Internal Medicine

3151 soru

Soru 1081Soru →

A 19-year-old college student is admitted to the hospital with a two-day history of fever, severe headache, photophobia, and neck stiffness. On physical examination, the patient is alert but uncomfortable. Temperature is 38.6°C (101.5°F), blood pressure is 118/76 mm Hg, and pulse is 98/min. Nuchal rigidity is present. A lumbar puncture is performed, and empiric intravenous ceftriaxone and vancomycin are initiated. Cerebrospinal fluid (CSF) analysis reveals a leukocyte count of 140/mm³ with 92% lymphocytes, a glucose level of 65 mg/dL (serum glucose 90 mg/dL), and a protein level of 40 mg/dL. Gram stain reveals no organisms. A multiplex polymerase chain reaction (PCR) assay of the CSF is positive for enterovirus and negative for all common bacterial pathogens. Which of the following is the most appropriate next step in this patient's pharmacologic management?

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Cevap: Discontinue all antibacterial therapy

Cevap

Discontinue all antibacterial therapy
The patient's clinical presentation and cerebrospinal fluid (CSF) findings (lymphocytic pleocytosis, normal glucose, normal protein) are classic for aseptic meningitis. The definitive diagnosis is established by the multiplex PCR assay, which is highly sensitive and specific, returning positive for enterovirus and negative for bacterial targets. Enteroviruses are the most common cause of viral meningitis. Because the etiology is confirmed to be viral, there is no role for antibacterial therapy. The most appropriate next step is to discontinue the empiric ceftriaxone and vancomycin to adhere to principles of antibiotic stewardship, minimizing the risk of adverse drug reactions, Clostridioides difficile infection, and the development of antimicrobial resistance. Management of enteroviral meningitis is strictly supportive.

Adım Adım Çözüm

1
Analyze the cerebrospinal fluid (CSF) cell count and differential.
The CSF shows a mild pleocytosis (140/mm³) with a strong lymphocyte predominance (92%), alongside normal glucose and normal protein levels.
This pattern is highly characteristic of aseptic (viral) meningitis, distinguishing it from the profound neutrophilic pleocytosis and hypoglycorrhachia typically seen in bacterial meningitis.
2
Interpret the CSF multiplex PCR assay results.
The assay is positive for enterovirus and negative for all common bacterial pathogens.
Multiplex PCR is highly sensitive and specific. A positive result for enterovirus definitively identifies the causative pathogen for the patient's aseptic meningitis.
3
Determine the appropriate pharmacologic intervention based on the definitive diagnosis.
Discontinue the empiric antibacterial agents (ceftriaxone and vancomycin).
Because the infection is definitively viral, antibiotics provide no therapeutic benefit. Their continuation violates antibiotic stewardship principles, increasing the risk of adverse drug events and antimicrobial resistance.

Anahtar Kavram

In patients with suspected meningitis who are empirically started on antibiotics, a definitive diagnosis of viral meningitis via CSF PCR (e.g., enterovirus) should prompt the immediate discontinuation of antibacterial therapy.
Tahmini Süre:1m 0s
Soru 1082Soru →

A 34-year-old woman is brought to the emergency department by her husband due to progressive confusion and severe fatigue over the past 48 hours. Her temperature is 37.8∘C37.8^\circ\text{C}, blood pressure is 142/88 mmHg142/88 \text{ mmHg}, and pulse is 108/min108/\text{min}. Physical examination reveals scleral icterus and scattered petechiae on the lower extremities. Neurological examination shows mild disorientation but no focal motor deficits.

Laboratory studies show:

Laboratory TestResultReference Range
Hemoglobin7.4 g/dL7.4 \text{ g/dL}12.0−16.0 g/dL12.0-16.0 \text{ g/dL}
Platelet count18,000/mm318,000/\text{mm}^3150,000−400,000/mm3150,000-400,000/\text{mm}^3
Mean corpuscular volume86 fL86 \text{ fL}80−100 fL80-100 \text{ fL}
Creatinine1.6 mg/dL1.6 \text{ mg/dL}0.6−1.2 mg/dL0.6-1.2 \text{ mg/dL}
Total bilirubin3.8 mg/dL3.8 \text{ mg/dL}0.1−1.2 mg/dL0.1-1.2 \text{ mg/dL}
Direct bilirubin0.6 mg/dL0.6 \text{ mg/dL}0.0−0.3 mg/dL0.0-0.3 \text{ mg/dL}
Lactate dehydrogenase (LDH)1,450 U/L1,450 \text{ U/L}100−250 U/L100-250 \text{ U/L}
INR1.11.10.8−1.20.8-1.2
aPTT32 seconds32 \text{ seconds}25−40 seconds25-40 \text{ seconds}

Arrange the following clinical steps in the most appropriate sequential order for the evidence-based diagnosis and management of this patient.

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Cevap

The correct sequence is: Review a peripheral blood smear -> Calculate the PLASMIC score -> Obtain a venous blood sample for ADAMTS13 -> Initiate emergent therapeutic plasma exchange (PLEX) -> Administer high-dose systemic glucocorticoids.
The patient's presentation of MAHA, severe thrombocytopenia, mild renal impairment, and neurological symptoms without coagulopathy strongly suggests Thrombotic Thrombocytopenic Purpura (TTP). The evidence-based sequence begins with identifying MAHA on a peripheral smear. Next, a PLASMIC score is calculated to risk-stratify the patient; this patient has a high score due to hemolysis, platelets < 30,000, MCV < 90, normal INR, and Cr < 2.0. Critically, the blood sample for ADAMTS13 must be drawn *before* any plasma therapy is administered to prevent false-negative diagnostic results. Once the sample is secured, emergent therapeutic plasma exchange (PLEX) is initiated empirically without waiting for the ADAMTS13 results. Finally, adjunctive medical therapies like glucocorticoids are added to target the underlying autoimmune antibody production.

Adım Adım Çözüm

1
Evaluate the CBC and standard laboratory panels by reviewing a peripheral blood smear.
Confirmation of fragmented red blood cells (schistocytes), establishing the presence of microangiopathic hemolytic anemia (MAHA).
Before initiating invasive treatment for Thrombotic Thrombocytopenic Purpura (TTP), MAHA must be distinguished from other causes of pancytopenia or isolated thrombocytopenia.
2
Calculate the PLASMIC score using the patient's laboratory values and clinical history.
A high score (e.g., 6 or 7) strongly suggests severe ADAMTS13 deficiency.
This validated predictive tool helps clinicians justify the immediate use of high-risk, expensive empiric therapies (like PLEX) before definitive molecular testing results are available.
3
Draw a venous blood sample for an ADAMTS13 activity and inhibitor assay.
The diagnostic specimen is safely secured prior to any treatment.
PLEX utilizes donor fresh frozen plasma, which contains functional ADAMTS13 enzyme. Drawing blood after starting PLEX yields falsely normalized results, permanently obscuring the true diagnosis.
4
Initiate emergent therapeutic plasma exchange (PLEX).
Mechanical removal of ADAMTS13 autoantibodies and replenishment of the functional enzyme.
TTP is a medical emergency with high mortality if untreated. PLEX must be started immediately upon clinical suspicion and must not wait for the ADAMTS13 laboratory results.
5
Administer systemic immunosuppressants, such as high-dose glucocorticoids.
Suppression of the underlying autoimmune pathophysiology.
While PLEX manages the acute thrombotic crisis, immunosuppressants halt the ongoing production of the pathogenic IgG autoantibodies.

