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Question 3081Question →

A 64-year-old woman arrives at the emergency department with a 24-hour history of severe right-sided flank pain, intense chills, and acute confusion. Vital signs reveal a temperature of 39.2∘C39.2^\circ\text{C} (102.6∘F102.6^\circ\text{F}), blood pressure of 88/54 mmHg, and a heart rate of 118/min. Physical examination is notable for exquisite right costovertebral angle tenderness. Initial laboratory evaluation demonstrates a leukocyte count of 18,500/mm318,500/\text{mm}^3 and a serum creatinine level of 1.9 mg/dL1.9 \text{ mg/dL}. A non-contrast CT scan of the abdomen and pelvis shows a 9-mm calculus in the proximal right ureter accompanied by severe hydronephrosis and perinephric fat stranding.

Arrange the following patient management and procedural interventions in the most appropriate chronological sequence for this patient.

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Answer

The correct chronological sequence is: 1) Administration of intravenous crystalloids and empiric broad-spectrum antibiotics, 2) Urgent decompression of the renal collecting system via percutaneous nephrostomy, 3) Definitive calculus extraction via ureteroscopy and laser lithotripsy, and 4) Removal of the percutaneous nephrostomy drainage tube.
The management of an infected obstructing ureteral stone follows a strict protocol of medical stabilization, urgent source control, and delayed definitive treatment. Initial management requires fluid resuscitation and broad-spectrum antibiotics to address the septic shock. This must be immediately followed by urgent decompression of the collecting system (via percutaneous nephrostomy or retrograde ureteral stent) to drain the purulent urine under pressure. Definitive stone removal (ureteroscopy) is strictly contraindicated during the acute infection due to the risk of worsening sepsis from intraoperative irrigation fluid pressure. It is instead performed electively weeks later after the patient has completely stabilized. Finally, the nephrostomy tube is removed once stone clearance and ureteral patency are confirmed.

Step-by-Step Solution

1
Administer intravenous crystalloids and broad-spectrum antibiotics.
Restores intravascular volume and initiates antimicrobial action against the systemic infection.
The patient is in septic shock (hypotension, fever, leukocytosis) secondary to an infected obstructing stone. Immediate medical stabilization is required before any surgical intervention.
2
Perform urgent decompression of the renal collecting system.
Drains purulent urine under pressure from the renal pelvis.
An infected and obstructed kidney is a surgical emergency. Decompression via a percutaneous nephrostomy tube or ureteral stent provides necessary source control for the infection.
3
Delay definitive stone extraction until sepsis resolves, then perform elective ureteroscopy.
Safely fragments and removes the obstructing 9-mm calculus.
Performing lithotripsy during active infection involves irrigating the urinary tract, which dramatically increases intrarenal pressure and can precipitate fatal septic shock.
4
Remove the percutaneous nephrostomy drainage tube.
Completes the procedural intervention sequence.
The drainage tube is no longer needed once the obstruction is definitively relieved and normal ureteral patency is confirmed.

Key Concept

The initial management of an infected obstructing ureteral stone requires urgent systemic resuscitation followed immediately by decompression (source control) via percutaneous nephrostomy or ureteral stenting; definitive stone treatment is delayed until the infection fully resolves.
Estimated Time:1m 30s
Question 3082Question →

A 26-year-old woman comes to the urgent care clinic due to a 4-day history of joint pain and a new rash. The pain initially involved her left elbow and right wrist but currently affects her right ankle, making it difficult to walk. She also reports intermittent subjective fevers over the same period. Her medical history is unremarkable, and she takes an oral contraceptive. She has been sexually active with a new male partner for the past two months. Her temperature is 38.2°C (100.8°F), blood pressure is 110/70 mm Hg, and pulse is 98/min. Physical examination reveals swelling, warmth, and marked tenderness along the dorsum of the right wrist and over the left Achilles tendon. There is no significant joint effusion in the knees or ankles. Auscultation of the heart reveals a grade 1/6 early systolic murmur at the left lower sternal border. Skin examination shows a few sparse, discrete necrotic pustules on an erythematous base located on the distal upper and lower extremities. Pelvic examination reveals no cervical motion tenderness or vaginal discharge. Which of the following is the most likely diagnosis?

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Answer: Disseminated gonococcal infection

Answer

Disseminated gonococcal infection
The correct answer is Disseminated gonococcal infection. This condition frequently affects young, sexually active individuals, particularly women, who may have an asymptomatic primary mucosal infection (as evidenced by this patient's normal pelvic exam). The systemic spread of Neisseria gonorrhoeae typically results in a classic clinical triad: migratory polyarthralgia, tenosynovitis (inflammation of the tendon sheath, commonly affecting the wrists, fingers, ankles, and toes), and dermatitis (typically characterized by sparse, discrete necrotic pustules or vesiculopustules on the distal extremities). The presence of this complete triad makes it the most likely diagnosis.

Step-by-Step Solution

1
Analyze the patient's demographic risk factors and vital signs.
The patient is a young, sexually active female with a new partner, presenting with an acute febrile illness (temperature 38.2°C).
Identifying systemic inflammation in the context of recent sexual exposure narrows the differential diagnosis toward sexually transmitted infections and reactive processes.
2
Evaluate the specific musculoskeletal and dermatologic findings.
The patient has marked tenderness along tendon sheaths (Achilles, wrist dorsum) without significant joint effusion, indicating tenosynovitis rather than true arthritis. She also has discrete necrotic pustules on distal extremities.
Specific physical examination findings are critical for differentiating causes of polyarthralgia; tenosynovitis and pustular dermatitis are highly specific morphologic clues.
3
Synthesize the findings to formulate the most likely diagnosis.
The combination of migratory polyarthralgia, tenosynovitis, and a characteristic vesiculopustular rash in a sexually active patient points directly to disseminated gonococcal infection.
Recognizing this classic triad allows for prompt identification of the disease, even when localized genitourinary symptoms (e.g., cervicitis) are absent.

Key Concept

Disseminated gonococcal infection classically presents with a triad of polyarthralgia, tenosynovitis, and dermatitis (necrotic pustules), often without symptomatic primary mucosal infection in women.
Question 3083Question →

Match each classic high-resolution computed tomography (HRCT) chest imaging finding with its most strongly associated clinical diagnosis.

Click a left item, then click its matching right item

Items

Subpleural, basal-predominant reticular opacities with honeycombing and architectural distortion
Centrilobular nodules with branching linear opacities (tree-in-bud pattern)
Diffuse bilateral ground-glass opacities superimposed on thickened interlobular and intralobular septa (crazy-paving pattern)
Focal ground-glass opacities surrounded by a complete or incomplete ring of dense consolidation (reversed halo sign)

Matches

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Answer

Subpleural honeycombing matches with Usual interstitial pneumonia; Tree-in-bud pattern matches with Active endobronchial tuberculosis; Crazy-paving matches with Pulmonary alveolar proteinosis; Reversed halo sign matches with Cryptogenic organizing pneumonia.
Each radiological finding reflects a distinct underlying histopathological mechanism: honeycombing reflects dense fibrosis, the tree-in-bud sign reflects infectious bronchiolitis, crazy-paving reflects lipoproteinaceous alveolar filling, and the reversed halo sign reflects organizing granulation tissue in the distal airspaces.

