Internal Medicine

3151 soru

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A 19-year-old man presents to the university health clinic with a 2-day history of fever, severe sore throat, and painful swallowing. He reports no cough, rhinorrhea, or hoarseness. His temperature is 38.6°C (101.5°F), blood pressure is 118/76 mm Hg, and pulse is 98/min. Physical examination reveals enlarged, erythematous tonsils with whitish exudates and bilateral tender anterior cervical lymphadenopathy. A rapid antigen detection test for Group A *Streptococcus* is positive. The patient has no known drug allergies. Which of the following is the most appropriate antibiotic regimen?

Oral penicillin V

Oral amoxicillin-clavulanate

Oral levofloxacin

Oral azithromycin

Intramuscular ceftriaxone

Cevabı ve açıklamayı göster

Cevap: Oral penicillin V

Cevap

Oral penicillin V

The correct answer is oral penicillin V. Group A *Streptococcus* (Streptococcus pyogenes) is the most common bacterial cause of acute pharyngitis and remains universally susceptible to penicillin. Standard antibiotic stewardship guidelines recommend targeted, narrow-spectrum agents—such as oral penicillin V or amoxicillin—as first-line therapy to eradicate the pathogen, prevent rheumatic fever, and minimize the risk of developing broad-spectrum antimicrobial resistance.

Adım Adım Çözüm

Interpret the clinical presentation and diagnostic findings.

The patient has classic signs of streptococcal pharyngitis (fever, tonsillar exudates, tender cervical lymphadenopathy, absence of cough) confirmed by a positive rapid antigen detection test for Group A Streptococcus (GAS).

Establishing a definitive diagnosis is required before selecting targeted antimicrobial therapy.

Select the most appropriate evidence-based, narrow-spectrum pharmacotherapy.

Oral penicillin V (or amoxicillin) is chosen as the first-line treatment.

GAS remains universally susceptible to penicillin. Utilizing a narrow-spectrum antibiotic ensures effective treatment while adhering to antibiotic stewardship principles.

Anahtar Kavram

First-line treatment for confirmed Group A streptococcal pharyngitis is narrow-spectrum penicillin (or amoxicillin) to provide targeted therapy and minimize the development of antimicrobial resistance.

Tahmini Süre:45s

Soru 642Soru →

A $72$ -year-old man presents to the emergency department with a $3$ -day history of progressively worsening shortness of breath. He reports that his breathing becomes particularly difficult when he lies down, forcing him to sleep in a recliner chair for the past two nights. His medical history is significant for moderate chronic obstructive pulmonary disease (COPD), type 2 diabetes mellitus, hypertension, and a myocardial infarction $3$ years ago. His current medications include an albuterol inhaler, metformin, lisinopril, and metoprolol. Temperature is $37.1^\circ\text{C}$ ( $98.8^\circ\text{F}$ ), blood pressure is $168/94\text{ mm Hg}$ , pulse is $108/\text{min}$ and regular, and respirations are $26/\text{min}$ . Pulse oximetry shows $86\%$ on room air. Jugular venous pressure is estimated at $12\text{ cm H}_2\text{O}$ . Chest auscultation reveals diffuse bilateral wheezing with a markedly prolonged expiratory phase; no focal crackles are heard. Cardiac auscultation reveals distant heart sounds, but a faint third heart sound (S3) is appreciated at the apex. Bilateral $2+$ pitting edema is present up to the mid-calves.

Laboratory results are as follows:
Sodium: $136\text{ mEq/L}$
Potassium: $4.0\text{ mEq/L}$
Chloride: $100\text{ mEq/L}$
Bicarbonate: $24\text{ mEq/L}$
Blood urea nitrogen: $25\text{ mg/dL}$
Serum creatinine: $1.2\text{ mg/dL}$
Thyroid-stimulating hormone (TSH): $6.5\text{ }\mu\text{U/mL}$ (Normal: $0.4-4.0$ )
Free T4: $1.1\text{ ng/dL}$ (Normal: $0.9-1.7$ )

Arterial blood gas (room air):
pH: $7.26$
$\text{PaCO}_2$ : $58\text{ mm Hg}$
$\text{PaO}_2$ : $54\text{ mm Hg}$

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

Intravenous furosemide

Systemic glucocorticoids and nebulized albuterol

Intravenous ceftriaxone and azithromycin

Intravenous sodium bicarbonate

Initiation of oral levothyroxine

Cevabı ve açıklamayı göster

Cevap: Intravenous furosemide

Cevap

The most appropriate next step is to administer intravenous furosemide to treat acute decompensated heart failure.

The patient's presentation of orthopnea, elevated jugular venous pressure, an S3 gallop, and bilateral lower extremity edema is highly characteristic of acute decompensated heart failure (ADHF). Although the patient has a history of COPD and presents with diffuse wheezing, this is a classic manifestation of 'cardiac asthma', where peribronchial fluid accumulation leads to airway narrowing. The arterial blood gas confirms a pure acute respiratory acidosis (for a

\text{PaCO}_2

increase of

18\text{ mm Hg}

above normal, the pH drops by

1.8 \times 0.08 \approx 0.14

, yielding an expected pH of

7.26

). Furthermore, the normal serum bicarbonate is inconsistent with a chronic COPD retainer, who would typically have a compensatory metabolic alkalosis. The most appropriate initial step in management is to reduce pulmonary congestion and preload with a loop diuretic, such as intravenous furosemide.

Adım Adım Çözüm

Analyze the physical examination findings to differentiate between possible causes of dyspnea and wheezing.

The presence of orthopnea, elevated jugular venous pressure (

12\text{ cm H}_2\text{O}

), an S3 gallop, and bilateral lower extremity edema points strongly to volume overload and acute decompensated heart failure.

While the patient has a history of COPD and diffuse wheezing, these findings represent 'cardiac asthma', where peribronchial edema causes airway narrowing.

Evaluate the arterial blood gas (ABG) to determine the acid-base status and calculate the expected compensation.

The ABG shows a primary respiratory acidosis (pH

7.26

\text{PaCO}_2

58\text{ mm Hg}

). For an acute respiratory acidosis, the pH drops by

0.08

for every

10\text{ mm Hg}

increase in

\text{PaCO}_2

. (

1.8 \times 0.08 = 0.144

; expected pH =

7.40 - 0.144 = 7.256

, which matches the patient's pH of

7.26

The pure acute respiratory acidosis with a normal bicarbonate (

24\text{ mEq/L}

) confirms this is an acute event, rather than an acute-on-chronic COPD exacerbation in a CO2 retainer (who would exhibit an elevated baseline bicarbonate).

Synthesize the clinical and laboratory data to determine the correct initial intervention.

The primary pathology is acute decompensated heart failure. The correct initial treatment involves loop diuretics to reduce pulmonary congestion.

Intravenous furosemide rapidly reduces preload and relieves the peribronchial edema causing the respiratory failure.

Anahtar Kavram

Patients with acute decompensated heart failure can present with wheezing (cardiac asthma) that mimics a COPD exacerbation; differentiation requires identifying signs of left and right ventricular failure (S3 gallop, elevated JVP, orthopnea) and interpreting acid-base status.