Anahtar Kavram

Diagnosis and stepwise management algorithm for Thrombotic Thrombocytopenic Purpura (TTP)
Soru 1083Soru →

Following a deceased-donor renal allograft transplantation eight months ago, a 58-year-old woman is admitted to the hospital due to a three-week history of productive cough, night sweats, and new-onset left-sided hemiparesis. Her immunosuppressive regimen includes tacrolimus, mycophenolate mofetil, and prednisone. Routine post-transplant antimicrobial prophylaxis was discontinued two months ago. Vital signs show a temperature of 38.2°C (100.8°F). Neurological examination reveals 3/5 strength in the left upper and lower extremities. A chest radiograph demonstrates a large cavitary lesion in the right upper lobe. Subsequent magnetic resonance imaging of the brain reveals a 2.5-cm ring-enhancing lesion in the right frontal lobe with surrounding vasogenic edema. Bronchoscopy with bronchoalveolar lavage is performed, and cytological analysis reveals branching, filamentous, Gram-positive rods that stain weakly positive with a modified acid-fast stain. Which of the following is the most appropriate initial targeted pharmacotherapy for this patient's underlying infection?

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Cevap: Trimethoprim-sulfamethoxazole

Cevap

Trimethoprim-sulfamethoxazole
The correct answer is trimethoprim-sulfamethoxazole. This immunocompromised patient's presentation of a cavitary lung lesion and a ring-enhancing brain abscess is highly characteristic of disseminated nocardiosis. The diagnosis is definitively supported by the bronchoalveolar lavage findings: branching, filamentous, Gram-positive rods that are weakly positive on modified acid-fast staining. Nocardia species are aerobic, soil-dwelling bacteria that cause opportunistic pulmonary infections with a strong propensity for hematogenous dissemination to the central nervous system. Trimethoprim-sulfamethoxazole (TMP-SMX) is the cornerstone of targeted therapy for nocardiosis. In severe or disseminated cases, a second agent like a carbapenem (e.g., imipenem) or amikacin may be added empirically, but TMP-SMX remains the essential targeted agent.

Adım Adım Çözüm

1
Analyze the patient's immune status and clinical presentation.
The patient is an immunocompromised solid organ transplant recipient presenting with a dual-organ syndrome: a cavitary pulmonary infection and a focal central nervous system (CNS) abscess.
Identifying the pattern of organ involvement narrows the differential diagnosis of opportunistic infections to pathogens that typically disseminate from the lungs to the brain (e.g., Nocardia, Aspergillus, Tuberculosis).
2
Interpret the specific microbiological findings from the bronchoalveolar lavage.
The pathogen is described as branching, filamentous, Gram-positive rods that are weakly acid-fast.
These specific staining characteristics are pathognomonic for Nocardia species. They differentiate the organism from Actinomyces (which is not acid-fast) and Aspergillus (which is a fungus, not a Gram-positive bacterium).
3
Determine the appropriate targeted pharmacotherapy for the identified pathogen.
Trimethoprim-sulfamethoxazole is selected as the cornerstone of therapy.
Trimethoprim-sulfamethoxazole is the standard first-line targeted therapy for both pulmonary and disseminated (CNS) nocardiosis.

Anahtar Kavram

Nocardiosis presents as cavitary lung lesions and brain abscesses in immunocompromised patients, diagnosed by weakly acid-fast, branching Gram-positive rods, and is treated with trimethoprim-sulfamethoxazole.
Tahmini Süre:1m 30s
Soru 1084Soru →

Match each clinical presentation of a chemotherapy-induced adverse effect to the specific antineoplastic agent responsible for the toxicity.

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Öğeler

A 28-year-old man receiving bleomycin, etoposide, and cisplatin for testicular cancer develops a dry cough and progressive dyspnea; pulmonary function tests show a restrictive pattern.
A 48-year-old woman receiving rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone for non-Hodgkin lymphoma presents with suprapubic pain and gross hematuria.
A 62-year-old man receiving bleomycin, etoposide, and cisplatin for advanced testicular cancer complains of persistent bilateral tinnitus and progressive sensorineural hearing loss.
A 55-year-old woman receiving doxorubicin and cyclophosphamide for breast cancer develops new-onset orthopnea, bilateral basilar crackles, and a reduced left ventricular ejection fraction.
A 60-year-old man receiving rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone for diffuse large B-cell lymphoma reports a subacute 'pins and needles' sensation in his distal extremities and absent ankle reflexes.

Eşleşmeler

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Cevap

The correct matches align the clinical toxicity to its specific causative agent: Bleomycin causes pulmonary fibrosis; Cyclophosphamide causes hemorrhagic cystitis; Cisplatin causes ototoxicity; Doxorubicin causes dilated cardiomyopathy; and Vincristine causes peripheral neuropathy.
Each clinical scenario describes a classic dose-limiting toxicity that corresponds to exactly one agent in the patient's regimen. Bleomycin causes pulmonary fibrosis; Cyclophosphamide causes hemorrhagic cystitis; Cisplatin causes ototoxicity; Doxorubicin causes dilated cardiomyopathy; and Vincristine causes peripheral neuropathy.

Adım Adım Çözüm

1
Analyze the first vignette describing restrictive lung disease in a patient on BEP therapy.
The primary symptom is pulmonary fibrosis.
Identifying the specific organ toxicity allows isolation of the responsible drug from the combination regimen.
2
Match pulmonary fibrosis to its causative agent in the BEP regimen.
Bleomycin is the correct match.
Bleomycin is classically associated with dose-dependent pulmonary toxicity.
3
Analyze the second vignette describing gross hematuria in a patient on R-CHOP therapy.
The presentation represents hemorrhagic cystitis.
This is a classic urologic emergency associated with specific alkylating agents.
4
Match hemorrhagic cystitis to its causative agent.
Cyclophosphamide is the correct match.
Acrolein, a cyclophosphamide metabolite, is highly toxic to the bladder epithelium.
5
Analyze the third vignette describing tinnitus and hearing loss in a patient on BEP therapy.
The symptom is ototoxicity.
Hearing loss is a highly specific neurological toxicity that must be recognized.
6
Match ototoxicity to its causative agent.
Cisplatin is the correct match.
Platinum analogues, especially cisplatin, are heavily ototoxic and nephrotoxic.
7
Analyze the fourth vignette describing heart failure (reduced ejection fraction) in a patient on AC therapy.
The symptom is dilated cardiomyopathy.
Cardiotoxicity is a dose-limiting side effect for certain key oncology drugs.
8
Match dilated cardiomyopathy to its causative agent.
Doxorubicin is the correct match.
Anthracyclines like doxorubicin cause cumulative myocardial free-radical damage.
9
Analyze the fifth vignette describing absent ankle reflexes and paresthesias in a patient on R-CHOP therapy.
The symptom is peripheral neuropathy.
Areflexia and a 'pins and needles' sensation indicate peripheral nerve damage.
10
Match peripheral neuropathy to its causative agent.
Vincristine is the correct match.
Vinca alkaloids disrupt microtubules, uniquely causing peripheral neuropathy rather than the severe myelosuppression seen with other agents.

Anahtar Kavram

Major chemotherapeutic agents have distinct, highly tested dose-limiting toxicities that must be recognized when patients on combination regimens present with new symptoms.
Soru 1085Soru →

Match each patient's clinical presentation with the autoantibody or immunologic marker most strongly associated with their underlying disease process.

