Tüm alıştırma soruları

A forestry worker is airlifted to a regional trauma center after his leg was crushed under a fallen tree. Due to the remote location and complex extrication, the total time from the moment of injury to hospital arrival is seven and a half hours. Upon arrival, the patient is hemodynamically stable. The primary survey is otherwise clear, but the secondary survey reveals a grossly deformed left knee with an open, highly comminuted distal femur fracture (Gustilo-Anderson IIIB). The left foot is pale, poikilothermic, and cold, with absent dorsalis pedis and posterior tibial pulses. Capillary refill is completely absent. A rapid on-table angiogram in the hybrid operating room demonstrates a complete transection of the popliteal artery with no distal flow. The trauma and orthopedic surgery teams prepare for immediate combined surgical intervention.

Arrange the following operative steps in the most appropriate chronological sequence for this patient's limb salvage.

A 28-year-old woman is brought to the emergency department 20 minutes after being involved in a high-speed motor vehicle collision. She is in severe respiratory distress and complains of sharp, right-sided chest pain. Her blood pressure is 70/40 mmHg, pulse is 135/min, and respirations are 32/min. Pulse oximetry shows an oxygen saturation of 84% on room air. Physical examination reveals a deviated trachea to the left, markedly distended neck veins, and absent breath sounds over the right hemithorax. Which of the following is the most appropriate next step in management?

A public health department uses a fecal immunochemical test to screen for colorectal cancer. Initially, the test is administered to the general population aged $50$ to $75$ years, where the prevalence of the disease is relatively low. The department later updates its protocol to use the test exclusively in a high-risk cohort of individuals with a strong family history of colorectal cancer. The prevalence of the disease in this high-risk cohort is significantly higher than in the general population. Assuming the test's sensitivity and specificity remain constant, which of the following best describes how the predictive values of the fecal immunochemical test will change when applied to the high-risk cohort compared to the general population?

Match each patient's clinical presentation with the most likely underlying pathophysiologic diagnosis.

A public health department conducts a 10-year prospective cohort study to evaluate the association between a diet high in ultra-processed foods and the development of metabolic syndrome. The study enrolls 10,000 healthy adults without pre-existing metabolic conditions. Participants are categorized into two groups based on detailed dietary questionnaires. Over the 10-year follow-up period, the occurrence of new metabolic syndrome diagnoses is recorded. The results are summarized in the table below:

Based on these study results, what percentage of metabolic syndrome cases among the participants with high consumption of ultra-processed foods can be attributed to their dietary pattern?

A team of pediatric cardiologists identifies all infants born with a specific congenital heart defect at a large regional hospital over the past 5 years. For a comparison group, they randomly select an equal number of infants born without any structural heart defects at the same hospital during the same timeframe. The researchers then interview the mothers of both groups of infants to determine their history of prescription medication use during the first trimester of pregnancy. Which of the following best describes this epidemiologic study design?

A 52-year-old man is brought to the emergency department complaining of agonizing mid-back pain that has progressively worsened over the last week. This morning, he developed weakness in both legs and has been unable to urinate for the past 12 hours. He has a history of type 2 diabetes mellitus and had a central venous catheter placed during a hospitalization two weeks ago. His temperature is $38.9^\circ\text{C}$ ($102.0^\circ\text{F}$), blood pressure is $118/76\text{ mmHg}$, and heart rate is $105/\text{min}$. Neurologic examination shows $2/5$ strength in the bilateral lower extremities, patellar hyperreflexia, a sensory loss below the umbilicus, and a palpably distended bladder.

Arrange the following management steps in the most appropriate sequential order for this patient:

Match each clinical presentation with the most likely corresponding vascular diagnosis.

An emergency medicine physician is evaluating a 54-year-old woman complaining of severe right-sided back pain, rigors, and vomiting that began 12 hours ago. Her temperature is 39.2°C (102.6°F), blood pressure is 88/55 mmHg, and pulse is 115/min. Physical examination reveals exquisite right costovertebral angle tenderness. Laboratory testing shows a leukocyte count of 18,000/mm³. Arrange the following management steps in the most appropriate chronological sequence for this patient.

During a routine health maintenance examination, a 64-year-old African American male reports waking up twice a night to urinate but denies any dysuria, gross hematuria, or bone pain. His past medical history is notable for hypertension managed with lisinopril. Vital signs are within normal limits. Digital rectal examination reveals a distinctly firm, irregularly shaped nodule on the left posterior lobe of the prostate gland. Laboratory studies show a serum prostate-specific antigen (PSA) level of 7.8 ng/mL. Which of the following is the most appropriate next step in the management of this patient?

A $45$-year-old man is brought to the emergency department by his partner due to the sudden onset of an excruciating headache that began $2$ hours ago. He also reports blurred vision and extreme dizziness upon standing. The patient's medical history is significant for a known $2.5\text{-cm}$ nonfunctioning pituitary macroadenoma, which was being evaluated for elective surgical resection. His temperature is $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure is $82/50\text{ mmHg}$, pulse is $118/\text{min}$, and respirations are $16/\text{min}$. Physical examination reveals bitemporal hemianopsia and a dilated, unresponsive right pupil with a "down and out" gaze deviation. The patient is lethargic but oriented. Which of the following is the most appropriate next step in the management of this patient?

Match the following classic clinical presentations with their most likely vascular surgical diagnosis.

An overweight 13-year-old boy is brought to the outpatient clinic by his parents. He has been complaining of left knee and anterior thigh pain for the past four weeks. The pain is described as a dull ache that worsens with physical activity such as walking or climbing stairs. There is no history of recent trauma, falls, or fever. His temperature is 36.8°C (98.2°F), blood pressure is 112/72 mm Hg, pulse is 76/min, and respirations are 14/min. His body mass index is 31 kg/m². Upon physical evaluation, the left knee shows no evidence of erythema, swelling, or localized tenderness, and ligamentous testing is normal. However, examination of the left hip reveals restricted internal rotation. Furthermore, when the clinician passively flexes the patient's left hip, the thigh obligatorily rotates outward. Motor strength and sensory examinations in the lower extremities are unremarkable. Distal pulses are palpable and equal bilaterally.