Soru 643Soru →

A 55-year-old woman is evaluated in the hospital on day 2 of admission for uncomplicated community-acquired pneumonia. She was initially started on intravenous ceftriaxone and azithromycin. Over the past 48 hours, her temperature has normalized from an admission peak of 38.9°C (102.0°F) to 37.2°C (99.0°F), and her respiratory effort has markedly improved. Two sets of peripheral blood cultures (four bottles total) were obtained in the emergency department prior to antibiotic administration. Today, the laboratory reports that one aerobic bottle from the first set is growing Staphylococcus epidermidis. The other three bottles exhibit no growth after 48 hours of incubation. The patient has no indwelling vascular catheters or prosthetic devices. Upon receiving the culture report, the cross-covering physician immediately adds intravenous vancomycin to the patient's regimen. Which of the following is the most appropriate next step in the management of this patient's pharmacotherapy?

Continue vancomycin, ceftriaxone, and azithromycin for a total of 14 days

Discontinue ceftriaxone and azithromycin, and proceed with vancomycin monotherapy

Discontinue vancomycin immediately and maintain the initial regimen for pneumonia

Replace vancomycin with intravenous daptomycin to target biofilm-producing organisms

Add oral rifampin to the current regimen to achieve synergy against the staphylococcal isolate

Cevabı ve açıklamayı göster

Cevap: Discontinue vancomycin immediately and maintain the initial regimen for pneumonia

Cevap

Discontinue vancomycin immediately and maintain the initial regimen for pneumonia

The isolation of Staphylococcus epidermidis, a coagulase-negative staphylococcus (CoNS), in only one of four blood culture bottles strongly suggests a specimen contaminant rather than true bacteremia. CoNS are ubiquitous skin commensals. When interpreting blood cultures, growth of typical skin flora in a single bottle (from multiple sets) in a patient without prosthetic material or central venous catheters should be considered a contaminant. Furthermore, the patient is experiencing rapid clinical improvement on her initial regimen (ceftriaxone and azithromycin) for community-acquired pneumonia, which does not effectively target CoNS. Therefore, the addition of vancomycin by the cross-covering physician was inappropriate. The most correct action aligned with antimicrobial stewardship is to discontinue the unnecessary vancomycin immediately to prevent drug toxicity and resistance.

Adım Adım Çözüm

Analyze the blood culture results in the context of the patient's presentation.

Only one out of four blood culture bottles grew Staphylococcus epidermidis (a Coagulase-Negative Staphylococcus).

Determining the number of positive bottles is crucial for distinguishing between true bacteremia and a skin contaminant.

Correlate the culture findings with the patient's clinical status and risk factors.

The patient is rapidly improving on her initial pneumonia treatment and lacks indwelling hardware or catheters that would predispose her to true CoNS infection.

Clinical improvement on a regimen that does not cover the cultured organism further supports that the isolate is a contaminant.

Determine the appropriate antimicrobial stewardship intervention.

The addition of vancomycin was an error; it must be discontinued immediately.

Treating a contaminant exposes the patient to unnecessary drug toxicity (e.g., nephrotoxicity) and drives antimicrobial resistance.

Anahtar Kavram

Interpretation of Coagulase-Negative Staphylococci (CoNS) in blood cultures and application of antimicrobial stewardship principles

Soru 644Soru →

A 65-year-old man is evaluated in the general internal medicine clinic prior to an elective colonoscopy with planned polypectomy. He has a history of a mechanical mitral valve replacement and takes warfarin daily. His target international normalized ratio (INR) is 2.5 to 3.5. The patient is considered to be at high risk for thromboembolism, and bridging therapy is indicated.

Arrange the following steps for periprocedural anticoagulation management in the correct chronological sequence.

Öğeleri doğru sıraya koymak için sürükleyin

Cevabı ve açıklamayı göster

Cevap

The correct chronological sequence is to first discontinue warfarin 5 days prior, then initiate bridging therapy with LMWH 3 days prior, then hold the LMWH dose 24 hours prior, and finally resume warfarin on the evening after the procedure.

The standard protocol for bridging high-risk patients on warfarin involves stopping warfarin on day -5 to allow INR normalization. Bridging with LMWH begins on day -3 as the INR falls subtherapeutic. The LMWH is held on day -1 (24 hours prior) to clear the anticoagulant effect before surgery. Finally, warfarin is resumed on day 0 (evening post-procedure) once hemostasis is secure.

Adım Adım Çözüm

Determine when to stop the primary oral anticoagulant.

Discontinue warfarin 5 days prior to the procedure.

Warfarin's long half-life requires 5 days for the INR to normalize and minimize perioperative bleeding risk.

Determine when to initiate bridging therapy.

Start LMWH approximately 3 days prior to the procedure.

Bridging is indicated for high-risk patients (e.g., mechanical mitral valve) and should begin when the INR drops below the therapeutic range.

Determine when to pause the bridging agent before the procedure.

Hold LMWH 24 hours before the procedure.

Therapeutic-dose LMWH must be held for a full 24 hours to ensure its anticoagulant effects have dissipated prior to an invasive procedure with bleeding risk.

Determine when to resume anticoagulation post-procedure.

Restart warfarin on the evening of or the day after the procedure.

Once adequate hemostasis is confirmed post-procedure, warfarin should be resumed immediately since it takes several days to achieve a therapeutic INR.

Anahtar Kavram

Periprocedural management of anticoagulation in high-risk patients requires stopping warfarin 5 days prior, bridging with LMWH when the INR falls, holding LMWH 24 hours before the procedure, and resuming warfarin post-procedure.

Soru 645Soru →

A 72-year-old man is brought to the emergency department by his daughter due to worsening confusion, dizziness, and recurrent spontaneous epistaxis over the past 48 hours. He also reports that his vision has become increasingly blurred. His medical history is notable for hypertension and mild chronic obstructive pulmonary disease. On physical examination, temperature is $37.2^\circ \text{C}$ ( $99.0^\circ \text{F}$ ), blood pressure is 145/88 mmHg, pulse is 92/min, and respirations are 16/min. Funduscopic examination reveals bilateral retinal hemorrhages and prominently dilated, tortuous retinal veins. Cardiopulmonary examination is unremarkable. Abdominal examination demonstrates a palpable spleen tip 4 cm below the left costal margin.

Laboratory evaluation shows:

Test	Result
Hemoglobin	8.2 g/dL
Mean corpuscular volume	89 fL
Platelets	140,000 /\mu\text{L}
Leukocytes	6,500 /\mu\text{L}
Blood urea nitrogen	18 mg/dL
Creatinine	1.1 mg/dL
Calcium	9.2 mg/dL
Total protein	11.2 g/dL
Albumin	3.4 g/dL

Serum protein electrophoresis demonstrates a large monoclonal spike in the gamma region. Subsequent immunofixation confirms the presence of an IgM monoclonal protein.

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

Administration of intravenous pamidronate

Intravenous administration of furosemide

Initiation of empiric vancomycin and cefepime

Urgent therapeutic plasma exchange

Consultation for urgent hemodialysis

Cevabı ve açıklamayı göster

Cevap: Urgent therapeutic plasma exchange

Cevap

Urgent therapeutic plasma exchange

The patient's presentation of confusion, dizziness, blurred vision, and mucosal bleeding (epistaxis) in the setting of an IgM monoclonal spike and a large gamma gap (Total protein - Albumin > 4 g/dL) is highly characteristic of Waldenström macroglobulinemia (WM) complicated by hyperviscosity syndrome. The pentameric structure of IgM makes it a very large molecule; high serum concentrations drastically increase blood viscosity, leading to sluggish microcirculation. This causes classic funduscopic findings such as dilated, tortuous retinal veins ('sausage-link' appearance) and retinal hemorrhages, as well as neurological symptoms and impaired platelet function. The most appropriate next step in management for acute, symptomatic hyperviscosity is urgent therapeutic plasma exchange (plasmapheresis). This intervention rapidly removes the heavy IgM molecules from the intravascular space, promptly relieving symptoms. Once the acute emergency is managed, definitive therapy targeting the underlying clonal B-cell population can be initiated.

