Clin Lab 1 Flashcards
What is the role of medical laboratory testing?
Detection, diagnosis and treatment of PT diseases
What are the Primary and Secondary functions of the Clinical Laboratory?
Primary: Generate Information
Secondary: Educate providers/staff
What are the 5 rationales for ordering tests?
ID changes in PT health Diagnose disease/condition Plan treatment for disease/condition Evaluate treatment response Monitor course of disease over time
What are the 3 parts of Evidence Based Medicine?
Individual Clinical Expertise
Best External Evidence
PT Values/Expectations
Define “Good Test”
Provides info useful in PT management decisions
Screening: High sensitivity, Negative predictive value
Diagnosis: High Specificity, Positive predictive value
Define “Bad Test”
Uses resources but fails to provide info useful in PT management decisions
Define “Ugly Test”
Uses resources and provides info that is misleading or irrelevant
Define Positive and Negative Predictive Value?
PPV: Pos screening, Pos disease
NPV: Neg screening, Neg disease
What are the 3 parts of Anatomic Pathology?
Histology
Cytology
Autopsy
What are the 6 parts of Clinical Pathology?
Microbiology Hematology Urinalysis Serology Chemistry Immunohematology
What are the 4 support services of the lab?
Central Process/Client Services
Phlebotomy
Clerical Services
Lab Info Services
Cytology studies what 3 things?
Structure, function and chemistry of cells
What are the most common specimens that go through the Chemistry branch of Clinical Pathology?
Blood
Urine
List 6 tests that may be seen ordered that would go through the Chemistry branch of Clinical Pathology?
Blood Glucose Electrolytes Enzymes Hormones Lipids Proteins
ABO Blood Group Ag, Ab and Notes
A= A Ag, B Ab, N/A B= B Ag, A Ab, N/A AB= AB Ag, 0 Ab, Universal Recipient O= 0 Ag, AB Ab, Universal Donor
Immunology and Serology tests focus on what 3 things?
ID Abs
Investigate immune problems
Determine/measures organ compatibility
Name 5 testing locations within the lab?
Central/Main lab Satellite Lab POCT Reference Lab Physician Office Lab
What are the 3 phases of testing under CLIA?
1: before testing (ordering and collection)
2: during testing ( Control, Test, Interpretation)
3: after testing (Reporting, Documentation, Confirmation, BioHazard Waste disposal)
What are the 4 categories of CLIA test complexity?
Minimal- AKA Waived Testing
Provider Performed- subcategory of moderate complexity
Moderate Complexity
High Complexity
What are the 5 criteria for classification within CLIA testing?
1- Risk of harm to PT 2- Risk of erroneous result 3- Type of testing method used 4- Degree of independent judgement/interpretation 5- Availability of test for home use
Define Waived Tests and give 6 examples
Pose no reasonable risk of harm to PT if test is performed incorrectly
Dipstick UA, Fecal Occult, Ovulation, Pregnancy, Erythrocyte Sedimentation, Hemoglobin, Bed Side tests
Give 5 examples of Moderate Complexity Testing
General Chemistry Specific Proteins Drug abuse/Toxicology Therapeutic Drug Monitoring Hematology Testing
Who can perform Provider Performed Microscopy?
What level of testing does this fall into?
PA, NP, RN, MidWife, DDS
Moderately Complex
What are 6 examples of Provider Performed Microscopy tests?
Wet Prep Mounts KOH Preps Pinworm Exams Fern Test Urine Sediment Nasal Smears for granulocytes
Basic Metabolic Panel is a _____ panel that includes what two things?
Chemistry
Electrolytes and kidney functions
Blood for BMP can be dran in what color tube tops?
Light Green PST
Gold SST
Red
What is the major ECF cation?
Na
What two ions combine to make the majority of the plasma osmotic pressure?
Na and Cl
What do in/decreased serum sodium levels mean?
Hyper= total body water deficit Hypo= total body water excess
What is the major ICF cation?
