Cardiovascular
A 24-year-old man is brought to the emergency department 15 minutes after he sustained a stab wound to the left chest. On arrival, he has rapid, shallow breathing and appears anxious. His pulse is 135/min, respirations are 30/min and shallow, and palpable systolic blood pressure is 80 mm Hg. Examination shows no active external bleeding. There is a 2.5-cm single stab wound to the left chest at the 4th intercostal space at the midclavicular line. Cardiovascular examination shows muffled heart sounds and jugular venous distention. Breath sounds are normal. Further evaluation of this patient is most likely to show which of the following findings?
A. Tracheal deviation towards the right side
B. A drop in systolic blood pressure of 14 mm Hg during inspiration
C. Subcutaneous emphysema
D. Paradoxical motion of part of the chest with breathing
B. A drop in systolic blood pressure of 14 mm Hg during inspiration
A 71-year-old woman comes to the physician with a 2-month history of fatigue, anorexia, abdominal swelling, shortness of breath, and a 5-kg (11-lb) weight loss. She appears chronically ill. Examination shows jaundice, bilateral temporalis muscle wasting, hepatosplenomegaly, and tense ascites. Ultrasonography of the abdomen shows multiple hepatic masses and enlargement of the portal vein. Which of the following is the most likely cause of these masses?
A. Metastatic spread of malignant cells of the colon
B. Malignant transformation of hepatocytes
C. Hyperplasia of atypical bile duct tissue
D. Lymphoproliferative disorder of hepatic sinusoids
A. Metastatic spread of malignant cells of the colon
The most common malignant lesion of the liver is metastatic liver disease, which can manifest with muscle wasting (due to cancer cachexia), hepatosplenomegaly, and features of portal hypertension (e.g., enlarged portal vein, ascites). A liver ultrasound typically shows multiple lesions, as seen in this patient. The most common primary tumor in the case of liver metastases is a colorectal carcinoma, which can be caused by a diet rich in processed meats and low in fiber. Other primary tumor sites for hepatic metastases include the lungs and breasts.
A 48-year-old man comes to the physician because of a 4-month history of persistent cough productive of white phlegm. He coughs consistently throughout the day, and he has not noticed any particular triggers that make it worse. He has also recently experienced some shortness of breath with exertion. He has not had any weight loss, fever, or chills. He had similar symptoms last year, which lasted about 6 months. He has hypertension, for which he takes amlodipine. He has worked in construction for the past 10 years. He has smoked one pack of cigarettes per day for 30 years. Vital signs are within normal limits. Examination shows an end-expiratory wheeze throughout all lung zones. Which of the following is the most likely diagnosis?
A. Bronchiectasis
B. Hypersensitivity pneumonitis
C. Asthma
D. Chronic bronchitis
D. Chronic bronchitis
Chronic bronchitis, a subtype of COPD, is the most likely diagnosis in a patient with a history of productive cough for 4–6 months each year for the past 2 years. The vast majority of cases of COPD can be attributed to smoking, and patients with ≥ 20–30 pack years have an 80–90% lifetime risk of developing COPD. Occupational exposure to organic/nonorganic dust can also significantly increase risk. Dyspnea will continue to become more severe until it is present even at rest. Smokers should, therefore, be counseled about cessation to reduce the rate of respiratory decline.
A 56-year-old man comes to the physician for a follow-up examination. Physical examination shows hyperpigmented plaques on the posterior neck and in the axillae. His hemoglobin A1c concentration is 7.4% and fasting serum glucose concentration is 174 mg/dL. Which of the following is the strongest predisposing factor for this patient's laboratory findings?
A. African American ethnicity
B. Increased BMI during childhood
C. History of smoking
D. High waist circumference
D. High waist circumference
A high waist circumference or waist-to-hip ratio is a sign of central obesity, which is a strong predisposing factor for the development of type 2 diabetes mellitus. Increased abdominal and visceral fat is associated with increased lipolytic activity and increased levels of serum free fatty acids. Increased levels of fatty acids induce insulin resistance by decreasing peripheral insulin-mediated glucose uptake.