Adım Adım Çözüm

Analyze the clinical presentation

The patient has confusion, dizziness, blurred vision, epistaxis, and dilated/tortuous retinal veins.

These are classic neurologic, visual, and bleeding manifestations of hyperviscosity syndrome.

Evaluate the laboratory findings

There is a large gamma gap (Total protein 11.2 - Albumin 3.4 = 7.8 g/dL) and a confirmed IgM monoclonal spike.

This confirms a diagnosis of Waldenström macroglobulinemia, which classically produces large pentameric IgM molecules that significantly increase serum viscosity.

Determine the appropriate acute management

The patient is highly symptomatic from hyperviscosity, requiring immediate intervention.

Therapeutic plasma exchange physically removes the large IgM molecules from the intravascular space, rapidly reversing the potentially fatal neurologic and bleeding complications.

Anahtar Kavram

Symptomatic hyperviscosity syndrome in Waldenström macroglobulinemia is a medical emergency that requires urgent therapeutic plasma exchange to mechanically clear IgM molecules.

Soru 646Soru →

A 68-year-old man is admitted to the hospital due to a 4-week history of progressively worsening lower back pain. The pain is localized to the lower lumbar area, is dull and constant, and frequently awakens him from sleep. It is not relieved by rest or over-the-counter ibuprofen. He has a history of type 2 diabetes mellitus and benign prostatic hyperplasia. Six weeks ago, he underwent a transurethral resection of the prostate. His temperature is $38.2^\circ\text{C}$ ( $100.8^\circ\text{F}$ ), blood pressure is $135/85\text{ mmHg}$ , pulse is $88/\text{min}$ , and respiratory rate is $14/\text{min}$ . Physical examination reveals exquisite point tenderness over the L4 and L5 spinous processes. Neurological examination of the lower extremities shows 5/5 motor strength, normal sensation, and 2+ symmetric deep tendon reflexes. Anal sphincter tone is normal. Laboratory studies show a leukocyte count of $11,500/\text{mm}^3$ , an erythrocyte sedimentation rate of $85\text{ mm/h}$ , and a C-reactive protein level of $72\text{ mg/L}$ . Magnetic resonance imaging of the lumbar spine reveals fluid in the L4-L5 intervertebral disc space with T2 hyperintensity and gadolinium enhancement of the adjacent vertebral endplates. Blood cultures are drawn on admission. Forty-eight hours later, the blood cultures show no growth, and the patient's clinical status remains unchanged. Which of the following is the most appropriate next step in management?

CT-guided needle biopsy of the intervertebral disc space

Initiation of intravenous vancomycin and cefepime

Initiation of oral ciprofloxacin

Urgent surgical decompression of the spinal cord

Prescription of naproxen and referral for physical therapy

Cevabı ve açıklamayı göster

Cevap: CT-guided needle biopsy of the intervertebral disc space

Cevap

CT-guided needle biopsy of the intervertebral disc space

The correct answer is CT-guided needle biopsy of the intervertebral disc space. The standard of care for a hemodynamically stable, neurologically intact patient with suspected native vertebral osteomyelitis (NVO) whose blood cultures are negative (or pending) is to withhold antimicrobial therapy and obtain a tissue diagnosis. An image-guided needle aspiration or biopsy of the disc space and adjacent vertebral bodies is necessary to isolate the causative pathogen. Because NVO requires a prolonged course of targeted antibiotics (typically 6 weeks or more), identifying the exact organism and its susceptibility profile is crucial. Starting empiric antibiotics prior to biopsy significantly decreases the yield of the bone/disc culture.

Adım Adım Çözüm

Interpret the patient's clinical presentation and imaging results.

The combination of worsening back pain, fever, elevated inflammatory markers, and characteristic MRI findings (T2 hyperintensity and endplate enhancement) strongly indicates vertebral osteomyelitis (discitis-osteomyelitis).

Establishing the primary diagnosis is necessary to guide the workup. The recent urologic procedure suggests hematogenous seeding.

Assess the patient's neurological and hemodynamic status.

The patient is hemodynamically stable and has a completely normal neurological examination with no signs of spinal cord compression or epidural abscess.

Neurological compromise or sepsis would necessitate immediate empiric antibiotic therapy or surgical intervention.

Determine the next diagnostic or therapeutic step given the negative blood cultures.

Because blood cultures are negative and the patient is stable, a tissue sample must be obtained via CT-guided needle biopsy of the disc space before starting any antibiotics.

Empiric antibiotics can sterilize the biopsy site, leading to a culture-negative result. A definitive microbiological diagnosis is critical for guiding the 6-to-8 week course of targeted antimicrobial therapy required for vertebral osteomyelitis.

Anahtar Kavram

In hemodynamically stable, neurologically intact patients with suspected native vertebral osteomyelitis and negative blood cultures, a CT-guided biopsy of the disc space/vertebra must be performed to obtain a microbiological diagnosis before initiating empiric antimicrobial therapy.

Tahmini Süre:1m 30s

Soru 647Soru →

An oncologist is evaluating a 67-year-old male who has been receiving chemotherapy for advanced pancreatic adenocarcinoma. The patient reports a two-day history of progressive swelling and a 'heavy, aching sensation' in his right calf. He denies chest pain, shortness of breath, or recent trauma to the area. His temperature is 37.0°C (98.6°F), blood pressure is 128/82 mmHg, heart rate is 92/min, and respiratory rate is 16/min. Physical examination reveals a right lower leg that is visibly enlarged, mildly erythematous, and tender to palpation along the popliteal fossa. The right calf circumference is 5 cm greater than the left calf. Which of the following is the most appropriate initial step in evaluating this patient's symptoms?

Lower extremity compression ultrasonography

Administration of intravenous furosemide

Prescription of broad-spectrum oral antibiotics

Measurement of serum thyroid-stimulating hormone level

Reassurance and instructions to elevate the leg

Cevabı ve açıklamayı göster

Cevap: Lower extremity compression ultrasonography

Cevap

Lower extremity compression ultrasonography

The correct answer is lower extremity compression ultrasonography. This patient presents with classic signs of a deep vein thrombosis (DVT), including acute unilateral calf swelling, mild erythema, and tenderness. His active pancreatic cancer and ongoing chemotherapy place him in a severely hypercoagulable state (Trousseau syndrome). In patients with a high pretest probability for DVT (e.g., Modified Wells score ≥ 2), the most appropriate initial diagnostic test is a venous duplex ultrasound (compression ultrasonography) to visualize the deep veins and check for lack of compressibility, which indicates a clot. D-dimer testing is not appropriate here as it is only useful for ruling out DVT in low-probability patients; it would almost certainly be elevated in a patient with metastatic cancer regardless of a clot's presence.

Adım Adım Çözüm

Analyze the patient's risk factors.

The patient has advanced pancreatic adenocarcinoma and is on active chemotherapy, placing him in a highly hypercoagulable state.

Malignancy is a major criterion in Virchow's triad for thrombosis risk.

Evaluate the clinical presentation.

The acute onset of unilateral, tender leg swelling with a >3 cm difference in calf circumference is highly specific for a deep vein thrombosis (DVT).

