CLIA CCC flashcards

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

Anion gap formula

Sodium minus the sum of chloride and bicarbonate. A normal gap is roughly 8 to 12 mmol/L; an elevated gap points to unmeasured anions such as lactate, ketones, or toxins.

Osmolal gap

Measured osmolality minus calculated osmolality (2Na + glucose/18 + BUN/2.8). A gap above 10 mmol/L suggests an unmeasured osmole such as methanol, ethylene glycol, or isopropanol.

Friedewald LDL calculation

LDL equals total cholesterol minus HDL minus triglycerides divided by five. The formula is unreliable when triglycerides exceed 400 mg/dL, so direct measurement or non-HDL cholesterol is preferred.

Corrected calcium

Add 0.8 mg/dL to measured calcium for every 1 g/dL that albumin is below 4.0. Ionized calcium is the physiologically active fraction and does not require albumin correction.

HbA1c interpretation

Reflects average glucose over roughly 90 to 120 days, the red cell lifespan. Methods must be NGSP certified, and some hemoglobin variants interfere with certain assay platforms.

MCV and MCHC formulas

MCV equals hematocrit times ten divided by red cell count. MCHC equals hemoglobin divided by hematocrit times 100; values above 36 g/dL suggest spherocytosis, lipemia, or cold agglutinin artifact.

Corrected WBC count

Multiply the observed WBC by 100 divided by the sum of 100 plus nucleated red cells per 100 WBC. Failing to correct causes falsely elevated leukocyte counts, especially in newborns.

Reticulocyte index

Reticulocyte percentage times patient hematocrit divided by normal hematocrit, then divided by a maturation factor of about two when hematocrit is below 25 percent. An index above two indicates an adequate marrow response.

PT versus aPTT

PT evaluates the extrinsic and common pathway, including factor VII. aPTT evaluates the intrinsic and common pathway, including factors VIII, IX, XI, and XII.

Mixing study interpretation

Correcting a prolonged aPTT after one-to-one mixing with normal plasma suggests factor deficiency. Failure to correct suggests an inhibitor such as lupus anticoagulant or a factor VIII antibody.

Staphylococcus aureus identification

S. aureus is catalase positive and coagulase positive and grows in 6.5 percent sodium chloride. Streptococci are catalase negative and are grouped by Lancefield antigens.

Lancefield group A and B

Group A is Streptococcus pyogenes, bacitracin susceptible. Group B is Streptococcus agalactiae, hippurate positive and CAMP positive. Both are catalase negative gram-positive cocci in chains.

Oxidase test meaning

Enterobacteriaceae are oxidase negative, ferment glucose, and reduce nitrate. Pseudomonas aeruginosa is oxidase positive, non-fermentative, and often produces a grape-like odor and blue-green pigment.

Bacterial meningitis CSF profile

Elevated white count with neutrophil predominance, high protein, and low glucose below 40 mg/dL or a CSF-to-serum ratio under 0.4. Viral meningitis usually shows normal glucose and lymphocyte predominance.

ABO antigen and antibody pairs

Group A has A antigen and anti-B. Group B has B antigen and anti-A. Group AB has both antigens and no antibodies. Group O has no antigens and both anti-A and anti-B.

Red cell storage expiration

Red cells are stored at 1 to 6 degrees Celsius. AS-1 or AS-3 units expire in 42 days, CPDA-1 in 35 days, and CPD or CP2D in 21 days.

Platelet storage conditions

Platelets are stored at 20 to 24 degrees Celsius with continuous agitation for up to five days. Refrigeration causes platelet activation and loss of function.

Transfusion reaction immediate action

Stop the transfusion at once, keep the intravenous line open with saline, and return the bag and tubing with post-transfusion samples. Notify the blood bank and provider immediately.

Sensitivity and specificity

Sensitivity equals true positives divided by true positives plus false negatives. Specificity equals true negatives divided by true negatives plus false positives. Predictive values also depend on disease prevalence.

ANA pattern associations

Homogeneous pattern suggests anti-dsDNA or anti-histone antibodies. Speckled pattern suggests anti-Sm, anti-RNP, anti-SSA, or anti-SSB. Nucleolar pattern suggests scleroderma-associated antibodies.

Syphilis serology algorithm

Nontreponemal tests such as RPR and VDRL are used for screening and monitoring treatment. Treponemal tests such as FTA-ABS and TP-PA confirm infection and generally remain positive for life.

Urine cast significance

Hyaline casts are normal. Red cell casts indicate glomerular bleeding. White cell casts suggest pyelonephritis. Waxy casts indicate chronic renal failure and nephron degeneration.

Leukocyte esterase and nitrite

Leukocyte esterase detects neutrophil esterases. Nitrite positivity indicates nitrate-reducing organisms such as Enterobacteriaceae. Both positive together strongly support urinary tract infection.

Synovial fluid categories

Normal fluid is clear and viscous with fewer than 200 white cells per microliter. Septic fluid is turbid with low viscosity and more than 50,000 white cells per microliter, mostly neutrophils.

Real-time PCR Ct value

The cycle threshold is the cycle at which fluorescence exceeds background. Ct is inversely proportional to starting template concentration, so a lower Ct means a higher target amount.

Common leukemia translocations

t(9;22) BCR-ABL occurs in chronic myeloid leukemia. t(15;17) PML-RARA occurs in acute promyelocytic leukemia. t(8;21) RUNX1-RUNX1T1 occurs in acute myeloid leukemia.

Turner and Klinefelter karyotypes

Turner syndrome is 45,X with a single X chromosome. Klinefelter syndrome is 47,XXY with an extra X chromosome. Both are detectable by routine karyotype analysis.

Westgard rejection rules

Reject when one control exceeds 3 SD, two consecutive controls exceed 2 SD on the same side, the range exceeds 4 SD, four consecutive exceed 1 SD, or ten fall on one side.

Coefficient of variation

CV equals standard deviation divided by the mean, multiplied by 100. A lower CV indicates better precision. It allows comparison of precision across assays with different units.

Fire extinguisher PASS

Pull the pin, aim at the base of the fire, squeeze the handle, and sweep side to side. Class C extinguishers are used for electrical fires and never water.

CLIA certificate types

A Certificate of Waiver permits only waived testing. Moderate- and high-complexity testing requires a Certificate of Compliance or a Certificate of Accreditation from an approved organization.

CLIA laboratory director duties

The director ensures quality, approves procedures, and oversees proficiency testing and personnel. High-complexity testing requires a doctoral degree with appropriate training and experience.