A 56-year-old woman comes to the emergency department because of a 3-day history of malaise, dysuria, blurred vision, and a painful, itchy rash. The rash began on her chest and face and spread to her limbs, palms, and soles. One week ago, she was diagnosed with trigeminal neuralgia and started on a new medicine. She appears ill. Her temperature is 38°C (100.4°F) and pulse is 110/min. Physical examination shows conjunctival injection and ulceration on the tongue and palate. There is no lymphadenopathy. Examination of the skin shows confluent annular, erythematous macules, bullae, and desquamation of the palms and soles. The epidermis separates when the skin is lightly stroked. Which of the following is the most likely diagnosis?
A. Bullous pemphigoid
B. Stevens-Johnson syndrome
C. Pemphigus vulgaris
D. DRESS syndrome
B. Stevens-Johnson syndrome
Stevens-Johnson syndrome (SJS) is a rare yet serious adverse effect of carbamazepine, as well as many other drugs (e.g., phenytoin, lamotrigine, and valproate). It initially manifests with fever and flu-like symptoms (e.g., chills and myalgias). The classic cutaneous manifestation consists of painful, erythematous, annular macules with pruritic centers that begin on the face and thorax and spread symmetrically to the extremities, which are accompanied by stomatitis, mucositis, conjunctivitis, and/or corneal ulceration. Physical examination often shows a positive Nikolsky sign, as seen in this patient. The skin desquamation may progress to involve large areas of the skin. Involvement of > 30% of the total body surface area is referred to as toxic epidermal necrolysis (TEN), whereas involvement of 10–30% is considered SJS/TEN overlap. Treatment of SJS includes discontinuation of the offending drug and supportive therapy similar to that of burns (fluid resuscitation, wound management, antibiotics in case of infection). Cyclosporine may slow SJS progression.
A 62-year-old man comes to the physician for decreased exercise tolerance. Over the past four months, he has noticed progressively worsening shortness of breath while walking his dog. He also becomes short of breath when lying in bed at night. His temperature is 36.4°C (97.5°F), pulse is 82/min, respirations are 19/min, and blood pressure is 155/53 mm Hg. Cardiac examination shows a high-pitched, decrescendo murmur that occurs immediately after S2 and is heard best along the left sternal border. There is an S3 gallop. Carotid pulses are strong. Which of the following is the most likely diagnosis?
A. Mitral Valve Stenosis
B. Tricuspid Valve Regurgitation
C. Aortic Valve Stenosis
D. Aortic Valve Regurgitation
D. Aortic Valve Regurgitation
An early diastolic decrescendo murmur that is heard best at the left sternal border suggests aortic regurgitation (AR). Regurgitation of blood from the aorta into the left ventricle (LV) causes widened pulse pressure with a decreased diastolic blood pressure. To maintain an adequate cardiac output despite regurgitation, initially, there is a compensatory increase in stroke volume. Over time, the increased LV end-diastolic volume leads to LV enlargement and eccentric myocardial hypertrophy. Patients may be asymptomatic for decades despite progressive LV dilation. In chronic AR, this compensatory response results in left ventricular dysfunction, and patients develop signs and symptoms of left heart failure (exertional and nocturnal dyspnea, S3 gallop). The diagnosis of AR should be confirmed with transthoracic echocardiography.
Maneuvers that increase afterload (e.g., handgrip) increase the intensity of the associated murmur as a result of the enlargement of regurgitation volume across the valve.
A 42-year-old woman comes to the physician because of a 1-month history of episodic abdominal pain and fullness. She works as a veterinary technician. Physical examination shows hepatomegaly. Abdominal ultrasound shows a 4-cm calcified cyst with several daughter cysts in the liver. She undergoes CT-guided percutaneous aspiration under general anesthesia. Several minutes into the procedure, one liver cyst spills, and the patient's oxygen saturation decreases from 97% to 68%. Her pulse is 136/min and blood pressure is 86/58 mm Hg. Which of the following is the most likely causal organism of this patient's condition?
A. Ascaris Lumbricoides
B. Schistosoma Mansoni
C. Trichinella Spiralis
D. Echinococcus granulosus
D. Echinococcus granulosus
Echinococcus granulosus is a tapeworm of which the definitive hosts are foxes, dogs, and cats. The intermediate hosts are sheep and rodents. Infection occurs through fecal-oral transmission of eggs. Hepatic echinococcosis typically causes malaise, nausea, vomiting, hepatomegaly, and an anechoic, well-defined, hepatic cyst (hydatid cyst) with or without daughter cysts and eggshell calcification on ultrasonography. Any invasive procedure (drainage or surgery) of hydatid cysts should be performed with the utmost care to prevent spillage of cyst contents, which can cause life-threatening anaphylactic shock and/or secondary seeding of infection.