DVT must be the primary differential for any asymmetric lower extremity edema, especially with localized tenderness.

Determine the next best diagnostic step.

Compression ultrasonography is selected to confirm the presence of a venous thrombus.

Ultrasound is the safest, most rapid, and most accurate initial non-invasive test for suspected DVT.

Anahtar Kavram

Diagnosis of deep vein thrombosis in a hypercoagulable oncology patient.

Soru 648Soru →

During a routine clinic visit, a $71$ -year-old woman describes a $6$ -week history of profound stiffness in her shoulders, neck, and pelvic girdle. She reports that the stiffness is most severe upon awakening and typically lasts for $2$ to $3$ hours before gradually improving throughout the day. Over the past month, she has also experienced generalized fatigue and a $2$ -kg ( $4.4$ -lb) weight loss. She explicitly denies headaches, visual changes, scalp tenderness, and jaw pain with chewing. Her past medical history is notable for mild essential hypertension. Vital signs are within normal limits.

Physical examination reveals a well-appearing but visibly uncomfortable woman. There is no focal joint effusion, erythema, or warmth. Active range of motion in the shoulders and hips is limited by pain, but passive range of motion is fully preserved. Muscle strength is $5/5$ in the proximal and distal extremities.

Laboratory studies show:

Test	Result	Reference Range
Hemoglobin	$10.8$ g/dL	$12.0$ - $15.5$ g/dL
Leukocyte count	$7,500$ /mm $^3$	$4,500$ - $11,000$ /mm $^3$
Erythrocyte sedimentation rate	$88$ mm/h	$0$ - $20$ mm/h
Creatine kinase	$85$ U/L	$40$ - $150$ U/L
Thyroid-stimulating hormone (TSH)	$2.4$ $\mu$ U/mL	$0.5$ - $5.0$ $\mu$ U/mL

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

Perform a temporal artery biopsy

Administer intravenous ceftriaxone

Initiate low-dose oral prednisone therapy

Initiate levothyroxine therapy

Initiate fluoxetine therapy

Cevabı ve açıklamayı göster

Cevap: Initiate low-dose oral prednisone therapy

Cevap

Initiate low-dose oral prednisone therapy

The correct answer is to initiate low-dose oral prednisone therapy. This patient presents with the classic clinical triad for polymyalgia rheumatica (PMR): age greater than

50

years, bilateral aching and morning stiffness (lasting

>1

hour) in the proximal joint girdles (shoulders, neck, hips), and an elevated erythrocyte sedimentation rate (ESR). Furthermore, her normal creatine kinase level distinguishes this condition from inflammatory myopathies like polymyositis, where muscle weakness (rather than just pain-limited movement) and elevated muscle enzymes are prominent. Because she lacks any cranial symptoms (such as new-onset headache, visual disturbances, or jaw claudication), there is no clinical suspicion for concurrent giant cell arteritis (GCA). The gold-standard treatment for isolated PMR is low-dose oral glucocorticoids (e.g.,

10

20

mg of prednisone daily), which typically results in rapid, dramatic symptom relief within

24

72

hours.

Adım Adım Çözüm

Analyze the patient's demographic and clinical presentation.

A woman over age

50

presents with symmetric aching and prolonged morning stiffness (

>1

hour) in the shoulders and pelvic girdle, alongside systemic symptoms like fatigue and weight loss.

These are the hallmark clinical features of polymyalgia rheumatica (PMR).

Evaluate for 'red flag' symptoms of related conditions.

The patient explicitly denies headache, visual changes, scalp tenderness, and jaw claudication.

This rules out concurrent giant cell arteritis (GCA), meaning the patient has isolated PMR.

Interpret the laboratory findings to rule out mimics.

The ESR is markedly elevated (

88

mm/h), confirming systemic inflammation. Creatine kinase and TSH are normal.

Normal CK rules out inflammatory myopathies (e.g., polymyositis), and normal TSH rules out hypothyroid myopathy.

Determine the standard pharmacological intervention.

Select low-dose oral prednisone (

10

20

mg/day).

Isolated PMR is highly responsive to low-dose glucocorticoids, which serve as both a diagnostic aid and the primary treatment.

Anahtar Kavram

Diagnosis and management of isolated polymyalgia rheumatica (PMR)

Tahmini Süre:1m 15s

Soru 649Soru →

A hospital's clinical toxicology service is reviewing protocols for the acute management of various hazardous ingestions and exposures. For each patient presentation described below, match the clinical scenario and associated findings with the most appropriate specific pharmacological intervention.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Cevabı ve açıklamayı göster

Cevap

Match the sympathomimetic toxidrome with intravenous benzodiazepines, the beta-blocker toxicity with intravenous glucagon, the digoxin toxicity with digoxin-specific antibody fragments, and the cholinergic toxidrome with intravenous atropine followed by pralidoxime.

Each clinical scenario outlines a classic pattern of intoxication that corresponds to a unique and targeted pharmacological intervention. Recognizing the distinct pattern of vital sign derangements (e.g., bradycardia vs. tachycardia), pupillary changes (e.g., miosis vs. mydriasis), and specific metabolic abnormalities (e.g., hypoglycemia, hyperkalemia) allows for rapid selection of the correct antidote.

Adım Adım Çözüm

Analyze the first clinical presentation for key toxidrome features.

Identify a sympathomimetic toxidrome, requiring central sympathetic inhibition.

Benzodiazepines are the safest and most effective first-line agents for sympathomimetic-induced cardiovascular and central nervous system hyperactivity.

Analyze the second clinical presentation for key toxidrome features.

Identify beta-blocker toxicity (manifested by bradycardia, wheezing, and hypoglycemia), requiring receptor-independent inotropy.

Glucagon bypasses the blocked beta-receptors to directly activate adenylate cyclase in myocardial tissue.

Analyze the third clinical presentation for key toxidrome features.

Identify severe digoxin toxicity complicated by life-threatening hyperkalemia, requiring specific drug neutralization.

Digoxin-specific antibody fragments are definitively indicated for digoxin toxicity when accompanied by severe hyperkalemia or life-threatening arrhythmias.

Analyze the fourth clinical presentation for key toxidrome features.

Identify a cholinergic toxidrome (organophosphate poisoning), requiring both muscarinic and nicotinic reversal.

Atropine blocks the life-threatening muscarinic effects (such as bronchorrhea and bradycardia), while pralidoxime addresses the nicotinic effects (such as muscle fasciculations) by reactivating the inhibited cholinesterase enzyme.

Anahtar Kavram

Recognition of classic toxicological syndromes (toxidromes) based on vital sign derangements, pupillary findings, and specific laboratory abnormalities is essential for the timely administration of targeted, life-saving antidotes.

Soru 650Soru →

Match each of the following patient clinical vignettes to the most likely specific vasculitis diagnosis.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Cevabı ve açıklamayı göster

Cevap

The presentations match as follows: the c-ANCA positive patient with respiratory/renal disease matches Granulomatosis with polyangiitis; the p-ANCA positive asthmatic with foot drop matches Eosinophilic granulomatosis with polyangiitis; the Hepatitis B positive patient with abdominal angina matches Polyarteritis nodosa; the young pulseless woman matches Takayasu arteritis; and the child with purpura matches IgA vasculitis.

