Tüm alıştırma soruları

An 81-year-old male with a history of hypertension and a 50-pack-year smoking history is brought to the emergency department after a syncopal episode at home. Upon arrival, he reports sudden, severe, and constant abdominal and left flank pain. His current medications include lisinopril and hydrochlorothiazide. His temperature is 36.8°C (98.2°F), blood pressure is 82/45 mm Hg, pulse is 118/min, and respiratory rate is 22/min. He appears pale, diaphoretic, and lethargic. Physical examination reveals a distended abdomen with a palpable, pulsatile mass located above the umbilicus. A bedside focused assessment with sonography for trauma (FAST) demonstrates a 7.5-cm dilation of the infrarenal aorta with an adjacent anechoic fluid collection in the retroperitoneum. Two large-bore peripheral intravenous lines are placed, and fluid resuscitation is initiated.

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

A $58$-year-old male with poorly controlled type 2 diabetes mellitus is evaluated in the emergency department for severe perineal pain and swelling that has progressively worsened over the past $48$ hours. He reports subjective fevers, chills, and generalized weakness. His temperature is $39.2^\circ\text{C}$ ($102.6^\circ\text{F}$), blood pressure is $90/60\text{ mmHg}$, heart rate is $118/\text{min}$, and respiratory rate is $22/\text{min}$. Physical examination reveals a tense, swollen, and diffusely erythematous scrotum. There is a central $3\text{-cm}$ area of grayish-purple skin discoloration. Palpation of the perineum and scrotum elicits exquisite tenderness, and a distinct crackling sensation is felt beneath the skin. Laboratory studies demonstrate a leukocyte count of $24,000/\text{mm}^3$ and a serum glucose of $385\text{ mg/dL}$. Intravenous fluid resuscitation and broad-spectrum antimicrobial therapy are initiated. Which of the following is the most appropriate next step in the management of this patient?

Investigators are designing an observational retrospective cohort study using electronic health records to evaluate the risk of major gastrointestinal bleeding associated with a newly approved oral anticoagulant compared to standard warfarin therapy in patients with nonvalvular atrial fibrillation. During the planning phase, the research team identifies that patients with a prior history of peptic ulcer disease are significantly less likely to be prescribed the new anticoagulant due to provider apprehension. Furthermore, a history of peptic ulcer disease is an independent known risk factor for subsequent gastrointestinal bleeding.

Which of the following methodological strategies can the investigators utilize to adequately control for the effect of prior peptic ulcer disease in this study? (Select all that apply)

Emergency medicine researchers are investigating a novel rapid point-of-care ultrasound algorithm for deep vein thrombosis (DVT). In their study cohort of symptomatic patients with a high pre-test probability, the true prevalence of DVT is $40\%$.

During the initial evaluation using standard diagnostic criteria, the algorithm yields a sensitivity of $85\%$ and a specificity of $85\%$.

To minimize missed diagnoses, the researchers broaden the criteria for a positive scan. Statistical analysis of the cohort reveals that this protocol change reduces the absolute number of false-negative results by exactly $50\%$ compared to the standard criteria. However, this adjustment simultaneously causes the absolute number of false-positive results to increase by exactly $100\%$ compared to the standard criteria.

Calculate the negative predictive value (NPV) of the ultrasound algorithm using the broadened criteria. Express your answer as a percentage rounded to the nearest whole number.

A 26-year-old professional rugby player is transported to the trauma bay after sustaining a direct, high-velocity blow to his right knee during a match. He complains of excruciating leg pain. On physical examination, the right knee is visibly deformed. His right foot is pale and cool to the touch. He is hemodynamically stable and has no other systemic injuries. Arrange the following steps in the acute management of this patient's limb in the most appropriate chronological sequence.

A case-control study is conducted to evaluate the association between the consumption of a widely used artificial sweetener and the incidence of transitional cell carcinoma of the bladder. The investigators enroll $500$ patients with newly diagnosed bladder cancer and $500$ age-matched controls without bladder cancer. An initial crude data analysis reveals an odds ratio (OR) of $2.8$ ($95\%$ CI: $2.1-3.7$, $p < 0.05$) for bladder cancer among artificial sweetener users compared to non-users.

During the study's review phase, an epidemiologist points out that cigarette smoking is a significant risk factor for bladder cancer and is also strongly associated with higher artificial sweetener consumption in this population. To address this, the investigators perform a stratified analysis based on the participants' smoking history. The results are presented below:

Based on these findings, which of the following statements is most accurate?