Echinococcus granulosus, which causes cystic echinococcosis, typically presents with unilocular hydatid cysts, while Echinococcus multilocularis, the causal organism of alveolar echinococcosis, is characterized by formation of multiple cysts with infiltrative growth.
A 62-year-old man with a history of chronic bronchitis comes to the physician because of a 1-month history of worsening shortness of breath and cough productive of thick sputum. He smoked one pack of cigarettes daily for 20 years but quit 5 years ago. Physical examination shows an increased anteroposterior chest diameter and coarse crackles in the lower lung fields bilaterally. Treatment with a drug that directly antagonizes the effects of vagal stimulation on the airways is begun. Which of the following drugs was most likely started?
A. Fluticasone
B. Albuterol
C. Tiotropium
D. Theophylline
C. Tiotropium
Tiotropium is an antimuscarinic agent used to treat chronic obstructive pulmonary disease (COPD) and asthma. This patient has a history of tobacco use, presents with chronic productive cough, and has an increased anteroposterior chest diameter with coarse crackles on examination. Together, these features strongly suggest a diagnosis of COPD. Tiotropium (and other long-acting parasympatholytics) competitively binds to muscarinic receptors, which subsequently reduces parasympathetic tone on the bronchioles, blocking bronchoconstriction. These effects reduce the symptoms of airway obstruction and improve pulmonary functionality.
A 56-year-old woman comes to the physician because of frequent urination. For the past year, she has had to urinate multiple times per hour. She has been thirstier and hungrier than usual. She has not had any pain with urination. She has no time to exercise because her job is demanding. Her diet mostly consists of pizza and cheeseburgers. Her vital signs are within normal limits. Physical examination shows no abnormalities. Today, her blood glucose level is 200 mg/dL and her hemoglobin A1C is 7.4%. Urinalysis shows microalbuminuria. Which of the following is the most likely cause of this patient's proteinuria?
A. Increased glomerular filtration
B. Diffuse nodular glomerulosclerosis
C. Continuous activation of complement C3
D. Renal papillary necrosis
A. Increased glomerular filtration
Increased glomerular filtration is the underlying cause of proteinuria. Increased glomerular filtration is caused by glycation, which results from chronic hyperglycemia. Glycation causes increased permeability and thickening of the basement membrane, thereby leading to urinary excretion of albumin. Glycation also increases the rigidity of the efferent glomerular arterioles, which accelerates hyperfiltration and mesangial expansion and causes progressive loss of glomerular function. This chronic degenerative process can be monitored by measuring urine albumin levels.
Microalbuminuria (urine albumin levels of 30–300 mg/day) is the earliest sign of diabetic nephropathy. ACE inhibitors, which have a protective effect against renal tubulointerstitial fibrosis and prevent the progression of albuminuria, are the first-line antihypertensive treatment for patients with diabetes.
A 48-year-old man is brought to the emergency department after he was found in a stuporous state with a small cut on his forehead on a cold night in front of his apartment. Noncontrast head CT is normal, and he is monitored in the emergency department. Twelve hours later, he yells for help because he hears the wallpaper threatening his family. The patient started drinking regularly 10 years ago and consumed a pint of vodka prior to admission. He occasionally smokes marijuana and uses cocaine. His vital signs are within normal limits. On mental status examination, the patient is alert and oriented. He appears markedly distressed and is diaphoretic. A fine digital tremor on his right hand is noted. The remainder of the neurological examination shows no abnormalities. Urine toxicologic screening is pending. Which of the following is the most likely diagnosis?
A. Alcohol hallucinosis
B. Cocaine intoxication
C. Wernicke encephalopathy
D. Delirium tremens
A. Alcohol hallucinosis
Alcohol withdrawal occurs in stages with unique clinical manifestations. Alcohol hallucinosis occurs 12–48 hours after the last alcoholic beverage and usually presents with visual (most common), auditory, or tactile hallucinations. An intact sensorium (i.e., alert and oriented) and the absence of autonomic instability (e.g., hypertension, tachycardia, hyperthermia) help distinguish this diagnosis from delirium tremens. Alcohol hallucinosis usually resolves within 24–48 hours of onset and withdrawal symptoms can be managed with benzodiazepines.
