Final Exam Flashcards
For what four reasons might amniotic fluid be collected during pregnancy?
genetic and congenital disorders, lung maturity, sex determination, and assessment of fetal distress due to infection or Rh/other isoimmunization
At what stage of pregnancy would amniocentesis be performed for the detection of genetic or congenital disease?
15-18 weeks
What is oligohydraminos?
deficiency of amniotic fluid
Why would amniotic fluid need to be protected from light sources?
preserving any bilirubin that is present
When present in amniotic fluid, fetal cells are adversely affected by what?
refrigeration
What is the normal color and turbidity of amniotic fluid?
pale yellow, slightly cloudy (depending on stage of pregnancy)
What would cause amniotic fluid to appear dark yellow or amber?
bilirubin
What would cause amniotic fluid to appear green?
meconium
What would cause amniotic fluid to appear pink?
blood
What is associated with amniotic fluid that is dark red-brown?
fetal death
What four tests are done to evaluate the surfactants present to the fetal pulmonary system?
lecithin : sphingomyelin (L/S) ratio; phosphatidyl glycerol (PG); foam stability index; microviscosity
In regards to the L/S ratio and PG determination, what indicates fetal lung maturity?
L/S ratio >/= 2.0 (affected by blood and meconium); PG needs to be present (not affected by any other factors)
What is important to remember about the PG factor?
lack of PG with an L/S ratio >2 can suggest lung maturity, but this can also be seen in diabetics
What do the three zones mean in reference to the delta A540 and the Liley’s 3-zone chart.
Zone 1: normal; Zone 2: moderate hemolysis; Zone 3: severe hemolysis (fetus will die without intervention)
What are the appearance and characteristics of transudates?
usually clear, do not contain clots, contains few cells, specific gravity
What are the appearance and characteristics of exudates?
cloudy, contains clots and many cells, specific gravity >1.015, and total protein >3.0
What is the difference between transudates and exudates in terms of their causes?
transudates are non-inflammatory and usually the result of oncotic pressure; exudates are inflammatory and usually secondary to disease states
Name the three biochemical indicators used to evaluate the secretory function of the prostate, including which one can positively identify seminal fluid and is useful in cases of sexual assault (*).
acid phosphatase*, zinc, citric acid
What are four reasons for a physician to order a semen analysis?
fertility determinations, forensic applications, donation purposes, vasectomy follow-up
Which structures contribute secretions to seminal fluid?
seminal vesicles, testes, prostate gland, epididymis
What is the normal concentration of seminal fluid?
20-250 million sperm per mL (cc)
Is the normal concentration of seminal fluid constant within a single individual, and what factors might influence concentration?
no; abstinence, viral infections, and stress can all affect concentration
Is concentration the most important factor in fertility determinations?
no
What percentage of sperm with normal morphology is considered normal or acceptable?
> /= 50%
How is sperm morphology determined?
stained smears of a fresh specimen
What parameter of a semen analysis is directly related to and provides a check of the motility evaluation (include how)?
viability; distinguishes dead from immobile
What is the normal pH of seminal fluid?
7.2-7.8
What might a pH
congenital aplasia of vasa deferentia and seminal vesicles or epididymis
What might a pH of >7.2 indicate?
reproductive tract infection
What does testing fructose in seminal fluid reflect?
secretory function of the seminal vesicles and the functional integrity of the ejaculatory duct and vasa deferentia
What is the primary function of seminal function?
transport of sperm
What are the requirements for the collection of a specimen for semen analysis?
collected after 48-72 hours of abstinence (no longer than one week); patient must be given a private room (can only be collected through masturbation); collected in a wide-mouth clean container that is properly labeled and delivered to the lab within 30-60 minutes, kept warm; if more than one specimen is requested, should be collected over a 3 month period, at least 7 days apart
What is the normal length of time (in minutes) for a semen specimen to liquefy?
30-60 minutes
What does the viscosity resemble after liquefaction, and what is considered abnormal liquefaction?
resembles water; process takes longer than 60 minutes
Motility should be evaluated within how many minutes following collection?
60 minutes
Explain the color, clarity, viscosity, and clot formation of normal synovial fluid.
colorless/pale yellow, clear; use “string test” - 5cm string before breaking considered normal; should not contain clots
Is fibrinogen a constituent of normal synovial fluid?
no
Does hyaluronate affect the turbidity of synovial fluid? What other factors may affect turbidity?
no; red cells, white cells, crystals, synoviocytes, fat, and cellular debris
Why should a synovial fluid be examined as soon as possible?
crystals can form or break down during refrigeration, and white cells can phagocytize crystals
Which anticoagulant should be used on synovial fluids for microscopic examination purposes, and why should other anticoagulants be avoided?
sodium heparin; others can cause artifacts
Which diluent should be used for synovial fluid if necessary?
0.85% NaCl (blood bank saline)
A joint disease process is indicated by what?
presence of >25% neutrophils
What type of microscopy differentiates synovial fluid crystals based on their birefringence, and how is this achieved?
compensated polarized microscopy; based on colors achieved (yellow or blue) when crystals are oriented parallel or perpendicular to the axis
Which crystal appears yellow when parallel to the axis and blue when perpendicular to the axis, and what disease is associated with it?
monosodium urate monohydrate (MSU, uric acid); gout
Which crystal appears blue when parallel to the axis and yellow when perpendicular to the axis, and what disease is associated with it?
calcium pyrophosphate dihydrate; pseudogout
Are monosodium urate, calcium pyrophosphate dihydrate, and cholesterol crystals all birefringent?
yes
Which analytes are present in synovial fluid at concentrations equal to blood plasma levels?
glucose and uric acid
If a bloody CSF is received in the lab, what steps can be taken to determine if it is due to traumatic tap or from the patient having actually hemorrhaged?
look at all tubes in order of collection (if the amount of blood decreases from tube to tube, it is probably from traumatic tap; if the amount is about the same, hemorrhage is indicated); spin down all tubes - xanthochromic supernatant is indicative of hemorrhage, clear supernatant is indicative of traumatic tap
What is xanthochromia?
pigment in the supernatant from lysed red cells
Does fibrinogen normally pass through the blood-brain barrier?
no
According to the lumbar puncture procedure, what is the first CSF tube collected used for?
chemical and immunologic testing
A predominance of lymphocytes within CSF indicated which type of meningitis?
viral
What are the normal ranges for glucose and protein in normal CSF?
glucose: 50-80 mg/dL, protein: 15-45 mg/dL
What condition would decreased glucose and increased protein in CSF indicate?
meningitis
What is the concentration of glucose in CSF in relation to the concentration in plasma?
60-70% or 2/3
Define pleocytosis as it relates to CSF?
increase in the number of cells
Can an increased number of white cells within CSF cause xanthochromia?
no
What are the normal white cell counts of CSF in adults, children, and newborns?
adults: 0-5 cells/uL, children: 0-10 cells/uL, newborns: 0-30 cells/uL
What two cell types are considered normal if seen in the CSF from an adult?
lymphocytes and monocytes
A predominance of neutrophils within CSF indicates which type of meningitis?
bacterial
What is the normal range for lactate in CSF?
10-22 mg/dL
Normal lactate levels can be found in the CSF of patients with what type of meningitis?
viral
Which procedure frequently provides a rapid presumptive diagnosis of bacterial meningitis?
Gram stain