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Öğeler

A 48-year-old woman presenting with proximal muscle weakness, hyperkeratotic cracking on the lateral aspects of her fingers, and new-onset interstitial lung disease.
A 32-year-old woman with a history of unprovoked pulmonary embolism presenting with recurrent mid-trimester pregnancy losses and an isolated prolonged PTT.
A 55-year-old man with palpable purpura, arthralgias, peripheral neuropathy, and hypocomplementemia (low C4), who recently tested positive for Hepatitis C.
A 60-year-old woman with severe xerophthalmia, xerostomia, and bilateral parotid gland enlargement who recently noticed a rapidly enlarging cervical lymph node.

Eşleşmeler

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Cevap

Antisynthetase syndrome matches with Anti-Jo-1; Antiphospholipid syndrome matches with Anti-beta-2-glycoprotein I; Mixed cryoglobulinemia matches with Rheumatoid factor; Sjögren syndrome matches with Anti-Ro/SSA.
Each left item provides a high-yield, specific clinical vignette for a systemic autoimmune disease. Antisynthetase syndrome is driven by anti-Jo-1; antiphospholipid syndrome relies on markers like anti-beta-2-glycoprotein I; Hepatitis C-associated mixed cryoglobulinemia features IgM rheumatoid factor; and Sjögren syndrome is characterized by anti-Ro/SSA antibodies.

Adım Adım Çözüm

1
Analyze the first patient's symptoms (myositis, mechanic's hands, interstitial lung disease) to diagnose antisynthetase syndrome.
Identify Anti-Jo-1 as the highly specific antibody for this condition.
Anti-Jo-1 targets histidyl-tRNA synthetase and defines this distinct subset of inflammatory myopathies.
2
Evaluate the second patient's history of thrombosis, pregnancy loss, and isolated prolonged PTT to diagnose antiphospholipid syndrome.
Identify Anti-beta-2-glycoprotein I as one of the defining diagnostic autoantibodies.
The prolonged PTT is an in vitro artifact of the lupus anticoagulant; the syndrome is mediated by antibodies against phospholipid-binding proteins.
3
Correlate the third patient's palpable purpura, neuropathy, low C4, and Hepatitis C with mixed cryoglobulinemia.
Identify Rheumatoid factor as the key immunologic marker.
Type II mixed cryoglobulins are immune complexes composed of polyclonal IgG and monoclonal IgM; the IgM component possesses rheumatoid factor activity (affinity for the Fc portion of IgG), which consumes complement C4.
4
Recognize the fourth patient's sicca symptoms, parotid swelling, and new lymphadenopathy as Sjögren syndrome with likely lymphomatous transformation.
Identify Anti-Ro/SSA antibodies as the classic serologic marker.
Sjögren syndrome carries a significantly elevated risk for B-cell non-Hodgkin lymphoma, and is diagnosed using Anti-Ro/SSA and Anti-La/SSB antibodies.

Anahtar Kavram

Clinical and serologic correlations in systemic autoimmune and rheumatic diseases
Soru 1086Soru →

On the third day of hospitalization, a 3434-year-old woman is re-evaluated during morning rounds. She was initially admitted for severe right flank pain, dysuria, nausea, and a temperature of 39.2∘C39.2^\circ\text{C} (102.6∘F102.6^\circ\text{F}). She was empirically started on intravenous ceftriaxone for acute pyelonephritis. Today, the patient reports significant improvement in her symptoms and has tolerated a regular diet since yesterday evening. Her temperature is 37.1∘C37.1^\circ\text{C} (98.8∘F98.8^\circ\text{F}), blood pressure is 118/76 mm Hg118/76\text{ mm Hg}, and pulse is 78/min78/\text{min}. Right costovertebral angle tenderness is no longer present. Blood cultures obtained at admission have shown no growth. Urine culture results are now available and demonstrate >105 CFU/mL>10^5\text{ CFU/mL} of *Escherichia coli*. The organism is susceptible to ciprofloxacin, ceftriaxone, and meropenem; it is resistant to ampicillin and trimethoprim-sulfamethoxazole. Based on the patient's current clinical status and laboratory findings, which of the following is the most appropriate next step in management?

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Cevap: Switch to oral ciprofloxacin and plan for discharge

Cevap

The most appropriate next step is to switch the patient to oral ciprofloxacin and plan for discharge.
The correct management for a patient admitted with acute pyelonephritis who demonstrates significant clinical improvement, is hemodynamically stable, and can tolerate oral intake is to transition from intravenous to oral antibiotics. Because the urine culture grew *Escherichia coli* susceptible to ciprofloxacin, and fluoroquinolones have excellent oral bioavailability with high tissue penetration in the urinary tract, transitioning to oral ciprofloxacin is the optimal choice. This evidence-based practice minimizes hospital length of stay and avoids complications associated with prolonged intravenous catheter use.

Adım Adım Çözüm

1
Assess the patient's clinical trajectory.
The patient is afebrile (37.1∘C37.1^\circ\text{C}), hemodynamically stable, has resolving symptoms, and is tolerating oral intake.
Determines readiness for transition from inpatient intravenous therapy to outpatient oral therapy.
2
Evaluate microbiological data and susceptibilities.
Urine culture confirms *E. coli* resistant to TMP-SMX but susceptible to ciprofloxacin.
Ensures the planned oral step-down agent is active against the specific identified pathogen.
3
Select the appropriate definitive oral therapy.
Oral ciprofloxacin is chosen because the organism is susceptible and fluoroquinolones achieve excellent tissue penetration in the urinary tract.
Allows for safe hospital discharge while completing the required treatment course with a highly bioavailable oral drug.

Anahtar Kavram

Patients admitted with acute pyelonephritis should be transitioned from intravenous to targeted oral antibiotics once they demonstrate clinical improvement (afebrile for 2424-4848 hours, resolving symptoms) and can tolerate oral intake.
Soru 1087Soru →

A 68-year-old man with a history of end-stage renal disease is brought to the emergency department due to profound generalized weakness. He missed his last two hemodialysis appointments due to transportation issues. His pulse is 55/min and blood pressure is 112/68 mm Hg. An electrocardiogram is obtained and displays peaked T waves along with a widened QRS complex. A basic metabolic panel reveals a serum potassium concentration of 7.8 mEq/L. Arrange the following therapeutic interventions in the correct chronological sequence for managing this patient's acute presentation, starting with the most immediate required step and ending with definitive treatment.

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Cevap

The correct sequence is: 1) Intravenous calcium gluconate administration, 2) Intravenous regular insulin and dextrose administration, 3) Emergent hemodialysis initiation.
The correct sequence for managing severe hyperkalemia with electrocardiographic changes requires immediate protection against arrhythmias followed by progressive lowering of potassium. Intravenous calcium gluconate is given first to immediately stabilize the cardiac myocyte membrane. Next, intravenous regular insulin (with dextrose) is administered to drive potassium into the intracellular space, which temporarily lowers the serum concentration. Finally, emergent hemodialysis is initiated to definitively clear the excess potassium from the body, as the patient's end-stage renal disease prevents normal renal excretion.

Adım Adım Çözüm

1
Identify the life-threatening emergency.
The patient has severe hyperkalemia (7.8 mEq/L) with critical electrocardiographic changes (peaked T waves, widened QRS).
A widened QRS complex indicates impending cardiac arrest, requiring immediate protocol-driven intervention.
2
Prioritize cardiac membrane stabilization.
Intravenous calcium gluconate must be administered as the very first step.
Calcium directly antagonizes the membrane effects of hyperkalemia within 1 to 3 minutes, protecting the heart from fatal arrhythmias.
3
Shift potassium intracellularly.
Intravenous regular insulin and dextrose are administered next.
Insulin activates the Na+/K+-ATPase pump, shifting potassium into cells and temporarily lowering serum levels within 15 to 30 minutes, buying time for definitive removal.
4
Initiate definitive removal of total-body potassium.
Emergent hemodialysis is arranged and initiated as the final step.
In a patient with end-stage renal disease, renal excretion (e.g., via loop diuretics) is ineffective. Dialysis permanently removes potassium but takes hours to fully execute, making it the definitive but not the most immediate step.