The diagnosis of systemic vasculitis relies heavily on recognizing distinct clinical syndromes. Granulomatosis with polyangiitis classically presents with upper respiratory tract disease, lower respiratory tract disease, and glomerulonephritis, alongside c-ANCA (PR3) positivity. Eosinophilic granulomatosis with polyangiitis is distinguished by asthma, allergic rhinitis, and eosinophilia, typically with p-ANCA (MPO) positivity. Polyarteritis nodosa is a medium-vessel vasculitis that typically spares the lungs, frequently involves the mesenteric and renal arteries, and has a known strong association with hepatitis B infection. Takayasu arteritis involves the aorta and its major branches, frequently causing arm claudication and absent pulses in young women. IgA vasculitis is the most common childhood vasculitis, recognized by the distinct tetrad of palpable purpura on gravity-dependent areas, arthralgia, abdominal pain, and renal involvement.

Adım Adım Çözüm

Analyze each patient's demographic profile, organ system involvement, and serological findings.

Identified unique patterns such as c-ANCA with lung/renal involvement, p-ANCA with asthma/neuropathy, Hepatitis B association, pulseless disease in a young woman, and a pediatric lower-extremity purpuric rash.

Systemic vasculitides are categorized by vessel size and present with distinct, recognizable syndromic clusters.

Match the identified syndromic clusters to the established diagnostic criteria for systemic vasculitides.

The vignettes correctly pair with their respective small, medium, and large vessel vasculitic syndromes.

Accurate diagnosis based on clinical and laboratory patterns dictates the specific therapeutic intervention and prognostic counseling.

Anahtar Kavram

Clinical recognition and differentiation of systemic vasculitides based on vessel size, specific organ involvement, demographic factors, and serological markers.

Soru 651Soru →

A 47-year-old woman is evaluated on her third day of hospitalization for community-acquired pneumonia. At the time of admission, empiric therapy with intravenous ceftriaxone and oral azithromycin was initiated. She currently feels much better, and her cough has significantly decreased. Vital signs are temperature 37.0°C (98.6°F), blood pressure 124/76 mm Hg, pulse 78/min, and respirations 14/min. Oxygen saturation is 98% on room air. Sputum culture collected prior to antibiotic administration now grows Streptococcus pneumoniae. Susceptibility testing indicates the isolate is highly susceptible to penicillin, ceftriaxone, macrolides, and respiratory fluoroquinolones. The patient is tolerating a regular diet and has adequate gastrointestinal absorption. Which of the following is the most appropriate next step in pharmacotherapy?

Transition to oral amoxicillin

Transition to oral moxifloxacin

Transition to oral linezolid

Transition to oral cefuroxime

Maintain the current regimen of intravenous ceftriaxone and oral azithromycin

Cevabı ve açıklamayı göster

Cevap: Transition to oral amoxicillin

Cevap

Transition to oral amoxicillin

The correct next step is to transition the patient to oral amoxicillin. This patient with community-acquired pneumonia has met the criteria for clinical stability (afebrile, normal heart rate, normal blood pressure, normal respiratory rate, and resolving symptoms) and is tolerating oral intake. Therefore, she should be transitioned from intravenous to oral antibiotics. Furthermore, her sputum culture grew Streptococcus pneumoniae that is susceptible to penicillin. The core principle of antibiotic stewardship requires narrowing the spectrum of coverage to the most targeted, effective agent once susceptibility data are available. High-dose oral amoxicillin is the preferred narrow-spectrum agent for penicillin-susceptible S. pneumoniae.

Adım Adım Çözüm

Assess the patient's clinical stability for transition to oral therapy.

The patient is afebrile, hemodynamically stable, has improving respiratory symptoms, and is tolerating a regular diet.

Intravenous to oral transition should occur as soon as the patient demonstrates clinical improvement and has functional gastrointestinal absorption to minimize catheter-related risks and facilitate discharge.

Evaluate the microbiology results and susceptibility data.

Sputum culture confirmed Streptococcus pneumoniae that is susceptible to penicillin and other standard agents.

Empiric broad-spectrum therapy must be de-escalated to a targeted regimen once a causative pathogen is identified and susceptibilities are known.

Select the most appropriate narrow-spectrum oral antibiotic.

Oral amoxicillin is chosen.

Amoxicillin provides excellent, narrow-spectrum coverage against penicillin-susceptible S. pneumoniae, aligning with the principles of antimicrobial stewardship by reducing the risk of resistance and adverse effects associated with broader agents.

Anahtar Kavram

Antibiotic stewardship in community-acquired pneumonia requires transitioning from broad-spectrum empiric intravenous therapy to targeted, narrow-spectrum oral therapy (such as amoxicillin for susceptible Streptococcus pneumoniae) once the patient is clinically stable and culture results are available.

Tahmini Süre:1m 15s

Soru 652Soru →

A 28-year-old woman presents to the clinic for evaluation of fatigue and decreased exercise tolerance over the past 3 months. She reports heavy menstrual periods lasting 7 to 8 days each month. She has no other medical conditions and takes no medications. Vital signs are within normal limits. Physical examination reveals pale conjunctivae.

Laboratory studies show:

Test	Result
Hemoglobin	9.2 g/dL
Mean corpuscular volume (MCV)	72 fL
White blood cell count	6,500/mm³
Platelet count	410,000/mm³

Which of the following laboratory findings is most likely to be present in this patient?

Decreased serum ferritin

Decreased total iron-binding capacity (TIBC)

Elevated hemoglobin A2 level

Normal red cell distribution width (RDW)

Positive direct antiglobulin test

Cevabı ve açıklamayı göster

Cevap: Decreased serum ferritin

Cevap

Decreased serum ferritin

The correct answer is decreased serum ferritin. This patient's history of heavy menses, combined with a microcytic anemia (low MCV) and a reactive thrombocytosis, strongly points to iron deficiency anemia (IDA). Ferritin is the primary intracellular iron-storage protein, and a decreased serum ferritin level is the most specific laboratory finding for confirming IDA. As iron stores are depleted from chronic blood loss, ferritin levels drop.

Adım Adım Çözüm

Analyze the patient's history and complete blood count (CBC) results.

The patient has a microcytic anemia (hemoglobin 9.2 g/dL, MCV 72 fL) with reactive thrombocytosis.

Identifying the type of anemia (microcytic, normocytic, or macrocytic) narrows down the differential diagnosis.

Correlate the microcytic anemia with the clinical presentation.

The most likely diagnosis is iron deficiency anemia due to chronic blood loss from menorrhagia.

Menorrhagia is a classic and common cause of iron loss leading to iron deficiency in premenopausal women.

Determine the expected confirmatory laboratory finding for the suspected diagnosis.

Decreased serum ferritin.

Ferritin represents body iron stores and is typically the first marker to decrease in iron deficiency, making it the most specific diagnostic test.

Anahtar Kavram

Iron deficiency anemia is the most common cause of microcytic anemia in premenopausal women with heavy menses and is characteristically confirmed by a decreased serum ferritin level.

Soru 653Soru →

A 31-year-old woman presents to her primary care clinic reporting persistent fatigue, generalized weakness, and cold intolerance that have progressively worsened over the past several months. She also notes that she has not menstruated since the birth of her daughter 10 months ago. Her pregnancy was uncomplicated, but her delivery was followed by a massive obstetric hemorrhage necessitating a massive transfusion protocol and emergency arterial embolization. Following the delivery, she was unable to produce breast milk.

Vital signs show a blood pressure of 88/54 mm Hg and a heart rate of 52/min. Physical examination reveals dry, pale skin and delayed relaxation of deep tendon reflexes. Visual fields are full to confrontation.

