E3: Clin Med Study Guide PART 2

Which type of FFP can be given to O blood type? A? B? AB?

O: any
A: A, AB
B: B, AB
AB: AB only

**AB universal donor in this case
**Rh type does not matter

What are the symptoms of an acute hemolytic transfusion reaction? How soon after transfusion?

Within 24 hours - chest/back pain, anxiety, nausea, vomiting, flushing, chills/fever, shock, renal failure - oliguria/anuria, hemoglobinuria

What is a delayed hemolytic transfusion reaction?

After Primary Immunization: Mild hemolysis days to weeks after transfusion, severity depends on amount of antibody produced and number of transfused cells in circulation

After Secondary: occurs in a previously immunized individual, antibody screen is negative and direct antiglobulin test is positive: malaise, jaundice, fever, decrease in hemoglobin, hemoglobinuria

What is the treatment when a transfusion reaction occurs?

1.) STOP transfusion
2.) Keep IV line open with saline
3.) Recheck all labels, forms, patient ID band for accuracy
4.) Report reaction to Lab/Blood Bank
5.) Collect blood and specimens from patient for reevaluation

When are packed RBCs indicated for transfusion?

>40% loss requires rapid volume replacement

Hgb <7 g/dL

30-40% loss requires volume replacement with crystalloids, and pRBCs may be required

What is the most common type of blood donation? Safest?

Common: Voluntary Allogenic Donation

Safest: Autologous Donation (self)

What is hemolytic disease of the newborn? When does it occur?

Occurs at the second pregnancy 16th week- the mother makes IgG antibodies incompatible with fetal RBCs

What is measured to indicate lung maturity via amniotic testing?

Fetal Alveolar Surfactant (lecithin and phosphatidylglycerol (PG)) and L/S ratio

What is each CSF collection tube used for?

1 - Protein and glucose levels (chemistry analytes)
2 - Gram stain, meningitis PCR panel, cultures
3 - Cell count and differential
4 - VDRL test or India ink stain when indicated

What does xanthochromic CSF indicate?

Orange/yellow color:

~Hemoglobin from lysed RBCs
~Bilirubin from degraded hemoglobin or hyperbilirubinemia
~Protein levels exceeding 150 mg/dL

Which type of blood can be given to O blood type? A? B? AB? Rh neg?

O: ONLY O
A: A, O
B: B, O
AB: can receive any
Rh neg: ONLY Rh-

Preferred to get the same type

Why would you transfuse type O- blood to someone of childbearing age of unknown blood type?

If an Rh- woman carries an Rh+ child the antibodies against Rh+ would already be made if given O+: want to avoid HDN

Once exposed to the D antigen, Rh-negative persons are very likely to become sensitized and will produce anti-D antibodies

What is the most common type of transfusion reaction? Possible etiology?

Febrile Non-hemolytic: temperature increase of 1 degree C

caused by antibodies in the recipient's plasma reacting against antigens present on cell membranes of transfused granulocytes, lymphocytes or platelets (NOT RBCs)

What are the symptoms of an anaphylactic transfusion reaction? How soon?

Within a few mL of transfusion (within minutes) - tachycardia, flushing, headache, dyspnea, chest pain

What is graft versus host disease?

When immunocompetent donor lymphocytes engraft and multiply in the recipient, who is usually immunocompromised - rejection of host by donor cells

What is apheresis? What component is collected using this method?

Removal of whole blood from a donor/patient, followed by its separation into components, retention of the desired component, return of the recombined remaining elements to the donor/patient

What is used to prevent HDN? When is it administered?

Rhogam (Anti-D) - 28 weeks and again following birth

What is the CSF albumin index?

All albumin in CSF = passage across blood-brain barrier
~Increase in the ratio (CSF/serum albumin)= impairment of BBB

What does an elevated CSF IgG Index and an elevated myelin basic protein indicate?

-Multiple Sclerosis
An increased index value indicates local CSF tissue production of IgG

What does an increase in CSF oligoclonal bands indicate?

Helpful in diagnosing multiple sclerosis

Describe the CSF findings in bacterial meningitis? Viral meningitis?

Bacterial - decreased glucose level, increase in lactate, elevated protein, high WBC neutrophils

Viral - normal glucose, lactate. Protein may be normal OR elevated, high WBC lymphocytes

What is the most common pathogen in bacterial meningitis?

Streptococcus

Which test is best for suspected Cryptococcus neoformans meningitis?

