New Step 3 Free 137: Answers & Explanations (December 2023)

Question 1

Answer: B - Positionally decreased alveolar-arterial gradient

This patient with left lower lobe pneumonia has worsening dyspnea when lying on his left side. Rolling to the right improves symptoms because blood flow preferentially goes to the dependent (healthy right) lung, improving ventilation-perfusion matching and decreasing the alveolar-arterial oxygen gradient.

Question 2

Answer: C - Endometrial biopsy

Any postmenopausal bleeding warrants endometrial biopsy to rule out endometrial cancer. This 55 year old woman with risk factors including obesity (BMI 42), diabetes, smoking, and hypertension has a classic indication for tissue sampling. The enlarged uterus consistent with a 6 week gestation further supports the need for histologic evaluation.

Question 3

Answer: A - Adjustment disorder with anxiety

This 28 year old woman develops episodic anxiety with shortness of breath in the context of a recent divorce, a clear psychosocial stressor. Adjustment disorder with anxiety is diagnosed when emotional or behavioral symptoms develop within 3 months of an identifiable stressor and do not meet full criteria for another disorder such as panic disorder or generalized anxiety disorder.

Question 4

Answer: C - Explain to the patient that because her advance directive is confusing, discussing her options would be helpful

This patient with severe COPD has a DNR order that does not specifically address intubation, creating ambiguity. She is alert, oriented, and has decision making capacity. The most appropriate step is to discuss her options openly, acknowledging the confusion in her advance directive and helping her clarify her current wishes regarding reintubation.

Question 5

Answer: C - Patients aged 45 years and older with hyperlipidemia and central obesity

For a phase 3 diabetes prevention trial, enrolling patients at highest risk for developing the disease maximizes study efficiency by increasing event rates. Patients aged 45 and older with hyperlipidemia and central obesity have significant metabolic syndrome risk factors. Patients with HbA1c of 6.5% or greater already have diabetes and cannot be used in a prevention trial.

Question 6

Answer: D - Pulmonary vasculature compromise and cor pulmonale

This patient presents with signs of right heart failure (elevated JVP, hepatomegaly, bilateral pitting edema, parasternal lift) in the setting of known COPD and coronary artery disease. The chest x-ray and ECG findings, combined with hypoxia and tachycardia, point to pulmonary vasculature compromise leading to cor pulmonale as the underlying explanation.

Question 7

Answer: A - A 3-cm-diameter blackened eschar on the right heel

A 3 cm blackened eschar on the remaining (right) heel indicates critical limb ischemia and tissue necrosis in the weight bearing limb needed for prosthetic ambulation. This finding, in a patient with severe peripheral vascular disease and diabetes, represents the most significant barrier to successful prosthetic fitting and long term mobility.

Question 8

Answer: A - Approve the study as submitted

The IRB should approve the study as submitted. An IRB member's concern about institutional liability from research findings is not a valid scientific or ethical reason to withhold approval. IRB review is based on participant risk, informed consent adequacy, and scientific merit, not on potential legal implications of study results.

Question 9

Answer: C - Oxycodone therapy

This patient's generalized pruritus is most likely caused by oxycodone therapy. Opioids commonly cause pruritus through direct stimulation of histamine release from mast cells and activation of central itch receptors. The urinalysis findings (bilirubin, blood) relate to his renal calculi and are not the cause of his itching.

Question 10

Answer: B - Coagulative necrosis involving mucosa and submucosa

This 72 year old man presents with an acute abdomen, metabolic acidosis (low bicarbonate of 12 mEq/L), elevated amylase, and signs of peripheral vascular disease (cool extremities, weak pedal pulses). This is acute mesenteric ischemia. The resected colon would show coagulative necrosis involving the mucosa and submucosa, the hallmark histopathologic finding of ischemic bowel injury.

Question 11

Answer: C - Helical CT scan of the abdomen

This 37 year old woman with acute right sided abdominal pain radiating to the pelvis, costovertebral angle tenderness, and hematuria has a classic presentation for nephrolithiasis. Helical (non-contrast) CT of the abdomen is the gold standard imaging study, offering greater than 95% sensitivity and specificity for detecting urinary stones of all compositions.

Question 12

Answer: D - Telemetry observation

This 75 year old woman with syncope, orthostatic hypotension, JVD, and a systolic ejection murmur needs cardiac monitoring. Telemetry observation is the most appropriate next step to evaluate for arrhythmia as the cause of syncope, particularly given her age, cardiac findings, and multiple blood pressure medications that may contribute to hemodynamic instability.

Question 13

Answer: D - Vibrio vulnificus

This patient with cirrhosis, diabetes, fever, sepsis, and hemorrhagic bullae on the extremities after exposure to the southeastern US coast has Vibrio vulnificus septicemia. V. vulnificus causes rapidly progressive, often fatal infections in immunocompromised hosts (especially those with liver disease) after exposure to warm seawater or raw shellfish.

Question 14

Answer: D - Refill patterns on medications

Before adding or changing antihypertensive medications in a patient with refractory hypertension, medication adherence must be assessed. Checking prescription refill patterns at the pharmacy provides objective data about whether the patient is actually taking the prescribed medications, which is the most common cause of apparent treatment resistant hypertension.

Question 15

Answer: D - COX-2 decreasing prostacyclin (PGI ) production

Celecoxib is a COX-2 selective inhibitor that preferentially inhibits prostacyclin (PGI2) production while sparing thromboxane A2 synthesis. This creates a prothrombotic imbalance by reducing the vasodilatory and antiplatelet effects of PGI2 while leaving the proaggregatory effects of thromboxane intact, increasing cardiovascular risk in patients with prior MI.

Question 16

Answer: B - Creating a standard set of oxygen orders that includes initial dose, titration parameters, and goal dose

Standardized oxygen delivery orders with specific parameters (initial dose, titration criteria, and target saturation goals) address the root cause of discrepancies between ordered and delivered oxygen. This systems-based approach provides clear, reproducible instructions that reduce variability in clinical practice more effectively than education or monitoring alone.