K+
What 3 roles does K+ have within the body?
Maintains body fluid balance
Muscle/nerve function
Why is plasma K+ tightly regulated?
Hyper= aldosterone secretion and K+ excretion Hypo= excretion of urine completely lacking K+
Hyper and Hypo K+ levels can be indicative of what conditions?
Hyper= Primary/Secondary hypoaldosteronism Hypo= Diabetes mellitus, Cushings, Hyperaldosteronism
What is the major EXF anion?
Cl-
What do hypo/hyperchloremia indicate?
Rarely occur, indicative of shifts between Na/BiCarb levels to maintain electrical neutrality
BMP CO2 content measures what 3 things?
H2CO3
Dissolved CO2
HCO3
What do Inc/Dec BiCarb levels indicate?
Inc= Metabolic alkalosis, 1*/2* to respiratory acidosis Dec= Metabolic acidosis
What does an increased BUN level indicate?
Dec glomerular filtration
Inc tubular reabsorption
Inadequate excretion
Inc production in the gut
BUN levels are interpreted with what other thest?
Creatinine test
What two thing make up a renal function study?
BUN
Creatinine test
Where does creatinine come from?
Creatine phosphate used for skeletal muscle contractions
What is one of the most commonly measured tests in the laboratory?
Glucose
Total serum Ca+ is a measurement of what two calcium levels?
Free (ionized) calcium
Protein bound calcium
Changes to serum albumin can/will affect the total serum level of what other ion?
Ca+
What is the rule of thumb when total serum calcium levels decrease?
Total Ca+ decreases by 0.8mg per 1 gram decrease in serum albumin levels
Where is Ca+ absorbed within the body?
What hormone influences this absorption?
Small Intestine
Proximal Renal Tubule
Parathyroid Hormone
What tests are included in a BMP?
Na K Cl CO2 BUN Cr Glu Ca+
What tests are included in a Complete Metabolic Panel?
BMP and ALB ALT ALP AST TP Bilirubin
What is the most abundant extracellular protein?
What is the most abundant intracellular protein?
Albumin
Hgb
What protein is used to measure hepatic function?
Albumin, synthesized in liver
Where is alanine aminotransferase found within the body?
Hepatocytes
Smaller amounts in skeletal and heart muscles
Why/when is alanine aminotransferase enzyme released into circulation?
Upon cell damage/necrosis
What events causes increased alanine aminotransferase levels in the blood?
Liver damage
Skeletal muscle damage
The two major circulating alkaline phosphatase isoenzymes are found where?
Bone
Liver
Elecated serum alkaline phosphatase is most commonly a sign of what issues?
Liver or bone disorders
Elevated Aspartate Aminotransferases is an indication of what?
Liver injury
Aspartate Aminotransferase serum levels usually increases with what other enzyme level?
AST goes up with ALT
PT with AST levels that are more than 2.0 times the ALT levels indicates what issues?
Alcohol abuse w/ cirrhosis
Alcoholic hepatitis
What kind of bilirubin makes up the majority of bilirubin in the body?
Unconjugated
Total protein measures what two classes of proteins?
Albumin
Globulin
Where are most serum proteins synthesized?
Liver
Mature plasma cells (immunoglobulins)
CBC blood draw is pulled in what color tube?
Lavender, contain anticoagulant EDTA
What is the “Rule of 3s” with a CBC?
RBC= 5 mill/microliter Hgb= 15g/deciliter Hct= 45% + / - 2
Define Total Red Blood Cell Count
of circulating RBCs per 1mm of blood
Define hematocrit?
Total blood volume made up by RBCs
What causes abnormal hematocrit levels?
Anemia Bleeding RBC destruction Leukemia Malnutrition Over hydration
What causes critical value hematocrit levels?
Dehydration
Hypoxia
Congenital heart disease
Polycythemia
What does the type of MCV help with diagnostically?
