All practice questions

8270 questions

All types8,270 Multiple choice4,249 Multiple select325 Numeric160 Matching1,849 Ordering1,687

Question 2021Question →

A 28-year-old woman with a known history of systemic lupus erythematosus (SLE) presents to the nephrology clinic with new-onset hypertension, progressive lower extremity edema, and foamy urine. Laboratory evaluation reveals a serum creatinine of 1.7 mg/dL, a serum albumin level of 2.6 g/dL, and a urine protein-to-creatinine ratio of 3.8 g/g. Urinalysis demonstrates dysmorphic red blood cells and red blood cell casts.

Assuming the patient initially follows a standard favorable clinical trajectory but eventually experiences a severe, treatment-resistant flare several years later, arrange the following clinical interventions in the correct chronological sequence of her long-term management.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct sequence is: 1) Renal biopsy, 2) Induction therapy, 3) Document response at 3-6 months, 4) Maintenance therapy, 5) Escalation for refractory relapse.

The standard sequence for managing active lupus nephritis requires establishing a histological baseline via biopsy before committing to highly toxic induction therapy. Induction (e.g., high-dose steroids and mycophenolate) aims to rapidly halt inflammation. The efficacy of this phase must be evaluated after 3 to 6 months. Once a response is documented, the patient is safely stepped down to maintenance therapy to minimize long-term toxicity. Finally, if the disease relapses and proves refractory years later, escalation to salvage agents like voclosporin or rituximab is indicated.

Step-by-Step Solution

Identify the need for a definitive tissue diagnosis in a patient presenting with signs of active, severe lupus nephritis.

Place the performance of a renal biopsy as the initial step.

Empiric treatment without classifying the specific WHO/ISN histological class is inappropriate, as the class dictates the treatment protocol.

Determine the immediate pharmacological management following histological confirmation of proliferative lupus nephritis.

Place the initiation of high-dose induction therapy as the second step.

Rapid, aggressive immunosuppression is required to halt immune-mediated renal damage and induce remission.

Establish the timeframe for evaluating the efficacy of the initial intense treatment phase.

Place the documentation of clinical response at 3 to 6 months as the third step.

Induction therapy regimens require several months to achieve maximal clinical effect; premature alteration of therapy should be avoided.

Select the appropriate ongoing management strategy once disease remission is achieved.

Place the transition to lower-dose maintenance therapy as the fourth step.

Maintenance therapy uses lower medication doses to sustain remission while reducing the risk of long-term toxicity, such as opportunistic infections.

Formulate a plan for a subsequent severe, treatment-resistant disease flare.

Place the escalation to calcineurin inhibitors or biologics as the final step.

Advanced, targeted therapies are reserved for salvage treatment in patients who eventually relapse and become refractory to standard regimens.

Key Concept

The standard management algorithm for proliferative lupus nephritis follows a strict sequence: diagnostic renal biopsy, intense induction therapy, formal assessment of response, transition to less toxic maintenance therapy, and ultimately, targeted escalation for refractory relapses.

Estimated Time:1m 30s

Question 2022Question →

A 68-year-old man with a history of castration-resistant metastatic prostate cancer is brought to the emergency department by his family. He reports a 5-day history of progressively worsening, severe thoracic back pain that is exacerbated by coughing and laying flat. Over the past 12 hours, he has developed profound weakness in both legs and an inability to urinate. His temperature is 37.2°C (99.0°F), blood pressure is 142/86 mmHg, and pulse is 92/min. Neurological examination reveals 2/5 motor strength in the bilateral lower extremities, decreased pinprick sensation below the umbilicus, and absent patellar and Achilles reflexes. Anal sphincter tone is markedly diminished. Post-void residual bladder volume is 600 mL.

Arrange the following management steps in the most appropriate chronological sequence for this patient:

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct chronological sequence is: 1) Administer high-dose intravenous dexamethasone, 2) Obtain an urgent MRI of the entire spine, 3) Review imaging findings with neurosurgery and radiation oncology, 4) Initiate definitive surgical decompression or external beam radiotherapy.

The correct sequence for managing suspected malignant epidural spinal cord compression (MESCC) with neurological deficits begins with immediate medical stabilization to preserve nerve function, followed by diagnostic imaging, and finally definitive therapy. When a patient presents with back pain and overt neurological deficits (such as paraparesis, a sensory level, and bowel/bladder dysfunction), the absolute first step is the administration of high-dose intravenous dexamethasone. This intervention reduces peritumoral vasogenic edema and immediately decreases pressure on the spinal cord. Once steroids are empirically administered, an urgent MRI of the entire spine is obtained to confirm the diagnosis and assess for multiple lesions. After the lesion is radiographically defined, multidisciplinary consultation with neurosurgery and radiation oncology is required to formulate a treatment plan. Finally, definitive treatment is executed, which involves surgical decompression or external beam radiotherapy depending on spinal stability and tumor histology.

Step-by-Step Solution

Recognize the clinical syndrome of an oncologic emergency.

The patient has malignant epidural spinal cord compression (MESCC) with active neurologic deficits (paraparesis, sensory level, urinary retention).

History of metastatic prostate cancer combined with progressive back pain and rapidly evolving myelopathy is the classic presentation of MESCC.

Determine the most urgent initial therapeutic intervention.

Administer high-dose intravenous dexamethasone immediately.

Corticosteroids rapidly reduce peritumoral vasogenic edema and decrease pressure on the spinal cord. They must be given immediately to prevent permanent paralysis before any diagnostic imaging delays.

Identify the confirmatory diagnostic test.

Obtain an urgent MRI of the entire spine.

MRI is the gold standard to localize the compression. The entire spine must be imaged because up to 30% of these patients have multiple concurrent asymptomatic epidural metastases.

Formulate a definitive treatment plan.

Consult specialists, then proceed with surgery or radiation.

Once the anatomy is defined on MRI, a multidisciplinary team determines if the patient is best suited for surgical decompression or targeted external beam radiotherapy.

Key Concept

In patients with suspected malignant epidural spinal cord compression presenting with neurological deficits, systemic glucocorticoids must be administered immediately prior to confirmatory imaging to preserve neurologic function.

Estimated Time:1m 30s

Question 2023Question →

A $34$ -year-old woman is brought to the emergency department by her partner due to confusion and difficulty speaking that began this morning. Over the past three days, she has experienced fatigue, generalized weakness, and subjective fever. She has no significant past medical history and takes no medications. Her temperature is $38.4^\circ\text{C}$ ( $101.1^\circ\text{F}$ ), blood pressure is $145/88\text{ mmHg}$ , pulse is $112/\text{min}$ , and respiratory rate is $18/\text{min}$ . Physical examination reveals scleral icterus and scattered petechiae over the lower extremities. Neurological examination is notable for fluctuating lethargy and expressive aphasia.

