Other questions for Lab BOC

Light sensitivity and headaches are symptoms of what disorder?

Eyestrain

A patient experiences a mild allergic reaction to a transfusion, including urticaria, erythema (skin redness), and itching. What is the most likely source of the allergen?

Plasma Proteins

The majority of all laboratory errors occur during which phase of laboratory testing

Preanalytic

What is the focus of both Lean and Six Sigma?

Process improvement

What should be done with a box of 10 Red Blood Cell units that was received with a measured temperature inside the box at 15ºC?

Quarantine and destroy the products

The degree in which a measure is consistent in producing the same results when measuring the same analyte is called:

Reliability

Which infection control measure should be used by a healthcare worker who will be collecting a blood specimen from a TB patient?

Respiratory protection controls Respiratory protection controls are used for situations with a high risk of exposure.

A WBC differential count on CSF should be performed using the what technique?

Stained smear of a cytocentrifuged specimen

The estimation of hyaluronic acid concentration by measurement of viscosity is useful in evaluating which type of fluid?

Synovial

When performing your mixing study, you aliquot your sample plasma and the pooled normal plasma to create your "mix". You then place the sample in a water bath to incubate for 90 minutes before running your new mixed sample. What is the problem with the steps involved in the procedure above?

You have not run a PT or aPTT on the new mix before incubating

The results which would be MOST consistent with macro-amylasemia are? a) Normal serum amylase and elevated urine amylase values b) Increased serum amylase and normal to low urine amylase values c) Increased serum and increased urine amylase values d) Normal serum and normal urine amylase values

b) Increased serum amylase and normal to low urine amylase values

A patient is admitted to the hospital with acute chest pain, but which of the following cardiac markers will be elevated FIRST if the patient had an MI? a) LD b) CK c) Myoglobin d) Troponin

c) Myoglobin Myoglobin rises typically within 2-4 hours after a myocardial infarction and stay elevated for days, with a peak at the 6-9-hour mark post-MI.

MCV is calculated using which of the following parameters: a) Hgb and RBC b) RBC histogram c) RBC and Hct d) RBC and MCHC

c) RBC and Hct

If a potential donor has been previously transfused with blood products, he must be deferred from blood donation for:

1 year

An Rh negative mother has just given birth to an Rh positive baby. Her physician suspects that she has experienced a fetal-maternal hemmorhage since her rosette test was positive. Upon performing the Kleihauer-Betke stain procedure, the percentage of fetal cells is found to be 0.85%. The mother's total blood volume is 4,565 mL. What dose of Rh Ig (RhoGam) should be administered to the mother?

2 vials Rh immune globulin, also known as Rh Ig or RhoGam, is used to help prevent an Rh negative mother from becoming sensitized to the D antigen from an Rh positive baby. To do this, vials of Rh Ig must be administered correctly. One full dose vial (300µg or equivalent) per 30 ml of D+ whole blood (15 ml D+ packed RBCs). To calculate how many vials are needed, the following formula can be employed: KB% x blood volume = volume of baby blood In this case: 0.85% (0.0085) x 4,565mL= 38.8 mL baby blood in maternal circulation 38.8mL / 30 mL per Rh Ig vial = 1.29 vials 1.29 vials can be rounded to 1 vial. In addition, an extra vial is always added. Therefore, 2 vials is the correct answer

Which class of immunoglobulins is implicated in hemolytic disease of the fetus and newborn (HDFN)?

IgG

The ultimate end product of both epinephrine and norepinephrine metabolism is:

vanillylmandellic acid (VMA)

What is Coombs sera comprised of:

Anti-human globulins

What is the function of ADAMTS13 enzyme?

Cleaving ultra-large molecules of von Willebrand factor to keep them out of the circulation ADAMTS13 is responsible for cleaving ultra-large molecules of von Willebrand factor into smaller fractions, thereby preventing these large molecules from getting into circulation where they may be responsible for unnecessary blood clotting. During a TTP or HUS episode, ADAMTS13-enzyme does not cleave ultra-large vWF and these ultra- large molecules do get into circulation, resulting in excessive platelet aggregation and microvascular thrombus formation. The ADAMTS13 enzyme does not have a role in breaking down fibrinogen, transporting antibody-coated platelets to the spleen, or maturation of platelets.

What is the MOST common cause of acute hemolytic transfusion reactions?

Clerical errors Acute hemolytic transfusion reactions are rare, but when they do occur, they are usually life-threatening. Clerical errors that include mislabeling blood or misidentification of patients, account for 80% of these reactions.

Analytical sensitivity of a method generally refers to:

Its ability to measure low concentrations of analytes

Which parasite enters its host through ingestion of infected pork?

Trichinella spiralis

Which one of the following statements about blood cultures is NOT correct? a) A specific amount of blood is required to fill blood culture bottles to optimize the growth and detection of bacteria. b) If two separate sets (two bottles each set) of blood cultures are requested, draw them both from the same site at the same time. c) Prior to performing the venipuncture, allow the cleansing agent to air dry completely on the skin to ensure sterilization of the venipuncture site. d) All of the above statements are incorrect.

b) If two separate sets (two bottles each set) of blood cultures are requested, draw them both from the same site at the same time.

The use of the direct antiglobulin test is indicated in all the following except: a) Transfusion reactions b) Autoimmune hemolytic anemia c) Hemolytic disease of the newborn d) Detection of alloantibodies in serum

d) Detection of alloantibodies in serum

Which of the following factors is not involved in the initial contact phase of the intrinsic pathway: a )Factor XII b)Fitzgerald Factor (high-molecular weight kininogen) c) Fletcher Factor (prekallikrein) d) Factor X

d) Factor X

Unconjugated bilirubin is conjugated in the liver with which substance to become water soluble?

glucuronic acid

In skin tests for allergy, a wheal and flare development is indicative of:

immediate hypersensitivity In skin tests for allergies, a skin eruption can follow an injection of an antigen. It is characterized by redness and swelling; this is caused by a release of histamine. This type of reaction typically occurs in stages. First, the appearance of an erythematous area at the site of injury. Next, the development of a flare surrounding the site. Third, a wheal forms at the site when fluid leaks under the skin.