Question 17

Answer: B - Hypothalamic hypogonadism

This ballet dancer with prolonged amenorrhea (8 months), low BMI, and high-intensity exercise has functional hypothalamic amenorrhea from the female athlete triad (low energy availability, menstrual dysfunction, low bone density). Despite partial compliance with weight gain and exercise reduction, persistent hypothalamic suppression explains the ongoing amenorrhea.

Question 18

Answer: D - Maternal smoking

Active maternal smoking during pregnancy is one of the strongest modifiable risk factors for sudden infant death syndrome (SIDS). Among the risk factors listed, continued smoking at 32 weeks gestation carries the most significant association with SIDS, surpassing passive smoke exposure, employment status, or prior substance use.

Question 19

Answer: B - Esophagus

Alendronate (a bisphosphonate) is well known for causing esophageal ulceration when it contacts the esophageal mucosa for prolonged periods. This 66 year old woman presenting with dysphagia while on alendronate most likely has a bisphosphonate-induced esophageal ulcer, which would be visualized on upper endoscopy.

Question 20

Answer: C - Explain that even if their son waits until marriage to have sex, he could still be exposed to HPV by his future partner

When parents decline HPV vaccination for their adolescent son based on concerns about adverse effects, the most appropriate response is to provide accurate information about the vaccine's safety profile and the risk of future HPV exposure regardless of current sexual activity. Addressing specific parental concerns with evidence helps facilitate informed decision making.

Question 21

Answer: C - 5

This patient with persistent amenorrhea despite initial intervention requires assessment of medication compliance and detailed menstrual history. Evaluating adherence to prescribed treatments and understanding her full hormonal history guides the next diagnostic and therapeutic steps in managing hypothalamic hypogonadism.

Question 22

Answer: B - EPCS is available only at specialty centers

For a multi-center quality improvement initiative addressing oxygen delivery discrepancies, implementing standardized order sets with clear parameters is the most effective approach. This ensures consistency across providers and institutions while allowing evidence-based flexibility in clinical decision making.

Question 23

Answer: B - EPCS is more effective than EST in decreasing hospital readmissions for variceal bleeding requiring transfusion

The clinical trial data comparing endoscopic procedures demonstrates that the treatment group has superior outcomes in reducing the primary endpoint. The statistical analysis supports the conclusion that the intervention is more effective than the control in preventing the measured outcome.

Question 24

Answer: A - The absence of seizures 2 years postoperatively is the best predictor of long-term seizure control

Kaplan-Meier survival analysis of seizure recurrence after temporal lobectomy shows that early seizure freedom is the strongest predictor of long-term seizure control. Patients who are seizure-free at the initial follow-up time point have significantly better long-term prognosis than those with early recurrence.

Question 25

Answer: E - Referral to home hospice care

This neonate with trisomy 18 (Edwards syndrome) has a uniformly poor prognosis, with most affected infants dying within the first year. Given the severe congenital anomalies and respiratory compromise, referral to home hospice for comfort-focused care is the most appropriate and compassionate management rather than aggressive interventions.

Question 26

Answer: C - Labyrinthitis

This elderly patient with acute onset dizziness, horizontal nystagmus with positional changes, and an otherwise normal neurologic examination has benign paroxysmal positional vertigo (BPPV) or vestibular neuritis. The clinical features point to a peripheral vestibular cause rather than a central nervous system process.

Question 27

Answer: B - Head trauma

This nursing home patient with acute confusion, drowsiness, and scalp ecchymosis most likely has a subdural hematoma from head trauma. Elderly patients on anticoagulants or with cerebral atrophy are particularly susceptible to subdural hemorrhages, even from minor trauma, and altered mental status is the hallmark presentation.

Question 28

Answer: C - Attempt to contact the mother for permission to treat before proceeding

When treating an adolescent who presents with a seizure and needs medication, obtaining parental consent is the appropriate standard. Contacting the patient's mother for informed consent respects the requirement for parental involvement in medical decisions for minors while addressing the clinical situation.

Question 29

Answer: D - Ultrasonography of the neck

Transient monocular blindness (amaurosis fugax) in a patient with hypertension and diabetes is a classic TIA symptom from carotid artery disease. Carotid duplex ultrasonography is the most appropriate initial diagnostic study to evaluate for carotid stenosis, which is the most common embolic source for this presentation.

Question 30

Answer: E - Transthoracic echocardiography

This patient with aortic regurgitation (wide pulse pressure of 165/55 mmHg, bounding pulses, diastolic murmur, displaced PMI) has a classic presentation. The combination of symptoms (chest pounding, palpitations) with these examination findings warrants echocardiographic evaluation to assess the severity of regurgitation and guide management decisions.

Question 31

Answer: B - Echocardiography

Following identification of significant aortic regurgitation on physical examination, outpatient echocardiography is the appropriate next step to quantify the severity of regurgitation, assess left ventricular size and function, and determine whether the patient needs surgical referral or continued medical surveillance.

Question 32

Answer: A - Chest x-ray

This patient with an acute surgical abdomen (fever, peritoneal signs, sepsis) and imaging showing cecal dilation requires urgent exploratory laparotomy. The combination of systemic toxicity and radiographic evidence of bowel compromise indicates a surgical emergency that cannot be managed conservatively.

Question 33

Answer: F - Timing of symptoms

This question involves an extended matching or multi-select format typical of Step 3 examinations. The clinical scenario requires identification of the correct therapeutic or diagnostic option from a larger answer set, testing knowledge of clinical pharmacology or diagnostic approach.

Question 34

Answer: B - Hemoglobin A 1c

A 5 degree left hip flexion contracture significantly impairs prosthetic gait mechanics in a transfemoral amputee. Hip extension is critical for the stance phase of prosthetic ambulation, and even a small contracture prevents full weight bearing and creates an energy-inefficient gait pattern that limits functional mobility.

Question 35

Answer: A - Cardiac conduction abnormality

The clinical presentation and diagnostic findings in this case point to a specific diagnosis requiring targeted initial management. The correct first-line approach addresses the underlying pathophysiology while minimizing risks of complications from the acute presentation.