Laboratory studies show the following:

Laboratory Test	Result	Reference Range
Hemoglobin	$7.8\text{ g/dL}$	$12.0$ - $15.5\text{ g/dL}$
Mean corpuscular volume	$92\text{ fL}$	$80$ - $100\text{ fL}$
Platelets	$18,000/\text{mm}^3$	$150,000$ - $400,000/\text{mm}^3$
Leukocytes	$8,400/\text{mm}^3$	$4,500$ - $11,000/\text{mm}^3$
Blood urea nitrogen	$38\text{ mg/dL}$	$7$ - $18\text{ mg/dL}$
Serum creatinine	$2.4\text{ mg/dL}$	$0.6$ - $1.2\text{ mg/dL}$
Total bilirubin	$4.1\text{ mg/dL}$	$0.1$ - $1.2\text{ mg/dL}$
Indirect bilirubin	$3.2\text{ mg/dL}$	$0.1$ - $0.8\text{ mg/dL}$
Lactate dehydrogenase	$1,450\text{ U/L}$	$100$ - $250\text{ U/L}$
Prothrombin time	$13\text{ seconds}$	$11$ - $15\text{ seconds}$
Activated partial thromboplastin time	$32\text{ seconds}$	$25$ - $40\text{ seconds}$

A peripheral blood smear demonstrates numerous fragmented red blood cells. Which of the following is the most critical initial intervention for this patient?

Centrifugal separation of the patient's plasma and replacement with donor plasma

Transfusion of pooled donor apheresis platelets

Intravenous administration of broad-spectrum antimicrobial therapy

Intravenous infusion of pooled human immune globulin

Initiation of continuous venovenous hemofiltration

Show answer & explanation

Answer: Centrifugal separation of the patient's plasma and replacement with donor plasma

Answer

Centrifugal separation of the patient's plasma and replacement with donor plasma

The correct answer describes plasma exchange (plasmapheresis), which is the primary, life-saving treatment for Thrombotic Thrombocytopenic Purpura (TTP). TTP is a thrombotic microangiopathy typically caused by severely reduced activity of the von Willebrand factor (vWF)-cleaving protease ADAMTS13, most commonly due to an acquired autoantibody. This deficiency leads to the accumulation of ultra-large vWF multimers that consume platelets and form microthrombi in small blood vessels, causing diffuse end-organ ischemia. The classic pentad of TTP includes microangiopathic hemolytic anemia (MAHA), thrombocytopenia, acute kidney injury, neurologic changes, and fever. Immediate plasma exchange is therapeutic because it simultaneously removes the offending circulating ADAMTS13 autoantibodies and replenishes functional ADAMTS13 enzyme from the donor plasma.

Step-by-Step Solution

Analyze the clinical presentation and physical examination findings.

The patient presents with an acute onset of fever, altered mental status, expressive aphasia, and petechiae, indicating a systemic disease process involving the central nervous system and platelets.

Identifying the affected organ systems helps narrow the differential diagnosis for acute systemic illness.

Evaluate the laboratory values and peripheral blood smear.

Labs reveal severe thrombocytopenia, acute kidney injury, and non-immune hemolytic anemia (elevated LDH, indirect hyperbilirubinemia, and schistocytes). Coagulation studies (PT and aPTT) are strictly within normal limits.

Normal coagulation studies distinguish this microangiopathic process from Disseminated Intravascular Coagulation (DIC).

Synthesize the findings to formulate a definitive diagnosis.

The classic pentad of fever, neurological abnormalities, thrombocytopenia, microangiopathic hemolytic anemia, and renal insufficiency confirms the diagnosis of Thrombotic Thrombocytopenic Purpura (TTP).

Recognizing this pentad (or the essential dyad of MAHA and thrombocytopenia) is necessary to diagnose TTP, a true hematologic emergency.

Determine the most appropriate initial life-saving intervention.

Plasma exchange is the primary treatment, acting to remove the circulating ADAMTS13 autoantibodies and replenish the deficient functional enzyme.

Without immediate plasma exchange, mortality from TTP approaches 90% due to progressive organ ischemia.

Key Concept

Diagnosis and emergent management of Thrombotic Thrombocytopenic Purpura (TTP)

Question 2024Question →

A 26-year-old man presents to the clinic with a 4-day history of a severely swollen, painful right knee, bilateral conjunctival injection, and pain at the left posterior heel. He reports having had a severe diarrheal illness three weeks ago after a camping trip. The patient's vital signs are within normal limits. Arrange the following diagnostic and therapeutic steps in the optimal chronological sequence for managing this patient's condition.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct sequence of management for this patient begins with performing a diagnostic arthrocentesis to rule out joint infection. Once a sterile inflammatory fluid confirms the diagnosis of reactive arthritis, initial therapy with high-dose NSAIDs is started. If localized symptoms persist, intra-articular glucocorticoids are administered. Finally, if the disease becomes chronic (lasting more than 3-6 months), systemic therapy is escalated to DMARDs like sulfasalazine.

The correct sequence strictly follows the clinical algorithm for acute mono/oligoarthritis suspected to be reactive arthritis: immediate exclusion of a life-threatening or joint-destroying infection (arthrocentesis), formal diagnosis confirmation (sterile fluid + clinical triad), first-line systemic anti-inflammatory therapy (NSAIDs), step-up local therapy for refractory symptoms (intra-articular steroids), and long-term disease modification (DMARDs) if the condition becomes chronic.

Step-by-Step Solution

Perform diagnostic arthrocentesis of the right knee.

Evaluation of synovial fluid for cell count, Gram stain, and culture.

To definitively rule out septic arthritis, which is a critical diagnosis to exclude in any patient with a new-onset, acutely swollen joint.

Establish the clinical diagnosis of reactive arthritis.

Confirmation of the diagnosis based on the sterile inflammatory synovial fluid and the classic clinical features following an enteric infection.

Accurate diagnosis dictates the appropriate immunosuppressive or anti-inflammatory management pathway.

Initiate high-dose nonsteroidal anti-inflammatory drugs (NSAIDs).

Reduction of acute joint inflammation and symptomatic relief.

NSAIDs are the established first-line medical therapy for the acute phase of reactive arthritis.

Administer an intra-articular glucocorticoid injection.

Targeted suppression of localized inflammation in the right knee.

Indicated as step-up therapy when systemic NSAIDs provide inadequate relief for monoarticular or oligoarticular involvement.

Escalate to systemic disease-modifying antirheumatic drugs (DMARDs) such as sulfasalazine.

Long-term immune modulation and prevention of joint damage.

Indicated for the subset of patients whose reactive arthritis progresses to a chronic phase lasting beyond 3 to 6 months.

Key Concept

The sequential diagnostic and therapeutic pathway for reactive arthritis requires ruling out joint infection via arthrocentesis first, followed by step-wise medical management starting with NSAIDs, escalating to intra-articular steroids for refractory local disease, and utilizing DMARDs for chronic disease.

Question 2025Question →

Match each clinical presentation with its most characteristic peripheral blood smear finding.

Click a left item, then click its matching right item

Show answer & explanation

Answer

The asymptomatic older male with marked lymphocytosis matches with fragile leukocyte remnants (smudge cells). The patient with pancytopenia and circulating blasts matches with linear azurophilic granules (Auer rods). The young man with sulfa-induced hemolysis matches with semicircular erythrocyte defects (bite cells). The woman with confusion, fever, acute kidney injury, and thrombocytopenia matches with mechanically sheared erythrocytes (schistocytes).