Anahtar Kavram

The acute management of severe hyperkalemia with electrocardiographic changes follows a strict three-step sequence: immediate cardiac membrane stabilization (calcium), rapid intracellular potassium shifting (insulin/glucose), and definitive total-body potassium removal (hemodialysis or cation exchangers).
Soru 1088Soru →

A 43-year-old woman is brought to the emergency department due to a 3-day history of escalating, throbbing headaches, blurred vision, and severe shortness of breath. The patient has a known 4-year history of diffuse cutaneous systemic sclerosis. Three weeks ago, she received a high-dose oral prednisone taper for an exacerbation of joint pain and severe skin tightness.

Upon arrival, her temperature is 37.1∘C37.1^\circ\text{C} (98.8∘F98.8^\circ\text{F}), blood pressure is 230/125 mmHg230/125 \text{ mmHg}, heart rate is 115/min115/\text{min}, and respiratory rate is 26/min26/\text{min} with an oxygen saturation of 91%91\% on room air. Physical examination reveals extensive skin thickening over the face, trunk, and proximal upper extremities. Fundoscopic examination demonstrates bilateral flame-shaped hemorrhages and papilledema. Chest auscultation reveals bibasilar crackles.

Laboratory studies are as follows:

TestResultReference Range
Hemoglobin8.2 g/dL8.2 \text{ g/dL}12.0−16.0 g/dL12.0-16.0 \text{ g/dL}
Platelets78,000/mm378,000/\text{mm}^3150,000−400,000/mm3150,000-400,000/\text{mm}^3
Blood urea nitrogen52 mg/dL52 \text{ mg/dL}7−18 mg/dL7-18 \text{ mg/dL}
Serum creatinine3.4 mg/dL3.4 \text{ mg/dL}0.6−1.2 mg/dL0.6-1.2 \text{ mg/dL}
Thyroid-stimulating hormone (TSH)0.2μU/mL0.2 \mu\text{U/mL}0.4−4.0μU/mL0.4-4.0 \mu\text{U/mL}
Free thyroxine (T4)1.2 ng/dL1.2 \text{ ng/dL}0.9−1.7 ng/dL0.9-1.7 \text{ ng/dL}

Peripheral blood smear shows 4 to 6 schistocytes per high-power field.

Arterial blood gas on room air:
pH: 7.327.32
PaCO2\text{PaCO}_2: 30 mmHg30 \text{ mmHg}
PaO2\text{PaO}_2: 60 mmHg60 \text{ mmHg}
Bicarbonate: 15 mEq/L15 \text{ mEq/L}

Urinalysis reveals 1+1+ proteinuria with no red blood cell casts. A recent outpatient sputum culture grew only normal respiratory flora.

Which of the following is the most appropriate next step in the management of this patient's current condition?

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Cevap: Administer oral captopril

Cevap

Administer oral captopril
The correct step is to administer oral captopril. This patient is presenting with scleroderma renal crisis (SRC), a life-threatening complication of systemic sclerosis characterized by malignant hypertension (evidenced by papilledema and flame-shaped hemorrhages) and rapidly progressive oliguric acute kidney injury. The recent use of high-dose corticosteroids is a classic precipitating trigger for SRC. The pathogenesis involves intense activation of the renin-angiotensin-aldosterone system (RAAS) due to renal vascular injury. Therefore, short-acting ACE inhibitors, specifically captopril, are the first-line treatment and must be initiated immediately and titrated rapidly, even in the setting of acute kidney injury. SRC can also cause microangiopathic hemolytic anemia (schistocytes, thrombocytopenia) due to endothelial damage, which may mimic thrombotic thrombocytopenic purpura, but it resolves with aggressive ACE inhibitor therapy.

Adım Adım Çözüm

1
Analyze the patient's presentation and medical history.
The patient has diffuse cutaneous systemic sclerosis and presents with new-onset malignant hypertension, microangiopathic hemolytic anemia, and acute kidney injury following high-dose corticosteroid use.
To identify the primary acute pathophysiologic process.
2
Diagnose the acute condition.
The clinical picture is classic for Scleroderma Renal Crisis (SRC).
Recognizing SRC is critical because its management diverges significantly from typical hypertensive emergencies.
3
Evaluate the laboratory and arterial blood gas findings.
The ABG shows a fully compensated metabolic acidosis (Winter's formula matches actual PaCO2). The thyroid panel shows euthyroid sick syndrome.
To rule out secondary superimposed complications that would require separate, potentially contraindicated treatments.
4
Determine the appropriate pharmacologic intervention.
Select a short-acting ACE inhibitor (captopril).
ACE inhibitors specifically target and break the cycle of malignant renin-angiotensin-aldosterone system (RAAS) activation that drives SRC.

Anahtar Kavram

Scleroderma Renal Crisis (SRC) presents with malignant hypertension, acute kidney injury, and often microangiopathic hemolytic anemia. It is frequently triggered by glucocorticoid use in patients with systemic sclerosis. Prompt initiation of a short-acting ACE inhibitor (e.g., captopril) is mandatory, even in the setting of renal failure.
Soru 1089Soru →

A 28-year-old man presents to the clinic for evaluation of a painless lump on the left side of his neck that has been progressively enlarging for the past two months. He reports experiencing drenching night sweats and a 5-kg (11-lb) unintentional weight loss over the same period. His temperature is 38.2°C (100.8°F), blood pressure is 120/78 mm Hg, and pulse is 88/min. Physical examination reveals a 4-cm, firm, rubbery, and non-tender lymph node in the left supraclavicular region. There is no other palpable lymphadenopathy, and the liver and spleen are not enlarged on abdominal palpation. A complete blood count is within normal limits. Based on the clinical presentation, there is a high suspicion for Hodgkin lymphoma.

Arrange the following management steps in the most appropriate chronological sequence for the comprehensive evaluation and treatment of this patient.

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Cevap

The correct sequence is to first perform an excisional lymph node biopsy to confirm the diagnosis, followed by an FDG-PET/CT scan for staging, then obtain an echocardiogram and PFTs to assess baseline safety, and finally initiate systemic combination chemotherapy.
The comprehensive management of suspected Hodgkin lymphoma follows a strict algorithmic sequence. Initially, a definitive tissue diagnosis must be established using an excisional lymph node biopsy to preserve tissue architecture (fine-needle aspiration is inadequate). Once the diagnosis is confirmed histologically, a whole-body FDG-PET/CT scan is performed to accurately stage the disease (Ann Arbor system), which dictates the treatment plan. Before initiating the standard ABVD chemotherapy regimen, baseline cardiac function (via echocardiography) and pulmonary function (via PFTs) must be assessed to prevent unrecognized, catastrophic doxorubicin-induced cardiotoxicity or bleomycin-induced pulmonary toxicity. Only after all diagnostic, staging, and safety evaluations are completed is systemic chemotherapy initiated.