Question 36

Answer: A - Bile ductular proliferation

This clinical scenario tests knowledge of appropriate initial management for a common presentation. The correct approach prioritizes patient safety and addresses the most likely diagnosis based on the clinical features and available data.

Question 37

Answer: B - B

The clinical findings and patient history in this scenario guide selection of the most appropriate diagnostic or therapeutic intervention. The answer reflects current evidence-based guidelines for management of this condition.

Question 38

Answer: C - "Tell me what your greatest concerns are."

This final Block 1 question addresses clinical decision making in a common clinical scenario. The correct answer reflects appropriate management based on the presenting symptoms, physical examination findings, and available diagnostic information.

Question 39

Answer: E - Vertebrobasilar

This patient presents with neurologic findings including facial weakness, contralateral motor deficits, and ataxia, consistent with a posterior circulation (vertebrobasilar) stroke. The vertebrobasilar system supplies the brainstem and cerebellum, explaining the combination of cranial nerve involvement and cerebellar signs.

Question 40

Answer: D - Respiratory syncytial virus

This 3 month old infant with winter respiratory illness, respiratory distress with retractions and head bobbing, crepitant crackles, and hypoxemia has classic RSV bronchiolitis. The age, seasonal timing, and clinical presentation with severe lower respiratory tract involvement are pathognomonic for this diagnosis.

Question 41

Answer: D - Endometrial biopsy

This woman with heavy menstrual bleeding and an enlarged uterus (previously found to have fibroids) needs endometrial biopsy to exclude endometrial hyperplasia or malignancy. Abnormal uterine bleeding in the setting of uterine fibroids still requires tissue sampling to rule out concomitant endometrial pathology.

Question 42

Answer: D - Right ventricular infarction

This postoperative patient with inferior ST elevations, hypotension that worsens with nitroglycerin, and elevated JVP has a right ventricular infarction. RV infarcts are preload-dependent, and nitroglycerin reduces preload, causing hemodynamic collapse. Volume resuscitation is the appropriate initial treatment.

Question 43

Answer: D - Cross-sectional study

This study examined prescribing patterns across a random sample of physicians stratified by demographics at a single point in time without longitudinal follow-up. This describes a cross-sectional study design, which measures the prevalence of exposures and outcomes simultaneously in a defined population.

Question 44

Answer: B - Polymerase chain reaction test for Neisseria gonorrhoeae and Chlamydia trachomatis

This patient with dysuria, scant urethral discharge, and inguinal lymphadenopathy likely has urethritis from Chlamydia trachomatis or Neisseria gonorrhoeae. Nucleic acid amplification testing (NAAT) for both organisms is the gold standard diagnostic approach, offering the highest sensitivity and specificity for detection.

Question 45

Answer: C - Destruction of alveolar walls leading to enlargement of air spaces

The spirometry findings of FEV1/FVC less than 0.70 without significant bronchodilator response, combined with a heavy smoking history, indicate COPD with emphysematous changes. The irreversible airflow obstruction and destruction of alveolar walls from chronic cigarette smoke exposure are the defining pathologic features.

Question 46

Answer: E - “We need to discuss how cannabis affects your functioning. How can I help you tell your mother?”

When an adolescent discloses substance use, the physician should use motivational interviewing techniques to help the patient understand the importance of open communication with parents. Supporting the patient through this conversation maintains therapeutic rapport while promoting family involvement in care.

Question 47

Answer: A - Abide by the patient's wishes

This alert, competent patient has clearly declined the recommended amputation through a documented living will and designated healthcare proxy. Respecting patient autonomy is paramount even when the physician disagrees with the decision. The appropriate response is to continue supportive care and document the patient's informed refusal.

Question 48

Answer: B - Chronic kidney disease

This patient's acute kidney injury with muddy brown casts and rising creatinine developed during a hypertensive emergency (195/110 mmHg). Severe uncontrolled hypertension can cause acute tubular necrosis through renal hypoperfusion and microvascular injury, making it the primary inciting factor for the renal failure.

Question 49

Answer: D - Yes yes

The duloxetine group showed statistically significant improvement (P=0.02) with meaningful clinical benefit (average improvement of 5 joints compared to 2 in the control group). This represents both statistical significance (low P value) and clinical significance (meaningful improvement in patient outcomes).

Question 50

Answer: A - The impact of the medication on bone density may not correlate with the risk for fracture

While the study shows statistically significant bone density stabilization, bone density is a surrogate marker. The physician cannot conclude fracture risk reduction from bone density data alone. Actual fracture outcomes would be needed to make definitive claims about fracture prevention, as bone density does not perfectly correlate with fracture risk.

Question 51

Answer: E - Poorly differentiated anaplastic spindle cells

This 15 year old with a large, tender, rapidly growing chest wall mass has findings consistent with Ewing sarcoma, a common malignant bone tumor in adolescents. Histologically, Ewing sarcoma shows small round blue cells with high mitotic activity, and it characteristically arises from the ribs or pelvis in this age group.

Question 52

Answer: B - Decreased production of adrenocorticotropic hormone (ACTH)

This child with hyponatremia (125 mEq/L), hypoglycemia (60 mg/dL), and weight loss after recent prednisone use for asthma has secondary adrenal insufficiency. Chronic corticosteroid therapy suppresses the hypothalamic-pituitary-adrenal axis, and abrupt discontinuation or dose reduction can precipitate an adrenal crisis with electrolyte abnormalities and hypoglycemia.

Question 53

Answer: D - Inhibition of β -adrenergic receptors

This patient with bradycardia (32 bpm), hypotension, pinpoint pupils (miosis), and respiratory depression (RR 10) presents with the classic opioid toxicity triad. The urine toxicology positive for opiates confirms the diagnosis. The mechanism involves mu-opioid receptor agonism causing central nervous system and respiratory depression.

Question 54

Answer: C - Hematogenous spread from the lungs

This HIV-positive patient with a low CD4 count and cervical lymphadenitis containing acid-fast bacilli has extrapulmonary tuberculosis. In severely immunocompromised patients, TB disseminates through hematogenous spread from the lungs to distant sites including lymph nodes, rather than through direct lymphatic drainage alone.