Step-by-Step Solution

1
Analyze the description of subpleural, basal reticular opacities with honeycombing.
Identify this as irreversible fibrotic architectural destruction.
This specific topographic distribution and destructive fibrosis defines the usual interstitial pneumonia (UIP) pattern.
2
Evaluate the tree-in-bud pattern.
Recognize it as small airway (bronchiolar) inflammation with structural impaction.
This finding reliably points toward the endobronchial spread of infectious pathogens, particularly active tuberculosis.
3
Assess the crazy-paving pattern.
Correlate ground-glass opacities accompanied by septal thickening with widespread alveolar filling processes.
This specific combination of alveolar and interstitial involvement is the pathognomonic radiological appearance for pulmonary alveolar proteinosis.
4
Interpret the reversed halo sign.
Link the central ground-glass appearance framed by peripheral consolidation to organizing granulation tissue.
This concentric structural arrangement is highly specific for diagnosing cryptogenic organizing pneumonia.

Key Concept

Interpretation of pathognomonic high-resolution CT (HRCT) patterns for interstitial and alveolar lung diseases
Question 3084Question →

A 67-year-old woman is brought to the emergency department from a skilled nursing facility due to a 2-day history of progressively worsening abdominal pain, distension, and obstipation. She has a medical history significant for Parkinson disease, chronic constipation, and severe osteoarthritis. Her current medications include carbidopa-levodopa, polyethylene glycol, and acetaminophen. Vital signs show a temperature of 37.6°C (99.7°F), blood pressure of 105/65 mmHg, heart rate of 115/min, and respiratory rate of 20/min. Physical examination reveals a markedly distended and tympanitic abdomen with diffuse tenderness. There is no rebound tenderness or guarding. Laboratory studies show a leukocyte count of 11,500/mm³ and normal serum electrolyte levels. An abdominal plain radiograph demonstrates a massively dilated, comma-shaped loop of bowel projecting from the right lower quadrant toward the left upper quadrant. A subsequent computed tomography scan of the abdomen shows a markedly distended cecum with mesenteric twisting and a transition point in the right colon. Which of the following is the most appropriate next step in management?

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Answer: Exploratory laparotomy and right hemicolectomy

Answer

The most appropriate next step in management is exploratory laparotomy and right hemicolectomy.
The correct answer proposes immediate surgical intervention. A cecal volvulus involves axial twisting of the cecum, terminal ileum, and ascending colon. Because the anatomical twist makes endoscopic access very difficult and highly prone to perforation, endoscopic detorsion is generally unsuccessful and not recommended. The standard of care is urgent surgical intervention. A right hemicolectomy or ileocecal resection with primary anastomosis is the preferred procedure in a hemodynamically stable patient with viable bowel, as it definitive treats the obstruction and prevents recurrence.

Step-by-Step Solution

1
Analyze the clinical presentation and imaging findings.
The patient presents with signs of large bowel obstruction. The radiograph shows a dilated bowel loop projecting from the right lower quadrant to the left upper quadrant, and CT confirms a transition point in the right colon with mesenteric twisting.
These findings are classic for a cecal volvulus, which occurs when the cecum twists on its mesentery.
2
Differentiate the pathology from other similar conditions.
The pathology is identified as cecal volvulus, not sigmoid volvulus (which classically projects from the left lower quadrant to the right upper quadrant) or Ogilvie syndrome (which lacks a mechanical transition point or twist).
Accurate anatomical differentiation dictates the completely different procedural management required.
3
Determine the optimal procedural intervention based on the diagnosis.
Surgical intervention (laparotomy with right hemicolectomy or ileocecal resection) is selected as the necessary treatment.
Unlike sigmoid volvulus, cecal volvulus cannot be safely or effectively decompressed endoscopically. Immediate surgical resection is required to prevent or treat bowel ischemia and prevent recurrence.

Key Concept

Cecal volvulus requires immediate surgical intervention (e.g., right hemicolectomy) as opposed to sigmoid volvulus, which is initially managed with endoscopic detorsion.
Question 3085Question →

A 4545-year-old woman is evaluated in the intensive care unit for fever and hypotension. She was admitted 1212 days ago for induction chemotherapy for acute myeloid leukemia. Over the past 2424 hours, her temperature has spiked to 39.2∘C39.2^\circ\text{C} (102.6∘F102.6^\circ\text{F}), and her blood pressure has dropped to 85/50 mmHg85/50\text{ mmHg}, remaining hypotensive despite a 2 L2\text{ L} intravenous normal saline bolus. She has a central venous catheter in her right internal jugular vein. She currently complains of severe perianal pain. Physical examination reveals an indurated, exquisitely tender, and erythematous perianal region without fluctuance. Laboratory studies show an absolute neutrophil count of 100/μL100/\mu\text{L}. The patient's medical record documents a history of severe anaphylaxis (laryngeal edema and hypotension) to amoxicillin. Blood and perianal tissue cultures are obtained.

Which of the following intravenous pharmacologic agents should be included in this patient's empiric antimicrobial regimen? (Select all that apply)

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Answer: Aztreonam; Metronidazole; Vancomycin

Answer

The correct interventions are Aztreonam, Metronidazole, and Vancomycin.
This patient presents with high-risk febrile neutropenia, septic shock, a central venous catheter, and a severe perianal infection, complicated by a history of penicillin anaphylaxis. Guidelines mandate immediate empiric antipseudomonal therapy. Due to her IgE-mediated penicillin allergy, beta-lactams like piperacillin-tazobactam or cefepime are contraindicated. Aztreonam is a monobactam that safely provides antipseudomonal coverage in penicillin-allergic patients. However, aztreonam lacks both Gram-positive and anaerobic activity. Vancomycin must be added to cover Gram-positive organisms (e.g., MRSA, Coagulase-negative Staphylococci) given her hemodynamic instability and central venous catheter. Furthermore, her perianal infection necessitates targeted anaerobic coverage, which is achieved by adding metronidazole.

Step-by-Step Solution

1
Assess clinical stability, infectious risk, and allergy profile.
The patient has high-risk febrile neutropenia with septic shock, a severe penicillin allergy (anaphylaxis), a central line, and a perianal infection.
Identifying these exact parameters is necessary to select a broad-spectrum antibiotic regimen that safely avoids contraindicated drug classes while covering all likely pathogens.
2
Select appropriate Gram-negative and antipseudomonal coverage.
Aztreonam is selected.
Guidelines mandate immediate empiric antipseudomonal therapy. Because the patient has an IgE-mediated penicillin allergy, standard beta-lactams like piperacillin-tazobactam or cefepime are contraindicated. Aztreonam is a monobactam that lacks cross-reactivity with penicillins and provides excellent Gram-negative coverage.
3
Determine the need for specific Gram-positive coverage.
Vancomycin is added to the regimen.
Aztreonam has zero Gram-positive activity. Empiric MRSA and broad Gram-positive coverage with vancomycin is indicated for febrile neutropenia patients who are hemodynamically unstable (shock) or have a central venous catheter.
4
Determine the need for specific anaerobic coverage.
Metronidazole is added to the regimen.
The patient has a severe perianal infection, which strongly implicates gut anaerobes (e.g., Bacteroides species). Neither aztreonam nor vancomycin covers these anaerobes, making the addition of metronidazole necessary.