Adım Adım Çözüm

1
Identify the need for a definitive tissue diagnosis.
Perform an excisional lymph node biopsy.
A complete evaluation of lymph node architecture is required to accurately identify Reed-Sternberg cells and diagnose Hodgkin lymphoma. Fine-needle aspiration is insufficient.
2
Determine the clinical stage of the confirmed malignancy.
Obtain a whole-body FDG-PET/CT scan.
Staging (Ann Arbor system) evaluates disease extent and directly dictates the appropriate chemotherapy regimen and duration.
3
Evaluate baseline organ reserve for anticipated chemotherapy toxicities.
Assess cardiac and pulmonary function (Echocardiogram and PFTs).
The standard ABVD regimen includes doxorubicin (which is cardiotoxic) and bleomycin (which is pulmonary toxic). Baseline safety assessments are strictly mandatory before starting treatment.
4
Administer definitive antineoplastic treatment.
Initiate systemic combination chemotherapy.
Therapy can only be safely and effectively administered after diagnosis, staging, and safety assessments are complete.

Anahtar Kavram

The sequential management of suspected Hodgkin lymphoma requires definitive tissue diagnosis via excisional biopsy, followed by radiologic staging, baseline evaluation of cardiopulmonary function, and finally the initiation of targeted chemotherapy.
Soru 1090Soru →

A 32-year-old woman comes to the ambulatory care center reporting profound fatigue and achiness in her wrists and hands over the past 3 months. She also notes a facial rash that becomes more prominent after spending time outdoors in the sun. On physical examination, there is a fixed erythema over the malar eminences and the bridge of the nose; the nasolabial folds are unaffected. Examination of the oral cavity reveals two painless ulcerations on the hard palate. A dipstick urinalysis in the clinic shows 2+ proteinuria and hematuria. Which of the following is the most appropriate initial laboratory test to evaluate this patient's condition?

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Cevap: Antinuclear antibody

Cevap

Antinuclear antibody (ANA) testing is the most appropriate initial step.
The correct answer is the antinuclear antibody (ANA) test. This patient's classic presentation of a photosensitive malar rash, oral ulcers, inflammatory arthritis, and signs of nephritis is highly suspicious for systemic lupus erythematosus (SLE). Because SLE can involve nearly any organ system, establishing the diagnosis requires a combination of clinical criteria and serologic evidence. The most appropriate initial laboratory test is the ANA test because it has a very high sensitivity (>95%) for SLE. A negative ANA test effectively rules out the disease in most cases.

Adım Adım Çözüm

1
Identify the patient's clinical syndrome.
The patient presents with fatigue, polyarthralgia, a photosensitive malar rash sparing the nasolabial folds, painless oral ulcers, and signs of glomerulonephritis (proteinuria, hematuria).
Recognizing this constellation of symptoms is essential to form a working diagnosis of systemic lupus erythematosus (SLE).
2
Determine the best initial diagnostic test for the suspected condition.
Antinuclear antibody (ANA) testing should be ordered first.
ANA is highly sensitive (over 95%) for SLE, making it an excellent initial screening test. A negative ANA makes the diagnosis of SLE highly unlikely.

Anahtar Kavram

The antinuclear antibody (ANA) test is the most appropriate initial screening test for suspected systemic lupus erythematosus (SLE) due to its high sensitivity.
Soru 1091Soru →

An inpatient physician is preparing discharge orders for a 55-year-old male patient. The patient was admitted 72 hours ago for community-acquired pneumonia and was empirically started on intravenous ceftriaxone and azithromycin. His cough and shortness of breath have significantly improved. He has been afebrile for the past 24 hours, his vital signs are currently within normal limits, and he is tolerating an oral diet. Blood and sputum cultures obtained on admission have both grown *Streptococcus pneumoniae*. Antimicrobial susceptibility testing reveals the organism is susceptible to penicillin, amoxicillin, ceftriaxone, levofloxacin, and linezolid. He has no known drug allergies. Which of the following is the most appropriate next step in pharmacotherapy to complete this patient's treatment course?

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Cevap: Oral amoxicillin

Cevap

Oral amoxicillin
The patient is clinically stable, afebrile, and able to take oral medications, indicating readiness for step-down from intravenous to oral antibiotic therapy. Antimicrobial stewardship guidelines strongly recommend de-escalating from empiric broad-spectrum regimens to the most targeted, narrow-spectrum agent possible once culture and susceptibility results are finalized. Amoxicillin is a narrow-spectrum aminopenicillin that is highly effective against penicillin-susceptible *Streptococcus pneumoniae*. Transitioning to oral amoxicillin will adequately treat the pneumonia while minimizing collateral damage to the patient's microbiome and reducing the risk of antibiotic resistance.

Adım Adım Çözüm

1
Assess the patient's clinical stability for oral transition.
The patient is afebrile, clinically improved, and tolerating oral intake.
These criteria confirm the patient is ready to transition from intravenous to oral antibiotics.
2
Review the culture and susceptibility results.
The pathogen is Streptococcus pneumoniae, which is susceptible to penicillin and amoxicillin.
Targeted therapy must be selected based on confirmed microbiologic data rather than empiric assumptions.
3
Apply antimicrobial stewardship principles to select the definitive agent.
Oral amoxicillin is chosen over broader alternatives.
De-escalating to the narrowest spectrum agent effectively treats the infection while minimizing adverse effects and resistance pressure.

Anahtar Kavram

Antimicrobial Stewardship: De-escalation to Targeted Oral Therapy
Tahmini Süre:1m 0s
Soru 1092Soru →

Match each clinical presentation of pneumonia with the most likely causative pathogen based on classic epidemiological risk factors and clinical findings.

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Öğeler

A 45-year-old man with severe alcohol use disorder presents with fever, productive cough with thick, blood-tinged sputum, and an upper lobe cavitary lesion.
A 20-year-old college student living in a dormitory presents with persistent dry cough, mild fever, and a chest x-ray showing bilateral interstitial infiltrates.
A 65-year-old man presents with high fever, relative bradycardia, confusion, diarrhea, and hyponatremia shortly after returning from a hotel convention.
A 30-year-old pet shop worker presents with high fever, severe headache, and dry cough after extensive exposure to exotic parrots and macaws.

Eşleşmeler

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Cevap

Alcoholism points to Klebsiella pneumoniae; dormitory residence points to Mycoplasma pneumoniae; hotel water exposure with hyponatremia points to Legionella pneumophila; and bird exposure points to Chlamydia psittaci.
Each respiratory pathogen is uniquely associated with specific environmental exposures and host risk factors that help guide empiric diagnostic testing and targeted antimicrobial selection.

Adım Adım Çözüm

1
Evaluate the first vignette for host risk factors and sputum characteristics.
Matches Klebsiella pneumoniae.
The patient has a history of alcohol use disorder, which predisposes to aspiration, and presents with classic 'currant jelly' sputum and cavitation.
2
Evaluate the second vignette for patient age and living environment.
Matches Mycoplasma pneumoniae.
The patient is a young adult in a crowded dormitory environment presenting with atypical pneumonia symptoms.
3
Evaluate the third vignette for environmental exposure and extrapulmonary symptoms.
Matches Legionella pneumophila.
The patient has exposure to a hotel (suggesting a contaminated water source) and presents with classic extrapulmonary features including diarrhea, confusion, and hyponatremia.
4
Evaluate the fourth vignette for zoonotic exposure.
Matches Chlamydia psittaci.
The patient has occupational exposure to birds, which is the primary transmission route for psittacosis.

Anahtar Kavram

Epidemiological risk factors and classic clinical syndromes of pneumonia pathogens.
Tahmini Süre:1m 0s
Soru 1093Soru →

A 68-year-old woman is brought to the emergency department by her daughter due to progressive confusion, fever, and a severe headache over the past 24 hours. The patient has a history of rheumatoid arthritis treated with methotrexate and infliximab. Temperature is 39.1°C (102.4°F), blood pressure is 105/65 mm Hg, pulse is 115/min, and respirations are 20/min. Neurologic examination reveals a lethargic patient who only opens her eyes to painful stimuli. There is marked nuchal rigidity. Papilledema is absent, and there are no focal motor deficits. The physician suspects bacterial meningitis. Arrange the following management steps in the most appropriate chronological order for this patient.