A 48-year-old woman comes to the emergency room with chest pain. She describes the pain as a squeezing sensation in her chest with radiation to the left shoulder. The episode began about 15 minutes ago when she was sitting reading a book. She has had this pain before, typically in the evenings, though prior episodes usually resolved after a couple of minutes. Her pulse is 112/min, blood pressure is 121/87 mm Hg, and respiratory rate is 21/min. An ECG shows ST-segment elevations in the inferior leads. Serum troponins are negative on two successive blood draws and the ECG shows no abnormalities 30 minutes later. Which of the following is the best long-term treatment for this patient's symptoms?
A. Clopidogrel
B. Diltiazem
C. Aspirin
D. Metoprolol
B. Diltiazem
Calcium channel blockers (CCBs) such as diltiazem are the first-line treatment for vasospastic angina. CCBs are effective for both acute attacks and prophylaxis. In addition to CCBs, lifestyle modifications should be attempted, such as smoking cessation and abstaining from stimulants.
Nitroglycerin is often used in the acute abortive treatment of vasospastic angina. Long-acting nitrates (e.g., isosorbide mononitrate) are only used as second-line agents for control of vasospastic episodes because the development of nitrate tolerance limits their long-term use.
A 48-year-old woman comes to the physician because of a 6-month history of excessive fatigue and a 1-month history of progressively increasing generalized pruritus. She has hypothyroidism, for which she receives thyroid replacement therapy. Physical examination shows jaundice. The liver is palpated 4 cm below the right costal margin. Serum studies show a direct bilirubin concentration of 2.9 mg/dL, alkaline phosphatase activity of 580 U/L, and increased titers of antimitochondrial antibodies and anti-thyroid peroxidase antibodies. Which of the following is the most likely cause of this patient's condition?
A. Hepatocellular accumulation of copper
B. Autoimmune-mediated destruction of hepatocytes
C. Destruction of intrahepatic bile ducts
D. Inflammation and fibrosis of the biliary tree
C. Destruction of intrahepatic bile ducts
Destruction of intrahepatic bile ducts is the underlying mechanism of primary biliary cholangitis (PBC). As a result, chronic cholestasis with ensuing secondary hepatic damage and liver cirrhosis can develop. While most patients are asymptomatic in the early stages of the disease, affected individuals can develop cholestatic pruritus, as seen here. Antimitochondrial antibodies are found in 95% of patients with PBC. This patient's hypothyroidism is most likely due to Hashimoto thyroiditis (as evidenced by elevated anti-thyroid peroxidase antibodies), which is commonly associated with PBC.
Other autoimmune conditions associated with PBC include Sjögren syndrome, CREST syndrome, and rheumatoid arthritis.
A 53-year-old man comes to the physician because of a 1-day history of fever and chills, severe malaise, and cough with yellow-green sputum. He works as a commercial fisherman on Lake Superior. Current medications include metoprolol and warfarin. His temperature is 38.5°C (101.3°F), pulse is 96/min, respirations are 26/min, and blood pressure is 98/62 mm Hg. Examination shows increased fremitus and bronchial breath sounds over the right middle lung field. An x-ray of the chest shows consolidation of the right upper lobe. Which of the following is the most likely causal pathogen?
A. Legionella pneumophila
B. Pseudomonas aeruginosa
C. Histoplasma capsulatum
D. Streptococcus pneumoniae
D. Streptococcus pneumoniae
This patient's acute onset of malaise, fever, and chills, productive cough, and tachypnea in combination with the physical examination findings (increased fremitus, bronchial breath sounds) and the chest x-ray showing lobar consolidation is indicative of typical pneumonia. The most common causal pathogen of this condition is Streptococcus pneumoniae.
A 36-year-old woman comes to the physician because of a 3-month history of a painless lump on her neck. She says that the lump has gradually increased in size and is hard to the touch. Family history is unremarkable. She appears healthy. Examination shows a 2.5-cm (1-in) firm, irregular swelling on the left side of the neck that moves with swallowing. There is painless cervical lymphadenopathy. Ultrasound of the neck shows a solitary left lobe thyroid mass with increased vascularity and hyperechogenic punctate regions. A fine-needle aspiration biopsy is scheduled for the upcoming week. Which of the following is the most likely diagnosis?
