiff to prove four distinct elements to establish a successful claim of negligence. Match each of the following clinical vignettes to the primary legal element of negligence that is definitively MISSING, thereby rendering the malpractice lawsuit invalid.

In the context of root cause analysis and quality improvement, hospital safety committees must appropriately classify adverse events to identify systems-level vulnerabilities and implement effectively tiered corrective actions. Match each of the following patient safety events or interventions with its correct classification.

A hospital's infection control and quality improvement committee is reviewing an unexpected 40% increase in the facility's reported rate of hospital-onset Clostridioides difficile infection (HO-CDI) over the past quarter. A root cause analysis of the recent cases reveals that 55% of the patients who tested positive had fewer than three unformed stools in a 24-hour period, and 45% had been administered bowel preparations or osmotic laxatives within the 48 hours preceding the test. The hospital microbiology laboratory currently utilizes a highly sensitive, standalone nucleic acid amplification test (NAAT) for C. difficile on all submitted stool specimens. Which of the following systemic interventions is the most appropriate next step to accurately reflect the true infection rate and improve patient safety?

A 67-year-old man is brought to the emergency department by a concerned neighbor who found him wandering in the hallway of their apartment building wearing only undergarments. It is December, and the outside temperature is near freezing. The patient is shivering and visibly diaphoretic. His temperature is 39.4°C (102.9°F), blood pressure is 82/45 mm Hg, pulse is 128/min, and respirations are 24/min. Physical examination reveals dry mucous membranes and marked right costovertebral angle tenderness. The patient is oriented only to his name and does not know where he is. When the emergency physician approaches to place an intravenous catheter, the patient becomes combative, pushes the physician away, and yells, "I don't know who you people are! I have to go feed my dog right now!" He repeatedly attempts to climb off the stretcher to leave the emergency department. Which of the following is the most appropriate next step in the management of this patient?

Match each clinical scenario regarding consent or refusal of treatment with the most appropriate legal or ethical principle that guides the physician's action.

A 67-year-old woman is hospitalized in the cardiac intensive care unit following a prolonged out-of-hospital cardiac arrest. She was successfully resuscitated but suffered a severe anoxic brain injury. She is currently comatose, ventilator-dependent, and displays continuous post-anoxic myoclonus. Serial neurologic examinations confirm she lacks brainstem reflexes, though formal brain death criteria have not yet been met. She lacks medical decision-making capacity and has no written advance directive for healthcare.

The patient is a widow and has two adult daughters who arrive at the bedside together.

The older daughter presents a notarized legal document titled "Durable Power of Attorney for Finances and Property," executed five years ago, which designates her as the sole agent to manage the patient's assets. She states, "I am legally in charge of my mother's affairs. I know she would want everything possible done to keep her alive. I want the breathing machine continued and a feeding tube placed."

The younger daughter strongly disagrees and states, "Mom and I talked about this extensively after Dad passed away. She explicitly told me she would never want to be kept alive on machines if she couldn't interact with us. She would want the ventilator removed."

The older daughter argues that her formal legal document gives her the final authority over her younger sister's recollection of a conversation.

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

A prospective cohort study is conducted to evaluate the incidence of major adverse cardiovascular events (MACE) in patients receiving a novel lipid-lowering therapy. The investigators enroll $1,000$ patients who are free of cardiovascular disease at baseline. The study follows these patients for exactly $4$ years. During the study period, the following events are recorded:

- $200$ patients experience a MACE at exactly the end of Year $1$.
- $100$ patients are lost to follow-up (without experiencing a MACE) at exactly the end of Year $2$.
- The remaining $700$ patients complete the full $4$-year follow-up without experiencing a MACE.

Based on these data, what is the incidence rate of MACE per $1,000$ person-years in this cohort?

A 42-year-old woman with advanced amyotrophic lateral sclerosis is admitted to the intensive care unit with acute respiratory failure secondary to aspiration pneumonia. She is currently receiving noninvasive positive-pressure ventilation but is experiencing worsening hypercapnia and severe respiratory fatigue. The attending physician informs the patient that without endotracheal intubation and mechanical ventilation, she will likely die from respiratory failure within hours. The patient is severely dysarthric but communicates effectively using an eye-tracking speech-generating device. She states, "I understand that I will die without the breathing tube, but I absolutely refuse to be intubated. I do not want to live dependent on a machine."

The patient's husband arrives with a legally binding advance directive executed two years ago. The document designates him as her healthcare proxy and explicitly states: "I wish to receive all available life-sustaining treatments, including mechanical ventilation, for any potentially reversible condition such as pneumonia." The husband is distraught and demands that the team intubate her, stating, "Her oxygen is low, so she must be confused. She wrote this directive specifically for this situation!"

The physician performs a structured assessment. The patient correctly answers orientation questions, explains her current medical condition accurately, and types, "I know what my directive says, but I changed my mind as my paralysis worsened over the last few months. I just never updated the paperwork." She shows no signs of delirium, and her reasoning is logical.

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

An 81-year-old man is brought to the emergency department from a nursing facility due to severe respiratory distress. He is rapidly intubated and placed on mechanical ventilation. The patient is comatose, lacks decision-making capacity, and needs a percutaneous endoscopic gastrostomy tube for long-term enteral nutrition. A review of his records reveals no advance directive and no prior designation of a healthcare proxy. Arrange the following individuals or entities in the standard legally recognized hierarchy for surrogate decision-making, from highest priority (first to be consulted) to lowest priority.

A clinical study investigates a newly developed oral medication aimed at reducing the incidence of recurrent urinary tract infections (UTIs) in postmenopausal women. The investigation includes $1,000$ participants who are randomly allocated in equal numbers to either the new medication or a placebo. Over a $12$-month period, $150$ out of the $500$ participants taking the placebo develop a recurrent UTI. Meanwhile, $100$ out of the $500$ participants taking the new oral medication develop a recurrent UTI.

What is the number needed to treat (NNT) to prevent one recurrent UTI in this population?