Key Concept

Empiric antimicrobial selection in high-risk febrile neutropenia requires synthesizing the patient's allergy profile, hemodynamic status, and site-specific infectious risks to ensure comprehensive coverage of Pseudomonas aeruginosa, MRSA, and anaerobes when specifically indicated.
Question 3086Question →

A 29-year-old G1P0 woman at 22 weeks gestation presents to the emergency department complaining of sudden-onset shortness of breath and right-sided chest pain that worsens with deep inspiration. The symptoms started 3 hours ago. She has no significant past medical history. Vital signs show a temperature of 37.1°C (98.8°F), heart rate of 118/min, blood pressure of 112/72 mmHg, respiratory rate of 24/min, and oxygen saturation of 94% on room air. Physical examination reveals clear lung fields bilaterally. Cardiac auscultation reveals tachycardia with a regular rhythm and no murmurs. Examination of the lower extremities demonstrates mild, asymmetric swelling of the left calf with localized tenderness. An electrocardiogram shows sinus tachycardia. A chest radiograph is unremarkable. Which of the following is the most appropriate next diagnostic test?

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Answer: Compression ultrasonography of the bilateral lower extremities

Answer

The most appropriate next step is compression ultrasonography of the bilateral lower extremities.
The correct sequence for evaluating suspected pulmonary embolism in a pregnant patient prioritizes minimizing radiation exposure to the fetus and mother. Guidelines recommend a chest radiograph as the initial study. If the radiograph is normal, the next best step is bilateral lower extremity compression ultrasonography, particularly when the patient has clinical signs of a deep vein thrombosis (DVT) such as calf swelling and tenderness. Confirming a DVT establishes the diagnosis of venous thromboembolism (VTE) and provides sufficient indication to initiate therapeutic anticoagulation, making further tests like CT pulmonary angiography (CTPA) or V/Q scanning unnecessary.

Step-by-Step Solution

1
Identify the primary clinical presentation.
A pregnant patient presents with pleuritic chest pain, dyspnea, and an asymmetrically swollen, tender calf, highly suggestive of venous thromboembolism (VTE).
Recognizing the high pre-test probability for both deep vein thrombosis (DVT) and pulmonary embolism (PE) dictates the diagnostic algorithm.
2
Evaluate the constraints of diagnostic testing in pregnancy.
Maternal and fetal radiation exposure must be minimized. The initial test for suspected PE in pregnancy is a chest radiograph, which was normal.
A normal chest radiograph rules out common alternative diagnoses (e.g., pneumonia, pneumothorax) but does not rule out PE.
3
Determine the optimal sequencing to confirm the diagnosis safely.
Select bilateral lower extremity compression ultrasonography.
Because the patient has signs of DVT, a positive ultrasound will confirm a VTE diagnosis and provide an immediate indication for therapeutic anticoagulation, successfully bypassing the need for radiation-based thoracic imaging.

Key Concept

In pregnant patients with suspected pulmonary embolism and a normal chest radiograph, bilateral lower extremity compression ultrasonography is the most appropriate next step, especially if symptoms of deep vein thrombosis are present, as a positive finding circumvents the need for radiation-based imaging.
Question 3087Question →

Emergency medical responders bring a 42-year-old man to the trauma center following a fall from a 6-meter (20-foot) scaffold. The patient is confused and visibly diaphoretic. Vital signs upon arrival include a heart rate of 138/min, blood pressure of 76/40 mm Hg, and respiratory rate of 28/min. Oxygen saturation is 91% on high-flow oxygen. Primary survey demonstrates tracheal deviation to the left, absent breath sounds on the right, and severe dullness to percussion over the right hemithorax. Bilateral large-bore intravenous access is established, and the institutional massive transfusion protocol is activated. A 36-French thoracostomy tube is promptly inserted into the right pleural space, which immediately drains 1,650 mL of frank blood. Despite the ongoing administration of blood products, the patient's blood pressure remains 82/45 mm Hg five minutes later. Which of the following is the most appropriate next step in the management of this patient?

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Answer: Urgent exploratory thoracotomy

Answer

Urgent exploratory thoracotomy
The correct intervention is an urgent exploratory thoracotomy. This patient has sustained severe blunt chest trauma leading to a massive hemothorax. A thoracostomy tube is the initial step in management to evacuate blood and re-expand the lung. However, the standard indications for proceeding immediately to an urgent thoracotomy include the initial, sudden drainage of greater than 1,500 mL of blood upon chest tube placement, continuous output of greater than 200 mL/hr for 2 to 4 consecutive hours, or hemodynamic instability refractory to aggressive volume and blood product resuscitation. This patient meets the criteria with an initial output of 1,650 mL, signifying a major intrathoracic vascular or parenchymal injury that requires immediate direct surgical hemostasis to prevent death.

Step-by-Step Solution

1
Identify the primary clinical condition.
The patient has a massive right-sided hemothorax resulting from high-mechanism blunt trauma, confirmed by the immediate evacuation of 1,650 mL of frank blood.
Recognizing the extent of intrathoracic hemorrhage is essential for determining the need for surgical rather than medical management.
2
Assess the patient's hemodynamic stability.
The patient remains in hemorrhagic shock with a blood pressure of 82/45 mm Hg despite fluid and blood product resuscitation.
Persistent instability indicates ongoing, uncontrolled bleeding that exceeds the capacity of medical resuscitation alone.
3
Apply the standard criteria for surgical intervention in chest trauma.
Urgent exploratory thoracotomy is indicated.
In the setting of a traumatic hemothorax, an initial chest tube output exceeding 1,500 mL is an established, absolute indication for immediate operative intervention to achieve direct hemostasis.

Key Concept

Indications for urgent thoracotomy in massive hemothorax include an initial thoracostomy output of >1,500 mL, ongoing output of >200 mL/hr for 2-4 hours, or persistent hemodynamic instability.
Question 3088Question →

A 54-year-old female teacher is brought to the emergency department by her spouse due to the sudden onset of a severe, diffuse headache that began roughly 8 hours ago. She describes it as unlike any headache she has ever experienced, reaching maximum intensity within seconds. The patient also reports significant nausea and sensitivity to light. Her past medical history is notable for well-controlled essential hypertension and hypothyroidism. Current medications include lisinopril and levothyroxine. On arrival, her temperature is 37.2°C (99.0°F), blood pressure is 162/94 mmHg, pulse is 92/min, and respiratory rate is 16/min. Physical examination demonstrates moderate resistance to passive neck flexion, but cranial nerves, motor strength, and sensory functions are fully intact. A non-contrast computed tomography (CT) scan of the head is obtained immediately and reveals no evidence of intracranial hemorrhage, mass effect, or midline shift. Which of the following is the most appropriate next step in the diagnostic workup?

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Answer: Lumbar puncture

Answer

Lumbar puncture
The correct answer is a lumbar puncture. The patient presents with classic signs of a subarachnoid hemorrhage (SAH), including a 'thunderclap' headache and nuchal rigidity. While a non-contrast head CT is the best initial screening test, its sensitivity approaches 100% only if performed within 6 hours of symptom onset. Because this patient's symptoms began 8 hours prior to the scan, a negative CT cannot definitively rule out SAH. In this scenario, a lumbar puncture is required to evaluate the cerebrospinal fluid for red blood cells and xanthochromia (bilirubin resulting from hemoglobin breakdown), which would confirm the diagnosis.

