A 68-year-old White male, with a history of hypertension, an 80 pack-year history of tobacco use and emphysema, is brought into the ER because of 4 days of progressive confusion and lethargy. His wife notes that he takes amlodipine for his hypertension. He does not use over-the-counter (OTC) medications, alcohol, or drugs. Furthermore, she indicates that he has unintentionally lost approximately 30 lbs in the last 6 months. His physical examination shows that he is afebrile with a blood pressure of 142/85, heart rate of 92 (no orthostatic changes), and a room-air O2 saturation of 91%. He is 70 kg. The patient appears cachectic. He is arousable but lethargic and unable to follow any commands. His mucous membranes are moist, heart rate regular without murmurs or a S3/S4 gallop, and extremities without any edema. His pulmonary examination shows mildly diminished breath sounds in the right lower lobe with wheezing bilaterally. The patient is unable to follow commands during neurologic examination but moves all his extremities spontaneously. Laboratory results are as follows:
Blood Sodium: 109 Potassium: 3.8 Chloride: 103 CO2: 33 BUN: 17 Creatinine: 1.1 Glucose: 95 Urine osmolality: 600 Plasma osmolality: 229 White blood cell (WBC): 8000 Hgb: 15.8 Hematocrit (HCT): 45.3 Platelets: 410 Arterial blood gas: pH 7.36/pCO2 60/pO2 285 A chest x-ray (CXR) reveals a large right hilar mass.
What is the most likely cause of this patient's altered mental status?
A. sepsis syndrome with pneumonia
B. ischemic stroke
C. central pontine myelinolysis
D. cerebral edema
E. respiratory acidosis
Correct Answer: D Section: (none)
Explanation:
The patient has hypotonic hyponatremia, which can lead to increased water shifting into the brain, resulting in cerebral edema. This patient has nothing in history or physical examination to suggest a stroke or the presence of sepsis as the etiology of his altered mental status. Central pontine myelinolysis is a potentially devastating neurologic complication that can result from the treatment of hyponatremia, not hyponatremia itself. While respiratory acidosis could potentially contribute to this patient's change in mental status, cerebral edema due to hypotonicity is the most likely etiology. The patient's laboratory studies indicate a low plasma osmolality with an inappropriately increased urine osmolality. With this degree of hypotonicity, the urine should be maximally dilute (osmolality of <100 mOsmol/kg H2O). The high urine osmolality suggests the presence of antidiuretic hormone. In psychogenic polydipsia, the urine would be maximally dilute. Choice C is unlikely since his physical examination does not suggest volume depletion; furthermore, the patient is taking a calcium channel blocker, not a diuretic, for the treatment of his hypertension. Decreased expression of renal collecting duct water channels would lead to water wasting and, thus, the development of diabetes insipidus and hypernatremia. The patient has symptomatic hypotonic hyponatremia with signs of cerebral edema.
This requires immediate attention. Choices A, C, and E are essentially hypotonic solutions which should be withheld in patients with hyponatremia. The serum sodium in this case should be increased by at least 5% for the treatment of cerebral edema. The use of 0.9% saline would require nearly 5 L of infusate to address this cerebral edema. This could lead to pulmonary edema and volume overload. The use of hypertonic saline (3% saline) is the ideal solution to use in this scenario, as the infusion of 3% saline will correct the symptoms while avoiding volume overload. As in all cases of hyponatremia management, frequent serum sodium assays are necessary in order to avoid too rapid of a correction, which could result in neurologic injury--pontine myelinolysis.
Question 772:
Bupivacaine is a local anesthetic agent that is much more potent and the duration of action of which is considerably longer than procaine. Possible reasons for this difference include which of the following?
A. higher partition coefficient for bupivacaine than for procaine
B. covalent binding to the receptor site
C. lower protein binding of bupivacaine than procaine
D. decreased rate of metabolism of procaine compared to bupivacaine
E. bupivacaine constricts blood vessels
Correct Answer: A Section: (none)
Explanation:
Local anesthetics exist in solution in both uncharged base and charged cationic forms. The base diffuses across the nerve sheath and membrane and then re-equilibrates within the axoplasm. It is intracellular penetration of the cation into, and attachment to a receptor at a site within the sodium channel, that leads to inhibition of sodium conductance and ultimate conduction blockade. Bupivacaine is typical of amide-linked local anesthetics with high anesthetic potency and long duration of action (class III). Procaine is typical of class I agents that are ester linked and have low anesthetic potency and short duration of action. Important features of group III compounds include: (1) high degree of lipid solubility or high partition coefficient that aid in penetration of the drug, (2) high degree of protein binding that aids in attachment of the drug once it has penetrated the cell, and (3) pKa closer to pH = 7.4 so that more of the drug is in the unionized form and is free to penetrate the membrane. Esterlinked anesthetics, such as procaine, are rapidly metabolized by pseudocholinesterases, whereas bupivacaine is slowly degraded by hepatic enzymes
Question 773:
A 54-year-old male with uncontrolled type II diabetes and well-controlled hypertension presents with complaints of erectile dysfunction. The patient requests Viagra (sildenafil), as his friends have used it with success. However, he is concerned as he was told by someone that Viagra can be fatal if used with some blood pressure medications. You would advise the patient that the use of which of the following is contraindicated in patients taking sildenafil?