India Ink Preparation (best)
gram stain and PCR can also be used

Describe the synovial fluid findings in septic arthritis, gout, and pseudogout

Septic: Cloudy, yellow-green fluid, abnormal mucin clot test, decreased glucose

Gout: uric acid crystals, cloudy yellow fluid

Pseudogout: calcium pyrophosphate crystals, cloudy yellow fluid

Which tests can be performed on amniotic fluid? Which tests are used to evaluate fetal lung development?

Tests: amniocentesis: tests amniotic fluid for chromosome, neural tube defects, HDN, lung development

Lung development: lecithin and phosophatidylglycerol (PG), L/S ratio (low = bad)

What abnormality would indicate the presence of HDN? Neural tube defects?

HDN: high bilirubin levels

Neural Tube: high alpha-fetoprotein (AFP) levels

What is the physiologic difference between a transudate and an exudate?

Transudate: An effusion that forms because of a systemic disorder that disrupts the balance in the regulation of fluid filtration and reabsorption

ex, ascites b/c of liver cirrhosis

Exudate: An effusion that forms because of disorders that directly involve the membrane of the cavity that increase capillary permeability

ex, bacteria pneumonia, malignancies

How do you determine whether the fluid is a transudate or an exudate?

1.) Glucose level in fluid v. serum
2.) Ratio of protein in fluid v. serum
3.) Ratio of lactate dehydrogenase in fluid v. serum
4.) Ratio of albumin in serum v. fluid
- serum/ascites albumin gradient (SAAG): >1.1 indicates transudate, <1.1 = exudate

What is an SAAG?

Serum/ascites albumin gradient
- Ratio of albumin in serum to that in ascitic fluid
- SAAG > 1.1 indicates transudate
- SAAG < 1.1 indicates exudate

Which tests are included in a semen analysis for infertility?

3 days of sexual abstinance -> collection -> test no more than 30 minutes after
Checking for abnormal sperm: large head, multiple heads, no motility

What may be the cause of black colored stool? Red? Pale/White?

Black: upper GI bleeding, iron therapy, bismuth (Pepto Bismol)

Red: lower GI bleeding, beets, food dye

Pale/White: Post-hepatic obstruction, barium

What test is utilized to detect blood in the stool? What causes a false positive? False negative?

Occult blood test (guaiac)

False negative: Ascorbic acid (vitamin C), Antacids

False positive: Rare cooked meats and fish, some vegetables (broccoli), some fruits (bananas), drugs that irritate GI tract (aspirin)

Which stool test is indicated for inflammatory bowel diseases?

microscopic examination of feces for presence of WBCs

Which tests of vaginal secretions are often done in the office? What is the indication for each?

Wet prep/KOH prep - candidiasis, trichomoniasis, bacterial vaginosis

Indications: pain/irritation in pelvic region, abnormally colored discharge

What are clue cells?

Large squamous epithelial cells that are covered with numerous bacteria, may be accompanied by numerous WBCs
-indicative of bacterial vaginosis

Why is KOH added to the sample?

KOH obliterates the cellular and bacterial elements in the smear making the detection of C. albicans/pathogen easier

When are most therapeutic drug levels drawn?

Peak specimens are drawn shortly after a dose is given
Trough specimens are drawn shortly before the next dose

Drawn on noncompliant patients, unusual drug effects, and when a patients needs an adjustment of prolonged therapeutic drug regiments

Which medications are commonly monitored?

- Digoxin
- Phenobarbital
- Phenytoin (Dilantin)
- Theophylline
- Vancomycin
- Lithium
- Aminoglycosides (gentamicin, tobramycin, amikacin)

Which toxins/drugs are commonly tested for?

Acetaminophen
Carboxyhemoglobin (CO)
Ethanol
Salicylates
Drugs of abuse (Marijuana, Cocaine, EtOH, Heroin)
Lead

pneumonic: SCALED

What tool is used for risk assessment of tylenol overdoses? What is the most significant adverse effect?

Rumack-Matthew Nomogram (NAPQI) -Utilizes a serum acetaminophen level plus a known time interval since ingestion when toxic amount of drug was ingested (range 10-30 mg/L)

-Cannot be used for alcoholics as it is less reliable: increased CYP2E1 increases toxic metabolite production

What is the indication for cholinesterase levels?

Exposure to organophosphate pesticides - these inhibit cholinesterases, causing buildup

What is the most important aspect of forensic testing?

Follow the lab protocol - typically for legal investigations