A. Follicular carcinoma of the thyroid
B. Medullary carcinoma of the thyroid
C. Papillary carcinoma of the thyroid
D. Anaplastic carcinoma of the thyroid
C. Papillary carcinoma of the thyroid
Papillary thyroid carcinomas are the most common type of thyroid cancer (∼ 80% of cases) and have a peak incidence between 30–50 years of age. These carcinomas commonly manifest with early lymphatic spread. Patients often present with painless cervical lymphadenopathy that may be detectable before the primary tumor. The hyperechogenic punctate regions seen on this patient's ultrasound likely represent microcalcifications, another characteristic feature of this type of thyroid cancer. Based on the overall incidence rate, affected age group, and metastatic pattern, papillary thyroid carcinoma is the most likely diagnosis in this patient.
A 71-year-old man is admitted to the hospital because of a 12-hour history of lower back pain and no urine output. Medical history is remarkable for Hodgkin lymphoma. Physical examination shows inguinal lymphadenopathy. There is no suprapubic fullness or tenderness. Serum creatinine is elevated compared to 1 week prior. A contrast-enhanced CT scan of the abdomen shows retroperitoneal fibrosis, bilateral hydronephrosis, and a collapsed bladder. Which of the following is the most appropriate next step in treatment?
A. Place a urethral catheter
B. Perform ureteral stenting
C. Place a suprapubic catheter
D. Initiate oxybutynin therapy
B. Perform ureteral stenting
Ureteral stenting is the first-line management of uncomplicated upper UTO. In this patient, retroperitoneal fibrosis due to Hodgkin lymphoma most likely obstructs the ureters, leading to upper UTO. Other common causes include traumatic injury, instrumentation, malignancy, infection, and congenital obstruction. Further evaluation and treatment of the underlying cause are indicated once the acute obstruction has been resolved.
A 76-year-old woman is brought to the emergency department because of a 1-day history of upper abdominal pain, nausea, and dyspnea. She was diagnosed with an inferior wall myocardial infarction 3 days ago and was successfully treated with coronary stent placement. She lives alone since her husband died 2 years ago. Her medical history is significant for type 2 diabetes mellitus and recently diagnosed Alzheimer disease. Her medications include aspirin, clopidogrel, atorvastatin, metoprolol, lisinopril, and metformin. The son reports that she has trouble remembering to take medications regularly. She drinks two to three glasses of wine daily. She is alert and oriented to person and place but not to time. Her temperature is 36.9°C (98.4°F), pulse is 59/min, respirations are 17/min, and blood pressure is 145/77 mm Hg. Physical examination shows no other abnormalities. Which of the following is most likely to establish the diagnosis?
A. CT Pulmonary angiography
B. Serial measurement of serum troponin concentration
C. Echocardiography
D. CT angiography of the abdomen
B. Serial measurement of serum troponin concentration
Cardiac troponin T is one of the most sensitive biomarkers for myocardial infarction (MI), and it can also be used to detect reinfarction. Because it can take 6–14 days for troponin T levels to return to normal, a single measurement of elevated troponin T level 3 days after MI does not allow for reliable differentiation between a prior infarct and reinfarction. However, a second measurement 3–6 hours later showing a 20% increase in troponin T levels indicates reinfarction in the presence of suggestive symptoms. Creatine kinase MB (CK-MB) measurement can help in the evaluation of reinfarction because of its short half-life (return to normal within 2–3 days), but it is no longer commonly used. In addition, an ECG should be obtained immediately in every patient with suspected MI.
Atypical features (i.e., no or minimal chest pain, nausea) of MI are more common in older people, individuals with diabetes, and women. Reinfarction can happen at any time following MI but the risk increases over time. This patient likely did not adhere to her dual antiplatelet therapy, further increasing the risk of reinfarction.
A 50-year-old man comes to the physician because of a 6-month history of increasingly frequent episodes of upper abdominal pain, nausea, vomiting, and diarrhea. He has had a 3.2-kg (7-lb) weight loss during this time. Medical history is otherwise unremarkable. Physical examination shows bilateral pitting pedal edema. An endoscopy shows prominent rugae in the gastric fundus. Biopsy shows parietal cell atrophy. Which of the following is the most likely underlying cause of this patient's condition?
A. Chronic Helicobacter pylori infection
B. Proliferation of gastric mucus-producing cells
C. Excessive somatostatin secretion
D. Ectopic secretion of gastrin
B. Proliferation of gastric mucus-producing cells
The patient's findings are consistent with Ménétrier disease (protein-losing hyperplastic gastropathy), which is a result of the proliferation of gastric mucus-producing cells. The pathogenesis involves increased signaling of EGFR, which results in the proliferation of epithelial cells of the mucous cell compartment.