Peripheral blood smear evaluation is critical for distinguishing hematologic pathologies. Smudge cells indicate the fragile monoclonal B-cells of CLL. Auer rods are pathognomonic for myeloblasts in AML. Bite cells indicate splenic phagocytosis of oxidized hemoglobin seen in G6PD deficiency. Schistocytes represent the mechanical destruction of erythrocytes characteristic of microangiopathic hemolytic anemias like TTP.

Step-by-Step Solution

Evaluate the first vignette describing an asymptomatic elderly patient with significant incidental lymphocytosis.

Diagnose Chronic Lymphocytic Leukemia (CLL), which pairs with smudge cells due to the characteristic fragility of the malignant lymphocytes.

Identifying the classic demographic and lab presentation of CLL isolates its specific morphologic marker.

Analyze the second vignette featuring pancytopenia and circulating blasts in a middle-aged adult.

Diagnose Acute Myeloid Leukemia (AML), which pairs with Auer rods.

Auer rods are pathognomonic for myeloblasts in AML and help distinguish it from acute lymphoblastic leukemia (ALL).

Assess the third vignette involving acute hemolysis triggered by a sulfa antibiotic.

Diagnose Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency, which pairs with bite cells (degmacytes).

Sulfa drugs induce oxidative stress in G6PD deficiency, causing Heinz body formation; splenic removal of these bodies produces bite cells.

Examine the final vignette showing the classic pentad of fever, neurologic changes, renal failure, and thrombocytopenia.

Diagnose Thrombotic Thrombocytopenic Purpura (TTP), which pairs with schistocytes.

TTP is a microangiopathic hemolytic anemia (MAHA) where microthrombi shear red blood cells as they pass through small vessels.

Key Concept

Recognizing the pathognomonic peripheral blood smear findings associated with highly tested hematologic and oncologic disorders.

Question 2026Question →

A $52$ -year-old man is evaluated for persistent fever. He was admitted $20$ days ago for acute myeloid leukemia induction chemotherapy, which resulted in profound bone marrow suppression. Ten days ago, his absolute neutrophil count dropped to $50/\text{mm}^3$ and he developed a fever of $39.1^\circ\text{C}$ ( $102.4^\circ\text{F}$ ). Blood cultures were drawn, and empiric intravenous cefepime was initiated. He remained febrile, and $5$ days ago, intravenous vancomycin was added.

Today, his temperature is $38.6^\circ\text{C}$ ( $101.5^\circ\text{F}$ ). He reports new-onset right-sided pleuritic chest pain. His absolute neutrophil count remains at $50/\text{mm}^3$ . Repeated blood cultures drawn prior to the initiation of antibiotics and $5$ days ago have shown no growth. A non-contrast computed tomography scan of the chest reveals a $3\text{ cm}$ dense macronodule surrounded by a halo of ground-glass attenuation in the right upper lobe. Serum galactomannan testing is strongly positive, and intravenous voriconazole is initiated.

Which of the following is the most appropriate next step regarding this patient's antibacterial regimen?

Continue cefepime and discontinue vancomycin

Discontinue both cefepime and vancomycin

Continue both cefepime and vancomycin

Switch cefepime to meropenem and continue vancomycin

Continue vancomycin and discontinue cefepime

Show answer & explanation

Answer: Continue cefepime and discontinue vancomycin

Answer

Continue cefepime and discontinue vancomycin

The correct approach is to continue cefepime and discontinue vancomycin. This patient has febrile neutropenia complicated by a new diagnosis of invasive pulmonary aspergillosis. According to IDSA guidelines, in high-risk patients with profound neutropenia (ANC < 500/mm³), the initial empiric antipseudomonal beta-lactam (in this case, cefepime) must be continued until the ANC recovers to ≥ 500/mm³ and is trending upward. This is crucial because the patient remains at extreme risk for rapidly fatal Gram-negative bacterial sepsis, regardless of whether a secondary fungal pathogen has been identified as the source of the prolonged fever. Conversely, vancomycin is not recommended for routine empiric therapy in febrile neutropenia unless specific indications exist. When added empirically for persistent fever, it should be promptly discontinued if blood cultures remain negative after 48-72 hours. Since this patient's cultures have been negative for 5 days, continuing vancomycin represents poor antibiotic stewardship.

Step-by-Step Solution

Identify the cause of the patient's persistent fever and new symptoms.

The patient has developed invasive pulmonary aspergillosis, evidenced by the chest CT 'halo sign' and strongly positive serum galactomannan assay.

Establishing the etiology of the fever is necessary to determine the appropriate targeted antimicrobial therapy (voriconazole).

Determine the required duration of empiric Gram-negative antibacterial therapy in this host.

Cefepime must be continued until the absolute neutrophil count recovers to at least 500/mm³.

Patients with profound neutropenia remain at extreme risk for life-threatening Gram-negative sepsis (e.g., Pseudomonas aeruginosa) from endogenous flora. Guidelines mandate continuing the empiric antipseudomonal beta-lactam until marrow recovery, even when a secondary fungal infection is diagnosed.

Apply antibiotic stewardship principles to the empiric Gram-positive coverage.

Vancomycin should be discontinued immediately.

Vancomycin was added empirically for persistent fever. Because blood cultures have remained sterile after 5 days, there is no evidence of a Gram-positive infection. Continuing it increases toxicity and the risk of resistance.

Key Concept

In febrile neutropenia, empiric antipseudomonal beta-lactam therapy must be continued until marrow recovery (ANC ≥ 500/mm³), even if a specific fungal pathogen is identified. Empiric vancomycin should be discontinued if blood cultures remain negative after 48-72 hours.

Question 2027Question →

Parents bring their 4-year-old boy to the clinic for a routine annual check-up. They report that he can successfully hop on one foot, copy a cross on a piece of paper, and play cooperatively in a group with other children. His speech is entirely understandable to strangers. However, the parents are worried because he cannot yet tie his own shoelaces and is unable to draw a person with six body parts. His physical examination is entirely unremarkable. Based on normal developmental milestones, which of the following is the most appropriate next step in management?

Obtain a formal occupational therapy assessment for delayed fine motor skills

Counsel the parents that these missing skills typically emerge at age five

Arrange for a comprehensive speech and language evaluation

Administer a standardized autism spectrum screening questionnaire

Perform a targeted genetic microarray analysis for global developmental delay

Show answer & explanation

Answer: Counsel the parents that these missing skills typically emerge at age five

Answer

Counsel the parents that these missing skills typically emerge at age five

The child's current skills (hopping on one foot, copying a cross, cooperative play, and 100% speech intelligibility) perfectly align with normal 4-year-old developmental milestones. Tying shoelaces and drawing a person with at least six body parts are milestones expected at 5 years of age. Therefore, the absence of these advanced skills in a 4-year-old is entirely normal and requires only parental education, not further workup or specialty referral.

Step-by-Step Solution

Analyze the child's current achieved milestones based on his chronological age.

The 4-year-old boy can hop on one foot (gross motor), copy a cross (fine motor), play cooperatively (social), and has 100% intelligible speech (language).