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

A 75-year-old woman is evaluated in the emergency department for severe right leg pain. She was found on the floor of her apartment after a fall and was last known to be in her usual state of health 36 hours ago. Medical history is significant for hypertension, prior myocardial infarction, and paroxysmal atrial fibrillation for which she has not been taking anticoagulation. Her temperature is 37.1°C (98.8°F), blood pressure is 142/86 mmHg, and heart rate is 112/min and irregularly irregular. On physical examination, the right lower extremity is pale, cold to the touch, and mottled from the toes extending up to the mid-thigh. There is complete absence of sensation below the right knee. The patient is unable to move her right ankle or toes, and the calf muscles are remarkably firm and rigid to palpation. Handheld Doppler ultrasound evaluation reveals absent arterial and venous signals in the right popliteal, dorsalis pedis, and posterior tibial vessels. Which of the following is the most appropriate next step in management?

A 50-year-old woman presents to the surgery clinic for evaluation of a right-sided neck swelling. She first noticed the lump 6 months ago, and it has slowly enlarged. She denies dysphagia, hoarseness, palpitations, or weight changes. Vital signs are within normal limits. Physical examination reveals a 3.5-cm, firm, mobile, non-tender nodule in the right lobe of the thyroid gland. There is no cervical lymphadenopathy. Laboratory studies show a serum thyroid-stimulating hormone (TSH) level of 2.1 mU/L (normal: 0.4-4.0 mU/L). Neck ultrasound demonstrates a 3.5-cm solid, isoechoic nodule with smooth margins and a thin hypoechoic halo. A fine-needle aspiration (FNA) biopsy is performed. Cytology reveals a hypercellular aspirate composed of microfollicles with scant colloid, and the pathologist reports the lesion as a 'follicular neoplasm'. What is the most appropriate next step in the management of this patient?

Following a three-day hospitalization for conservative management of a small bowel obstruction, a $72$-year-old man undergoes acute clinical deterioration. He initially presented with colicky abdominal pain, profound abdominal distension, and failure to pass flatus. His medical history includes paroxysmal atrial fibrillation, for which he takes apixaban, and his surgical history includes a sigmoid colectomy performed a decade ago for complicated diverticulitis. During the first $48$ hours of admission, he remained afebrile and was managed with a nasogastric tube and intravenous crystalloid therapy.

Over the past $2$ hours, the patient's nurse reports that he has become increasingly lethargic and is now complaining of a new, relentless, severe aching pain centered in the periumbilical region.

Current vital signs demonstrate a temperature of $38.8^\circ\text{C}$ ($101.8^\circ\text{F}$), a blood pressure of $92/54\text{ mmHg}$, a pulse of $122/\text{min}$, and respirations of $24/\text{min}$.

Physical examination reveals a markedly distended, rigid abdomen with absent bowel sounds. Palpation elicits involuntary muscle spasm and severe pain upon quick release of the examining hand.

Laboratory evaluation reveals:
Leukocyte count: $18,200/\text{mm}^3$ ($85\%$ neutrophils, $10\%$ bands)
Serum bicarbonate: $16\text{ mEq/L}$
Lactate: $4.2\text{ mmol/L}$

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

Match the following diagnostic and screening test performance characteristics with their appropriate clinical interpretations.

A research team is designing a clinical trial to evaluate the effectiveness of a novel electronic health record (EHR) alert system aimed at improving physician adherence to deep vein thrombosis (DVT) prophylaxis protocols. The researchers are debating between two randomization strategies: randomizing individual patients at the time of admission or randomizing entire hospital medical wards. They ultimately decide to randomize the hospital medical wards, such that all patients admitted to a specific ward will be cared for by physicians exposed to either the novel alert system or the standard EHR interface. The primary outcome is the incidence of hospital-acquired DVT over a 12-month period. Which of the following is the most likely statistical or methodological consequence of choosing this specific randomization strategy instead of randomizing individual patients?

A cohort study is conducted to investigate the association between regular alcohol consumption and the incidence of oral cancer. The investigators analyze the initial data and calculate a crude relative risk (RR) of 3.2 (95% CI, 2.4-4.1). However, the researchers suspect that concurrent tobacco smoking might be influencing the results. To further investigate this, they perform a stratified analysis based on smoking status. The RR for oral cancer among smokers is calculated as 1.2 (95% CI, 0.9-1.5), and the RR among non-smokers is calculated as 1.1 (95% CI, 0.8-1.4). Which of the following concepts is best demonstrated by the difference between the crude and stratified relative risks in this study?

A public health department is evaluating a workplace intervention at a large chemical manufacturing plant. Plant records indicate that $20\%$ of the workers are stationed in the 'Zone A' processing area, where they are exposed to a specific volatile organic compound (VOC). The remaining $80\%$ of workers are stationed in other areas and are not exposed to this VOC.

An epidemiological analysis reveals that the overall incidence of a particular respiratory condition among all workers in the plant is $18$ cases per $1,000$ workers per year. The relative risk of developing this respiratory condition for workers in Zone A, compared to workers in other areas of the plant, is $5.0$.

The plant management is considering a targeted intervention to upgrade ventilation strictly in Zone A, which would completely eliminate the VOC exposure and reduce the risk for Zone A workers to that of the unexposed workers.

Based on these data, how many workers need to benefit from this ventilation upgrade in Zone A to prevent one additional case of the respiratory condition per year?