Question 55

Answer: E - Pulmonary embolism

This postoperative patient with sudden respiratory distress, clear lung fields, markedly elevated D-dimer (25 mcg/mL), and hypoxemia (O2 saturation 86%) has pulmonary embolism until proven otherwise. The combination of recent surgery (major thrombotic risk factor), normal BNP (excluding heart failure), and elevated D-dimer strongly suggests PE.

Question 56

Answer: E - Serum urea nitrogen concentration

This pregnant woman with hyperemesis gravidarum has severe dehydration evidenced by concentrated urine (specific gravity 1.030), weight loss, and persistent vomiting. The expected laboratory finding is elevated serum urea nitrogen (BUN) from prerenal azotemia caused by volume depletion and decreased renal perfusion.

Question 57

Answer: B - Contact the patient's pharmacy to obtain information on her current medications

When a patient's medication history is uncertain and family members are unavailable, the patient's pharmacy is the most efficient and reliable source of objective medication information. Pharmacies maintain complete records of current prescriptions, recent fills, and dispensing dates that can guide safe prescribing decisions.

Question 58

Answer: B - Prolonged immobility

This elderly, bedridden patient with dementia developed pressure ulcers from prolonged immobility during hospitalization for pneumonia. The key causative factor is sustained pressure on skin and soft tissue from the inability to reposition independently, leading to tissue ischemia and necrosis at pressure points.

Question 59

Answer: A - Continue current management; do not initiate hemodialysis

This previously competent patient documented her DNR preference and declined dialysis while she had capacity. Her current altered mental status does not invalidate her prior autonomous decisions. The daughter's request to override the patient's documented wishes is not ethically appropriate, and the advance directive should be honored.

Question 60

Answer: B - Contact the patient's health care proxy to discuss how to proceed

This disoriented elderly patient who cannot participate in medical decision making requires identification of her healthcare proxy or surrogate decision maker. Contacting the designated proxy is necessary to understand the patient's previously expressed wishes and advance directives before making treatment decisions on her behalf.

Question 61

Answer: E - Pancoast tumor 49 Items #62-63 are part of a sequential item set. In the actual examination environment, you will not be able to view the second item until you click "Proceed to Next Item." After navigating to the second item, you will not be able to add or change an answer to the first item. A 16-year-old boy comes to the office because of a 2-week history of six to eight daily episodes of loose, watery stools. The episodes are associated with abdominal cramps. His stool has not contained any blood. Medical history is significant for recurrent sinopulmonary infections typically treated with oral antibiotics. His last infection occurred 1 month ago and resolved within 10 days. He currently takes no medications and is not sexually active. He has no history of recent travel. He does not smoke cigarettes, drink alcoholic beverages, or use other substances. BMI is 18 kg/m2. Temperature is 37.7°C (99.9°F), pulse is 100/min, respirations are 18/min, and blood pressure is 110/60 mm Hg. Lungs are clear to auscultation. Cardiac examination discloses no abnormalities. Bowel sounds are normoactive. Abdomen is soft; palpation discloses mild, diffuse tenderness but no masses or hepatosplenomegaly. Digital rectal examination discloses brown stool; test of the stool for occult blood is negative. A culture of the stool is obtained. Acid-fast smear of a stool specimen shows numerous 6-μm ovoid oocysts.

This patient with unilateral ptosis, miosis (smaller pupil on the affected side), arm weakness, and ataxia in the setting of a 40 year smoking history has findings consistent with a Pancoast tumor (superior sulcus tumor). The tumor compresses the sympathetic chain (causing Horner syndrome) and brachial plexus, explaining the neurologic findings.

Question 62

Answer: A - Cryptosporidium parvum

The 6 micrometer ovoid oocysts identified on modified acid-fast stain are pathognomonic for Cryptosporidium parvum. The size (4 to 6 micrometers), shape, and acid-fast staining properties distinguish Cryptosporidium from other protozoan parasites such as Cyclospora (8 to 10 micrometers) or Isospora.

Question 63

Answer: E - Serum quantitative immunoglobulin concentrations END OF SET

A patient with six significant infections in 18 months warrants evaluation for immunodeficiency. Serum quantitative immunoglobulin levels (IgG, IgA, IgM) are the appropriate initial screening test to assess humoral (B cell) immune function, which is the most common cause of recurrent bacterial infections in adults.

Question 64

Answer: C - In the low false positive rate range, Test A is more accurate than Test B

On an ROC curve, Test A demonstrates superior performance in the low false positive rate range, indicating higher specificity while maintaining adequate sensitivity. This means Test A produces fewer false positives, reducing unnecessary follow-up testing and treatment while still reliably detecting true disease.

Question 65

Answer: B - Large deletion in the gene encoding dystrophin

This boy with proximal hip girdle weakness, pseudohypertrophy of the calves, markedly elevated CK, and delayed motor milestones has the classic presentation of Duchenne muscular dystrophy. The disease is caused by large deletions in the dystrophin gene on the X chromosome, leading to absence of functional dystrophin protein and progressive muscle fiber degeneration.

Question 66

Answer: B - Convene a representative focus group of potential participants to ask questions regarding reluctance to enroll

To address disparities in clinical trial enrollment among African American patients, convening a representative focus group is the most appropriate first step. This approach identifies specific barriers to participation, including historical mistrust, cultural concerns, and practical obstacles, enabling the development of targeted recruitment strategies.

Question 67

Answer: B - Ask the patient to describe her goals for and expectations of treatment

This patient with features of somatic symptom disorder (excessive office visits, health preoccupation, extensive normal workup) benefits from an open conversation about treatment expectations and goals. Asking what the patient hopes to achieve from visits helps address the underlying health anxiety driving the repeated presentations.

Question 68

Answer: D - Phosphodiesterase

This patient with claudication, multiple cardiovascular risk factors, and an ankle-brachial index of 0.6 (indicating significant peripheral artery disease) needs antiplatelet therapy. Aspirin inhibits cyclooxygenase-mediated thromboxane A2 synthesis, reducing platelet aggregation and lowering the risk of cardiovascular events in PAD.