Laboratory studies reveal:

Test	Result	Reference Range
Thyroid-stimulating hormone (TSH)	0.2 µU/mL	0.4–4.0 µU/mL
Free thyroxine (T4)	0.4 ng/dL	0.9–1.7 ng/dL

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

Measure 8 AM serum cortisol level

Initiate levothyroxine monotherapy

Obtain serum thyroid peroxidase antibodies

Schedule a magnetic resonance imaging of the brain

Measure serum prolactin level

Cevabı ve açıklamayı göster

Cevap: Measure 8 AM serum cortisol level

Cevap

The most appropriate next step is to measure the 8 AM serum cortisol level.

The correct answer is to measure the 8 AM serum cortisol level. This patient's history of massive postpartum hemorrhage followed by amenorrhea, agalactia, and symptoms of hypothyroidism strongly suggests Sheehan syndrome (ischemic necrosis of the pituitary gland). The laboratory findings of low TSH and low free T4 confirm central hypothyroidism. Because Sheehan syndrome typically causes panhypopituitarism, this patient likely also has central adrenal insufficiency (decreased ACTH leading to decreased cortisol). It is a critical medical rule that in panhypopituitarism, the adrenal axis must be evaluated and replaced (with glucocorticoids) BEFORE initiating thyroid hormone replacement. Administering levothyroxine alone increases metabolic demand and hepatic clearance of cortisol, which can precipitate a fatal acute adrenal crisis.

Adım Adım Çözüm

Analyze the clinical history and physical exam findings.

The patient has fatigue, cold intolerance, amenorrhea, and agalactia following a severe postpartum hemorrhage.

This combination of multiaxial pituitary deficiencies following obstetric hemorrhage is pathognomonic for Sheehan syndrome (postpartum ischemic necrosis of the pituitary gland).

Interpret the laboratory results.

Both TSH and Free T4 are low.

This confirms central (secondary) hypothyroidism, consistent with panhypopituitarism, rather than primary hypothyroidism where TSH would be elevated.

Determine the safest sequencing of hormone replacement.

The adrenal axis must be evaluated (and treated if deficient) before treating the thyroid axis.

Levothyroxine increases the basal metabolic rate and accelerates the hepatic clearance of cortisol. In a patient with unrecognized central adrenal insufficiency, giving levothyroxine alone can precipitate an acute, life-threatening adrenal crisis.

Anahtar Kavram

In patients with suspected panhypopituitarism (e.g., Sheehan syndrome), adrenal insufficiency must be ruled out or treated prior to initiating levothyroxine therapy to prevent an iatrogenic adrenal crisis.

Soru 654Soru →

A 62-year-old woman is evaluated in the hospital on day 4 of admission. She initially presented to the emergency department with a 2-day history of high fever, chills, and severe right-sided back pain. On admission, her temperature was $39.2^\circ\text{C}$ ( $102.6^\circ\text{F}$ ), blood pressure was $110/70\text{ mmHg}$ , and heart rate was $115\text{/min}$ . Physical examination revealed pronounced right costovertebral angle tenderness. Laboratory studies showed a leukocyte count of $16,500\text{/mm}^3$ . She was started on empiric intravenous ceftriaxone.

On hospital day 2, her fever persisted. Urine culture grew $>10^5\text{ CFU/mL}$ of *Escherichia coli*. The isolate was identified as an extended-spectrum beta-lactamase (ESBL) producer. Antimicrobial susceptibility testing showed the following:

- Ceftriaxone: Resistant
- Cefepime: Resistant
- Piperacillin-tazobactam: Resistant
- Meropenem: Susceptible
- Ertapenem: Susceptible
- Ciprofloxacin: Susceptible
- Nitrofurantoin: Susceptible
- Fosfomycin: Susceptible

Her regimen was subsequently changed to intravenous ertapenem. Today (hospital day 4), the patient is afebrile, her flank pain has resolved, and her leukocyte count has normalized to $8,500\text{/mm}^3$ . She is tolerating a regular diet and is eager to be discharged.

Which of the following is the most appropriate antimicrobial regimen for discharge?

Oral ciprofloxacin

Oral nitrofurantoin

Oral fosfomycin

Intravenous ertapenem via a peripherally inserted central catheter

Oral cefdinir

Cevabı ve açıklamayı göster

Cevap: Oral ciprofloxacin

Cevap

The most appropriate regimen for discharge is oral ciprofloxacin.

The patient has acute pyelonephritis caused by an ESBL-producing E. coli. She has clinically improved on intravenous ertapenem and is ready for discharge. The ideal step-down therapy should be an oral agent that is active against the isolate and achieves high concentrations in the renal parenchyma. Fluoroquinolones, such as ciprofloxacin, have excellent oral bioavailability and tissue penetration. Because the susceptibility report explicitly shows the isolate is susceptible to ciprofloxacin, it is the safest and most appropriate oral option to complete her treatment course.

Adım Adım Çözüm

Diagnose the clinical condition and severity.

The patient presented with fever, flank pain, CVA tenderness, and leukocytosis, consistent with acute complicated pyelonephritis. She has now clinically resolved on intravenous therapy.

Establishing the diagnosis determines the required tissue penetration for the chosen antibiotic.

Analyze the microbiological data and susceptibility profile.

The pathogen is an ESBL-producing E. coli. While resistant to most beta-lactams, it is susceptible to carbapenems, fluoroquinolones, nitrofurantoin, and fosfomycin.

Identifying susceptible agents is the first step in selecting a step-down therapy.

Apply pharmacokinetic principles to rule out inappropriate susceptible agents.

Nitrofurantoin and fosfomycin are eliminated from consideration because they do not achieve adequate concentrations in the renal parenchyma.

An antibiotic must reach the site of infection; pyelonephritis requires renal tissue penetration, not just bladder concentration.

Apply antimicrobial stewardship principles to finalize selection.

Ciprofloxacin is selected over continuing intravenous ertapenem because it is highly bioavailable orally and effectively targets the susceptible organism.

Transitioning stable patients to appropriate oral therapy minimizes hospital stay length and reduces the risk of central line complications.

Anahtar Kavram

In patients with acute pyelonephritis who are clinically stable and ready for step-down therapy, highly bioavailable oral agents like fluoroquinolones are preferred if the isolate is susceptible. Nitrofurantoin and fosfomycin are contraindicated in pyelonephritis regardless of in vitro susceptibility due to inadequate renal tissue penetration.

Tahmini Süre:1m 30s

Soru 655Soru →

Match each patient's clinical presentation and laboratory coagulation profile to the most likely underlying hemostatic disorder.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Cevabı ve açıklamayı göster

Cevap

The correct matches correlate von Willebrand disease with combined primary and secondary hemostasis defects, Hemophilia A with a correctable prolonged aPTT, acquired factor VIII inhibitor with an uncorrectable prolonged aPTT, and DIC with consumptive coagulopathy.

Each clinical scenario presents a distinct coagulopathy. von Willebrand disease affects both primary hemostasis and factor VIII stability. Hemophilia represents a true factor deficiency that corrects with normal plasma. Acquired inhibitors neutralize coagulation factors, resisting correction in mixing studies. DIC causes global depletion of coagulation factors, fibrinogen, and platelets.

Adım Adım Çözüm

Analyze the bleeding pattern.

Mucocutaneous bleeding (epistaxis, menorrhagia) suggests a primary hemostatic defect, whereas deep tissue bleeding (hemarthrosis, large hematomas) suggests a secondary hemostatic (coagulation factor) defect.