Step-by-Step Solution

1
Evaluate the clinical presentation.
The patient has a sudden-onset 'thunderclap' headache with meningismus, which is highly suspicious for a subarachnoid hemorrhage (SAH).
Identifying the most life-threatening condition in the differential diagnosis is critical for guiding the initial and subsequent diagnostic workup.
2
Assess the results and timing of the initial diagnostic study.
A non-contrast head CT is negative, but it was performed 8 hours after symptom onset.
The sensitivity of a non-contrast CT for detecting SAH is nearly 100% within the first 6 hours, but drops significantly thereafter. Thus, a negative scan outside this window does not definitively rule out the condition.
3
Determine the most appropriate next step in the testing sequence.
A lumbar puncture must be performed.
When clinical suspicion for SAH remains high and the head CT is performed outside the highly sensitive time window, examining the cerebrospinal fluid for red blood cells and xanthochromia is the mandatory next step.

Key Concept

Diagnostic test sequencing for suspected subarachnoid hemorrhage based on symptom onset timing.
Question 3089Question →

A 72-year-old man presents to the emergency department with sudden, severe pain in his left lower leg that began 2 hours ago. He has a history of permanent atrial fibrillation but reports running out of his prescribed oral anticoagulant medication three weeks ago. On physical examination, his left foot and calf are pale and cool to the touch. The left femoral pulse is palpable, but the popliteal, dorsalis pedis, and posterior tibial pulses are absent to palpation and inaudible on continuous-wave Doppler ultrasound. Sensation is markedly decreased over the dorsum of the foot, and the patient is unable to move his toes. The right lower extremity is warm with strong distal pulses. Which of the following interventions are indicated for the immediate management of this patient? (Select all that apply)

Select all that apply

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Answer: Initiation of a continuous intravenous unfractionated heparin infusion; Urgent open surgical thromboembolectomy

Answer

The correct interventions are the initiation of a continuous intravenous unfractionated heparin infusion and urgent open surgical thromboembolectomy.
The correct interventions directly address the pathophysiology of acute limb ischemia in an immediately threatened extremity (Rutherford IIb). Intravenous unfractionated heparin provides rapid systemic anticoagulation to prevent the existing clot from propagating into stagnant distal collateral vessels. Because the patient already has a motor deficit (inability to move toes), the tissue is highly susceptible to irreversible infarction, necessitating immediate mechanical clot removal via urgent open surgical thromboembolectomy. Together, these steps form the standard perioperative and surgical management sequence for limb salvage.

Step-by-Step Solution

1
Diagnose the acute condition based on the clinical presentation.
The patient's sudden onset of pain, pallor, pulselessness, paresthesias, and paralysis (inability to move toes) in the setting of unantagonized atrial fibrillation points to acute limb ischemia (ALI) secondary to an arterial embolus.
Accurate clinical diagnosis is the first step in determining the urgency and type of intervention required.
2
Stratify the severity of the ischemia.
The presence of a motor deficit (paralysis) and inaudible arterial Doppler signals classifies the limb as Rutherford category IIb (immediately threatened).
Severity classification dictates the acceptable timeframe for reperfusion and guides the choice between surgical and endovascular management.
3
Determine the mandatory concurrent medical and surgical interventions.
Immediate systemic anticoagulation with IV heparin must be started to halt clot propagation, followed rapidly by urgent surgical thromboembolectomy for definitive reperfusion.
Category IIb limbs cannot tolerate the time delays associated with imaging or catheter-directed thrombolysis.

Key Concept

Patients with acute limb ischemia presenting with profound sensorimotor deficits (Rutherford category IIb) require immediate systemic anticoagulation with intravenous heparin and urgent open surgical revascularization.
Question 3090Question →

A 6262-year-old woman is evaluated in the hospital for new-onset swelling and pain in her right lower extremity. She was admitted 66 days ago for an acute pulmonary embolism and was immediately started on a continuous intravenous infusion of unfractionated heparin. Her respiratory status has significantly improved, but today she reports severe calf pain. Vital signs are within normal limits. Physical examination shows a right calf that is swollen, erythematous, and tender to palpation. Duplex ultrasonography confirms a new deep vein thrombosis in the right popliteal vein. Laboratory studies show a platelet count of 95,000/μL95,000/\mu L, a significant decline from her admission platelet count of 260,000/μL260,000/\mu L. Renal and hepatic function tests are within normal limits. Which of the following is the most appropriate next step in the pharmacologic management of this patient?

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Answer: Discontinue unfractionated heparin and initiate an argatroban infusion

Answer

Discontinue unfractionated heparin and initiate an argatroban infusion
The correct intervention is to discontinue unfractionated heparin and initiate a direct thrombin inhibitor, such as argatroban. This patient's presentation of a new thrombotic event (deep vein thrombosis) coupled with a platelet count drop of greater than 50% within 5 to 10 days of heparin initiation is classic for type 2 heparin-induced thrombocytopenia (HIT). HIT is a life-threatening, immune-mediated prothrombotic disorder caused by antibodies against heparin-platelet factor 4 (PF4) complexes. The cornerstone of management is the immediate cessation of all heparin products and the initiation of a non-heparin anticoagulant to treat the active thrombosis and underlying hypercoagulable state.

Step-by-Step Solution

1
Evaluate the clinical presentation and laboratory timeline.
The patient developed a new thrombosis (DVT) and a >50% drop in platelet count exactly 6 days after starting unfractionated heparin.
This specific temporal relationship and clinical picture (thrombosis plus thrombocytopenia) yields a high 4T score, strongly indicating type 2 Heparin-Induced Thrombocytopenia (HIT).
2
Determine the necessary acute intervention for the primary drug involved.
All forms of heparin (unfractionated and low-molecular-weight) must be immediately discontinued.
HIT is caused by IgG antibodies against the heparin-platelet factor 4 (PF4) complex, leading to widespread platelet activation. Ongoing exposure will perpetuate the prothrombotic state.
3
Select the appropriate alternative pharmacologic therapy for the new thrombosis.
A non-heparin anticoagulant, such as a direct thrombin inhibitor (e.g., argatroban, bivalirudin) or fondaparinux, must be initiated.
The patient has an active new DVT and an underlying hypercoagulable state requiring immediate, safe anticoagulation without cross-reactivity.

Key Concept

Management of Heparin-Induced Thrombocytopenia (HIT)
Question 3091Question →

A 7272-year-old woman is brought to the emergency department from a skilled nursing facility due to severe lethargy and confusion over the past 1212 hours. Transport personnel report that she had a productive cough and foul-smelling urine for 33 days prior to this acute decline. On arrival, she is unarousable to verbal stimuli but moans in response to painful stimuli. Vital signs include a temperature of 39.2∘C39.2^\circ\text{C} (102.6∘F102.6^\circ\text{F}), blood pressure of 76/40 mm Hg76/40\text{ mm Hg}, pulse of 128/min128/\text{min}, and respiratory rate of 28/min28/\text{min}. Oxygen saturation is 86%86\% on room air. Capillary refill time is 55 seconds. Arrange the following initial stabilization and management steps in the most appropriate chronological sequence for this patient.

Drag items to arrange them in the correct order

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Answer

The correct sequence prioritizes the ABCs (Airway, Breathing, Circulation), followed by diagnostic sampling prior to targeted therapy, and finally escalation of hemodynamic support: 1) Administer supplemental oxygen, 2) Establish IV access and give crystalloids, 3) Draw blood cultures, 4) Administer antibiotics, 5) Initiate norepinephrine.
The correct sequence adheres strictly to the principles of acute trauma and medical resuscitation (Airway, Breathing, Circulation) and the surviving sepsis campaign guidelines. Oxygenation resolves the immediate airway/breathing threat. Fluids address the circulatory collapse. Cultures must precede antibiotics to ensure proper microbiological data collection, and antibiotics must be given as quickly as possible thereafter. Vasopressors are reserved for patients who fail to respond to the initial fluid challenge.