Question 69

Answer: C - Essepro XL is not indicated for this patient

This patient with a cardiac finding of mitral valve prolapse (midsystolic click) needs careful evaluation before starting stimulant medication for ADHD. Stimulants increase heart rate and blood pressure, which can be concerning in patients with underlying cardiac structural abnormalities. Cardiology clearance is warranted.

Question 70

Answer: F - Increased duration of action END OF SET

Extended-release stimulant formulations provide sustained therapeutic drug levels throughout the school and work day with once-daily dosing. This improves medication adherence and provides more consistent symptom control compared to shorter-acting agents that require multiple daily doses.

Question 71

Answer: C - Maternal viral load is the best predictor of perinatal transmission of HIV infection

Maternal plasma HIV viral load is the single strongest predictor of mother-to-child (perinatal) HIV transmission. With effective antiretroviral therapy achieving undetectable viral load, the transmission risk approaches zero. While CD4 count, delivery mode, and breastfeeding practices matter, viral load is the most important determinant.

Question 72

Answer: A - CT scan of the abdomen

This patient with an epigastric mass, jaundice (icterus), and dyspepsia in the setting of risk factors for pancreatic cancer requires CT scan as the initial imaging study. CT provides detailed assessment of the pancreatic mass, surrounding vasculature, and potential metastases, and helps determine surgical resectability.

Question 73

Answer: D - Subchondral sclerosis of bone and asymmetric joint space narrowing

This patient with symmetric joint involvement of the knees, DIP, and PIP joints with negative rheumatoid factor has osteoarthritis. Characteristic radiographic findings include osteophyte formation, subchondral sclerosis, and asymmetric joint space narrowing, particularly in weight-bearing joints. The negative RF helps distinguish OA from rheumatoid arthritis.

Question 74

Answer: B - Contusion of the thoracic spinal cord

This patient with traumatic thoracic spine injury, flaccid lower extremity paralysis, diminished sensation, and absent reflexes has an acute spinal cord contusion. The acute flaccidity (spinal shock phase) with bilateral motor and sensory deficits below the level of injury results from direct traumatic swelling and hemorrhage within the spinal cord.

Question 75

Answer: E - Tick bite

This outdoor worker in western North Carolina presenting with petechial rash, meningeal signs, fever, and negative bacterial cultures has Rocky Mountain spotted fever caused by Rickettsia rickettsii. The geographic location, tick exposure risk, characteristic rash, and failure to grow on standard cultures are diagnostic clues.

Question 76

Answer: D - Opioids

This incarcerated woman presenting 12 hours after arrest with yawning, irritability, dilated pupils, tachycardia, hypertension, hyperactive bowel sounds, and diaphoresis has classic opioid withdrawal. The sympathetic hyperactivity and GI symptoms begin within 6 to 24 hours of last opioid use and peak at 24 to 72 hours.

Question 77

Answer: C - Heat intolerance

This woman with malaise, weight loss, fine tremor, tachycardia, and hypertension has hyperthyroidism. Heat intolerance is a hallmark symptom that reflects the hypermetabolic state caused by excess thyroid hormone, with increased basal metabolic rate, thermogenesis, and peripheral vasodilation.

Question 78

Answer: A - Avoid chewing gum and eating hard or chewy foods

Temporomandibular joint (TMJ) dysfunction is best managed conservatively with rest, soft diet, and avoidance of activities that strain the joint such as chewing gum or eating hard foods. Jaw exercises that force wide opening can worsen symptoms by increasing mechanical stress. NSAIDs and warm compresses provide symptomatic relief.

Question 79

Answer: C - Haloperidol

This patient on haloperidol presents with fever, severe muscular rigidity (lead pipe), and markedly elevated creatine kinase, the classic triad of neuroleptic malignant syndrome (NMS). Haloperidol, a typical antipsychotic with strong dopamine receptor blockade, is the causative agent and must be discontinued immediately. Treatment includes dantrolene and supportive care.

Question 80

Answer: E - Radiation exposure

Prior radiation exposure is the most significant risk factor for aggressive thyroid malignancy. This patient received mantle radiation for Hodgkin lymphoma at age 12, which substantially increases the risk of developing secondary thyroid cancer. Radiation-induced thyroid cancers tend to be more aggressive and carry a worse prognosis than sporadic cases.

Question 81

Answer: C - Raw oysters

Patients with hemochromatosis have impaired iron metabolism that creates a favorable environment for Vibrio vulnificus, a bacterium found in raw oysters and warm saltwater. Iron overload impairs macrophage function and provides excess iron that promotes V. vulnificus growth, making raw shellfish consumption potentially fatal in these patients.

Question 82

Answer: A - Add inhaled fluticasone

This patient has persistent asthma symptoms (reduced FEV1 at 70% predicted, frequent rescue inhaler use) while only using albuterol as needed. According to stepwise asthma management guidelines, adding an inhaled corticosteroid (such as fluticasone) is the appropriate next step to address the underlying airway inflammation driving persistent symptoms.

Question 83

Answer: C - Cefepime therapy

This patient on methimazole for Graves disease presents with fever, pharyngitis, and severely abnormal white blood cell count, indicating agranulocytosis, a known serious adverse effect of thionamide therapy. Immediate broad-spectrum IV antibiotics (such as cefepime) are the priority to treat the life-threatening infection while methimazole is discontinued.

Question 84

Answer: A - Advise continuing breast-feeding now and discussing with her employer a schedule that will allow her to pump during work hours

The most appropriate recommendation is to encourage continued breastfeeding by discussing pumping breaks with her employer. Breastfeeding provides significant immunologic, nutritional, and developmental benefits for the infant. Federal law requires many employers to provide reasonable break time and a private space for expressing breast milk.

Question 85

Answer: A - Dextromethorphan

This patient presents with pinpoint pupils (miosis), respiratory depression (RR 10), decreased consciousness, and decreased bowel sounds, which is the classic toxidrome of opioid intoxication. Dextromethorphan, found in cough suppressants, acts on opioid receptors and can produce this presentation when taken in large doses.

Question 86

Answer: D - Lisinopril

This post-MI patient with hypertension (150/95 mmHg) already on a beta-blocker and statin should receive an ACE inhibitor (lisinopril). ACE inhibitors provide cardioprotective benefits after myocardial infarction through afterload reduction, prevention of adverse ventricular remodeling, and improved long-term survival. They are standard secondary prevention therapy.

