Section 1.1 Part 2

What pathogen represents an exogenous bacteria flora (i.e., acquired from the hospital)? Characteristics of this pathogen are non-lactose fermenting gram-negative bacilli.

• A) Neisseria meningitidis

• B) Enterobacter cloacae

• C) Streptococcus pneumoniae

• D) Pseudomonas aeruginosa

Answer explanation

Explanation:

The correct answer is (D).

 

Pseudomonas aeruginosa (D) is a non-lactose fermenting gram-negative bacilli. Other non-lactose fermenting gram-negative bacilli include Proteus, Serratia, Morganella, Stenotrophomonas, and Acinetobacter.

Neisseria meningitidis (A) is a gram-negative cocci. Enterobacter cloacae (B) is a lactose-fermenting gram- negative bacilli. Streptococcus pneumoniae (C) is a gram-positive cocci (diplococcic).

74% of users answered correctly.

A 49-year-old woman with previous peptic ulcer disease was admitted with persistent vomiting. She looked dehydrated, with dry mucus membranes and skin tenting. Her blood results were Na 141 mEq/L, K 2.6 mEq/L, Cl 87 mEq/L, pH 7.51, Pa CO2 50 mm Hg, and HCO 3 40 mEq/L. Has the patient been appropriately compensated for the primary acid-base disorder?

• A) Yes, the PaCO2 is elevated, indicating appropriate compensation.

• B) Yes, the PaCO2 is low, indicating appropriate compensation.

• C) Yes, the HCO3 is normal, indicating appropriate compensation.

• D) Yes, the HCO3 is low, indicating appropriate compensation.

Answer explanation

Explanation:

The correct answer is (A).

 

Because the pH is elevated secondary to metabolic alkalosis, the most appropriate respiratory compensation would be for the lungs to hold on to acid (Pa CO 2 ), resulting in a respiratory acidosis, which is the case here with a Pa CO 2 of 50 mm Hg (A).

As indicated, the Pa CO 2 is not low (B), and we know there is a primary metabolic disorder (C and D).

71% of users answered correctly.

GM is a 58-year-old African American man with systolic heart failure presenting with a 10-day history of shortness of breath which limits his normal daily activities and increases lower extremity edema. His weight has recently increased by 12 lb. His physical examination is notable for BP 144/77 mm Hg, HR 85 bpm, RR 22 rpm, rales and 4+ lower extremity edema. Pertinent laboratory values include: sodium 136 mmol/L, potassium 5.4 mmol/L, BUN 23 mg/dL, creatinine 1.1 mg/dL and digoxin 1.9 ng/mL. Past medical history is significant for hypertension (HTN), gout, COPD and atrial fibrillation. Current medications include lisinopril 20 mg daily, diltiazem CD 120 mg daily and digoxin 0.250 mg daily salmeterol/fluticasone 250/50 two puffs bid. GM recently began taking naproxen 220 mg tid for gout pain. In addition to counseling on salt and fluid restriction, which pharmacologic option is most appropriate for managing GM's fluid overload?

• A) Initiate hydrochlorothiazide 50 mg daily.

• B) Initiate furosemide 40 mg twice daily.

• C) Initiate metolazone 2.5 mg daily.

• D) Initiate spironolactone 25 mg daily

Answer explanation

Explanation:

The correct answer is (B).

 

Loop diuretics, such as furosemide, are the treatment of choice for managing volume overload in HF patients.

 

Answer (A) is incorrect. Thiazide diuretics such as hydrochlorothiazide are not effective options for monotherapy. However, thiazides may be added if patients are not responding adequately to loop diuretic dose escalation. In the setting of refractory fluid overload, combined use of a loop and thiazide diuretic work synergistically through complementary mechanisms of action.

Answer (C) is incorrect. Metolazone is not an effective option for monotherapy; however, it may be added if patients are not responding adequately to loop diuretic dose escalation. In the setting of refractory fluid overload, combined use of a loop and metolazone work synergistically through complementary mechanisms of action.