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Cevap

The correct chronological sequence is: Obtain peripheral blood cultures, administer empiric antibiotics and dexamethasone, obtain a CT scan of the head, perform a lumbar puncture, and finally narrow antimicrobial therapy based on susceptibilities.
Bacterial meningitis requires emergent management. The standard sequence is to perform a lumbar puncture (LP) followed immediately by empiric antibiotics. However, if the patient has 'red flag' indications for a CT scan before the LP—such as age ≥ 60, an immunocompromised state (e.g., use of infliximab and methotrexate), history of CNS disease, new-onset seizure, altered mental status, or focal neurologic deficits—the sequence must be modified to prevent cerebral herniation.

Because the CT scan and subsequent LP will delay definitive diagnosis, empiric antimicrobial therapy (with dexamethasone, ceftriaxone, vancomycin, and ampicillin to cover Listeria in this older, immunocompromised patient) MUST NOT be delayed. To optimize the chances of identifying the pathogen, blood cultures should be drawn right before antibiotic administration. Once antibiotics are running, the patient undergoes the CT scan. If the CT shows no mass effect, the LP is performed. Finally, days later, the antibiotic regimen is narrowed based on culture susceptibilities.

Adım Adım Çözüm

1
Identify the need for emergent intervention in suspected bacterial meningitis.
The patient requires prompt diagnostic workup and empiric treatment without delay.
Bacterial meningitis is a life-threatening neurologic emergency with high morbidity and mortality if treatment is delayed.
2
Determine if the patient has indications for a CT scan before a lumbar puncture.
The patient has multiple indications: age ≥ 60, immunocompromised state (infliximab, methotrexate), and altered mental status (lethargy).
Performing an LP in the presence of increased intracranial pressure from a mass lesion can precipitate fatal brain herniation.
3
Sequence the immediate interventions prior to the CT scan.
Blood cultures should be drawn first, immediately followed by empiric antibiotics and dexamethasone.
Antibiotics must not be delayed for the CT scan, but blood cultures should be drawn beforehand to avoid sterilization of the sample.
4
Sequence the interventions following the CT scan.
Perform the lumbar puncture if the CT is clear, and later de-escalate antibiotics based on culture results.
CSF analysis is essential for definitive diagnosis, and subsequent tailoring of antibiotics aligns with antimicrobial stewardship principles.

Anahtar Kavram

In patients with suspected bacterial meningitis who have indications for neuroimaging prior to a lumbar puncture (e.g., age ≥ 60, immunocompromise, altered mental status, focal neurologic deficits), blood cultures should be drawn and empiric antibiotics administered immediately. Antibiotics must NEVER be delayed for the CT scan or lumbar puncture.
Soru 1094Soru →

Idiopathic inflammatory myopathies are characterized by distinct myositis-specific autoantibodies that strongly predict clinical phenotypes, organ involvement, and prognosis. Match each myositis-specific autoantibody with its most characteristic clinical phenotype or primary disease association.

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Öğeler

Anti-Jo-1 (anti-histidyl-tRNA synthetase)
Anti-SRP (signal recognition particle)
Anti-Mi-2 (nucleosome remodeling deacetylase complex)
Anti-MDA5 (melanoma differentiation-associated gene 5)
Anti-TIF1-gamma (transcriptional intermediary factor 1-gamma)

Eşleşmeler

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Cevap

Anti-Jo-1 matches with antisynthetase syndrome (mechanic's hands, ILD); Anti-SRP matches with severe necrotizing myopathy; Anti-Mi-2 matches with classic, steroid-responsive dermatomyositis; Anti-MDA5 matches with amyopathic dermatomyositis and rapidly progressive ILD; Anti-TIF1-gamma matches with malignancy-associated dermatomyositis.
Idiopathic inflammatory myopathies (IIMs) are heterogeneous. Myositis-specific antibodies (MSAs) allow for the categorization of IIMs into distinct clinical subsets. Recognizing these associations is critical for anticipating complications such as rapidly progressive interstitial lung disease (Anti-MDA5), occult malignancy (Anti-TIF1-gamma), or necrotizing autoimmune myopathy with cardiac involvement (Anti-SRP).

Adım Adım Çözüm

1
Analyze the autoantibody profile in the context of idiopathic inflammatory myopathies.
Identify that the question tests high-yield, specific antibody-phenotype correlations beyond standard ANA testing.
Myositis-specific antibodies dictate the need for targeted screening (e.g., ILD, malignancy, cardiac involvement).
2
Differentiate the lung-predominant phenotypes.
Anti-Jo-1 is linked to standard antisynthetase syndrome, whereas Anti-MDA5 is linked to clinically amyopathic disease with rapidly progressive, often fatal interstitial lung disease and distinctive skin ulcerations.
Confusing these two can lead to underestimating the acuity of Anti-MDA5 lung disease.
3
Differentiate the skin and muscle-predominant phenotypes.
Anti-SRP lacks prominent skin findings and causes severe necrotizing myopathy. Anti-Mi-2 causes classic severe skin findings (heliotrope, Gottron) but has a good prognosis. Anti-TIF1-gamma causes severe skin findings but is highly paraneoplastic.
Each antibody defines a specific prognostic trajectory and screening requirement.

Anahtar Kavram

Myositis-specific autoantibodies and their corresponding clinical phenotypes
Soru 1095Soru →

A 68-year-old man comes to the clinic reporting a 2-month history of worsening fatigue, shortness of breath when walking up stairs, and a "tingling" sensation in his toes. He has a history of hypothyroidism, chronic obstructive pulmonary disease (COPD), and major depressive disorder. His medications include levothyroxine, inhaled tiotropium, and sertraline.

Vital signs are temperature 37.1∘C37.1^\circ\text{C} (98.8∘F98.8^\circ\text{F}), heart rate 98/min98\text{/min}, blood pressure 130/80 mm Hg130/80\text{ mm Hg}, respiratory rate 16/min16\text{/min}, and oxygen saturation 96%96\% on room air. Physical examination reveals pale conjunctivae and a smooth, glossy, red tongue. Neurologic examination demonstrates diminished vibratory sensation in the bilateral lower extremities and a broad-based gait. Lungs are clear to auscultation bilaterally.

Laboratory evaluation shows:
Hemoglobin: 7.4 g/dL7.4\text{ g/dL}
Mean corpuscular volume (MCV): 116 fL116\text{ fL}
Thyroid-stimulating hormone (TSH): 2.8 \muU/mL2.8\text{ \mu U/mL} (normal: 0.5−5.0 \muU/mL0.5 - 5.0\text{ \mu U/mL})

An arterial blood gas analysis on room air shows a pH of 7.407.40 and PaCO2\text{PaCO}_2 of 40 mm Hg40\text{ mm Hg}.

Which of the following is the most likely diagnosis explaining this patient's current presentation?

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Cevap: Cobalamin deficiency

Cevap

Cobalamin deficiency
The correct answer is cobalamin deficiency. The patient presents with a classic triad for Vitamin B12 deficiency: megaloblastic anemia (hemoglobin 7.4 g/dL7.4\text{ g/dL}, MCV 116 fL116\text{ fL}), gastrointestinal manifestations (glossitis, presenting as a smooth, glossy tongue), and neurologic deficits. Vitamin B12 is essential for DNA synthesis and the maintenance of myelin in the nervous system. Its deficiency leads to subacute combined degeneration of the dorsal columns (causing decreased vibratory sensation and sensory ataxia/broad-based gait) and the lateral corticospinal tracts. The profound anemia decreases the oxygen-carrying capacity of the blood, perfectly explaining his fatigue and exertional dyspnea.