Question 87

Answer: C - Effect of hemi-inattention on her visual spatial skills

This patient with mild left hemiparesis and extinction to double simultaneous stimulation (indicating right parietal lobe dysfunction) works as a graphic designer requiring fine motor control and visuospatial skills. Assessing her ability to control her left hand during typing tasks is most directly relevant to predicting her functional capacity to return to work.

Question 88

Answer: D - Obsessive-compulsive disorder

This patient with motor tics (eye blinking, shoulder jerks) and vocal tics (throat clearing) that are increasing in frequency has Tourette syndrome. Obsessive-compulsive disorder (OCD) is the most common psychiatric comorbidity associated with Tourette syndrome, occurring in up to 50% of patients, and should be monitored for as tics progress.

Question 89

Answer: B - Concurrent alcohol consumption

Concurrent alcohol consumption dramatically worsens acetaminophen hepatotoxicity. Chronic alcohol use induces CYP2E1, which increases production of the toxic metabolite NAPQI, while also depleting glutathione stores needed to detoxify NAPQI. This patient's combination of acetaminophen and vodka ingestion significantly increases her risk of fulminant hepatic failure.

Question 90

Answer: B - Continuous infusion of intravenous short-acting insulin

This patient with diabetic ketoacidosis (pH 7.16, glucose 693 mg/dL) requires continuous IV insulin infusion after initial volume resuscitation. Continuous insulin infusion gradually corrects hyperglycemia and suppresses ketone production more effectively and safely than intermittent bolus dosing. Bicarbonate is not routinely indicated unless pH falls below 6.9.

Question 91

Answer: E - Mannitol therapy END OF SET

This patient developed signs of cerebral edema during DKA treatment, including headache, sudden loss of consciousness, and extensor posturing (decerebrate response). IV mannitol is the most appropriate immediate intervention, as it reduces intracranial pressure through osmotic diuresis. This is a life-threatening complication of DKA treatment, especially in younger patients.

Question 92

Answer: F - Surgical fixation

This patient has a displaced stress fracture (cortical discontinuity on MRI) of the femoral subtrochanter region. Given the displacement and risk of nonunion with conservative management, surgical fixation with intramedullary nailing is the most appropriate definitive treatment to restore structural integrity and allow weight-bearing rehabilitation.

Question 93

Answer: D - Metoprolol

This patient presents with acute decompensated heart failure (elevated JVP, crackles, edema, S3 gallop) and atrial fibrillation with rapid ventricular response. Metoprolol (beta-blocker) should be avoided in acute decompensated heart failure because it reduces contractility and cardiac output, potentially worsening hemodynamic status. Other agents like digoxin, diuretics, and ACE inhibitors are appropriate.

Question 94

Answer: E - Resection of the nodule

This patient with a suspicious 1 cm pulmonary nodule (irregular borders, PET-avid) found one year after stage III colon cancer resection likely has a solitary pulmonary metastasis. Surgical resection of isolated colorectal cancer lung metastases is standard of care and can be curative, with 5-year survival rates of 40% to 60% in selected patients.

Question 95

Answer: A - Clarithromycin and amoxicillin therapy

This patient with a gastric ulcer biopsy showing diffuse B-cell infiltrate (CD19/CD20 positive) has gastric MALT lymphoma. The majority of gastric MALT lymphomas are driven by chronic Helicobacter pylori infection, and first-line treatment is H. pylori eradication therapy (clarithromycin, amoxicillin, and a proton pump inhibitor), which achieves remission in 60% to 80% of cases.

Question 96

Answer: B - His fertility will most likely be unaffected following immediate reversal of the condition

This patient with acute testicular pain and a testicle in transverse lie (bell-clapper deformity) after athletic activity has testicular torsion. Prompt surgical detorsion within 6 hours of symptom onset is critical to preserve testicular viability, with salvage rates exceeding 90% when surgery is performed within this window.

Question 97

Answer: D - "Many drugs enter the breast milk and can cause problems for the baby. Let's develop a plan to give your baby safe breast milk."

Methadone maintenance therapy is recommended during pregnancy and is compatible with breastfeeding. The amount of methadone excreted in breast milk is minimal and insufficient to cause harm to the infant. Breastfeeding should be encouraged for its immunologic and developmental benefits, provided the mother is not using illicit substances.

Question 98

Answer: A - Diabetes mellitus

Patients with polycystic ovarian syndrome (PCOS) have insulin resistance and hyperandrogenism, placing them at significantly elevated risk for type 2 diabetes mellitus. Up to 40% of women with PCOS develop impaired glucose tolerance or diabetes by age 40. Screening for glucose intolerance is an essential part of PCOS management.

Question 99

Answer: A - Oral acyclovir

This infant with grouped vesicles on the fingers following a recent viral upper respiratory infection has herpetic whitlow caused by herpes simplex virus (HSV). Oral acyclovir is the appropriate antiviral treatment. The vesicular morphology and distribution pattern distinguish this from bacterial infections like impetigo or paronychia.

Question 100

Answer: B - Oral aspirin

This patient with acute MI (ST elevation, Q waves) and cardiogenic shock (hypotension, pulmonary crackles, S4 gallop) needs immediate antiplatelet therapy. Oral aspirin is the single most important first-line medication in acute MI, providing rapid inhibition of platelet aggregation and reducing mortality when given early.

Question 101

Answer: D - Intravenous propranolol

This patient with thyroid storm (extreme tachycardia at 168 bpm, fever, diaphoresis, tremor, hyperreflexia in the setting of untreated Graves disease) needs urgent beta-blockade. IV propranolol rapidly controls heart rate, reduces peripheral T4 to T3 conversion, and addresses the life-threatening sympathetic hyperactivity that drives cardiac complications.

Question 102

Answer: C - Schedule HIV serology testing in 3 months

After treating acute urethritis from a sexually transmitted infection, HIV testing at 3 months is the most appropriate follow-up. STIs indicate sexual risk behavior and mucosal disruption that increases HIV acquisition risk. Testing at 3 months captures the serologic window period for reliable HIV antibody detection.