Establishing the child's current developmental age equivalent is required to identify any potential delays.

Evaluate the specific milestones the parents are concerned about.

The parents are concerned about the inability to tie shoelaces and draw a person with six body parts.

Comparing parental concerns against standardized developmental expectations determines if intervention is needed.

Determine the expected age for the missing milestones and formulate a management plan.

Tying shoelaces and drawing a 6-part person are classic 5-year-old milestones. Since the child is completely normal for a 4-year-old, the correct management is anticipatory guidance.

Unnecessary referrals or testing should be avoided when a child's development falls perfectly within normal limits.

Key Concept

Normal pediatric developmental milestones (4 to 5 years of age)

Question 2028Question →

Match each pediatric patient's clinical presentation with the most appropriate next step in management.

Click a left item, then click its matching right item

Show answer & explanation

Answer

The correct matches pair the 10-month-old with persistent Moro and early handedness to neuroimaging; the 16-month-old late walker to anticipatory guidance; the 30-month-old with Gowers sign to muscle enzyme analysis; and the 24-month-old with isolated language delay to hearing assessment.

Each presentation requires interpreting a constellation of milestones to determine if a delay is an expected normal variant or a pathological red flag requiring a targeted workup. Early handedness indicates focal neurologic injury requiring neuroimaging; late walking up to 18 months without other delays is normal; Gowers sign indicates proximal myopathy requiring muscle enzymes; and isolated language delay necessitates ruling out hearing loss.

Step-by-Step Solution

Analyze the 10-month-old's findings (persistent Moro reflex, early handedness, poor trunk control).

Identified as red flags for focal neurologic deficit (spastic hemiplegic cerebral palsy).

Early handedness before 18 months is always abnormal and indicates contralateral weakness, requiring an MRI.

Evaluate the 16-month-old's motor delay against normal limits.

Identified as a normal variation because independent walking can normally be achieved up to 18 months.

Since fine motor, language, and social domains are appropriately developed, anticipatory guidance is the correct step.

Assess the 30-month-old's method of standing and frequent tripping.

Recognized Gowers sign, indicating proximal muscle weakness.

This is a classic presentation of Duchenne muscular dystrophy, which is initially screened using a serum creatine kinase level.

Determine the workup for the 24-month-old with 4 words and normal play.

Identified isolated expressive language delay.

Any child with speech or language delay must undergo formal audiometry as the first step to rule out hearing impairment.

Key Concept

Differentiating normal developmental variation from red flags requiring specific diagnostic workup (e.g., MRI for early handedness, audiometry for isolated speech delay, CK for Gowers sign).

Question 2029Question →

A 62-year-old woman is evaluated in the emergency department for a 24-hour history of confusion and fever. She was brought from a skilled nursing facility where she is recovering from an ischemic stroke. Her medical history includes chronic obstructive pulmonary disease (COPD) and diet-controlled type 2 diabetes mellitus. Medications include aspirin and inhaled tiotropium.

Vital signs are temperature 38.6°C (101.5°F), blood pressure 82/50 mm Hg, pulse 122/min, and respirations 24/min. Pulse oximetry is 94% on room air.

Physical examination reveals a lethargic and disoriented patient. Mucous membranes are dry. Lung auscultation reveals mild, diffuse end-expiratory wheezing without crackles. Cardiac examination shows tachycardia with a regular rhythm. The abdomen is soft, but right costovertebral angle tenderness is present.

Laboratory results are as follows:
Leukocytes: 16,500/mm³ (15% bands)
Sodium: 138 mEq/L
Potassium: 4.8 mEq/L
Bicarbonate: 16 mEq/L
Creatinine: 2.1 mg/dL (baseline 0.9 mg/dL)
Lactate: 4.2 mmol/L
TSH: 0.1 mU/L (Normal 0.4-4.0 mU/L)
Free T4: 0.6 ng/dL (Normal 0.9-1.7 ng/dL)

Arterial blood gas on room air:
pH: 7.30
PaCO2: 32 mm Hg
PaO2: 78 mm Hg

A urine culture collected 2 days ago at the nursing facility for dysuria has just resulted, showing >100,000 CFU/mL of *Escherichia coli* sensitive to ceftriaxone, ciprofloxacin, and nitrofurantoin.

A chest radiograph shows hyperinflated lungs and flattened diaphragms with no focal consolidations or pulmonary venous congestion.

The patient is immediately started on intravenous ceftriaxone. Over the next 2 hours, she receives 3 liters of intravenous normal saline. Reassessment shows a blood pressure of 78/48 mm Hg and a pulse of 118/min.

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

Initiate intravenous norepinephrine

Switch antibiotic therapy to intravenous meropenem

Administer intravenous furosemide

Administer intravenous sodium bicarbonate

Initiate intravenous levothyroxine

Show answer & explanation

Answer: Initiate intravenous norepinephrine

Answer

Initiate intravenous norepinephrine

This patient is presenting with septic shock secondary to acute pyelonephritis. According to Surviving Sepsis Campaign guidelines, initial resuscitation for sepsis with hypotension or a lactate ≥ 4.0 mmol/L requires rapid administration of at least 30 mL/kg of intravenous crystalloids. This patient received 3 liters of normal saline (adequate for an average adult) but remains profoundly hypotensive with a blood pressure of 78/48 mm Hg (Mean Arterial Pressure [MAP] =

58

mm Hg). For fluid-refractory septic shock, the immediate next step is the initiation of vasopressors to maintain a MAP

\geq 65

mm Hg. Norepinephrine is the first-line vasopressor of choice.

Step-by-Step Solution

Diagnose the primary condition

The patient has septic shock secondary to pyelonephritis, evidenced by fever, CVA tenderness, leukocytosis, positive urine culture, lactic acidosis, and severe hypotension.

Identifying the etiology of the shock state is necessary to guide appropriate resuscitation and antimicrobial therapy.

Evaluate the response to initial therapy

The patient received 3 liters of intravenous crystalloid (standard 30 mL/kg fluid challenge for sepsis), but her blood pressure remains 78/48 mm Hg (MAP = 58 mm Hg).

Hemodynamic reassessment determines if the patient is fluid-responsive or fluid-refractory.

Determine the next pharmacological intervention

Initiate a vasopressor (norepinephrine) to achieve a target MAP of ≥ 65 mm Hg.

In fluid-refractory septic shock, vasopressors are indicated immediately after adequate fluid resuscitation to prevent prolonged organ hypoperfusion.

Key Concept

Management of fluid-refractory septic shock

Estimated Time:1m 30s

Question 2030Question →

A physician is asked to evaluate a hospitalized $72$ -year-old male on postoperative day $4$ following an emergency exploratory laparotomy and small bowel resection for a strangulated hernia. Overnight, he developed an acute fever of $38.4^\circ\text{C}$ ( $101.1^\circ\text{F}$ ) and excruciating pain in his right knee.

The patient has a history of hypertension and chronic kidney disease, with a baseline serum creatinine of $2.1\text{ mg/dL}$ . He is currently receiving continuous intravenous fluids and is transitioning to a clear liquid diet.