Step-by-Step Solution

1
Assess and stabilize Airway and Breathing.
Supplemental oxygen is administered to correct hypoxia.
Airway and breathing are always the first priority in any critically ill patient. An oxygen saturation of 86%86\% is life-threatening and requires immediate intervention.
2
Stabilize Circulation.
Intravenous access is established and fluid resuscitation is initiated.
The patient is in distributive (septic) shock. Immediate restoration of intravascular volume with crystalloid fluids is required to improve end-organ perfusion.
3
Obtain necessary diagnostics before definitive therapy.
Blood cultures and lactate levels are drawn.
Obtaining cultures before administering antibiotics prevents sterilization of the sample, allowing for targeted antimicrobial therapy once sensitivities are known.
4
Administer definitive pharmacologic therapy.
Broad-spectrum intravenous antibiotics are given.
Early source control and antimicrobial therapy are critical for survival in septic shock and should be given within 11 hour of recognition, after cultures are drawn.
5
Reassess and escalate hemodynamic support if necessary.
A vasopressor (norepinephrine) is initiated.
Norepinephrine is indicated only if the patient's mean arterial pressure remains dangerously low after an adequate initial fluid challenge.

Key Concept

The initial stabilization of septic shock follows the ABCs (Airway, Breathing, Circulation) of resuscitation, followed by the rapid execution of the sepsis bundle: drawing cultures before antibiotics, administering broad-spectrum antimicrobials within one hour, and using vasopressors for fluid-refractory hypotension.
Question 3092Question →

A 28-year-old woman is brought to the emergency department by her husband due to severe, diffuse abdominal pain that began 2 days ago. She also reports generalized weakness and a tingling sensation in her hands and feet. Her husband notes that she has been unusually anxious, restless, and confused since yesterday. Her medical history is significant for an uncomplicated urinary tract infection, for which she began taking trimethoprim-sulfamethoxazole 3 days ago. Her temperature is 37.1°C (98.8°F), blood pressure is 158/98 mm Hg, and pulse is 112/min. Physical examination shows a soft, non-distended abdomen with diffuse tenderness to palpation but no guarding or rebound. Bowel sounds are hypoactive. Neurologic examination reveals decreased sensation to pinprick in the bilateral hands and feet, as well as diminished deep tendon reflexes. Complete blood count, comprehensive metabolic panel, and serum lipase are within normal limits. A urine pregnancy test is negative. Which of the following is the most likely diagnosis?

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Answer: Acute intermittent porphyria

Answer

Acute intermittent porphyria
The correct answer is acute intermittent porphyria (AIP). This patient presents with the classic triad of unexplained abdominal pain without peritoneal signs, peripheral neuropathy (sensory loss, diminished reflexes), and psychiatric symptoms (anxiety, confusion). Her autonomic instability (tachycardia, hypertension) is also highly characteristic. AIP is an autosomal dominant disorder of heme synthesis caused by a deficiency in porphobilinogen deaminase. Symptoms are typically episodic and triggered by factors that increase heme demand and induce hepatic cytochrome P450 enzymes, such as fasting, alcohol, and certain medications. Sulfonamides (e.g., trimethoprim-sulfamethoxazole) are notorious porphyrinogenic triggers. The diagnosis is confirmed by elevated urinary porphobilinogen during an acute attack.

Step-by-Step Solution

1
Analyze the patient's presenting symptoms.
The patient exhibits a triad of severe abdominal pain, peripheral neuropathy (tingling, diminished reflexes), and neuropsychiatric disturbances (anxiety, confusion).
Identifying the multi-system nature of the presentation is the first step in formulating a differential diagnosis.
2
Evaluate the objective physical examination findings.
Autonomic hyperactivity (tachycardia, hypertension) is present alongside a lack of peritoneal signs despite severe abdominal pain.
These findings point away from a primary intra-abdominal surgical emergency and toward a systemic or metabolic etiology.
3
Correlate symptom onset with recent medical history.
The symptoms began shortly after the initiation of trimethoprim-sulfamethoxazole.
Identifying a medication trigger helps narrow down specific drug-induced or drug-precipitated metabolic conditions.
4
Synthesize findings to confirm the diagnosis.
The clinical picture matches acute intermittent porphyria triggered by a sulfonamide.
Sulfonamides are known cytochrome P450 inducers that can precipitate acute attacks of porphyria in genetically susceptible individuals.

Key Concept

Acute intermittent porphyria presents with a triad of abdominal pain, neurological deficits, and psychiatric symptoms, and is commonly precipitated by cytochrome P450 inducers such as sulfonamides.
Question 3093Question →

A 45-year-old woman presents to the emergency department with a sudden-onset "thunderclap" headache, severe photophobia, and nuchal rigidity that began 12 hours ago. Her blood pressure is 155/90 mmHg, and her heart rate is 98/min. Neurologic examination reveals no focal deficits. Arrange the following diagnostic modalities and confirmatory protocols in the most appropriate sequential algorithm for the evaluation of this patient, starting with the initial diagnostic test.

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Answer

The correct diagnostic sequence is: Non-contrast computed tomography (NCCT) of the head, followed by a Lumbar puncture (if NCCT is negative), then Computed tomography angiography (CTA) of the head (once confirmed), and finally Digital subtraction angiography (DSA).
The evaluation of a suspected subarachnoid hemorrhage (SAH) follows a strict algorithmic sequence. A non-contrast CT (NCCT) of the head is the initial step due to its high sensitivity for acute blood and rapid acquisition time. Because this patient presents 12 hours after symptom onset, the sensitivity of NCCT is reduced. If the NCCT is negative, a lumbar puncture is mandatory to evaluate for xanthochromia and definitively rule out SAH. Once SAH is confirmed (by either a positive NCCT or lumbar puncture), vascular imaging is required to find the source. CTA of the head is the preferred initial non-invasive study to identify the aneurysm. Finally, Digital Subtraction Angiography (DSA) serves as the gold standard for detailed vascular mapping and is typically performed immediately prior to endovascular therapeutic interventions.

Step-by-Step Solution

1
Identify the suspected diagnosis from the clinical vignette.
The patient's sudden-onset "thunderclap" headache and meningeal signs are highly suspicious for a ruptured cerebral aneurysm causing a subarachnoid hemorrhage (SAH).
Recognizing the classic presentation of SAH is critical for initiating the correct time-sensitive diagnostic algorithm.
2
Determine the initial diagnostic test of choice.
Non-contrast computed tomography (NCCT) of the head.
NCCT is the fastest and most sensitive initial imaging study for detecting acute hemorrhage in the basal cisterns.
3
Identify the mandatory confirmatory protocol if the initial test is negative.
Lumbar puncture for cerebrospinal fluid (CSF) analysis.
Because the sensitivity of NCCT decreases significantly after 6 hours from symptom onset, a lumbar puncture to evaluate for xanthochromia is required to definitively rule out SAH if the NCCT is negative.
4
Determine the next step to identify the bleeding source once SAH is confirmed.
Computed tomography angiography (CTA) of the head.
Once SAH is confirmed by either NCCT or lumbar puncture, non-invasive vascular imaging (CTA) is needed to identify the presence, location, and anatomy of the ruptured aneurysm.
5
Identify the final definitive diagnostic and potentially therapeutic step.
Digital subtraction angiography (DSA).
DSA is the gold standard for characterizing cerebrovascular anatomy and is utilized if CTA is non-diagnostic, or to map the anatomy immediately prior to endovascular coiling or surgical clipping.