Answer (D) is incorrect. Spironolactone has been shown to be effective in reducing mortality when added to standard HF therapy in moderately severe to severe (NYHA class III-IV) patients. The low doses (eg, 12.5-25 mg/d) used to manage HF typically do not result in clinically significant diuresis.

79% of users answered correctly.

GT is a 26-year-old patient with a diagnosis of bipolar disorder. He is currently not receiving any medication for treatment and presents to the emergency room via ambulance in an acute manic phase. The psychiatry fellow evaluates the patient and orders lithium for treatment of bipolar disorder. The provider wants to order 8 mEq three times per day. The provider is also going to order a serum lithium level for GT. Select the time to monitor/order a serum lithium level.

• A) 2 hours after dose

• B) 4 hours after dose

• C) 6 hours after dose

• D) 8 hours after dose

Answer explanation

Explanation:

The correct answer is (D).

 

Since lithium distribution follows a two compartment model, it is imperative that lithium samples be obtained at consistent and reproducible times. The level should be obtained just before the first morning dose of lithium and at least 12 hours after the last evening dose. However, our patient is receiving the medication every 8 hours, so 12 hours after the last dose sampling time is not feasible. Therefore, 8 hours after the last dose would be the time to sample. The terminal half-life of 18 hours suggests that steady-state lithium levels should be obtained within 3 to 5 days. Although lithium levels appear to plateau within 3 to 5 days, full therapeutic effects are not generally observed for 14 to 21 days after therapy has been initiated.

Answer (A) is incorrect. Sampling time of 2 hours is too early. Answer (B) is incorrect. Sampling time of 4 hours is too early. Answer (C) is incorrect. Sampling time of 6 hours is too early.

40% of users answered correctly.

B and T lymphocytes may be distinguished from each other by the presence of lineage specific membrane markers termed:

• A) Clusters of differentiation (CD)

• B) Complement

• C) C-reactive protein (CRP)

• D) Chemokines

• E) CCR5 coreceptor

Answer explanation

Explanation:

The correct answer is (A).

 

Morphologic differentiation of lymphocytes is difficult and visual inspection of a blood smear cannot distinguish between T and B cells. Fortunately, lymphocytes can be distinguished by the presence of lineage- specific membrane markers, termed clusters of differentiation (CD). Mature T cells are CD4 or CD8 and B cells are CD20. Identification of the subtype of lymphocyte is not a routine clinical hematology test; lymphocytes are reported as a total lymphocyte count on the complete blood count (CBC). An exception is the reporting/monitoring of CD4 cells for patients with human immunodeficiency virus (HIV).

49% of users answered correctly.

QW is a 46-year-old African American man with a family history of prostate cancer who presents to his primary care physician for his annual examination. He asks about prostate cancer screening. Which of the following is the most appropriate course of action?

• A) Observation because he is not eligible for prostate cancer due to his age

• B) Perform a digital rectal examination to determine the size of the prostate

• C) Draw a PSA level to rule out benign prostatic hyperplasia

• D) Perform a digital rectal examination and draw a PSA level

Answer explanation

Explanation:

The Correct Answer is: D

 

Neither DRE nor PSA is sensitive or specific enough to be used alone as a screening test. Therefore, the combination of a DRE plus PSA determination is a better method in detecting prostate cancer than DRE alone (D).

A baseline PSA and DRE at age 40 with annual evaluations beginning at age 50 for all men of normal risk with a 10-year or greater life expectancy is recommended (A). Men with an increased risk of prostate cancer, including men of African American ancestry and men with a family history of prostate cancer may begin screening earlier, at age 40 to 45. This patient is eligible for screening because he is at high risk due to his race-ethnicity and family history. DRE as a single screening method has poor compliance, and has had little

effect on preventing metastatic prostate cancer. Therefore, prostate screening with a DRE alone is currently not recommended (B). PSA may be elevated in men with acute urinary retention, acute prostatitis, and prostatic ischemia or infarction, as well as BPH. PSA elevations between 4.1 (4.1 µg/L) and 10 ng/mL (10 µg/L) cannot distinguish between BPH and prostate cancer, limiting the utility of PSA alone for the early detection of prostate cancer (C).