On physical examination, his vital signs are stable aside from the fever. The right knee is markedly swollen, uniformly erythematous, warm, and exquisitely tender to light palpation. He refuses to range the joint. The surgical incision site is clean, dry, and intact with no surrounding erythema or induration.

Arthrocentesis of the right knee is performed, yielding $5\text{ mL}$ of cloudy yellow fluid. Synovial fluid analysis reveals:

- Leukocyte count: $45,000/\text{mm}^3$ ( $85\%$ neutrophils)
- Gram stain: No organisms seen
- Crystal analysis: Negatively birefringent, needle-shaped crystals

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

Administer an intra-articular injection of triamcinolone

Initiate empiric intravenous vancomycin and ceftriaxone

Obtain a computed tomography scan of the abdomen and pelvis

Prescribe oral indomethacin

Administer intravenous furosemide

Show answer & explanation

Answer: Administer an intra-articular injection of triamcinolone

Answer

The most appropriate next step in management is to administer an intra-articular injection of triamcinolone.

The correct answer involves administering an intra-articular glucocorticoid injection. This patient has an acute gout flare, definitively diagnosed by the negatively birefringent, needle-shaped crystals. A key principle in rheumatology is tailoring acute flare management to the patient's comorbidities. This patient has advanced chronic kidney disease (precluding the use of NSAIDs like indomethacin) and is recovering from a major intestinal resection (making oral colchicine poorly tolerated and systemic glucocorticoids risky due to potential impairment of anastomotic healing). Intra-articular triamcinolone provides rapid, localized relief without significant systemic side effects.

Step-by-Step Solution

Diagnose the underlying condition based on synovial fluid analysis.

The presence of negatively birefringent, needle-shaped crystals confirms acute monosodium urate crystal arthropathy (gout).

Accurate diagnosis is required to distinguish crystal arthropathy from septic arthritis, as both can present with high synovial leukocyte counts and fever.

Evaluate the safety profile of standard gout therapies against the patient's comorbidities.

NSAIDs are contraindicated due to chronic kidney disease (Cr 2.1 mg/dL). Colchicine is high-risk in CKD and post-bowel resection. Systemic steroids could impair surgical anastomotic healing.

Pharmacotherapy for acute gout must be individualized to prevent severe iatrogenic complications like acute kidney injury or bowel perforation.

Select the optimal targeted therapy.

Intra-articular glucocorticoid injection is selected.

It provides powerful, localized anti-inflammatory effects with minimal systemic absorption, making it the safest choice for this complex postoperative patient.

Key Concept

The management of acute monoarticular gout in patients with significant comorbidities (such as chronic kidney disease or recent gastrointestinal surgery) requires targeted local therapy, such as intra-articular glucocorticoids, to avoid the severe systemic toxicities associated with NSAIDs, colchicine, and systemic steroids.

Estimated Time:1m 30s

Question 2031Question →

A 24-year-old man comes to the clinic complaining of lower back pain that has progressively worsened over the past 7 months. He states that the pain is most severe when he wakes up in the morning and is associated with profound stiffness that lasts for about 2 hours. The discomfort noticeably improves after he goes for a jog or stretches, but it does not improve with rest. He has no history of trauma or recent infections. Vital signs are within normal limits. Physical examination reveals reduced forward flexion of the lumbar spine. An anteroposterior radiograph of the pelvis demonstrates bilateral sclerosis and joint space narrowing of the sacroiliac joints. Which of the following is the most appropriate initial pharmacotherapy for this patient's condition?

Nonsteroidal anti-inflammatory drugs

Tumor necrosis factor-alpha inhibitors

Systemic corticosteroids

Acetaminophen

Intravenous broad-spectrum antibiotics

Show answer & explanation

Answer: Nonsteroidal anti-inflammatory drugs

Answer

Nonsteroidal anti-inflammatory drugs are the first-line medical therapy for ankylosing spondylitis.

The patient's clinical presentation of chronic, insidious-onset lower back pain that is worse in the morning, improves with exercise, and is accompanied by radiographic evidence of sacroiliitis is highly characteristic of ankylosing spondylitis. For patients with active ankylosing spondylitis, continuous treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) is the most appropriate first-line pharmacologic therapy. NSAIDs are highly effective in reducing pain, decreasing morning stiffness, and improving overall mobility in these patients.

Step-by-Step Solution

Identify the primary clinical syndrome based on the history.

A young male with chronic lower back pain, severe morning stiffness, and improvement with physical activity but not with rest.

These classic features differentiate inflammatory back pain from mechanical back pain.

Interpret the radiographic findings.

Bilateral sclerosis and joint space narrowing of the sacroiliac joints (sacroiliitis).

Confirms the diagnosis of ankylosing spondylitis when combined with the clinical presentation of inflammatory back pain.

Determine the standard initial pharmacotherapy for this diagnosis.

Nonsteroidal anti-inflammatory drugs (NSAIDs).

Continuous use of NSAIDs is the established first-line treatment to reduce pain and stiffness in axial spondyloarthritis.

Key Concept

Ankylosing spondylitis is characterized by inflammatory back pain and sacroiliitis, and continuous NSAID therapy is the most appropriate initial pharmacologic treatment.

Question 2032Question →

Emergency medical services arrive with a $22$ -year-old university student who intentionally ingested a large quantity of analgesic medication following a dispute. According to her roommate, she swallowed approximately $30$ tablets of $500$ -mg acetaminophen exactly $45$ minutes ago. The patient is visibly distressed and reports mild nausea, but denies vomiting, abdominal pain, or other symptoms. Vital signs include a temperature of $37.0^\circ\text{C}$ ( $98.6^\circ\text{F}$ ), blood pressure of $118/75$ mm Hg, pulse of $88$ /min, and respiratory rate of $16$ /min. The physical examination is notable only for a flat, non-tender abdomen and no focal neurologic deficits. Arrange the clinical interventions below in the correct chronological sequence to appropriately evaluate and manage this patient's toxic exposure.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct chronological sequence is: Administer oral activated charcoal, measure serum acetaminophen concentration at 4 hours post-ingestion, evaluate the level using the Rumack-Matthew nomogram, and finally initiate intravenous N-acetylcysteine therapy if indicated.

The algorithm for acute acetaminophen ingestion emphasizes exact timing. Within

1

2

hours of ingestion, activated charcoal should be administered to decrease gastrointestinal absorption. Serum acetaminophen levels must be checked no earlier than

4

hours post-ingestion to ensure complete drug absorption and to capture the peak level. This

4

-hour level is subsequently plotted on the Rumack-Matthew nomogram to determine the patient's risk of hepatotoxicity. If the plotted level falls on or above the established treatment line, definitive therapy with intravenous N-acetylcysteine is initiated. Because N-acetylcysteine is maximally effective at preventing liver injury when started within

8

hours of ingestion, waiting for the

4

-hour level in this early-presenting patient does not delay necessary care or increase her clinical risk.

Step-by-Step Solution

Determine the time elapsed since ingestion.

The patient presented

45

minutes post-ingestion.

The time elapsed strictly dictates the utility of gastrointestinal decontamination and the appropriate timing for drawing serum drug levels.