Key Concept

The sequential diagnostic algorithm for suspected subarachnoid hemorrhage begins with NCCT of the head, followed by a lumbar puncture if the CT is negative, then CTA of the head to localize the aneurysm, and DSA for definitive evaluation or intervention.
Estimated Time:1m 30s
Question 3094Question →

A 45-year-old woman is evaluated in the surgical recovery unit two hours after an uncomplicated total thyroidectomy. The nursing staff urgently requests a physician assessment because the patient has become increasingly restless and reports severe neck tightness along with difficulty breathing. Physical examination reveals audible inspiratory stridor. Her surgical dressing is saturated with blood, and palpation reveals a tense, rapidly expanding swelling extending unilaterally beneath the incision line. Her vital signs are temperature 37.0°C (98.6°F), blood pressure 160/95 mm Hg, heart rate 118/min, and respiratory rate 28/min. Pulse oximetry demonstrates an oxygen saturation of 91% on room air. Which of the following is the most appropriate immediate next step in the management of this patient?

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Answer: Bedside opening of the surgical wound

Answer

Bedside opening of the surgical wound
The correct answer is bedside opening of the surgical wound. This patient is experiencing a life-threatening expanding neck hematoma following a total thyroidectomy. The presence of inspiratory stridor, respiratory distress, and an expanding neck mass indicates impending complete airway obstruction due to external tracheal compression and impaired venous drainage. The immediate, life-saving intervention is to release the tension by opening the surgical incision (removing sutures or staples) and evacuating the hematoma right at the bedside. This must be done immediately by the evaluating physician to relieve the pressure, which takes precedence over attempting intubation or waiting for specialized personnel.

Step-by-Step Solution

1
Assess the patient's airway, breathing, and circulation (ABCs) in the context of her recent neck surgery.
The patient exhibits stridor, hypoxia, and a visible, expanding neck mass, indicating impending airway collapse.
Initial triage must rapidly identify immediately life-threatening conditions before diagnostic workup or definitive subspecialty care.
2
Identify the primary pathophysiological cause of the airway compromise.
The rapidly expanding mass beneath a fresh thyroidectomy incision strongly suggests a post-operative neck hematoma.
Recognizing the mechanical nature of the obstruction (external compression) dictates the appropriate physical intervention.
3
Determine the most urgent stabilization step to reverse the pathology.
Bedside opening of the surgical wound to evacuate the hematoma is prioritized.
Relieving the external mechanical pressure on the trachea and venous system is required before standard airway interventions can be successful.

Key Concept

In patients presenting with an expanding neck hematoma causing airway compromise after neck surgery, the most urgent initial step is immediate bedside decompression by opening the surgical wound.
Estimated Time:1m 0s
Question 3095Question →

A 66-year-old man presents to the clinic for a follow-up evaluation of acute kidney injury. Over the past two months, he has experienced worsening fatigue and a dull, constant ache in his mid-to-lower back that is not relieved by rest. He has no significant past medical history and takes no medications. Vital signs are temperature 37.1°C (98.8°F), blood pressure 138/86 mmHg, pulse 82/min, and respirations 14/min. Physical examination reveals conjunctival pallor and mild tenderness to palpation over the lumbar spine. Laboratory studies are obtained and shown below:

TestResultReference Range
Hemoglobin9.2 g/dL13.5–17.5 g/dL
Mean corpuscular volume89 fL80–100 fL
Blood urea nitrogen42 mg/dL8–20 mg/dL
Serum creatinine3.4 mg/dL0.7–1.3 mg/dL
Calcium11.6 mg/dL8.4–10.2 mg/dL
Total protein9.4 g/dL6.0–7.8 g/dL
Albumin3.6 g/dL3.5–5.0 g/dL

Urinalysis
Color: Yellow
Specific gravity: 1.012
pH: 6.0
Protein: Trace
Blood: Negative
Glucose: Negative
Microscopy: 1-2 WBCs/hpf, 0-1 RBCs/hpf, occasional granular casts

A 24-hour urine collection is subsequently ordered and reveals a total protein excretion of 4.1 g/day. Based on these laboratory findings, which of the following is the most likely underlying mechanism of this patient's renal failure?

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Answer: Intratubular obstruction by precipitated monoclonal proteins

Answer

Intratubular obstruction by precipitated monoclonal proteins (Myeloma cast nephropathy)
The correct answer describes myeloma cast nephropathy. This patient's laboratory results demonstrate a significantly elevated serum protein gap (Total protein 9.4 - Albumin 3.6 = 5.8 g/dL), hypercalcemia, and normocytic anemia, which strongly suggest multiple myeloma. Furthermore, there is a striking discrepancy between the urine dipstick ('Trace' protein) and the 24-hour urine collection (4.1 g/day of protein). Because standard urine dipsticks primarily detect albumin, this discrepancy indicates the massive excretion of a non-albumin protein—specifically, monoclonal free light chains (Bence Jones proteins). In multiple myeloma, these freely filtered light chains precipitate with Tamm-Horsfall mucoprotein in the distal tubules, causing intratubular obstruction and toxic injury (cast nephropathy).

Step-by-Step Solution

1
Calculate the serum protein gap.
Total protein (9.4 g/dL) - Albumin (3.6 g/dL) = 5.8 g/dL (Normal is < 4 g/dL).
An elevated protein gap indicates the presence of excess non-albumin proteins in the serum, highly suggestive of a monoclonal gammopathy (paraproteinemia).
2
Compare the urine dipstick protein result with the 24-hour urine protein result.
Dipstick shows 'Trace' protein, but the 24-hour collection shows 4.1 g/day (massive proteinuria).
Urine dipsticks utilize a colorimetric assay that primarily detects albumin. A 24-hour urine collection or spot protein-to-creatinine ratio measures all proteins. A large discrepancy indicates heavy excretion of non-albumin proteins, such as free light chains (Bence Jones proteins).
3
Synthesize the laboratory findings with the clinical presentation.
The combination of an elevated protein gap, non-albumin proteinuria, hypercalcemia, normocytic anemia, bone pain, and acute kidney injury points to multiple myeloma.
These are the classic 'CRAB' criteria for multiple myeloma (Calcium elevation, Renal insufficiency, Anemia, Bone lesions).
4
Determine the specific mechanism of renal failure based on the isolated non-albumin proteinuria.
Myeloma cast nephropathy (intratubular obstruction by precipitated monoclonal proteins).
Free light chains are freely filtered at the glomerulus and precipitate with Tamm-Horsfall proteins in the distal tubules, forming obstructing casts. This causes renal failure without significant albuminuria.

