ABPath Combined AP/CP Primary Certification flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

ABO compatibility rule

Group O packed red cells may be given to A, B, AB, and O recipients; group AB plasma may be given to all ABO groups because it lacks anti-A and anti-B antibodies.

RhD negative recipients

RhD-negative females of childbearing age and RhD-negative transfusion recipients should receive RhD-negative red cells when feasible to prevent anti-D alloimmunization, which can cause hemolytic disease of the fetus and newborn.

Positive antibody screen

A positive antibody screen requires antibody identification, assessment of clinical significance, and selection of antigen-negative red cells; crossmatch-compatible units may still be needed for high-frequency antibodies.

DAT positive workup

Direct antiglobulin testing detects antibody or complement on red cells; polyspecific positivity is followed by monospecific IgG and C3 testing, elution, and correlation with hemolysis and recent transfusion.

Acute hemolytic reaction

Most often caused by ABO incompatibility from clerical error; features include fever, chills, flank pain, hemoglobinuria, and hypotension; stop the transfusion, maintain venous access, and send samples for hemolysis and compatibility testing.

TRALI diagnostic criteria

Transfusion-related acute lung injury occurs within six hours of transfusion with new hypoxemia and bilateral pulmonary infiltrates without circulatory overload; fever, hypotension, and anti-HLA or anti-neutrophil antibodies may accompany it.

Platelet storage conditions

Platelets are stored at 20-24 degrees Celsius with continuous agitation for up to five days; they are not refrigerated because cold storage reduces viability and can activate platelets.

Anion gap formula

Anion gap equals sodium minus the sum of chloride and bicarbonate; the reference range is approximately 8-12 mmol/L, and the gap rises by about 2.5 for each 1 g/dL decrease in albumin.

Corrected sodium for hyperglycemia

In hyperglycemia, measured sodium falls because water shifts into the extracellular space; add approximately 1.6 mmol/L to measured sodium for every 100 mg/dL glucose above 100 mg/dL.

Osmolal gap formula

Osmolal gap is measured serum osmolality minus calculated osmolality, where calculated osmolality equals 2 times sodium plus glucose divided by 18 plus blood urea nitrogen divided by 2.8; an elevated gap suggests unmeasured osmoles.

TSH and free T4

Primary hypothyroidism typically shows elevated TSH with low free T4; subclinical hypothyroidism has elevated TSH with normal free T4; central hypothyroidism shows low or inappropriately normal TSH with low free T4.

Anti-dsDNA significance

High-titer anti-double-stranded DNA antibodies are relatively specific for systemic lupus erythematosus and correlate with disease activity, especially lupus nephritis; they are less sensitive than antinuclear antibodies.

Hepatitis B serology

Hepatitis B surface antigen indicates current infection; IgM core antibody indicates acute infection; total core antibody indicates past or current infection; surface antibody indicates immunity; hepatitis B e antigen reflects high infectivity.

Syphilis serology algorithm

Reverse algorithm screens with a treponemal immunoassay, then reflexively tests nontreponemal RPR or VDRL; discordant results require a second treponemal test, and nontreponemal titers monitor treatment response.

Microcytic anemia iron studies

Iron deficiency shows low ferritin, low serum iron, high total iron-binding capacity, and low transferrin saturation; anemia of chronic disease shows normal or high ferritin, low iron, low TIBC, and low saturation.

Hemolysis laboratory triad

Hemolysis is supported by elevated lactate dehydrogenase, low haptoglobin, and elevated indirect bilirubin; reticulocytosis and increased urine urobilinogen may also occur, while urine hemosiderin suggests intravascular hemolysis.

Mixing study interpretation

A prolonged aPTT that corrects with normal plasma suggests factor deficiency; failure to correct suggests an inhibitor such as a lupus anticoagulant or a specific factor inhibitor; incubation may be needed for some inhibitors.

CML genetic hallmark

Chronic myeloid leukemia is defined by the Philadelphia chromosome, t(9;22), producing BCR-ABL1; the fusion tyrosine kinase drives myeloid proliferation and is targeted by tyrosine kinase inhibitors such as imatinib.

APL genetic hallmark

Acute promyelocytic leukemia carries t(15;17) producing PML-RARA; it is associated with disseminated intravascular coagulation and is treated with all-trans retinoic acid plus arsenic trioxide or chemotherapy.

Multiple myeloma screening

Screening includes serum protein electrophoresis, serum immunofixation, free light chain assay, and urine protein electrophoresis; diagnosis requires clonal plasma cells plus myeloma-defining events such as hypercalcemia, renal failure, anemia, or bone lesions.

Gram-positive cocci in clusters

Gram-positive cocci in clusters suggest Staphylococcus species; catalase testing distinguishes staphylococci from streptococci, and coagulase testing distinguishes Staphylococcus aureus from coagulase-negative staphylococci.

Optochin susceptibility

Streptococcus pneumoniae is optochin susceptible and bile soluble, whereas viridans group streptococci are optochin resistant and bile insoluble; these tests help distinguish them when alpha-hemolysis is present.

MacConkey agar purpose

MacConkey agar selects for gram-negative bacilli and differentiates lactose fermenters, which produce pink colonies, from non-lactose fermenters, which remain colorless; bile salts inhibit gram-positive organisms.

Oxidase-positive nonfermenter

Pseudomonas aeruginosa is an oxidase-positive, non-lactose-fermenting gram-negative rod that grows at 42 degrees Celsius, produces pyocyanin, and is a common cause of hospital-acquired and burn wound infections.

MRSA detection

Methicillin-resistant Staphylococcus aureus is detected by cefoxitin disk diffusion or oxacillin/methicillin MIC testing; the mecA gene or penicillin-binding protein 2a confirms resistance and predicts resistance to most beta-lactams.

Acid-fast stain

The Ziehl-Neelsen acid-fast stain detects mycobacteria, which retain carbolfuchsin after acid-alcohol decolorization; fluorescent auramine-rhodamine staining is more sensitive and is commonly used for screening respiratory specimens.

Levey-Jennings chart

A Levey-Jennings chart plots quality control results over time with mean and standard deviation lines; shifts, trends, and outliers signal analytic problems before patient results are reported.

Westgard 1-2s rule

The 1-2s rule flags a single control result exceeding two standard deviations as a warning; rejection usually requires a second rule such as 1-3s, 2-2s, R-4s, or 4-1s.

Positive predictive value

Positive predictive value is the proportion of test-positive patients who truly have disease; it depends on disease prevalence, so a highly specific test may still have low PPV in a low-prevalence population.

CLIA test complexity

CLIA categorizes tests as waived, moderate, or high complexity; complexity affects personnel qualifications, quality control, proficiency testing, and the certificate required for the laboratory performing the test.

Proficiency testing

Proficiency testing challenges a laboratory with unknown samples and compares results with peer laboratories; successful participation is required for CLIA certification, and failures trigger corrective action and possible sanctions.

Lean waste categories

Lean identifies waste as defects, overproduction, waiting, non-utilized talent, transportation, inventory, motion, and excess processing; reducing these improves turnaround time and laboratory efficiency.