A. isosorbide mononitrate
B. metoprolol
C. verapamil
D. captopril
E. clonidine
Correct Answer: A Section: (none)
Explanation:
Sildenafil is a phosphodiesterase inhibitor effective in the treatment of erectile dysfunction the mechanism of action of which is related to an increase in intracellular cyclic guanosine monophosphate (GMP). Nitrates increase cyclic GMP via the activation of guanylyl cyclase. When the two drugs interact, there can be a dramatic fall in blood pressure related to extreme vasodilation. The other selections can reduce blood pressure; however, since their mechanisms of action are not associated with the intracellular concentration of cyclic GMP, there is no synergistic interaction with sildenafil
Question 774:
A 28-year-old woman presents to your clinic complaining of feeling "on edge." Upon further questioning, you discover that she has also noticed problems with irritability, insomnia, fatigue, and restlessness. She also has a history of worrying about things that seem to not bother those around her. She states these symptoms have been present for years but have recently become worse. When you try to gather more information, she interrupts to say that she cannot stay much longer because she is afraid that she will lose her new job as a machinist. Which of the following medications would be most appropriate in this patient?
A. diazepam
B. amitriptyline
C. doxepin
D. oxazepam
E. buspirone
Correct Answer: E Section: (none)
Explanation: This patient's symptoms are consistent with an anxiety disorder. Given her occupation, an anxiolytic medication with no sedative properties would be most preferable. Buspirone is a nonsedating anxiolytic agent that is a partial agonist at 5-HT1A receptors. Unlike benzodiazepines, such as diazepam and oxazepam (Serax), it has no hypnotic, anticonvulsant, or muscle relaxant properties. Amitriptyline and doxepin have also been used to treat anxiety, especially when associated with depression; however, these drugs are also sedating.
Question 775:
A 72-year-old man comes to your clinic for the first time, accompanied by his wife. His wife states that she is concerned because he has been growing increasingly forgetful over the past year. Within the past month, he has forgotten to turn off the stove and has got lost while walking to the post office one block away from their home. His past medical history is significant for well-controlled diabetes and chronic lower back pain. He has no history of falls or traumatic injury to the head. Examination of the patient is significant for a score of 18 on a Mini Mental Status Examination (MMSE). During the administration of the MMSE, the patient blurts out that his wife brought him to the doctor because she is having an extramarital relationship.
Use of which of the following medications would be the most likely to lead to worsening of symptoms in this patient?
A. risperidone
B. amitriptyline
C. olanzapine
D. quetiapine
E. trazodone
Correct Answer: B Section: (none)
Explanation:
This patient's symptoms are most consistent with Alzheimer disease. Alzheimer disease is a prominent condition in developed nations, ranking as the third most common terminal illness behind heart disease and cancer. It is the most common form of dementia, with over 4 million Americans having the condition in the United States alone. There is a direct correlation between advanced age and increasing prevalence of Alzheimer disease. While there is an early-onset form of familial Alzheimer disease that may appear as early as the third decade of life, this accounts for only a small percentage of total Alzheimer cases. There does appear to be a genetic component to the development of Alzheimer disease, as it has been demonstrated that first-degree relatives of Alzheimer patients possess an increased risk for development of the condition. Genes on chromosomes 1, 14, and 21 have been implicated in this association. While age and family history are important risk factors, there is no evidence proving that environmental factors lead to an increased chance for development of the disease. Progression of Alzheimer dementia is typically insidious, spanning as many as several years.
Anticholinergic agents and any other medication with anticholinergic effects are contraindicated in the setting of Alzheimer dementia. Their use may lead to worsening of cognition and may contribute to decreased efficacy of medications used in the treatment of Alzheimer dementia. Tricyclic antidepressants such as amitriptyline should be avoided for this reason. Risperidone, olanzapine, and quetiapine are atypical antipsychotic medications which are useful in the treatment of emotional withdrawal and delusions which may arise in Alzheimer patients. Trazodone, carbamazepine, and divalproex are moodstabilizing medications which are useful in patients who display marked agitation. While trazodone does display some anticholinergic side effects, they are far less pronounced than those seen with amitriptyline.