62% of users answered correctly.

Which of the following cell types can present peptide fragments from an engulfed pathogen in association with MHC class II to T lymphocytes?

• A) Neutrophils

• B) Basophils

• C) Dendritic cell

• D) Eosinophils

Answer explanation

Explanation:

The correct answer is (C). Dendritic cells are a potent APC.

47% of users answered correctly.

QW is a 46-year-old African American man with a family history of prostate cancer who presents to his primary care physician for his annual examination. He asks about prostate cancer screening. Which of the following is the most appropriate course of action?

• A) Observation, because he is not eligible for prostate cancer due to his age.

• B) Perform a digital rectal examination to determine the size of the prostate.

• C) Draw a PSA level to rule out benign prostatic hyperplasia.

• D) Perform a digital rectal examination and draw a PSA level.

Answer explanation

Explanation:

The correct answer is (D).

 

Neither DRE nor PSA is sensitive or specific enough to be used alone as a screening test. Therefore, the combination of a DRE plus PSA determination is a better method in detecting prostate cancer than DRE alone.

Answer (A) is incorrect. A baseline PSA and DRE at age 40 with annual evaluations beginning at age 50 to all men of normal risk with a 10-year or greater life expectancy is recommended. Men with an increased risk of prostate cancer, including men of African American ancestry and men with a family history of prostate cancer may begin screening earlier, at age 40 to 45. Patient is eligible for screening because he is at high risk due to his race-ethnicity and family history.

Answer (B) is incorrect. DRE as a single screening method has poor compliance, and has had little effect on preventing metastatic prostate cancer. Therefore, prostate screening with a DRE alone is currently not recommended.

Answer (C) is incorrect. PSA may be elevated in men with acute urinary retention, acute prostatitis, and prostatic ischemia or infarction, as well as BPH. PSA elevations between 4.1 ng/mL (4.1 µg/L) and 10 ng/mL (10 µg/L) cannot distinguish between BPH and prostate cancer, limiting the utility of PSA alone for the early detection of prostate cancer.

61% of users answered correctly.

The most common analytical test used to assess whether exogenous testosterone or one of its derivatives has been used is which of the following?

• A) Androstenedione: testosterone ratio

• B) Testosterone: epitestosterone ratio

• C) Urine sample of 19-Nandrolone

• D) Blood specimen of 19-NA

Answer explanation

Explanation:

The correct answer is (B).

 

The most common test (urine) conducted examines the ratio of testosterone to epitestosterone. Normally, this occurs in a 1:1 ratio. Occasionally, some athletes will have an increased ratio of 2:1, and rarely 3:1. A threshold ratio of 4:1 currently exists with WADA; values above this ratio are consistent with exogenous administration of testosterone and its derivatives, suggesting illicit use.

Choice (A) is incorrect. No established ratio for A:T has been suggested to determine exogenous administration.

Choice (C) is incorrect. While this is a confirmatory test, it has been associated with false positives. The most common analytical test is T:E ratio.

Choice (D) is incorrect. While potentially doable, the feasibility and cost of blood specimens is not warranted at this time unless in-depth confirmatory testing is warranted.

37% of users answered correctly.

KZ is a patient with breast cancer and has just finished her last cycle of treatment. After previous treatment cycles, KZ developed a neutropenia about 10 days after the treatment. What is the definition of neutropenia?

• A) Neutrophil count of 0/mm3

• B) Neutrophil count less than 250/mm3

• C) Neutrophil count less than 500/mm3

• D) Neutrophil count less than 1000/mm3

Answer explanation

Explanation:

The correct answer is (C).

 

Neutropenia is defined as absolute neutrophil count (ANC) less than 500/mm3. The ANC is calculated by multiplying the percentage of neutrophils (segmented plus banded neutrophils) by the total white blood cell count.

Answers (A), (B) and (D) are incorrect.

51% of users answered correctly.