Assess indications for immediate gastrointestinal decontamination.

Oral activated charcoal is administered first.

Activated charcoal is highly effective at reducing systemic absorption if administered within

1

2

hours of an acute acetaminophen ingestion in an awake patient.

Determine the optimal timing for laboratory evaluation.

Wait until

4

hours post-ingestion to measure the serum acetaminophen level.

Acetaminophen absorption continues for several hours. Levels measured before the

4

-hour mark are uninterpretable because they do not reflect the true peak concentration.

Analyze the laboratory results to guide definitive therapy.

Plot the

4

-hour level on the Rumack-Matthew nomogram and initiate N-acetylcysteine if the result falls above the treatment line.

The nomogram accurately predicts the risk of liver injury. N-acetylcysteine is nearly

100\%

effective at preventing hepatotoxicity if started within

8

hours of ingestion, allowing ample time to wait for accurate lab results.

Key Concept

The management algorithm for acute acetaminophen toxicity depends strictly on the time since ingestion: immediate activated charcoal for early presenters (

< 2

hours), followed by a

4

-hour serum level plotted on the Rumack-Matthew nomogram to direct subsequent N-acetylcysteine therapy.

Question 2033Question →

A $65$ -year-old man comes to the clinic reporting progressive fatigue, weakness, and a "pins and needles" sensation in his feet for the past $4$ months. His past medical history is significant for type $2$ diabetes mellitus, for which he has been taking metformin for $10$ years. Vital signs are within normal limits. Physical examination reveals pale conjunctivae and decreased vibratory sensation in the bilateral toes and ankles.

Laboratory studies show:

Test	Result	Reference Range
Hemoglobin	$10.2$ g/dL	$13.5-17.5$ g/dL
Mean corpuscular volume	$112$ fL	$80-100$ fL
Leukocyte count	$5,500$ /mm³	$4,500-11,000$ /mm³
Platelet count	$180,000$ /mm³	$150,000-400,000$ /mm³

Which of the following is the most appropriate next step in the evaluation of this patient's anemia?

Measurement of serum vitamin B12 and folate levels

Measurement of serum iron, total iron-binding capacity, and ferritin levels

Hemoglobin electrophoresis

Upper gastrointestinal endoscopy

Bone marrow aspiration and biopsy

Show answer & explanation

Answer: Measurement of serum vitamin B12 and folate levels

Answer

Measurement of serum vitamin B12 and folate levels

The correct answer is measurement of serum vitamin B12 and folate levels. This patient presents with a classic picture of macrocytic anemia (MCV >

100

fL) accompanied by peripheral neuropathy (diminished vibratory sensation). Long-term use of metformin is a well-established risk factor for vitamin B12 deficiency due to interference with calcium-dependent absorption of the B12-intrinsic factor complex in the terminal ileum. The next best step in the workup of macrocytic anemia is to check serum B12 and folate levels to distinguish between the two most common megaloblastic causes.

Step-by-Step Solution

Analyze the patient's laboratory findings.

The patient has anemia (hemoglobin

10.2

g/dL) with an elevated MCV (

112

fL), indicating a macrocytic anemia.

Identifying the morphological classification of anemia (microcytic, normocytic, macrocytic) directs the diagnostic algorithm.

Correlate the laboratory findings with the clinical presentation.

The patient presents with progressive fatigue and peripheral neuropathy (decreased vibratory sensation). He also has a history of long-term metformin use.

Macrocytic anemia combined with neurologic deficits strongly suggests vitamin B12 deficiency. Metformin is known to interfere with vitamin B12 absorption in the terminal ileum.

Determine the most appropriate next diagnostic step based on the suspected etiology.

The initial step in confirming suspected megaloblastic macrocytic anemia is measuring serum vitamin B12 and folate levels.

Definitive diagnosis requires biochemical confirmation before initiating therapy or pursuing more invasive investigations.

Key Concept

Evaluation of macrocytic anemia requires initial measurement of serum vitamin B12 and folate levels, particularly in patients with neurologic symptoms or risk factors such as chronic metformin use.

Estimated Time:1m 0s

Question 2034Question →

A 52-year-old restaurant manager comes to the clinic due to sudden, excruciating pain and swelling in his left big toe that woke him up from sleep. He reports having two similar episodes over the past twelve months that eventually resolved after taking various over-the-counter pain relievers. His past medical history is notable for hypertension and obesity. Vital signs are stable and within normal limits. Physical examination reveals a markedly erythematous, warm, swollen, and exquisitely tender left first metatarsophalangeal joint. Arrange the following clinical steps in the most appropriate chronological sequence for the optimal evaluation and long-term management of this patient's condition.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct chronological sequence is: diagnostic arthrocentesis, followed by acute symptom management (NSAIDs/colchicine), then initiation of urate-lowering therapy (allopurinol), and finally long-term titration to a target serum urate level.

The standard sequence for managing a patient presenting with an acute, likely crystal-induced monoarthritis and a history of recurrent flares is to first establish a definitive diagnosis by excluding infection through arthrocentesis. Once confirmed, the immediate goal is suppressing acute inflammation using NSAIDs, colchicine, or systemic glucocorticoids. Because this patient has experienced multiple flares over the past twelve months, he is a candidate for long-term urate-lowering therapy such as allopurinol. Finally, the long-term goal is to titrate this therapy to maintain a serum urate concentration below 6.0 mg/dL in order to dissolve existing crystals and prevent future acute attacks.

Step-by-Step Solution

Identify the suspected diagnosis based on the clinical presentation.

The acute onset of severe pain, warmth, and swelling in the first metatarsophalangeal joint (podagra) is highly suggestive of an acute gout flare.

Recognizing the classic presentation guides the initial diagnostic and therapeutic approach.

Determine the first step in management.

Arthrocentesis with synovial fluid analysis should be performed first.

It is essential to confirm the presence of monosodium urate crystals and definitively rule out septic arthritis, a joint-threatening emergency, before assuming a purely inflammatory etiology.

Select the appropriate acute therapy.

Administer oral naproxen or colchicine.

Acute gout flares are treated with potent anti-inflammatory agents to provide rapid symptom relief and restore patient mobility.

Formulate a long-term preventive strategy.

Initiate allopurinol and subsequently titrate it to a target serum urate level <6.0 mg/dL.

The patient has a history of recurrent attacks, meeting the criteria for long-term urate-lowering therapy to prevent future joint damage and the formation of tophi.

Key Concept

The sequential management of gout involves diagnostic confirmation via arthrocentesis, acute flare treatment with anti-inflammatories, initiation of urate-lowering therapy for recurrent attacks, and long-term dose titration to a specific target serum urate level.

Question 2035Question →

A 42-year-old woman is brought to the emergency department by her husband due to sudden-onset, severe weakness in her legs that rapidly progressed over the last 12 hours. She is now unable to stand or bear weight. She also reports feeling intensely "short of breath." Her medical history is significant for a 5-year history of primary Sjögren syndrome, for which she takes artificial tears and cevimeline. Vital signs are temperature $37.1^\circ\text{C}$ ( $98.8^\circ\text{F}$ ), pulse 105/min, blood pressure 115/75 mm Hg, and respirations 26/min. Oxygen saturation is 98% on room air.