Question 776:
A 72-year-old man comes to your clinic for the first time, accompanied by his wife. His wife states that she is concerned because he has been growing increasingly forgetful over the past year. Within the past month, he has forgotten to turn off the stove and has got lost while walking to the post office one block away from their home. His past medical history is significant for well-controlled diabetes and chronic lower back pain. He has no history of falls or traumatic injury to the head. Examination of the patient is significant for a score of 18 on a Mini Mental Status Examination (MMSE). During the administration of the MMSE, the patient blurts out that his wife brought him to the doctor because she is having an extramarital relationship.
Which of the following accurately describes this patient's condition?
A. There is no genetic basis for development of this disease.
B. It is usually abrupt in onset.
C. There is no correlation between age and prevalence of this disease.
D. Environmental exposure is a proven risk factor for development of this disease.
E. It is one of the most common terminal illnesses in developed nations.
Correct Answer: E Section: (none)
Explanation:
This patient's symptoms are most consistent with Alzheimer disease. Alzheimer disease is a prominent condition in developed nations, ranking as the third most common terminal illness behind heart disease and cancer. It is the most common form of dementia, with over 4 million Americans having the condition in the United States alone. There is a direct correlation between advanced age and increasing prevalence of Alzheimer disease. While there is an early-onset form of familial Alzheimer disease that may appear as early as the third decade of life, this accounts for only a small percentage of total Alzheimer cases. There does appear to be a genetic component to the development of Alzheimer disease, as it has been demonstrated that first-degree relatives of Alzheimer patients possess an increased risk for development of the condition. Genes on chromosomes 1, 14, and 21 have been implicated in this association. While age and family history are important risk factors, there is no evidence proving that environmental factors lead to an increased chance for development of the disease. Progression of Alzheimer dementia is typically insidious, spanning as many as several years. Anticholinergic agents and any other medication with anticholinergic effects are contraindicated in the setting of Alzheimer dementia. Their use may lead to worsening of cognition and may contribute to decreased efficacy of medications used in the treatment of Alzheimer dementia. Tricyclic antidepressants such as amitriptyline should be avoided for this reason. Risperidone, olanzapine, and quetiapine are atypical antipsychotic medications which are useful in the treatment of emotional withdrawal and delusions which may arise in Alzheimer patients. Trazodone, carbamazepine, and divalproex are moodstabilizing medications which are useful in patients who display marked agitation. While trazodone does display some anticholinergic side effects, they are far less pronounced than those seen with amitriptyline.
Question 777:
A72-year-old African American male presents for a routine health examination. He states that he would like to have a "screening for cancer." In the United States, based on his sex, race, and age, what is the most likely malignancy for this patient?
A. lung cancer
B. prostate cancer
C. colon cancer
D. testicular cancer
E. multiple myeloma
Correct Answer: B Section: (none)
Explanation:
Prostate cancer is the leading cancer in African American males in the United States. The cancer with the
highest rate of mortality for the same subpopulation is lung cancer. Of African-American men diagnosed
with a new cancer, approximately 42% will have prostate cancer, 14.6% lung cancer, and 10% colorectal
cancer. The leading causes of cancer deaths in the same population are lung (28.4%), prostate (15.6%),
and colorectal cancer (10.5%).
Question 778:
A 52-year-old man presents to the ED with a complaint of rectal bleeding and hematuria. He has a medical
history significant for atrial fibrillation diagnosed 10 years ago and states that he takes metoprolol as well
as warfarin for this condition. Upon examination, you find that his blood pressure is 122/78, his pulse is 84,
his respiratory rate is 18, and his O2 saturation is 98% on room air. He has an irregularly irregular heart
rhythm, gingival bleeding, and some bruises on his extremities. He has a positive fecal occult blood test,
and laboratory studies return showing an international normalized ratio (INR) of 16.5.
You order that the patient's warfarin be held. Which of the following is the most appropriate additional
intervention at this time?
A. repeat INR measurement as an outpatient in 5 days
B. admit the patient to the hospital and conduct serial INR measurements
C. administer vitamin K1
D. administer fresh frozen plasma
E. administer vitamin K1 and fresh frozen plasma
Correct Answer: E Section: (none)
Explanation:
This patient has a markedly supratherapeutic INR and clinical evidence of bleeding. Discontinuation or dosage reduction of warfarin is an appropriate intervention by itself in patients with an INR less than 5.0 or in patients without signs of bleeding. In patients with bleeding or with an INR greater than 5.0, however, further interventions are indicated. Vitamin K1 administration provides a more rapid reversal of the anticoagulation caused by warfarin, but it takes 68 hours to begin having an effect and up to 24 hours to achieve its maximal effect. Immediate reversal may be obtained by the administration of fresh frozen plasma intravenously in addition to vitamin K1
Question 779:
A 64-year-old male with a history of hypertension and tobacco abuse presents for follow-up after a routine physical during which he was found to have 45 red blood cells (RBCs) per high-power field (HPF) on a screening urinalysis. The urinalysis was negative for leukocytes, nitrites, epithelial cells, and ketones. The patient denies any complaints and the review of systems is essentially negative.