Bleeding phenotype helps initially categorize the disorder.

Interpret the PT and aPTT.

An isolated prolonged aPTT points to the intrinsic pathway (factors VIII, IX, XI, XII). Prolongation of both PT and aPTT indicates a common pathway defect or consumptive process.

PT evaluates the extrinsic pathway, while aPTT evaluates the intrinsic pathway.

Evaluate the results of the mixing study for isolated prolonged aPTT.

Correction implies a factor deficiency, while failure to correct implies the presence of an inhibitor (such as an autoantibody).

Mixing studies differentiate between missing factors and neutralizing antibodies.

Anahtar Kavram

Interpretation of coagulation panels (PT, aPTT, bleeding time) and mixing studies to differentiate hemostatic disorders.

Soru 656Soru →

An otherwise healthy 24-year-old university student presents to the student health center reporting discomfort when urinating. Vital signs show a temperature of 37.0°C (98.6°F), blood pressure of 118/76 mmHg, and a heart rate of 78/min. She reports that she has been urinating more frequently than usual over the past 48 hours. She has not experienced any fevers, chills, nausea, back pain, or abnormal vaginal discharge. An abdominal examination demonstrates mild tenderness located just above the pubic symphysis, but there is no pain elicited upon percussion of the costovertebral angles bilaterally. A clean-catch urine specimen is analyzed and demonstrates positive results for both leukocyte esterase and nitrites. Which of the following is the most appropriate empiric pharmacotherapy for this patient?

Intravenous ceftriaxone

Oral amoxicillin-clavulanate

Oral ciprofloxacin

Oral nitrofurantoin

Oral moxifloxacin

Cevabı ve açıklamayı göster

Cevap: Oral nitrofurantoin

Cevap

Oral nitrofurantoin is the most appropriate empiric therapy.

The correct answer provides a narrow-spectrum antibiotic that achieves excellent concentrations in the lower urinary tract. This patient's presentation of dysuria, frequency, and suprapubic pain without systemic symptoms (fever, chills) or costovertebral angle tenderness is highly characteristic of acute uncomplicated cystitis. According to antibiotic stewardship guidelines, uncomplicated cystitis should be treated with first-line agents such as oral nitrofurantoin, trimethoprim-sulfamethoxazole, or fosfomycin. These medications effectively eradicate common uropathogens like Escherichia coli while minimizing collateral damage to the patient's normal flora and reducing the risk of community-wide antibiotic resistance.

Adım Adım Çözüm

Analyze the clinical presentation.

The patient has dysuria, urinary frequency, and suprapubic tenderness, with a urinalysis positive for nitrites and leukocyte esterase.

These findings are classic for acute uncomplicated cystitis (lower urinary tract infection).

Assess for signs of complicated infection or upper urinary tract involvement.

There is no fever, chills, nausea, or costovertebral angle (CVA) tenderness.

The absence of these signs rules out pyelonephritis, meaning aggressive or intravenous therapy is not indicated.

Apply antibiotic stewardship principles to select the best empiric pharmacotherapy.

Select a narrow-spectrum agent with high urinary concentration, such as oral nitrofurantoin.

First-line agents (nitrofurantoin, trimethoprim-sulfamethoxazole, or fosfomycin) effectively treat the infection while minimizing the risk of developing broad-spectrum antimicrobial resistance.

Anahtar Kavram

Acute uncomplicated cystitis should be treated empirically with first-line, narrow-spectrum agents (e.g., oral nitrofurantoin, trimethoprim-sulfamethoxazole, or fosfomycin) to promote antibiotic stewardship and avoid the unnecessary use of broad-spectrum antibiotics like fluoroquinolones.

Soru 657Soru →

A 26-year-old man comes to the clinic due to a 4-day history of right knee pain and swelling, as well as pain at the back of his left heel. He reports that the knee feels stiff in the morning and improves slightly as he moves around during the day. Four weeks ago, he experienced a brief episode of watery diarrhea, abdominal cramps, and a low-grade fever that resolved spontaneously after 3 days. He has no other medical conditions and takes no medications. He is sexually active with a new female partner and uses condoms inconsistently. His temperature is $37.2^\circ\text{C}$ ( $99.0^\circ\text{F}$ ), blood pressure is $118/76\text{ mmHg}$ , and pulse is $82/\text{min}$ . Physical examination shows a swollen, warm, and tender right knee with a palpable effusion. There is also pronounced tenderness over the insertion of the left Achilles tendon. Arthrocentesis of the right knee yields yellow, slightly cloudy synovial fluid with a leukocyte count of $22,000/\text{mm}^3$ ( $75\%$ neutrophils). Gram stain shows no organisms, and polarized light microscopy reveals no crystals. Which of the following is the most appropriate next step in management?

Oral naproxen

Intravenous ceftriaxone and vancomycin

Intravenous ceftriaxone and oral azithromycin

Oral ciprofloxacin

Oral allopurinol

Cevabı ve açıklamayı göster

Cevap: Oral naproxen

Cevap

Oral naproxen

The correct answer is oral naproxen. This patient's presentation of an acute, asymmetric monoarthritis (right knee) and enthesitis (Achilles tendon tenderness) following a self-limited diarrheal illness is highly characteristic of reactive arthritis. Reactive arthritis is an autoimmune spondyloarthropathy that typically develops 1 to 4 weeks after a gastrointestinal infection (e.g., Campylobacter, Salmonella, Shigella) or genitourinary infection (e.g., Chlamydia trachomatis). Synovial fluid analysis classically reveals an inflammatory effusion (leukocyte count between

2,000

and

50,000/\text{mm}^3

) with a negative Gram stain and culture, confirming that the joint is sterile. The first-line treatment for managing the acute symptoms of reactive arthritis is nonsteroidal anti-inflammatory drugs (NSAIDs) such as naproxen or ibuprofen.

Adım Adım Çözüm

Analyze the patient's history and timeline.

The patient developed an asymmetric monoarthritis and enthesitis (Achilles tendon tenderness) 4 weeks after an episode of acute gastroenteritis.

Establishing the sequence of an antecedent infection followed by sterile joint inflammation is key to diagnosing reactive arthritis.

Interpret the synovial fluid analysis.

The fluid has

22,000/\text{mm}^3

leukocytes (inflammatory but typically less than the

>50,000/\text{mm}^3

seen in septic arthritis), negative Gram stain, and no crystals.

This rules out crystal arthropathies (gout/pseudogout) and makes a bacterial septic arthritis highly unlikely, confirming an immune-mediated inflammatory process.

Determine the appropriate therapy for the diagnosed condition.

The diagnosis is reactive arthritis. The first-line therapy is nonsteroidal anti-inflammatory drugs (NSAIDs) such as naproxen.

Post-enteric reactive arthritis is a sterile autoimmune process; therefore, treating with NSAIDs is the standard of care to manage inflammation and pain.

Anahtar Kavram

Diagnosis and management of reactive arthritis

Soru 658Soru →

A 24-year-old man comes to the clinic with fever, myalgias, and a rash 14 days after high-risk sexual exposure. Acute human immunodeficiency virus (HIV) infection is suspected. Arrange the following steps of the HIV diagnostic and initial management algorithm in the correct chronological sequence, assuming each diagnostic test yields a result consistent with acute HIV infection.