A 40-year-old man comes to the physician because of a 2-year history of gradually worsening shortness of breath. He smoked half a pack of cigarettes daily for 10 years but stopped 8 years ago. His pulse is 72/min, blood pressure is 135/75 mm Hg, and respirations are 20/min. Examination shows an increased anteroposterior diameter of the chest. Diminished breath sounds are heard on auscultation of the chest. Chest x-ray shows widened intercostal spaces, a flattened diaphragm, and bilateral basilar hyperlucency. This patient is at greatest risk for developing which of the following?
A. Bronchiolitis obliterans
B. Pulmonary fibrosis
C. Bronchogenic carcinoma
D. Hepatocellular carcinoma
D. Hepatocellular carcinoma
About 40% of patients with A1AD develop significant liver damage and cirrhosis, which are common precursors to hepatocellular carcinoma (HCC), although progression to HCC can also occur in the absence of cirrhosis in these patients. In contrast to the enhanced protease activity leading to excessive breakdown of elastin that causes early-onset emphysema, liver disease is thought to occur due to toxic accumulation of the misfolded alpha-1 antitrypsin protein in hepatic tissue, which significantly increases the risk of liver damage, cirrhosis, and HCC.
A 39-year-old woman comes to the physician because of a 4-day history of fever, anterior neck pain, and throat swelling. She has no history of serious illness. Her temperature is 38.1°C (100.6°F) and pulse is 109/min. Physical examination shows diaphoresis and a fine tremor of the outstretched hands. The thyroid gland is enlarged, firm, and tender to palpation. Serum thyroid stimulating hormone level is 0.06 μU/mL and erythrocyte sedimentation rate is 65 mm/h. 123I scan shows an enlarged thyroid gland with diffusely decreased uptake. Pathologic examination of a thyroid biopsy specimen is most likely to show which of the following findings?
A. Follicular epithelial cell hyperplasia
B. Lymphocytic infiltration with germinal follicle formation
C. Undifferentiated giant cells with areas of necrosis and hemorrhage
D. Noncaseating granulomas with multinucleated giant cells
D. Noncaseating granulomas with multinucleated giant cells
De Quervain thyroiditis is a transient and self-limited disease characterized by patchy granulomatous inflammation of the thyroid. This disease is often preceded by a viral upper respiratory tract infection and typically presents initially with hyperthyroidism (as seen in this patient), followed by hypothyroidism. Classic signs include thyroid tenderness, increased ESR, and jaw pain.
An 82-year-old man is brought to the emergency department because of severe pain and joint stiffness in his right knee. The pain started 3 days ago and has worsened despite acetaminophen intake. He has benign prostatic hyperplasia and hypertension. One week ago, he had a urinary tract infection and was treated with nitrofurantoin. He does not smoke or drink alcohol. His current medications include enalapril, hydrochlorothiazide, and tamsulosin. He appears to be in severe pain and has trouble moving his right knee. His temperature is 38.7°C (101.5°F), pulse is 92/min, and blood pressure is 135/90 mm Hg. Physical examination shows a swollen, erythematous, warm right knee; range of motion is limited by pain. Synovial fluid aspiration shows a yellow-green turbid fluid. Gram stain of the synovial aspirate shows numerous leukocytes and multiple gram-negative rods. An x-ray of the right knee shows no abnormalities. Which of the following is the most appropriate pharmacotherapy?
A. Intravenous vancomycin and ceftazidime
B. Intravenous cefepime
C. Intravenous ceftazidime and gentamicin
D. Intravenous vancomycin
B. Intravenous cefepime
Empiric antibiotic therapy is based on the Gram stain of the synovial fluid of the affected joint and should be initiated as early as possible to minimize the risk of sepsis and damage to the affected joint. In this case, the Gram stain shows gram-negative bacilli, which, given the history of a preceding urinary tract infection, is most likely to be Escherichia coli. The empiric antibiotics of choice for gram-negative bacilli are third-generation cephalosporins (e.g., ceftazidime) or fourth-generation cephalosporins (e.g., cefepime). Alternative empiric antibiotics for gram-negative bacilli include piperacillin/tazobactam, carbapenems, and, in patients with a known allergy to beta-lactam antibiotics, fluoroquinolones or aztreonam.