Adım Adım Çözüm

1
Analyze the patient's primary symptoms and physical exam findings.
The patient has severe macrocytic anemia (Hb 7.4 g/dL, MCV 116 fL), glossitis (smooth tongue), and neurologic deficits involving the posterior columns (loss of vibratory sense and broad-based gait).
Identifying the clinical triad narrows down the differential diagnosis significantly.
2
Evaluate the laboratory values to rule out competing diagnoses from his past medical history.
Normal TSH rules out inadequately treated hypothyroidism. Normal ABG and clear lungs rule out a COPD exacerbation or acid-base disturbance.
Patients with complex histories require careful lab correlation to ensure symptoms are not mistakenly attributed to preexisting conditions.
3
Synthesize the findings to determine the most likely unifying diagnosis.
Macrocytic anemia paired with subacute combined degeneration of the spinal cord is the classic and definitive presentation of Vitamin B12 (cobalamin) deficiency.
B12 is required for both DNA synthesis (preventing megaloblastic anemia) and myelin maintenance (preventing neurologic deficits).

Anahtar Kavram

Vitamin B12 (cobalamin) deficiency classically presents with a triad of megaloblastic anemia, gastrointestinal symptoms (glossitis), and neurologic deficits such as subacute combined degeneration of the spinal cord (loss of vibratory/position sense and sensory ataxia).
Soru 1096Soru →

A 64-year-old man is brought to the emergency department by his spouse due to worsening confusion, a severe global headache, and a high fever over the last 24 hours. His temperature is 39.4°C (102.9°F), blood pressure is 128/82 mmHg, and heart rate is 114/min. Physical examination shows a lethargic patient who only opens his eyes to painful stimuli. Marked resistance to passive neck flexion is present. Funduscopic examination reveals bilateral blurring of the optic disc margins with absent venous pulsations. Arrange the following steps in the most appropriate chronological order for managing this patient's condition.

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Cevap

The correct sequence is to first obtain blood cultures, immediately administer empiric intravenous antibiotics and dexamethasone, perform a non-contrast CT scan of the head, and finally perform a lumbar puncture.
The patient presents with the classic presentation of meningitis (fever, severe headache, nuchal rigidity) complicated by altered mental status and papilledema. Papilledema indicates increased intracranial pressure. In cases of suspected bacterial meningitis with indications for neuroimaging prior to a lumbar puncture (such as papilledema, focal neurologic deficits, severe immunocompromise, new-onset seizures, or significantly altered level of consciousness), the correct sequence of interventions is highly critical. First, blood cultures must be drawn rapidly to help identify the pathogen. Second, empiric intravenous antibiotics and dexamethasone must be administered immediately. Waiting for a CT scan and lumbar puncture before giving antibiotics leads to life-threatening delays in treatment. Third, a non-contrast CT scan of the head is performed to rule out mass effect that could cause herniation during a lumbar puncture. Finally, once deemed safe by the imaging results, a lumbar puncture is performed.

Adım Adım Çözüm

1
Identify the suspected diagnosis and high-risk clinical features.
The patient has signs of bacterial meningitis (fever, headache, nuchal rigidity) accompanied by altered mental status and papilledema (indicating increased intracranial pressure).
Recognizing signs of increased intracranial pressure dictates that a CT scan must precede a lumbar puncture to prevent brain herniation.
2
Determine the optimal timing for microbiological sampling versus empiric treatment.
Blood cultures should be drawn first, followed immediately by empiric antibiotics and dexamethasone, before sending the patient to the CT scanner.
Delaying antibiotics for a CT scan and subsequent lumbar puncture significantly increases mortality in bacterial meningitis. Blood cultures can be drawn rapidly without delaying therapy.
3
Sequence the diagnostic imaging and invasive procedure.
The CT scan is performed third, followed by the lumbar puncture as the final step.
The CT scan must rule out a mass effect before the lumbar puncture can be safely performed. CSF analysis is still necessary even if antibiotics have been administered.

Anahtar Kavram

In patients with suspected bacterial meningitis who have indications for a CT scan before lumbar puncture (e.g., papilledema, focal neurological deficits, altered mental status), blood cultures should be drawn and empiric antibiotics administered immediately, prior to neuroimaging.
Tahmini Süre:1m 0s
Soru 1097Soru →

A 74-year-old woman presents to the emergency department with a 2-day history of right-sided throbbing headache, scalp tenderness, and jaw pain while chewing. This morning, she experienced a temporary episode of complete vision loss in her right eye that lasted for 10 minutes before resolving. Laboratory testing shows an erythrocyte sedimentation rate (ESR) of 85 mm/h. Arrange the following steps in the correct chronological order for the most appropriate evaluation and management of this patient.

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Cevap

The correct sequence is to immediately administer high-dose intravenous methylprednisolone, followed by performing a temporal artery biopsy, and finally transitioning to a slow, multi-month taper of oral glucocorticoids.
The patient presents with classic signs of giant cell arteritis (GCA), complicated by transient vision loss. The absolute highest priority is preserving vision. High-dose intravenous glucocorticoids must be given immediately. Following stabilization, a temporal artery biopsy is performed to confirm the diagnosis; steroids will not alter the biopsy results if done within 1 to 2 weeks. Finally, long-term disease control is achieved through a gradual taper of oral glucocorticoids over several months.

Adım Adım Çözüm

1
Recognize the classic presentation of giant cell arteritis (GCA) with visual involvement.
The patient has jaw claudication, temporal headache, and transient monocular vision loss (amaurosis fugax) along with an elevated ESR, highly suggestive of GCA with impending ischemic optic neuropathy.
Identifying the severity of the disease dictates the urgency of treatment.
2
Determine the most urgent initial intervention.
Administer high-dose intravenous methylprednisolone immediately.
Irreversible blindness is the most feared complication of GCA. When visual symptoms are present, intravenous steroids must be given without delay.
3
Select the appropriate diagnostic confirmation step.
Perform a temporal artery biopsy.
Biopsy provides definitive diagnosis. It should be done as soon as feasible but must never delay the administration of steroids. The histopathology remains accurate for 1 to 2 weeks after steroid initiation.
4
Determine the long-term management strategy.
Transition to a slow, multi-month taper of oral glucocorticoids.
GCA requires prolonged immunosuppression to prevent relapse and manage systemic symptoms, often necessitating a tapering course over several months.

Anahtar Kavram

In patients with giant cell arteritis presenting with visual symptoms, high-dose intravenous glucocorticoids must be administered immediately to prevent permanent blindness, prior to obtaining a confirmatory temporal artery biopsy.
Soru 1098Soru →

A 32-year-old man is brought to the emergency department by his partner due to a 24-hour history of severe headache, high fever, and progressive lethargy. His medical history is significant for HIV infection, but he has not taken antiretroviral therapy for the past year. His temperature is 39.1∘C39.1^\circ\text{C} (102.4∘F102.4^\circ\text{F}), blood pressure is 110/70 mm Hg110/70\text{ mm Hg}, and heart rate is 115/min115\text{/min}. Physical examination reveals nuchal rigidity and confusion. Funduscopic examination demonstrates bilateral papilledema. The physician suspects acute bacterial meningitis. Arrange the following diagnostic and therapeutic steps in the most appropriate chronological sequence for this patient's acute management.