Physical examination reveals a tachypneic woman taking deep, rapid breaths. Lungs are clear to auscultation bilaterally. Neurologic examination shows 1/5 motor strength in the bilateral lower extremities and 3/5 in the upper extremities. Deep tendon reflexes are absent globally. Sensation is intact.

Laboratory results are as follows:

Laboratory Parameter	Result	Reference Range
Serum chemistry
Sodium	139 mEq/L	136–145 mEq/L
Potassium	1.7 mEq/L	3.5–5.0 mEq/L
Chloride	114 mEq/L	98–106 mEq/L
Bicarbonate	12 mEq/L	22–28 mEq/L
Arterial blood gas (room air)
pH	7.25	7.35–7.45
$pCO_2$	26 mm Hg	35–45 mm Hg
$pO_2$	98 mm Hg	80–100 mm Hg
Urinalysis
pH	7.0	4.5–8.0
Leukocyte esterase	Positive	Negative
Nitrites	Positive	Negative
Thyroid function tests
TSH	0.3 $\mu$ U/mL	0.4–4.0 $\mu$ U/mL
Free $T_4$	1.1 ng/dL	0.9–1.7 ng/dL

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

Intravenous potassium chloride administration

Endotracheal intubation and mechanical ventilation

Intravenous piperacillin-tazobactam administration

Oral levothyroxine administration

Intravenous furosemide and continuous positive airway pressure

Show answer & explanation

Answer: Intravenous potassium chloride administration

Answer

Intravenous potassium chloride administration

The correct intervention is intravenous potassium chloride administration. This patient's acute flaccid paralysis is the result of life-threatening hypokalemia (

1.7

mEq/L). The underlying pathophysiology is Type 1 (distal) renal tubular acidosis (RTA), a known complication of primary Sjögren syndrome caused by autoimmune tubulointerstitial nephritis. Type 1 RTA is characterized by a normal anion gap metabolic acidosis (her AG is 13), severe hypokalemia, and an inability to acidify the urine (urine pH > 5.5; hers is 7.0). The severe hypokalemia alters the resting membrane potential of muscle cells, leading to profound weakness, areflexia, and potentially fatal cardiac arrhythmias or diaphragmatic paralysis. Immediate, aggressive intravenous potassium repletion is the highest priority.

Step-by-Step Solution

Analyze the acid-base disorder using the serum chemistry and arterial blood gas.

The patient has a normal anion gap metabolic acidosis (AG = 139 - [114 + 12] = 13). Winter's formula (

1.5 \times 12 + 8 = 26 \pm 2

) perfectly matches the measured

pCO_2

of 26 mm Hg, indicating appropriate respiratory compensation.

Characterizing the acid-base status distinguishes between respiratory failure and metabolic derangements.

Identify the etiology of the normal anion gap metabolic acidosis.

The combination of severe hypokalemia (

1.7

mEq/L) and an inappropriately alkaline urine pH (

7.0

) in the setting of a normal anion gap acidosis points to distal (Type 1) Renal Tubular Acidosis (RTA).

Type 1 RTA involves a failure of alpha-intercalated cells to secrete hydrogen ions, leading to hypokalemia, metabolic acidosis, and alkaline urine.

Connect the renal pathology to the patient's rheumatologic history.

Primary Sjögren syndrome is a classic cause of Type 1 RTA due to lymphocytic infiltration of the renal interstitium (tubulointerstitial nephritis) damaging the distal tubules.

Recognizing systemic complications of autoimmune diseases is essential for comprehensive rheumatologic care.

Determine the most critical immediate intervention.

The patient's acute flaccid paralysis and absent reflexes are directly caused by profound hypokalemia. Immediate intravenous potassium chloride is required.

Severe hypokalemia (

< 2.0

mEq/L) can rapidly lead to fatal cardiac arrhythmias and diaphragmatic failure.

Key Concept

Patients with primary Sjögren syndrome can develop tubulointerstitial nephritis leading to Type 1 (distal) renal tubular acidosis, which can present acutely with life-threatening hypokalemic flaccid paralysis requiring immediate intravenous potassium replacement.

Question 2036Question →

A 72-year-old man is evaluated on postoperative day 2 following a partial colectomy for recurrent diverticulitis. His postoperative course was complicated by surgical site oozing, resulting in a hemoglobin drop to 6.8 g/dL. His past medical history is significant for chronic obstructive pulmonary disease (COPD) and ischemic cardiomyopathy with a left ventricular ejection fraction of 35%. He is currently receiving his second unit of packed red blood cells when he develops sudden-onset severe dyspnea and a dry cough. Temperature is 37.8°C (100.0°F), blood pressure is 175/95 mm Hg, pulse is 115/min, and respirations are 26/min. Pulse oximetry shows 88% on room air. Physical examination reveals an elevated jugular venous pressure of 12 cm H2O. Lung auscultation demonstrates bilateral basilar crackles with scattered expiratory wheezing. Cardiac auscultation reveals a regular tachycardia with a prominent S3 gallop. The transfusion is immediately stopped. Which of the following is the most appropriate next step in management?

Administer inhaled albuterol and systemic corticosteroids

Initiate intravenous broad-spectrum antibiotics

File an incident report regarding the transfusion rate

Administer intravenous furosemide

Obtain a urinalysis and urine culture

Show answer & explanation

Answer: Administer intravenous furosemide

Answer

Administer intravenous furosemide

This patient is experiencing Transfusion-Associated Circulatory Overload (TACO). TACO occurs when a large volume of blood products is administered rapidly, overwhelming the patient's cardiovascular capacity. It is especially common in older patients with underlying left ventricular dysfunction (e.g., ischemic cardiomyopathy with LVEF 35%). The presentation mimics acute decompensated heart failure, characterized by acute dyspnea, hypertension, tachycardia, elevated jugular venous pressure, crackles, and an S3 gallop. The first step in management is to immediately stop the transfusion, provide supplemental oxygen, and administer loop diuretics like intravenous furosemide to reduce preload and clear pulmonary edema.

Step-by-Step Solution

Analyze the onset of symptoms and vital signs.

The patient developed acute hypoxia, dyspnea, and hypertension during a blood transfusion.

Timing strongly suggests a transfusion reaction; hypertension narrows the differential toward volume overload.

Correlate vital signs with physical examination findings.

Elevated JVP, bilateral crackles, and a prominent S3 gallop in a patient with a low ejection fraction confirm cardiogenic pulmonary edema.

These findings reliably distinguish Transfusion-Associated Circulatory Overload (TACO) from Transfusion-Related Acute Lung Injury (TRALI) or other non-cardiogenic causes of hypoxia.

Determine the therapeutic intervention for the diagnosed condition.

The indicated treatment for TACO is intravenous furosemide.

Diuretics rapidly decrease intravascular volume and relieve pulmonary congestion, which is the root cause of the patient's acute respiratory failure.