A 62-year-old man is evaluated for sudden left arm pain 7 days after being admitted to the hospital for anterior ST-elevation myocardial infarction, which was treated with percutaneous coronary angioplasty and stenting of the distal left anterior descending artery. The sharp pain woke him up and he now is also complaining of numbness in the fingers and difficulty moving his arm. He has a history of hypertension and hyperlipidemia. Current medications include atorvastatin, aspirin, lisinopril, metoprolol, and clopidogrel. His temperature is 37.5°C (99.5°F), pulse is 102/min, respirations are 14/min, and blood pressure is 115/75 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. His left arm is cool to touch and pale, and the left radial pulse is not palpable. Muscle strength is 1/5 in the left upper extremity and 5/5 in all other extremities. Which of the following is the most likely underlying diagnosis?
A. Postmyocardial infarction(Dressler) Syndrome
B. Iatrogenic brachial artery injury
C. Ventricular pseudoaneurysm
D. Ventricular septal rupture
E. Papillary muscle rupture
C. Ventricular pseudoaneurysm
Mural thromboembolism from a left ventricular pseudoaneurysm is the most likely cause of this patient's acute limb ischemia. A left ventricular pseudoaneurysm typically develops 3–14 days after myocardial infarction, and it can also lead to decreased cardiac output and arrhythmia. Initial diagnosis of a ventricular pseudoaneurysm is performed with transthoracic echocardiography, but a definitive diagnosis is determined with angiography, which allows direct visualization of the lesion.
Mural thromboembolism can also be associated with a true ventricular aneurysm. As true ventricular aneurysm typically develops 2 weeks to a few months postinfarction, this patient is more likely to have a ventricular pseudoaneurysm
A 38-year-old woman comes to the physician because of a 3-month history of moderate abdominal pain that is unresponsive to medication. She has a history of two spontaneous abortions at 11 and 12 weeks' gestation. Ultrasound examination of the abdomen shows normal liver parenchyma, a dilated portal vein, and splenic enlargement. Upper endoscopy shows dilated submucosal veins in the lower esophagus. Further evaluation of this patient is most likely to show which of the following findings?
A. Increased prothrombin time
B. Palmar erythema
C. Hepatic venous congestion
D. Increased serum bilirubin levels
E. Thrombocytopenia
E. Thrombocytopenia
Thrombocytopenia is a common presentation in patients with an enlarged spleen because enlargement can increase splenic activity (hypersplenism), leading to the rapid clearance of platelets from the blood stream. Splenic enlargement and esophageal varices (collateral circulation) are seen in all forms of portal hypertension. However, unlike post-hepatic and hepatic causes of portal hypertension (e.g., Budd-Chiari syndrome, cirrhosis), pre-hepatic causes of portal hypertension such as splenic or portal vein thrombosis are usually not associated with ascites. Repeated spontaneous miscarriages in patients with thrombophilia, as suggested here by the diagnosis of portal vein thrombosis, is suspicious of antiphospholipid syndrome (APS).
A 72-year-old woman is brought to the emergency department with fever, myalgia, and cough for 3 days. She lives in an assisted living facility and several of her neighbors have had similar symptoms. She has hypertension treated with lisinopril. She has not been vaccinated against influenza. Her temperature is 38.9°C (102.2°F), pulse is 105/min, respirations are 22/min, and blood pressure is 112/62 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 89%. Her leukocyte count is 10,500/mm3, serum creatinine is 0.9 mg/dL, and serum procalcitonin level is 0.05 μg/L (N < 0.06). An x-ray of the chest shows reticulonodular opacities in the lower lobes bilaterally. Blood and sputum cultures are negative. The patient is admitted to the hospital and empirical treatment with ceftriaxone and azithromycin is begun. Two days after admission, her temperature is 37.6°C (99.7°F) and pulse oximetry shows an oxygen saturation of 96% on room air. Her serum procalcitonin level is 0.04 μg/L. Which of the following is the most appropriate next step in management?