Key Concept

Interpreting discrepancies between urine dipstick and quantitative protein tests to identify non-albumin proteinuria (e.g., Bence Jones proteins) in the setting of multiple myeloma.
Question 3096Question →

Seeking evaluation for a predictable pattern of chest discomfort, a 62-year-old male executive visits his primary care physician. Over the last six weeks, he has experienced a squeezing sensation in the center of his chest whenever he walks the two blocks from his commuter train to his office. The discomfort consistently subsides within five minutes of resting or sitting down. He has a history of type 2 diabetes mellitus, hypertension, and advanced osteoarthritis of both knees requiring the use of a mobility aid. Current medications include metformin, lisinopril, and as-needed acetaminophen. Vital signs show a blood pressure of 138/86 mmHg and a heart rate of 72/min. Cardiac auscultation reveals a regular rhythm with no murmurs, rubs, or gallops. Lungs are clear to auscultation bilaterally. A resting 12-lead electrocardiogram demonstrates sinus rhythm, left axis deviation, and a left bundle branch block. Which of the following is the most appropriate next step in the diagnostic evaluation of this patient's symptoms?

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Answer: Pharmacologic vasodilator myocardial perfusion imaging

Answer

Pharmacologic vasodilator myocardial perfusion imaging
The patient's clinical presentation is classic for stable angina, necessitating functional testing for flow-limiting coronary artery disease. The choice of noninvasive stress testing depends on the patient's physical ability to exercise and the presence of baseline electrocardiogram abnormalities. This patient cannot exercise adequately due to severe knee osteoarthritis, mandating a pharmacologic stress test. Furthermore, his baseline left bundle branch block (LBBB) makes standard exercise electrocardiography uninterpretable. Among pharmacologic options, vasodilator stress (using agents like regadenoson or adenosine) with myocardial perfusion imaging (MPI) is specifically indicated for patients with LBBB. Using inotropic stress (like dobutamine) or exercise can induce tachycardia-related false-positive septal defects and worsen paradoxical septal motion on echocardiography, rendering them inappropriate choices.

Step-by-Step Solution

1
Determine the clinical syndrome and pretest probability of coronary artery disease.
The patient has typical exertional angina (substernal, provoked by exertion, relieved by rest), indicating an intermediate to high pretest probability of coronary artery disease.
This establishes the need for diagnostic functional or anatomical testing.
2
Assess the patient's physical capacity to exercise.
The patient has advanced osteoarthritis requiring a mobility aid, indicating an inability to reach target heart rates on a treadmill.
Inability to exercise dictates the need for a pharmacologic stress test rather than an exercise stress test.
3
Evaluate the resting EKG for baseline abnormalities.
The EKG shows a left bundle branch block (LBBB).
A baseline LBBB alters normal ventricular depolarization, rendering ST-segment changes uninterpretable during tachycardia.
4
Select the appropriate stress testing modality based on physical limitations and EKG findings.
Pharmacologic vasodilator myocardial perfusion imaging (MPI) is selected.
Vasodilators (e.g., regadenoson, dipyridamole) combined with MPI are the preferred modality in LBBB because they avoid the false-positive septal perfusion defects and paradoxical septal motion associated with exercise or inotropic (dobutamine) stress.

Key Concept

Patients with suspected stable angina who have a baseline left bundle branch block (LBBB) should undergo pharmacologic vasodilator stress testing with myocardial perfusion imaging.
Estimated Time:1m 15s
Question 3097Question →

A 74-year-old woman presents to her primary care clinic to discuss progressive right knee pain that has been worsening over the past 6 months. She describes the pain as a deep, dull ache that worsens when climbing stairs and improves with rest. She experiences approximately 15 minutes of stiffness in the right knee upon waking in the morning. Her medical history includes hypertension, type 2 diabetes mellitus, stage 4 chronic kidney disease (baseline creatinine 2.4 mg/dL), and a remote history of a bleeding gastric ulcer that required endoscopic intervention. Her current medications are amlodipine, insulin glargine, and acetaminophen 1,000 mg three times daily. She reports that the acetaminophen no longer provides adequate pain relief. Vital signs are within normal limits. Physical examination reveals bony enlargement of the right knee with palpable crepitus during active range of motion. There is no significant warmth, erythema, or joint effusion. A recent radiograph of the right knee shows asymmetric joint space narrowing and subchondral sclerosis.

Which of the following is the most appropriate next step in the pharmacologic management of this patient's knee pain?

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Answer: Topical diclofenac

Answer

Topical diclofenac is the most appropriate intervention because it provides effective localized analgesia for knee osteoarthritis while avoiding the systemic renal and gastrointestinal risks associated with oral agents.
The correct answer is topical diclofenac. This patient has osteoarthritis of the knee that is no longer controlled with acetaminophen. According to current guidelines, topical nonsteroidal anti-inflammatory drugs (NSAIDs) are strongly recommended as a first-line pharmacologic therapy for knee osteoarthritis. Topical NSAIDs like diclofenac provide comparable local pain relief to oral NSAIDs but have minimal systemic absorption. This is particularly advantageous for this patient, who has severe comorbidities—specifically stage 4 chronic kidney disease and a history of a bleeding gastric ulcer—that make oral NSAIDs highly contraindicated. Topical diclofenac safely avoids the risks of renal function deterioration and gastrointestinal bleeding.

Step-by-Step Solution

1
Identify the primary diagnosis and reason for modifying therapy.
The patient has symptomatic knee osteoarthritis that is refractory to maximum-dose acetaminophen.
Establishing the baseline condition and treatment failure is necessary to advance the management algorithm.
2
Analyze the patient's comorbidities to identify absolute and relative contraindications.
The patient has stage 4 chronic kidney disease, a history of a bleeding gastric ulcer, and type 2 diabetes mellitus.
Comorbidities dictate which standard osteoarthritis therapies must be avoided to prevent severe iatrogenic complications.
3
Select the most appropriate analgesic that avoids systemic toxicity.
Topical diclofenac provides effective local pain relief with minimal systemic absorption, safely bypassing both renal and gastrointestinal risks.
Oral NSAIDs and duloxetine are contraindicated due to the severe renal impairment, and systemic NSAIDs pose an unacceptable risk of recurrent gastrointestinal bleeding.

Key Concept

Topical NSAIDs are the preferred first-line pharmacologic therapy for localized osteoarthritis (e.g., knee) in patients with significant comorbidities, such as severe chronic kidney disease or a high risk of gastrointestinal bleeding.
Question 3098Question →

A 54-year-old man presents to the emergency department with a 3-hour history of sudden, severe, and diffuse abdominal pain. He has a history of chronic knee osteoarthritis and takes high-dose naproxen daily. He appears in acute distress and lies completely still on the stretcher. His temperature is 38.2°C (100.8°F), blood pressure is 102/64 mm Hg, pulse is 118/min, and respirations are 22/min. Abdominal examination reveals a rigid, board-like abdomen with diffuse guarding and rebound tenderness. Arrange the following steps in the most appropriate sequence for the management of this patient.

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Answer

The correct sequence of management is: 1) Administer intravenous crystalloids and empiric broad-spectrum antibiotics, 2) Obtain an upright chest radiograph, 3) Perform an emergent exploratory laparotomy, and 4) Initiate testing and eradication therapy for Helicobacter pylori.
This patient's sudden-onset, severe abdominal pain, rigid abdomen, and history of heavy NSAID use strongly suggest a perforated peptic ulcer. The standard of care dictates a sequential approach prioritizing life-saving interventions over definitive medical therapy. Initial management must focus on hemodynamic stabilization with intravenous fluids and broad-spectrum antibiotics to address the chemical peritonitis and developing sepsis. Following initial stabilization, an upright chest radiograph is the most rapid and appropriate diagnostic test to identify subdiaphragmatic free air (pneumoperitoneum), confirming the diagnosis. Once confirmed, emergent exploratory laparotomy is required for source control, typically utilizing an omental (Graham) patch repair and thorough peritoneal washout. Finally, because Helicobacter pylori and NSAID use are the primary drivers of peptic ulcer disease, testing for and eradicating H. pylori (along with NSAID cessation) is a critical postoperative step to prevent recurrence.