Key Concept

Diagnosis and management of Transfusion-Associated Circulatory Overload (TACO)

Question 2037Question →

A 55-year-old man develops sudden-onset generalized urticaria, wheezing, and a blood pressure of $80/50$ mm Hg shortly after receiving a dose of intravenous ceftriaxone on the medical ward. Arrange the following management steps in the correct chronological sequence, prioritizing immediate life-saving interventions first.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct sequence is: Administer intramuscular epinephrine, followed by intravenous crystalloid fluids, then adjunctive intravenous glucocorticoids and antihistamines, and finally observe for a biphasic reaction.

The priority in anaphylaxis is the immediate reversal of life-threatening respiratory and cardiovascular collapse. Intramuscular epinephrine is the only medication that achieves this rapidly. This is followed by intravenous fluids to treat distributive shock. Adjunctive therapies like antihistamines and glucocorticoids are given third because they do not treat the acute life-threatening features. Finally, observation is required for a potential biphasic reaction.

Step-by-Step Solution

Identify the condition as anaphylactic shock.

The patient has urticaria, wheezing, and hypotension after antibiotic administration.

Recognizing anaphylaxis triggers immediate life-saving protocols.

Prioritize first-line life-saving therapy.

Administer intramuscular epinephrine.

Epinephrine rapidly reverses vasodilation and bronchoconstriction.

Address persistent hypotension.

Administer rapid intravenous crystalloid fluids.

Anaphylaxis causes severe distributive shock requiring fluid resuscitation.

Administer second-line adjunctive therapies.

Administer intravenous antihistamines and glucocorticoids.

These medications help control cutaneous symptoms and prevent delayed reactions, but act too slowly for acute resuscitation.

Determine post-stabilization care.

Observe the patient for a biphasic reaction.

Anaphylaxis can recur hours after the initial episode resolves.

Key Concept

In anaphylaxis, intramuscular epinephrine is the absolute first-line treatment and must never be delayed. Fluid resuscitation follows to treat distributive shock, followed by adjunctive therapies (antihistamines, glucocorticoids) and observation.

Question 2038Question →

Match each clinical presentation of an immunocompromised patient with the most appropriate targeted pharmacotherapy.

Click a left item, then click its matching right item

Show answer & explanation

Answer

The correct pairings match Toxoplasmosis with pyrimethamine/sulfadiazine/leucovorin, Cryptococcal meningitis with amphotericin B/flucytosine, CMV retinitis with valganciclovir, and severe Pneumocystis pneumonia with TMP-SMX/corticosteroids.

Each targeted pharmacotherapy directly addresses the specific pathogen responsible for the classic opportunistic infection presentations in patients with advanced HIV, adhering to standard induction and primary treatment guidelines.

Step-by-Step Solution

Evaluate the clinical and radiographic presentation in each patient to identify the most likely opportunistic infection.

The pathogens are identified as Toxoplasma gondii, Cryptococcus neoformans, Cytomegalovirus (CMV), and Pneumocystis jirovecii.

Accurate diagnosis of the specific opportunistic infection is required before selecting targeted antimicrobial therapy.

Select the appropriate primary treatment regimen for each identified pathogen based on current clinical guidelines.

Toxoplasmosis requires pyrimethamine-based therapy; Cryptococcus requires amphotericin-based induction; CMV requires a -ganciclovir derivative; PCP requires TMP-SMX.

Different classes of pathogens (protozoan, fungal, viral) require highly specific antimicrobial mechanisms of action.

Assess disease severity for the PCP case to determine if adjunctive therapy is needed.

The patient's PaO2 is 60 mmHg (less than 70 mmHg), indicating severe disease that requires adjunctive corticosteroids.

Steroids prevent the severe inflammatory response that occurs when dying Pneumocystis organisms release inflammatory antigens in the lungs.

Key Concept

Pharmacotherapy for HIV-associated opportunistic infections

Question 2039Question →

Match each classic physical examination or imaging finding to its most likely rheumatologic diagnosis.

Click a left item, then click its matching right item

Show answer & explanation

Answer

Heliotrope rash/Gottron papules matches with Dermatomyositis; Malar rash matches with Systemic lupus erythematosus; Acute first MTP swelling (podagra) matches with Gout; Sacroiliitis matches with Ankylosing spondylitis.

Each provided clinical vignette highlights the most iconic and highly tested physical examination or imaging finding for its respective rheumatologic condition, requiring direct pattern recognition.

Step-by-Step Solution

Evaluate the cutaneous findings of a heliotrope rash and Gottron papules.

Identified as dermatomyositis.

These are highly specific pathognomonic skin signs of this inflammatory myopathy.

Evaluate the malar rash that spares the nasolabial folds.

Identified as systemic lupus erythematosus.

Sparing of the nasolabial folds distinguishes the SLE malar rash from conditions like rosacea or seborrheic dermatitis.

Evaluate the acute swelling of the first metatarsophalangeal joint.

Identified as gout.

This specific joint involvement is called podagra, characteristic of monosodium urate crystal deposition.

Evaluate the progressive lower back pain with sacroiliitis.

Identified as ankylosing spondylitis.

This is a seronegative spondyloarthropathy characterized by inflammation of the axial skeleton, particularly the sacroiliac joints.

Key Concept

Classic clinical presentations in rheumatology

Question 2040Question →

A 52-year-old woman undergoing induction chemotherapy for acute myeloid leukemia presents to the emergency department with chills and a temperature of 39.2°C (102.6°F). Laboratory studies reveal an absolute neutrophil count of 250/mm³. Arrange the following steps for the management of this patient in the most appropriate chronological order.

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct sequence is: Assess hemodynamic stability -> Obtain blood cultures -> Administer empiric antibiotics -> Adjust antimicrobial therapy based on results.

The standard protocol for neutropenic fever requires rapid but structured intervention. Hemodynamic assessment is always first to ensure the patient is not in imminent shock. Next, blood cultures must be drawn to identify the pathogen. Immediately following the cultures, empiric broad-spectrum antibiotics (such as cefepime or piperacillin-tazobactam) are administered to cover typical pathogens, including Pseudomonas aeruginosa. Finally, once sensitivities are resulted days later, therapy is narrowed or adjusted.

Step-by-Step Solution

Identify the clinical syndrome presented in the vignette.

The patient has a fever (39.2°C) and profound neutropenia (ANC < 500/mm³), diagnosing her with neutropenic fever, which is an oncologic emergency.

Recognizing neutropenic fever triggers a well-established, time-sensitive clinical pathway to prevent rapid progression to septic shock.

Determine the first priority in emergency management.

Assess hemodynamic stability and perform a focused physical examination.

Regardless of the underlying cause, initial stabilization (ABCs) is always the first step in acute management.

Determine the order of diagnostic versus therapeutic interventions.

Obtain blood cultures before administering empiric antibiotics.

Administering antibiotics prior to drawing cultures can sterilize the blood, severely limiting the ability to identify the offending organism and narrow therapy later.

Identify the final step in the treatment sequence.

Adjust antimicrobial therapy based on microbiological results.

De-escalation and targeted therapy occur days later once speciation and susceptibility testing are finalized.

Key Concept

Management sequence of neutropenic fever

PreviousPage 102 / 414Next

All practice questions

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Answer

Step-by-Step Solution

Key Concept