Öğeleri doğru sıraya koymak için sürükleyin

Cevabı ve açıklamayı göster

Cevap

The correct chronological sequence is: 1) HIV-1/2 antigen/antibody combination immunoassay, 2) HIV-1/HIV-2 antibody differentiation immunoassay, 3) HIV-1 nucleic acid testing (NAT), 4) Obtain baseline CD4 cell count, viral load, and genotypic resistance testing, 5) Initiate antiretroviral therapy (ART).

The standard CDC algorithm for HIV testing begins with a 4th-generation HIV-1/2 antigen/antibody combination immunoassay. If positive, this is followed by an HIV-1/HIV-2 antibody differentiation immunoassay. In the setting of acute HIV infection, the differentiation assay is often negative or indeterminate because antibodies have not yet fully seroconverted. This requires resolution with an HIV-1 nucleic acid test (NAT) to detect viral RNA. Once acute HIV is confirmed, the standard of care is to immediately draw baseline labs (including CD4 count, viral load, and genotypic resistance testing) and subsequently initiate rapid or same-day antiretroviral therapy (ART) without waiting for the lab results.

Adım Adım Çözüm

Identify the recommended initial HIV screening test.

HIV-1/2 antigen/antibody combination immunoassay.

This 4th-generation test is highly sensitive for early infection as it detects the p24 antigen before antibodies fully develop.

Determine the confirmatory test following a positive initial screen.

HIV-1/HIV-2 antibody differentiation immunoassay.

This step confirms the positive screening result and distinguishes the viral type, which impacts subsequent treatment choices.

Identify the necessary test to resolve a discrepancy in early acute infection.

HIV-1 nucleic acid testing (NAT).

In acute HIV, antibodies may be absent, causing a negative or indeterminate differentiation assay. NAT detects viral RNA to definitively confirm acute infection.

Sequence the pre-treatment evaluation.

Obtain baseline CD4 cell count, viral load, and genotypic resistance testing.

These baseline labs must be drawn after diagnosis but prior to starting therapy to guide long-term management.

Determine the final clinical intervention.

Initiate antiretroviral therapy (ART).

ART should be started as soon as possible, ideally on the same day the diagnosis is confirmed, to reduce the viral reservoir and decrease transmission risk.

Anahtar Kavram

HIV Diagnostic Algorithm and Rapid Antiretroviral Therapy Initiation

Soru 659Soru →

A 35-year-old woman with a history of limited cutaneous systemic sclerosis presents to the clinic complaining of worsening pain and episodic color changes in her fingers. When she is exposed to cold air, her digits turn distinctly white, then blue, and eventually red. She is currently not taking any medications for this specific symptom but wants to know how her condition will be managed if it continues to progress. Arrange the following interventions in the standard step-wise escalating sequence for the management of secondary Raynaud phenomenon, from initial conservative management to treatments reserved for severe, refractory digital ischemia.

Öğeleri doğru sıraya koymak için sürükleyin

Cevabı ve açıklamayı göster

Cevap

The standard step-wise management of secondary Raynaud phenomenon begins with conservative lifestyle modifications, followed by oral calcium channel blockers as first-line pharmacotherapy. If symptoms persist, phosphodiesterase-5 inhibitors are added as second-line oral agents. Intravenous prostanoids are reserved for severe, refractory digital ischemia.

The correct sequence mirrors the standard clinical escalation for secondary Raynaud phenomenon, which balances therapeutic efficacy against the risk of adverse medication effects. Management universally starts with conservative lifestyle modifications. When pharmacologic intervention becomes necessary, oral dihydropyridine calcium channel blockers are the preferred first-line agents. For patients who remain symptomatic, second-line oral agents like phosphodiesterase-5 inhibitors are added. Highly potent, invasive therapies such as intravenous prostanoids are exclusively reserved as a last resort for severe, refractory digital ischemia complicated by impending tissue loss or active ulceration.

Adım Adım Çözüm

Identify the clinical presentation and underlying condition.

The patient has secondary Raynaud phenomenon driven by limited cutaneous systemic sclerosis.

Establishing the severity and secondary nature of the vasospasm dictates the need for a formal, step-wise treatment algorithm.

Determine the initial, least invasive intervention.

Cold avoidance and smoking cessation.

Conservative lifestyle modifications carry no adverse medication effects and are universally indicated as the foundation of therapy.

Identify the first-line and second-line pharmacotherapies.

Oral calcium channel blockers, followed by phosphodiesterase-5 inhibitors.

Dihydropyridine calcium channel blockers are the most effective initial oral vasodilators. PDE-5 inhibitors are the preferred add-on agents if monotherapy fails.

Identify the treatment for severe, refractory cases.

Intravenous prostanoids.

Due to their invasive route of administration and side effect profile, these are strictly reserved for organ-threatening or digit-threatening ischemic crises.

Anahtar Kavram

Step-wise management of secondary Raynaud phenomenon

Tahmini Süre:1m 0s

Soru 660Soru →

Match each immunocompromised patient scenario with the most appropriate antimicrobial prophylaxis or maintenance regimen.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Cevabı ve açıklamayı göster

Cevap

The correct pairings match Patient 1 with atovaquone monotherapy, Patient 2 with dapsone, pyrimethamine, and leucovorin, Patient 3 with isoniazid and pyridoxine, and Patient 4 with fluconazole monotherapy.

Each patient scenario is correctly matched to a regimen by assessing the pathogen targets required by the CD4 count and patient history, and then navigating the specific pharmacological contraindications (such as G6PD deficiency and severe sulfa allergies) to find the safest and most effective standard-of-care regimen.

Adım Adım Çözüm

Analyze Patient 1's profile: CD4 85 cells/mm³ with positive Toxoplasma IgG.

The patient requires primary prophylaxis for both Pneumocystis jirovecii and Toxoplasma gondii.

Guidelines recommend PCP prophylaxis at CD4 < 200 cells/mm³ and Toxoplasma prophylaxis at CD4 < 100 cells/mm³.

Evaluate Patient 1's contraindications: sulfa allergy and G6PD deficiency.

Atovaquone monotherapy is selected.

Trimethoprim-sulfamethoxazole cannot be used due to sulfa allergy. Dapsone cannot be used due to the high risk of oxidative hemolytic anemia in G6PD deficiency. Atovaquone covers both pathogens and is safe in G6PD deficiency.

Analyze Patient 2's profile: CD4 40 cells/mm³ with positive Toxoplasma IgG, sulfa allergy, but normal G6PD levels.

Dapsone, pyrimethamine, and leucovorin are selected.

With normal G6PD, dapsone is safe to use for PCP prophylaxis. Pyrimethamine is added for Toxoplasma coverage, and leucovorin prevents bone marrow suppression caused by pyrimethamine.

Analyze Patient 3's profile: Positive interferon-gamma release assay (IGRA) and clear chest radiograph.

Diagnosis is latent tuberculosis infection (LTBI); isoniazid and pyridoxine are selected.

Active TB must be ruled out before treating LTBI. The clear radiograph does this, making isoniazid plus pyridoxine the standard prophylactic treatment to prevent active disease.

Analyze Patient 4's profile: Completed induction therapy for cryptococcal meningoencephalitis.

Fluconazole monotherapy is selected for secondary prophylaxis.

Cryptococcal infection requires prolonged consolidation and maintenance (secondary prophylaxis) therapy with fluconazole to prevent relapse until immune reconstitution occurs with antiretroviral therapy.

Anahtar Kavram

Selection of appropriate opportunistic infection prophylaxis and maintenance therapy in immunocompromised patients, tailored to specific medication allergies and enzyme deficiencies.

ÖncekiSayfa 33 / 158Sonraki

Internal Medicine

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