Question 103

Answer: E - Ultrasonography of the right upper abdominal quadrant

This patient presents with acute pancreatitis (elevated lipase at 846, sudden epigastric pain radiating to the back) likely secondary to hypertriglyceridemia. Contrast-enhanced CT is the standard imaging modality for assessing pancreatitis severity and detecting complications such as necrosis, pseudocysts, and peripancreatic fluid collections.

Question 104

Answer: C - Osteomalacia

This infant with hypophosphatemia, elevated alkaline phosphatase, and borderline low calcium along with growth failure and skeletal abnormalities has nutritional rickets from vitamin D deficiency. Inadequate vitamin D leads to impaired calcium and phosphorus absorption, resulting in defective bone mineralization (osteomalacia) and the characteristic laboratory pattern.

Question 105

Answer: E - Refer the patient to an allergist for further evaluation

This patient with a documented allergy to a local anesthetic of unknown type cannot safely receive any local anesthetic without further evaluation. Referral to an allergist for skin testing and graded challenge testing is the most appropriate next step to identify the specific allergen and determine which anesthetic agents can be safely used.

Question 106

Answer: B - Bupivacaine femoral nerve block

This patient with severe postoperative pain poorly controlled by systemic opioids (limited by respiratory depression and sedation) would benefit from a regional nerve block. A femoral nerve block provides excellent localized analgesia for knee surgery without the systemic side effects of opioids, allowing effective pain control while avoiding respiratory compromise.

Question 107

Answer: B - Apply a plaster cast that incorporates the thumb

This patient with an acute wrist fracture requiring immobilization and a history of carpal tunnel syndrome needs proper stabilization. A well-fitted splint or cast that immobilizes the fracture site while allowing appropriate hand function is essential to prevent nonunion and reduce the risk of developing complex regional pain syndrome.

Question 108

Answer: C - Assist the patient in strengthening her lower extremity muscles

This 65 year old with a hip fracture and newly controlled diabetes on insulin needs home physical therapy focused on lower extremity strengthening and mobility. Regaining functional independence and preventing falls through progressive strengthening exercises is the priority for post-hip fracture rehabilitation and long-term recovery.

Question 109

Answer: A - Associated shortness of breath and wheezing

The development of shortness of breath and wheezing alongside allergic rhinitis suggests progression to asthma, indicating more serious systemic allergic airway disease. This finding requires additional evaluation and treatment beyond nasal symptom management, as it represents lower airway involvement that can significantly impact quality of life.

Question 110

Answer: A - Inhaled fluticasone

After allergen avoidance measures fail to control lower airway symptoms (wheezing, shortness of breath), inhaled fluticasone (an inhaled corticosteroid) is the most appropriate next step. ICS therapy targets the underlying airway inflammation driving asthma symptoms and is first-line controller therapy per asthma management guidelines.

Question 111

Answer: C - It is indeterminant

Genetic counseling requires careful analysis of the pedigree pattern. Without definitive information about the inheritance pattern (autosomal dominant, recessive, or X-linked) and with this being the patient's first pregnancy with currently normal vision, no definitive prediction can be made about offspring risk without additional genetic testing.

Question 112

Answer: B - Pressure relief

Pressure relief through regular repositioning, specialized mattress surfaces, and wheelchair cushions is the single most important intervention for pressure ulcer healing and prevention. While nutrition, wound care, and topical treatments support healing, they cannot overcome the tissue ischemia caused by sustained mechanical pressure.

Question 113

Answer: C - Smoking cessation program

Smoking cessation is the single most impactful modifiable risk factor for coronary artery disease prevention in this 36 year old patient. Despite also having hyperlipidemia and obesity, quitting smoking provides the most immediate and significant cardiovascular benefit, reducing MI risk by 50% within one year of cessation.

Question 114

Answer: C - Administration of sodium bicarbonate

This patient presents with salicylate toxicity evidenced by a mixed acid-base disturbance (respiratory alkalosis initially, progressing to metabolic acidosis), altered mental status, and pulmonary edema. IV sodium bicarbonate alkalinizes the urine to enhance salicylate excretion and corrects the systemic acidosis, preventing further CNS penetration of salicylate.

Question 115

Answer: C - In 5 years

For women over 30 with both normal cytology and negative HPV co-testing, cervical cancer screening can be safely extended to every 5 years. This evidence-based interval reflects the low risk of developing cervical dysplasia or cancer when both screening tests are negative, regardless of sexual history.

Question 116

Answer: A - Complete recovery

This young, otherwise healthy military recruit with acute viral myocarditis (elevated BNP, dilated left ventricle, S3 gallop, systemic symptoms) has a favorable prognosis for complete recovery. Most cases of viral myocarditis in young patients resolve with supportive care, and full cardiac recovery is expected within weeks to months.

Question 117

Answer: D - Ibuprofen

This patient with pharyngeal vesicles, negative strep test, and a child with a hand-foot rash has hand-foot-and-mouth disease caused by Coxsackievirus (an enterovirus). The vesicular pharyngitis and epidemiologic link to a household contact with the characteristic rash pattern confirm the diagnosis. Treatment is supportive.

Question 118

Answer: B - Bulbar weakness

Bulbar involvement (inability to protrude the tongue, palatal weakness, dysarthria, tongue fasciculations) with EMG showing denervation indicates amyotrophic lateral sclerosis with bulbar onset. Bulbar-onset ALS carries a significantly worse prognosis than limb-onset disease, with median survival of approximately 2 years due to early swallowing and respiratory compromise.

Question 119

Answer: B - Anorectal manometry

This patient with chronic constipation, decreased anal sphincter tone, and soft stool present in the rectum despite difficulty evacuating suggests pelvic floor dysfunction (dyssynergic defecation). Anorectal manometry is the appropriate diagnostic test to evaluate sphincter pressures and pelvic floor coordination during attempted defecation.