In detecting microscopic hematuria, which of the following is true?
A. The office urine dipstick is 91100% sensitive and 6599% specific for detection of RBCs, Hgb, and myoglobin.
B. Urinalysis must reveal a minimum of 5 RBCs per HPF in order to continue the workup.
C. The presence of epithelial cells makes the urinalysis invalid.
D. The presence of "large blood" on a urine dipstick effectively distinguishes RBCs from myoglobinuria.
E. Any urinalysis with RBCs should be recollected via a catheterized specimen prior to initiating a workup for hematuria.
Correct Answer: A Section: (none)
Explanation:
Asymptomatic microscopic hematuria is defined by the American Urological Association as three or more RBCs per high power field on urinary sediment from two out of three properly collected urinalyses. A proper sample can be a midstream clean-catch specimen. The urine dipstick is roughly 91100% sensitive and 6599% specific for detection of RBCs, Hgb, and myoglobin. Urine dipstick is not reliable in distinguishing myoglobin from Hgb or RBCs. Therefore, urinalysis with microscopy should be ordered to assess the number of RBCs per high power field. Microscopic hematuria is usually an incidental finding but deserves a thorough workup, as 10% can be due to malignancy. The initial approach is to repeat the urinalysis to rule out infection. If the urinalysis suggests infection by the presence of WBCs or nitrites, a culture should be ordered and the patient treated appropriately. If RBCs are present without any leukocytes, nitrites, or epithelial cells on the repeated urinalysis, a proper workup should ensue. After history and physical are done to rule out risk factors, comorbidities, or other etiologies to account for the hematuria, one must look to diagnostic tests. A serum creatinine is useful to assess for renal insufficiency. During the course of the workup, if the urinalysis and serum creatinine suggest a glomerular etiology (casts, elevated creatinine, dysmorphic RBCs) a renal consultation and possible renal biopsy may be warranted. Evaluation of the upper tract with either an IVP or CT scan of the abdomen/pelvis with and without contrast should be ordered to rule out renal cell carcinoma, nephrolithiasis, or aneurysms. Next, the lower tract should be visualized by cystoscopy and washings sent for cytology. If all the above workup is negative, the patient can be reassured and followed with a repeat urinalysis in 6 months.
Question 780:
A 64-year-old male with a history of hypertension and tobacco abuse presents for follow-up after a routine physical during which he was found to have 45 red blood cells (RBCs) per high-power field (HPF) on a screening urinalysis. The urinalysis was negative for leukocytes, nitrites, epithelial cells, and ketones. The patient denies any complaints and the review of systems is essentially negative .
A. change of antihypertensive agent and recommendation to patient to discontinue smoking
B. image the upper and lower urinary tracts
C. antibiotics for 1 month
D. expectant management with follow-up urinalysis in 6 months
E. nephrology consultation
Correct Answer: B Section: (none)
Explanation:
Asymptomatic microscopic hematuria is defined by the American Urological Association as three or more RBCs per high power field on urinary sediment from two out of three properly collected urinalyses. A proper sample can be a midstream clean-catch specimen. The urine dipstick is roughly 91100% sensitive and 6599% specific for detection of RBCs, Hgb, and myoglobin. Urine dipstick is not reliable in distinguishing myoglobin from Hgb or RBCs. Therefore, urinalysis with microscopy should be ordered to assess the number of RBCs per high power field. Microscopic hematuria is usually an incidental finding but deserves a thorough workup, as 10% can be due to malignancy. The initial approach is to repeat the urinalysis to rule out infection. If the urinalysis suggests infection by the presence of WBCs or nitrites, a culture should be ordered and the patient treated appropriately. If RBCs are present without any leukocytes, nitrites, or epithelial cells on the repeated urinalysis, a proper workup should ensue. After history and physical are done to rule out risk factors, comorbidities, or other etiologies to account for the hematuria, one must look to diagnostic tests. A serum creatinine is useful to assess for renal insufficiency. During the course of the workup, if the urinalysis and serum creatinine suggest a glomerular etiology (casts, elevated creatinine, dysmorphic RBCs) a renal consultation and possible renal biopsy may be warranted. Evaluation of the upper tract with either an IVP or CT scan of the abdomen/pelvis with and without contrast should be ordered to rule out renal cell carcinoma, nephrolithiasis, or aneurysms. Next, the lower tract should be visualized by cystoscopy and washings sent for cytology. If all the above workup is negative, the patient can be reassured and followed with a repeat urinalysis in 6 months.
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