Step-by-Step Solution

1
Administer IV crystalloids and antibiotics
Hemodynamic stabilization and early sepsis control
Sepsis and hypovolemia are immediate threats to life in a patient with a perforated viscus and must be addressed before diagnostic delays.
2
Obtain an upright chest radiograph
Detection of pneumoperitoneum
Confirms the diagnosis of a perforated viscus rapidly and cost-effectively without removing the unstable patient from the clinical area for a prolonged period.
3
Perform emergent exploratory laparotomy
Closure of the perforation and peritoneal lavage
Surgical source control is mandatory to stop ongoing contamination of the abdominal cavity and resolve the chemical peritonitis.
4
Initiate H. pylori testing and therapy
Eradication of the underlying pathogen
Definitive medical management prevents future ulcer formation and recurrent perforation.

Key Concept

The standard management sequence for a suspected perforated peptic ulcer involves immediate hemodynamic resuscitation, rapid radiographic confirmation of free air, emergent surgical source control, and subsequent medical management of the underlying etiology.
Question 3099Question →

A 65-year-old man is evaluated in the surgical intensive care unit for acute right lower extremity pain and swelling. He underwent a coronary artery bypass graft 7 days ago. Since his surgery, he has been receiving subcutaneous unfractionated heparin for deep venous thrombosis (DVT) prophylaxis. Vital signs are stable. Physical examination reveals a swollen, erythematous, and tender right calf. Laboratory studies show a platelet count of 55,000/μL55,000/\mu L, a significant decline from his baseline of 260,000/μL260,000/\mu L immediately post-operation. A compression Doppler ultrasound of the right lower extremity confirms a new occlusive DVT in the popliteal vein. A serotonin release assay is strongly positive. Arrange the following pharmacologic management steps in the correct chronological sequence to optimally treat this patient's acute thrombosis and safely transition him to long-term oral anticoagulation.

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Answer

The correct sequence for managing HIT with thrombosis is: 1) Discontinue all heparin products immediately, 2) Initiate a direct thrombin inhibitor such as argatroban, 3) Wait for platelet count recovery (≥150,000/μL\geq 150,000/\mu L) before starting warfarin, 4) Overlap the direct thrombin inhibitor and warfarin for a minimum of 5 days, and 5) Discontinue the direct thrombin inhibitor only after the INR is therapeutic for 2 consecutive days.
The management of HIT with thrombosis follows a strict, guideline-directed pharmacologic sequence to mitigate the massive prothrombotic risk while safely bridging to outpatient therapy. All heparin must be stopped immediately to remove the immunologic trigger. Because the patient has an active DVT and a hypercoagulable state, an alternative rapidly acting parenteral anticoagulant (argatroban) must be started. The transition to warfarin is notoriously dangerous in HIT; it must be delayed until platelets recover to >150,000/μL>150,000/\mu L to avoid venous limb gangrene caused by rapid Protein C depletion. Finally, a strict minimum 5-day overlap of argatroban and warfarin is required to ensure adequate depletion of Factor II (prothrombin), and argatroban is only stopped after the INR is therapeutic for 2 consecutive days.

Step-by-Step Solution

1
Stop all heparin products immediately.
Halts further immune complex formation and platelet activation.
Heparin-PF4 antibodies drive the pathophysiology of HIT; removing the antigen stops the primary disease process.
2
Start a direct thrombin inhibitor (e.g., argatroban).
Provides immediate, effective anticoagulation.
The patient has a highly prothrombotic state and an acute DVT, requiring rapid alternate anticoagulation that does not cross-react with HIT antibodies.
3
Monitor platelet counts until recovery (≥150,000/μL\geq 150,000/\mu L).
Ensures the acute hypercoagulable phase of HIT has subsided before transition.
Starting a Vitamin K antagonist during severe thrombocytopenia risks profound hypercoagulability and venous limb gangrene.
4
Initiate warfarin and maintain overlap therapy for ≥5\geq 5 days.
Allows safe and gradual depletion of procoagulant Factor II.
Warfarin rapidly depletes Protein C (an endogenous anticoagulant) long before Factor II (a procoagulant). Overlap prevents warfarin-induced thrombosis.
5
Stop argatroban when INR is therapeutic for 48 hours.
Patient is safely transitioned to long-term oral monotherapy.
Confirms stable, adequate anticoagulation from warfarin alone.

Key Concept

Pharmacologic sequencing for Heparin-Induced Thrombocytopenia (HIT) with thrombosis
Question 3100Question →

A 34-year-old woman is brought to the emergency department by paramedics after collapsing at a seafood restaurant. Her partner states she began complaining of an itchy throat and difficulty breathing shortly after eating a shrimp appetizer. Her past medical history is significant for asthma and a known shellfish allergy, but she did not have her epinephrine autoinjector with her. Upon arrival, she is lethargic and gasping for air. Physical examination reveals diffuse erythematous hives, marked periorbital edema, and audible inspiratory stridor. Vital signs show a temperature of 37.1°C (98.8°F), blood pressure of 72/42 mm Hg, pulse of 142/min, respiratory rate of 32/min, and oxygen saturation of 86% on room air. Which of the following interventions should be ordered simultaneously as the immediate next steps in management? (Select all that apply)

Select all that apply

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Answer: Intramuscular administration of epinephrine; Rapid intravenous infusion of isotonic crystalloid; High-flow supplemental oxygen therapy

Answer

The correct interventions are intramuscular administration of epinephrine, rapid intravenous infusion of isotonic crystalloid, and high-flow supplemental oxygen therapy.
Severe anaphylaxis presents with distributive shock and impending airway compromise. Immediate stabilization requires a coordinated, simultaneous approach: high-flow oxygen addresses the immediate hypoxia, isotonic crystalloids counter massive vasodilation and capillary leak to restore perfusion, and intramuscular epinephrine reverses bronchoconstriction and induces critical vasoconstriction. These must be executed concurrently to prevent cardiac arrest.

Step-by-Step Solution

1
Assess the patient's clinical presentation and vital signs.
The patient is experiencing distributive shock (hypotension, tachycardia) and impending airway compromise (hypoxia, stridor, lethargy) following allergen exposure.
Rapid recognition of severe anaphylaxis is required to initiate life-saving therapy before complete cardiovascular collapse or airway loss.
2
Prioritize immediate life-saving stabilization over diagnostic workup or adjunctive medications.
Select simultaneous interventions that directly reverse the pathophysiology and address the ABCs (Airway, Breathing, Circulation).
Initial stabilization and triage protocols require immediate action for critical abnormalities without delaying for imaging or delayed-onset medications.
3
Select the specific agents for simultaneous administration.
Choose IM epinephrine to reverse bronchoconstriction and vasodilation, IV crystalloids for distributive shock, and high-flow oxygen for hypoxia.
These three interventions work synchronously to stabilize the patient's critical parameters.

Key Concept

Immediate simultaneous resuscitation in anaphylactic shock requires intramuscular epinephrine, airway management, and aggressive intravenous fluid resuscitation.
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