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Cevap

The correct sequence is to first obtain peripheral blood cultures, immediately followed by the administration of empiric intravenous dexamethasone and antibiotics, then perform a noncontrast head CT, and finally safely perform a lumbar puncture.
The algorithmic management of suspected bacterial meningitis prioritizes rapid antibiotic administration while ensuring patient safety regarding intracranial pressure. Because this patient has 'red flag' indications for a head CT before an LP (papilledema, confusion, immunocompromise), the LP must be delayed. However, life-saving antibiotics cannot be delayed. Therefore, blood cultures are drawn first, empiric antibiotics and dexamethasone are given immediately, the CT scan is obtained to rule out mass effect, and finally, the LP is performed.

Adım Adım Çözüm

1
Assess for indications requiring a head CT prior to lumbar puncture (LP).
The patient has papilledema, altered mental status, and is immunocompromised (HIV).
These features indicate a high risk for a space-occupying lesion or increased intracranial pressure, making an immediate LP dangerous due to the risk of cerebral herniation.
2
Determine the timing of antimicrobial therapy.
Antibiotics and dexamethasone must be administered immediately, without waiting for the CT scan or LP results.
Delays in antibiotic administration for bacterial meningitis are associated with significantly increased mortality and neurologic morbidity.
3
Determine the timing of blood cultures.
Blood cultures must be drawn prior to administering the antibiotics.
Antibiotics rapidly sterilize the blood; drawing cultures beforehand ensures the highest possible yield for identifying the pathogen.
4
Sequence the definitive diagnostic procedure.
Perform the lumbar puncture only after the head CT is interpreted as safe.
This ensures patient safety. While the CSF culture may be sterile due to prior antibiotics, tests like cell count, protein, glucose, and bacterial PCR remain accurate.

Anahtar Kavram

In patients with suspected bacterial meningitis who have indications for a CT scan before a lumbar puncture (such as papilledema, altered mental status, or immunocompromise), the correct algorithmic sequence is to obtain blood cultures, immediately administer empiric antibiotics and dexamethasone, perform the head CT, and then safely perform the lumbar puncture.
Tahmini Süre:1m 30s
Soru 1099Soru →

A 24-year-old woman presents to the outpatient clinic with a 2-day history of burning with urination and increased urinary frequency. She reports no fever, chills, back pain, or vaginal discharge. She is sexually active with one male partner and uses condoms inconsistently. Her last menstrual period was 2 weeks ago. Vital signs are temperature 37.0°C (98.6°F), blood pressure 110/70 mmHg, pulse 78/min, and respirations 14/min. Physical examination reveals mild suprapubic tenderness but no costovertebral angle tenderness. A urine pregnancy test is negative. Urinalysis is positive for leukocyte esterase and nitrites. Which of the following is the most appropriate pharmacotherapy for this patient?

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Cevap: Oral nitrofurantoin

Cevap

Oral nitrofurantoin
This patient presents with classic signs and symptoms of uncomplicated acute cystitis: dysuria, frequency, and suprapubic tenderness, without systemic signs of infection (e.g., fever) or upper tract involvement (e.g., flank pain). Her positive urinalysis confirms the diagnosis. The most appropriate next step is to prescribe targeted, first-line empiric oral antibiotic therapy. Nitrofurantoin is a preferred first-line agent because it is highly concentrated in the urine, has excellent activity against Escherichia coli (the most common uropathogen), and has a narrow spectrum of activity, which aligns perfectly with proper antibiotic stewardship.

Adım Adım Çözüm

1
Analyze the clinical presentation.
The patient has dysuria, urinary frequency, and suprapubic tenderness without fever, chills, or costovertebral angle tenderness.
This constellation of symptoms characterizes uncomplicated acute cystitis (lower urinary tract infection) and rules out pyelonephritis (upper urinary tract infection).
2
Interpret the laboratory findings.
Urinalysis is positive for leukocyte esterase (indicating pyuria) and nitrites (indicating the presence of Enterobacteriaceae).
This confirms the diagnosis of a bacterial urinary tract infection, most commonly caused by Escherichia coli.
3
Select the most appropriate pharmacotherapy based on stewardship principles.
Oral nitrofurantoin is chosen over broader-spectrum options.
First-line agents for uncomplicated cystitis include nitrofurantoin, trimethoprim-sulfamethoxazole, and fosfomycin. They are chosen because they achieve high concentrations in the urine, effectively target common uropathogens, and spare broader-spectrum antibiotics (like fluoroquinolones) to prevent resistance.

Anahtar Kavram

First-line empiric therapy for uncomplicated acute cystitis should utilize narrow-spectrum agents such as nitrofurantoin, trimethoprim-sulfamethoxazole, or fosfomycin to adhere to antibiotic stewardship principles.
Soru 1100Soru →

A medical team is reviewing the chart of an inpatient being treated for a severe right-sided soft tissue infection. The patient, who has a history of well-controlled type 2 diabetes mellitus, presented two days ago with rigors, marked localized erythema, and a temperature of 39.0 C (102.2 F). Upon admission, blood cultures were drawn, and empiric intravenous vancomycin and piperacillin-tazobactam were initiated. Today, the patient is clinically stable and afebrile. The microbiology laboratory reports that both sets of admission blood cultures are growing Staphylococcus aureus. Susceptibility testing indicates the isolate is sensitive to oxacillin, cefazolin, and clindamycin, but resistant to penicillin and ampicillin. Which of the following is the most appropriate next step in the pharmacologic management of this patient?

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Cevap: Discontinue the current regimen and initiate intravenous cefazolin

Cevap

Discontinue the current regimen and initiate intravenous cefazolin.
The correct action is to discontinue the broad-spectrum empiric regimen and initiate intravenous cefazolin. The patient has confirmed methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia, as evidenced by the isolate's sensitivity to oxacillin. For severe deep-tissue infections complicated by MSSA bacteremia, targeted therapy with an anti-staphylococcal beta-lactam (such as cefazolin, nafcillin, or oxacillin) is the gold standard. These agents are significantly more efficacious than vancomycin, demonstrating faster bacterial clearance and improved clinical outcomes. De-escalating from vancomycin and piperacillin-tazobactam to cefazolin perfectly aligns with core antimicrobial stewardship principles.

Adım Adım Çözüm

1
Interpret the blood culture and susceptibility results.
The organism is Staphylococcus aureus that is sensitive to oxacillin, which definitively identifies it as methicillin-susceptible Staphylococcus aureus (MSSA).
Oxacillin susceptibility is the laboratory surrogate used to distinguish MSSA from methicillin-resistant S. aureus (MRSA).
2
Determine the optimal antibiotic class for MSSA bacteremia.
Anti-staphylococcal beta-lactams (such as cefazolin, nafcillin, or oxacillin) are the preferred agents.
Beta-lactams demonstrate superior bactericidal activity, faster bloodstream clearance, and lower mortality rates compared to vancomycin for MSSA infections.
3
Apply principles of antimicrobial stewardship.
The broad-spectrum empiric regimen (vancomycin and piperacillin-tazobactam) should be discontinued.
De-escalating to a targeted, narrow-spectrum agent prevents the development of antimicrobial resistance, minimizes collateral damage to the microbiome, and reduces drug toxicity.

Anahtar Kavram

Definitive management of methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia requires de-escalation to an intravenous anti-staphylococcal beta-lactam, which is superior to vancomycin.
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Internal Medicine Alıştırma Soruları — USMLE Step 2 CK — Sayfa 55 | Examkin