A 68-year-old woman with a history of type 2 diabetes mellitus and a 30-pack-year smoking history presents to the clinic complaining of cramping pain in her left calf. She reports that the pain consistently occurs after walking two blocks and resolves entirely after five minutes of standing still. She denies any pain at rest or non-healing foot ulcers. On physical examination, her femoral pulses are $2+$ bilaterally, but her left popliteal and dorsalis pedis pulses are diminished ($1+$). Arrange the following steps in the most appropriate chronological sequence for the standard diagnostic and therapeutic management of this patient's condition.

A $28$-year-old man is brought to the emergency department by ambulance after a high-speed motorcycle collision. He was not wearing a helmet. On arrival, he is unresponsive. His blood pressure is $175/95 \text{ mmHg}$, heart rate is $52 \text{ /min}$, and respiratory rate is $10 \text{ /min}$ and irregular. Neurologic examination reveals a Glasgow Coma Scale score of $5$ (Eye opening: $1$, Verbal response: $1$, Motor response: $3$). His right pupil is $7 \text{ mm}$ and unreactive to light, while the left pupil is $3 \text{ mm}$ and briskly reactive. He exhibits decerebrate posturing on the left side. Arrange the following steps in the most appropriate chronological order for the management of this patient.

Match each patient profile to the most appropriate initial screening modality indicated by current United States Preventive Services Task Force (USPSTF) guidelines.

During a high school basketball tournament, a 16-year-old boy suddenly drops to the floor, gripping his groin. He is rushed to the nearest acute care center. Upon evaluation, he reports an abrupt onset of agonizing right-sided testicular pain accompanied by nausea and one episode of emesis. He denies any direct trauma to the groin during the game. His temperature is $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure is $130/80\text{ mm Hg}$, and pulse is $115/\text{min}$. Physical examination reveals a markedly swollen, tender, and erythematous right hemiscrotum. The right testis is significantly elevated compared to the left and rests in a transverse orientation. Stroking the superior medial aspect of the right thigh yields no elevation of the right testis, although the reflex is completely intact on the left side. Which of the following is the most appropriate next step in the management of this patient?

An epidemiological research team conducts a retrospective cohort study to investigate the association between residential proximity to major highways and the development of chronic obstructive pulmonary disease (COPD) in adults. The initial unadjusted analysis yields a Risk Ratio (RR) of $1.7$ ($95\%$ CI: $1.3 - 2.2$) for developing COPD among individuals living within $100$ meters of a major highway compared to those living further away.

To account for potential alternative explanations, the researchers perform a stratified analysis based on household income level:

Based on these findings, which of the following epidemiological concepts best describes the role of household income in the original association?

A 7-year-old girl is evaluated in the primary care clinic for a health maintenance examination before starting the second grade. She has a history of polyarticular juvenile idiopathic arthritis, which was diagnosed two years ago. Her symptoms are currently well controlled on a regimen of methotrexate and adalimumab (a tumor necrosis factor-alpha inhibitor). Review of the patient's vaccination record indicates that she received all routine immunizations during infancy. However, she missed her kindergarten boosters typically given between 4 and 6 years of age, including the diphtheria, tetanus, and acellular pertussis (DTaP) vaccine, inactivated poliovirus vaccine (IPV), measles, mumps, and rubella (MMR) vaccine, and varicella vaccine. The patient's father requests that she receive all necessary vaccinations today to meet school requirements. Which of the following is the most appropriate next step in preventive care for this patient?

A prospective cohort study is conducted to evaluate the risk of acute kidney injury (AKI) associated with a newly approved intravenous antifungal medication in hospitalized patients. The initial unadjusted analysis yields a relative risk (RR) of 3.2. The investigators suspect that concurrent use of a known nephrotoxic immunosuppressant medication might be influencing these results. To investigate this, they re-analyze the data by stratifying the patients based on concurrent immunosuppressant use. In the stratum of patients taking the immunosuppressant, the RR for AKI with the new antifungal is 5.8. In the stratum of patients not taking the immunosuppressant, the RR is 1.1. Which of the following epidemiologic principles best describes the role of concurrent immunosuppressant use in this study?

A 19-year-old college student presents to the urgent care clinic with right wrist pain after falling on an outstretched hand while skateboarding yesterday. Vital signs are within normal limits (temperature 37.0°C (98.6°F), blood pressure 118/76 mmHg, pulse 78/min, respirations 14/min). On physical examination, there is mild swelling over the radial aspect of the wrist and exquisite tenderness to palpation in the anatomical snuffbox. Sensation to pinprick is intact in all digits, and radial and ulnar pulses are 2+ and symmetric. Capillary refill is less than 2 seconds. Radiographs of the right wrist reveal no evidence of fracture or dislocation. What is the most appropriate next step in management?

