Interpretation of Lab and Basic Diagnostic Tests

The measure of how well a test detects a disease without giving a false-positive result is called: Sensitivity Standard deviation Mean Specificity None of the above d

In order to have in excess of a 99% confidence interval, the curve must extend out how far? -1 standard deviation from the mean 1 standard deviation from the mean 2 standard deviations from the mean 3 standard deviations from the mean None of the above d

A person does not have the disease in question and tests negative for the disease. This is referred to as: True negative False negative True positive False positive None of the above a

c The term “nanogram” means: One millionth of a gram One billionth of a gram One thousandth of a gram One million grams One billion grams c

The CBC for your patient reveals a hematocrit of 28%, a hemoglobin of 8.5 g/dL, an MCV of 125 um3, an MCH of 45 pg, and an MCHC of 45%. Which of the following is least likely a cause for these abnormal lab values? Alcoholism Iron deciciency Folate deficiency Vitamin B12 deficiency None of the above b

Which of the following white cell types would you expect to see elevated in a bacterial infection? Lymphocyte Eosinophil Basophil Monocyte neutrophil e

You are transporting a recent arrival from Africa who became ill shortly after arrival. On the CBC differential you note that the percentages of monocytes and eosinophils are elevated. What is the most likely cause? Allergies Malaria Parasites A and C B and C e

d A measure of less mature forms of red blood cells is: Band count Sed rate C-reactive protein Reticulocyte count None of the above d

The cell type in the marrow that gives rise to all blood cell types is: Hemocytoblast Myeloid stem cell Prosynthroblast Myeloblast None of the above a

b In leukemia, white blood cell values are: Normal Elevated Reduced Absent None of the above b

d A “left-shift” in the CBC differential is associated with: Appendicitis Bacterial infection Pyelonephritis All of the above None of the above d

Which of the following lab values is used to monitor heparin therapy? Partial thromoplatin time (PTT) D-dimer Prothrombin time (PT) Internationalized normalized ratio (INR) None of the above a

a Which of the following is a normal anion gap? 12-14 mEq/L 1-2 mEq/L None of the above a

d Which of the following is a bivalent cation? NA+ K+ Cl- MG++ None of the above d

d A BUN/creatinine ratio of 23:1 points to: Prerenal causes Postrenal causes A and C None of the above d

b Which of the following is characteristic of gout? Decreased uric acid Increased uric acid Decreased serum osmolality Increased serum osmolality B and D b

Scenario Questions 17-20 refer to the following scenario: Your patient has the following basic metabolic profile (BMP): NA+ = 151 mEq/L K+ = 4.9 mEq/L Cl- = 110 mEq/L HCO3 = 24 mEq/L BUN = 31 mg/dL Creatine = 1.1 mg/dL Glucose = 128 mg/dL

What is the BUN/creatinine ratio? 28:1 1:28 30 15 None of the above a

b What is the calculated anion gap? 15 mEq/L 22 mEq/L 31 mEq/L None of the above b

Which of the following ECG changes would you expect to see in this patient? Peaked T-waves Delta waves Osborne waves Inverted P waves None of the above e

c These lab values are most consistent with: Moderate overhydration Normal hydration Dehydration Acute pulmonary edema None of the above c

e Which of the following is not associated with hypochloremia? Vomiting Gastric suctioning Diarrhea Diuretic use Renal failure e

A patient tells you his Hemoglobin A1C was 12%. What does this indicate? The patient is a heavy smoker The patient has diabetes under excellent control The patient has markedly elevated cholesterol levels The patient has diabetes under poor control None of the above d

Which of the following is not associated with increased risk for heart disease? Elevated HDL Elevated cholesterol Elevated triglycerides Elevated LDL None of the above d

c, b, d, a, e Match each following LDH isoenzyme with its source: ______ LDH1 a. placenta, kidney, pancreas ______ LDH2 b. reticuloendothelial system ______ LDH3 c. heart, erythrocytes, renal cortex ______ LDH4 d. lung tissue ______ LDH 5 e. skeletal muscle, liver c, b, d, a, e

c, a, b Match each following CK isoenzyme with its source: ______ CK-I (BB) a. heart ______ CK-II (MB) b. skeletal muscle ______ CK-III (MM) c. brain & smooth muscle c, a, b

Which marker is the first to elevate following myocardial infarction? CK LDH Myoglobin Troponin None of the above c

Which of the following tests of liver function is the first to elevate during alcohol abuse? ALP GGT ALT AST Aldolase b

Your patient has a total bilirubin of 31 mg/dL of which 2 Your patient has a total bilirubin of 31 mg/dL of which 2.9 mg/dL is direct bilirubin. Which of the following is the most likely cause? Sickle cell disease Autoimmune disease Drug toxicity Gallstones None of the above d

Which of the following is a serological marker for Neisseria gonorrhea infection? VDRL RPR FTA-ABS MHA-TP None of the above e

Which of the following blood types is safest to administer in an emergency when the patient’s blood type is not known? AB+ AB- O+ O- None of the above d

You are transporting a patient between hospitals You are transporting a patient between hospitals. A quick look at his chart reveals the following: Anti-HAV = Negative Anti-HBV = Positive HBsAg = Positive Which of the following statements is true? The patient has been immunized against hepatitis A The patient has hepatitis A The patient has hepatitis B The patient has hepatitis C None of the above c

Which of the following findings on a urinalysis would point to a urinary tract infection? Positive leukocyte esterase Positive nitrate 10-12 WBC/HPF All of the above A and B d

In a concentrated urine sample, one would expect the specific gravity to be: Elevated Low Normal Not impacted by concentration None of the above a

a Which of the following tests uses ionizing radiation? Computed tomography Magnetic resonance imaging Positron emission tomography Ultrasound None of the above a

Which of the following findings is inconsistent with a diagnosis of respiratory acidosis? pH = 7.25 Increased PaCO2 Decreased PaCO2 Decreased HCO3 None of the above c

A patient is suffering diabetic ketoacidosis and being treated in an ICU with oxygen and a heprin drip. Which of the following laboratory findings would not be expected? PO2 = 158 mmHg PCO2 = 23 mmHg HCO3 = 12 mEg/L pH = 7.48 None of the above d

Questions 43-44 refer to the following scenario: You are transporting a patient with fulminant pancreatitis. He is receiving IV H2 blockers and has an NG tube in place. He is also on a morphine drip. His ABGs are: pH = 7.5 PO2 = 101 mmHg PCO2 = 38 mmHg HCO3 = 36 mEq/L HgB = 13.0 g/dL SaO2 = 99%

d Which acid-base derangement is present? Respiratory acidosis Respiratory alkalosis Metabolic acidosis Metabolic alkalosis None of the above d

d What is the most likely cause of the patient”s condition? Severe vomiting NG suctioning Diarrhea A and B A and C d

a Which of the following statements about blood gases is true? An abnormally decreased amount of bicarbonate is called “basic deficit” An abnormally high Ph is called “base deficit” An abnormally low pH is called “base deficit” An abnormally increased amount of carbon dioxide is called “base excess” An abnormally decreased amount of carbon dioxide is called “base excess” a