Question 120

Answer: F - Transcutaneous pacing

This patient with symptomatic bradycardia (pulse 30 bpm), hypotension, and altered mental status following syncope is hemodynamically unstable. Transcutaneous pacing is the most appropriate immediate intervention for unstable bradycardia, providing temporary cardiac pacing to restore adequate heart rate and perfusion while definitive management is arranged.

Question 121

Answer: A - Administer the HPV vaccine

HPV vaccination is recommended for all individuals through age 26 (and shared decision making through age 45) who have not been previously vaccinated. This 25 year old man is well within the recommended age range and should receive the vaccine regardless of current sexual activity, as future exposure remains a risk.

Question 122

Answer: B - Evaluate her for valve replacement

This patient with worsening mitral regurgitation and new symptoms of heart failure (dyspnea, fatigue, reduced exercise tolerance) needs echocardiographic evaluation to quantify MR severity and assess ventricular function. Progressive symptomatic MR despite medical management warrants surgical assessment for mitral valve repair or replacement.

Question 123

Answer: B - CT scan of the chest

The exudative pleural effusion (elevated LDH and protein) with serosanguineous character in a patient with pulmonary symptoms and weight loss requires further evaluation. Echocardiography is appropriate to evaluate for heart failure as a contributing cause, as cardiac disease remains the most common etiology of pleural effusions even when exudative criteria are met.

Question 124

Answer: B - Kidney function

Elevated plasma copeptin (a surrogate for antidiuretic hormone levels) indicates impaired renal concentrating ability and correlates with disease progression in polycystic kidney disease. This biomarker is a strong predictor of kidney volume growth and decline in GFR, making it the most clinically relevant prognostic indicator.

Question 125

Answer: E - No additional pharmacotherapy is indicated

This patient with newly diagnosed type 2 diabetes (fasting glucose 146 mg/dL, HbA1c 8.3%) and no albuminuria should be started on lifestyle modifications combined with metformin as first-line pharmacotherapy. Metformin is the preferred initial agent due to its efficacy, safety profile, weight neutrality, and cardiovascular benefits.

Question 126

Answer: A - Alendronate, orally

The clinical findings of tibial bowing (valgus deformity), cortical thickening, and intramedullary sclerosis in an older patient are characteristic of Paget disease of bone. Alendronate (an oral bisphosphonate) is first-line therapy, reducing osteoclast activity and bone turnover to decrease pain and prevent complications.

Question 127

Answer: C - Order a random urine test for oxycodone

When there is concern about possible opioid diversion (raised by a friend's report), a random urine drug screen is the appropriate clinical response before making changes to the pain management regimen. This provides objective evidence of medication compliance or misuse and guides subsequent management decisions.

Question 128

Answer: B - Congestive heart failure

This patient with weight loss, anxiety, tremor, tachycardia, exophthalmos, and suppressed TSH has Graves disease with thyrotoxicosis. Without treatment, the persistent hypermetabolic state and sustained tachycardia lead to high-output heart failure, the most serious cardiovascular complication of untreated hyperthyroidism.

Question 129

Answer: D - Intravenous vancomycin

This breastfeeding woman with mastitis that has not responded to oral antibiotics, with a large tender breast mass and systemic toxicity (fever, tachycardia), requires escalation to IV antibiotic therapy. IV antibiotics provide higher tissue concentrations needed to treat severe or complicated mastitis and possible developing abscess.

Question 130

Answer: A - Administer PPD skin tests to the whole family

After diagnosing latent tuberculosis in a patient (positive PPD, negative chest X-ray) who is starting isoniazid prophylaxis, all close household contacts must be evaluated with tuberculin skin testing. Contact investigation is a fundamental public health measure to identify additional individuals who may have been exposed and need treatment.

Question 131

Answer: E - Replacement of the aortic root

This patient with sudden onset severe tearing chest and back pain, hypotension, tachycardia, and a new diastolic murmur (aortic regurgitation) has acute aortic dissection involving the ascending aorta (Stanford Type A). Emergent surgical repair with aortic root replacement is the definitive and life-saving intervention for Type A dissections.

Question 132

Answer: D - Sleep-related hypoventilation

This patient presents with lateral medullary syndrome (Wallenberg syndrome) characterized by ipsilateral facial sensory loss, contralateral body pain and temperature loss, and cranial nerve involvement. The vagal and glossopharyngeal dysfunction from the lateral medullary infarct creates risk for aspiration and sleep-related hypoventilation from impaired respiratory drive.

Question 133

Answer: E - Methimazole

This patient with progressive thrombocytopenia (43,000), leukopenia (1,200), and anemia (9.3 g/dL) while on methimazole has drug-induced pancytopenia. Methimazole is a well-known cause of agranulocytosis and, less commonly, aplastic anemia. The medication must be discontinued immediately and alternative hyperthyroid management arranged.

Question 134

Answer: C - Maintenance of adequate sleep

Sleep deprivation is a powerful and well-established seizure trigger, particularly in patients with a predisposition to seizures. This patient's combination of excessive caffeine intake (48 oz daily) and chronic inadequate sleep significantly lowers the seizure threshold. Ensuring adequate sleep hygiene is the most important preventive measure.

Question 135

Answer: D - Ceftriaxone and doxycycline

This myasthenia gravis patient with community-acquired pneumonia requires antibiotic coverage for typical and atypical respiratory pathogens. A combination of ceftriaxone (covering Streptococcus pneumoniae and gram-negatives) and doxycycline (covering atypical organisms like Mycoplasma and Chlamydophila) provides appropriate broad-spectrum coverage for hospitalized patients.

Question 136

Answer: D - Pericardiocentesis

This preterm newborn on high ventilator settings with acute hemodynamic decompensation (poor perfusion, cyanosis) has developed a tension pneumothorax or pneumopericardium. Needle decompression or pericardiocentesis is the emergent intervention needed to relieve the pressure causing cardiovascular collapse and restore hemodynamic stability.

Question 137

Answer: A - Anal fistula

This adolescent with chronic abdominal pain, diarrhea, weight loss, oral ulcers (aphthous stomatitis), and anemia has a presentation highly suggestive of Crohn disease. Perianal disease, including anal fistulae, is a characteristic and common complication of Crohn disease that helps distinguish it from ulcerative colitis.