A team of researchers at an academic medical center is evaluating a novel noninvasive biomarker assay for the detection of advanced adenomas and colorectal cancer. In their initial validation study, the assay is tested on a cohort of $1,000$ high-risk patients referred for diagnostic colonoscopy. Within this cohort, $400$ patients are found to have advanced adenomas or colorectal cancer on biopsy. The novel biomarker assay is positive in $360$ of the patients with confirmed disease and negative in $555$ of the patients without disease.

Based on these promising results, the state department of public health plans to implement this biomarker assay as a primary screening tool for an asymptomatic, average-risk population. Epidemiological data indicates that the true prevalence of advanced adenomas and colorectal cancer in this average-risk screening population is $4\%$.

Assuming the intrinsic sensitivity and specificity of the assay remain constant across populations, which of the following is the best estimate of the positive predictive value of this biomarker when used in the average-risk screening population?

An emergency medical response team brings a $58$-year-old female patient to the acute care bay for evaluation of progressively worsening abdominal pain and obstipation lasting $48$ hours. She states that her pain was initially crampy, intermittent, and manageable, but it abruptly transitioned into a severe, constant, and diffuse ache approximately $4$ hours prior to arrival. She has had multiple episodes of bilious emesis today. Her medical history is significant for stage IIB cervical cancer, which was managed with a radical hysterectomy and adjuvant pelvic chemoradiation $15$ years ago. Vital signs include a temperature of $38.7^\circ\text{C}$ ($101.7^\circ\text{F}$), a pulse of $124\text{ /min}$, a blood pressure of $92/60\text{ mmHg}$, and a respiratory rate of $24\text{ /min}$. On physical examination, the patient lies completely rigid on the stretcher and refuses to change positions. Her abdomen is markedly distended and tympanic. There is exquisite, diffuse tenderness to light palpation across all quadrants, accompanied by prominent involuntary guarding and rebound tenderness. Bowel sounds are absent. Laboratory evaluation reveals a leukocyte count of $18,500/\text{mm}^3$ and a serum lactate concentration of $4.8\text{ mmol/L}$. An upright chest radiograph is negative for subdiaphragmatic free air. A supine abdominal radiograph demonstrates multiple dilated small bowel loops with prominent air-fluid levels and a complete absence of distal colonic gas. Which of the following is the most appropriate next step in management?

A state health department is evaluating the public health impact of a carcinogenic chemical used in certain plastic manufacturing processes. A 15-year retrospective cohort study is conducted to assess the association between occupational exposure to this chemical and the development of hepatocellular carcinoma (HCC). The study reveals that the incidence of HCC among workers exposed to the chemical is 200 cases per 100,000 person-years. In contrast, the incidence among workers in the same industry who are not exposed to the chemical is 40 cases per 100,000 person-years. Statewide demographic data indicates that 25% of the total plastic manufacturing workforce is routinely exposed to this chemical. Assuming the association is causal, which of the following best represents the percentage of HCC cases in the total plastic manufacturing workforce that can be attributed to this chemical exposure?

A 24-year-old man is brought to the emergency department following a high-speed motorcycle collision. He complains of severe pelvic pain and an inability to void. Vital signs are within normal limits, and he is hemodynamically stable. Physical examination reveals blood at the urethral meatus, a scrotal hematoma, and a 'high-riding' prostate on digital rectal examination. Pelvic radiography confirms a straddle fracture of the pelvis. Arrange the following steps in the most appropriate chronological sequence for the urologic management of this patient.

A healthy 48-year-old male visits his primary care physician to establish care. His medical record indicates no prior preventive screenings for gastrointestinal malignancies, and he has no family history of cancer. When counseled on available screening modalities, he explicitly requests a noninvasive stool-based test. Arrange the subsequent clinical interventions and findings in the correct chronological order, from the initial screening to the appropriate long-term surveillance interval.

A 52-year-old woman presents to the clinic for a routine well-woman examination. She has no significant past medical history and takes no daily medications. She went through menopause 2 years ago and has experienced no vaginal bleeding or spotting since that time. She had a normal screening colonoscopy at age 50 and a normal Papanicolaou (Pap) test with human papillomavirus (HPV) co-testing at age 50. She has not had a mammogram in the past 3 years. Her vital signs and physical examination are unremarkable.

Which of the following is the most appropriate next step in preventive care for this patient?