A. Continue ceftriaxone and azithromycin to complete 7-day course
B. Start treatment with oseltamivir
C. Discontinue ceftriaxone and azithromycin
D. Discontinue ceftriaxone and continue azithromycin to complete 7-day course
E. Repeat x-ray of the chest
C. Discontinue ceftriaxone and azithromycin
Discontinuing ceftriaxone and azithromycin is the most appropriate next step in the management of this patient with characteristic features of viral lower respiratory infection (e.g., bilateral reticulonodular opacities, consistently low PCT). PCT, which is produced by epithelial cells in response to bacterial toxins, is a sensitive indicator of bacterial infection. In patients with a history as well as clinical and imaging findings of viral pneumonia, persistently low PCT levels (< 0.25 μg/L) indicate viral pneumonia, which is not treated with antibiotics. Studies have found that measuring PCT levels helps guide antibiotic therapy and reduces the average duration of treatment by approximately 50% without increasing mortality.
A 68-year-old man comes to the physician because of fatigue and muscle cramps for the past 4 weeks. He has also noticed several episodes of tingling in both hands. He has not had fever or nausea. He has had a chronic cough for 10 years. He has chronic bronchitis, hypertension, and osteoarthritis of both knees. His father died from lung cancer. Current medications include salbutamol, ibuprofen, and ramipril. He has smoked 1 pack of cigarettes daily for 45 years. He is 175 cm (5 ft 9 in) tall and weighs 68 kg (163 lb); BMI is 22 kg/m2. His temperature is 36.7°C (98°F), pulse is 60/min, and blood pressure is 115/76 mm Hg. While measuring the patient's blood pressure, the physician observes carpopedal spasm. Cardiopulmonary examination shows no abnormalities. His hematocrit is 41%, leukocyte count is 5800/mm3, and platelet count is 195,000/mm3. Serum alkaline phosphatase activity is 55 U/L. An ECG shows sinus rhythm with a prolonged QT interval. Which of the following is the most likely underlying cause of this patient's symptoms?
A. Multiple endocrine neoplasia
B. Ectopic hormone production
C. Medication side effect
D. Destruction of parathyroid glands
E. Vitamin D deficiency
D. Destruction of parathyroid glands
This patient presents with hypocalcemia, which is often caused by hypoparathyroidism. The most common cause of hypoparathyroidism is surgical destruction of parathyroid glands (e.g., thyroidectomy, parathyroidectomy). Since this patient does not have a history of surgery, he most likely has hypoparathyroidism due to autoimmune destruction of parathyroid glands, which is the second most common cause of hypoparathyroidism in adults. Hypoparathyroidism also manifests with hyperphosphatemia and normal levels of ALP. Treatment for hypoparathyroidism includes correcting hypocalcemia through calcium and vitamin D supplementation.
A 17-year-old boy is brought to the physician by his father because of a 2-month history of painless swellings on his neck. He also reports a 4-kg (9-lb) weight loss during this period and increased fatigue. He has no history of previous illness. He does not smoke, drink alcohol, or use illicit drugs. His only medication is a multivitamin. His temperature is 38.2°C (100.8°F), pulse is 75/min, respirations are 14/min, and blood pressure is 115/76 mm Hg. Physical examination shows several enlarged, rubbery, nontender, cervical lymph nodes on both sides of his neck, with the largest measuring 2 x 2 cm. An excisional cervical lymph node biopsy is performed. Histologic examination of the biopsy specimen shows giant, CD15+ and CD30+, binucleated cells with prominent nucleoli. In this patient's condition, which of the following is most likely to be associated with an unfavorable prognosis?
A. 12;21 chromosomal translocation on karyotyping
B. High lactate dehydrogenase concentration on serum studies
C. Lymphocytosis on lymph node biopsy
D. 9;22 chromosomal translocation on karyotyping
E. Young age at disease onset
B. High lactate dehydrogenase concentration on serum studies
A high lactate dehydrogenase (LDH) concentration on serum studies is associated with a poor prognosis in HL and many other malignancies (e.g., non-Hodgkin lymphoma, testicular cancer, AML). Tumors are thought to preferentially metabolize glucose to lactate even in an aerobic state (Warburg effect), which causes an increase in LDH concentration. Two processes further exacerbate the Warburg effect: increased tumor glycolysis (to sustain the high proliferation rate of tumor cells) and necrosis at the center of large tumors (likely due to limited blood and, consequently, oxygen and nutrient supply). Therefore, elevated LDH levels correlate with tumor burden.
Other factors that indicate a poor prognosis in HL include a high ESR, the involvement of ≥ 3 lymph node areas, large mediastinal tumor, bulky disease, factors included in the International Prognostic Score, extranodal involvement, the presence of B symptoms, and histological characteristics (e.g., lymphocyte-depleted subtype).