Types of anemia
Define anisocytosis
Variation in RBC sizes
What causes Leukocytosis
Infections Leukemia Pregnancy Neoplasms Pneumonia Inflammation Tissue necrosis
What causes leukopenia?
Bone marrow failure Radiation Chemotherapy HIV Viral infections
What causes throbocytosis?
Bone marrow disorder Acute bleeding Exercise Heart attack Infections Splenectomy
What causes thrombocytopenia
Autoimmune Medicaitons Alcohol Viruses Cancer Anemia
What are the 5 types of leukocytes that are measured in a CBC + Differential
Neutrophils Lymphocytes Monocytes Eosinophils Basophils
What is a Urinalysis Screening
Group of 10 chemical tests to detect UTIs, metabolic and kidney disorders
What do high triglyceride levels mean?
PT regularly eats more calories than are burned
Function of LDL, HDL and VLDL
LDL: Carries fat from liver to body
HDL: binds fat in blood and carries to liver
VLDL: distributes triglycerides synthesized by liver
When does the AAP recommend testing children/adolescents for routine lipid testing?
9 - 11 y/o
17 - 21 y/o
Critical test values must be reported to ordering provider within what time frame?
STAT results must be delivered within what time?
1 hr of completion
W/in 1hr of receipt
When are cortisol level peaked and lowest?
Peak: 4-6am
Low: 8pm-12am
Insulin levels are usually lower during _____
Iron levels peak during ______
Night
Early to late morning
Pre-Collection variables that can alter blood chemistry
Time of draw Exercise Diet Posture Stress Age Gender Hemolysis
STAGED PH
High protein and low carb diets will have ______ ketones and BUN
Elevated
Ethanol ingestion will ____ plasma lactate, urate and triglyceride concentrations
Elevate
Mental and physcial stresses stiulate the production of what 3 things?
ACTH
Cortisol
Catecholamines
Mild stress induces and increase of ____ while decreasing _____
Total cholesterol
HDL
Hyperventilation elevates what 3 things
Leukocytes
Serum lactate
Free FAs
An upright position increases hydrostatic pressure which will _ plasma volumes and _ protein concentrations
Dec
Inc
Albumin and Ca+ levels change in what direction during changing positions from supine to upright?
Inc
Bed rest will change a PTs Hb in which direction?
Lowers
After 50 y/o, men’s testosterone decreases and women ____ increases
FSH
How does hemolysis slightly and significantly effect analytes?
Slight: haptoglobin, bilirubin
Significant: dec in Troponin T
Define Hemoconcentration
Increased enzymes, proteins, and protein-bound substances (cholesterol, Ca+, triglycerides)
Define Hemodilution
Standing to reclining causes extravascular water to transfer to vascular system and dilutes plasma constituents
10 common errors of specimen collection?
Incorrect ID of PT Mislabeled specimen Improper blood/additive ratio Mixing problem/clot Wrong tube/coagulant Hemolysis/lipemia Hemoconcentration from prolonged TQ time Exposure to light/temp Imroperly timed/delivery Processing errors
How quickly is glucose metabolized?
Room Temp: 7mg/dl/hr
4*C: 2mg/dl/hr
Acute viral hepatitis panel is drawn in what color tube?
Marble
Serum separator tube
How are stool cultures transported?
Cary Blair Transport Media
Define Whole Blood
Formed elements and fluid plasma combined (sample doesn’t clot)
Define Serum
Liquid portion of clotted blood samples, lacking coagulation protein fibrinogen
Define Plasma
Liquid portion of anti-coagulated whole blood with all coagulated proteins
(serum with anticoagulants now becomes plasma)
What are the two types of blood specimens?
Whole blood
Serum
What is the composition of a capillary/skin puncture sample?
Arteriole, capillary and venule blood with tissue fluid
What are the 3 preferred sites for venipuncture sites?
1- median cubital vein- connects cephalic and basilic
2- cephalic- empties into axillary
3- basilic- joins brachial vein
What is the sequence of events when processing blood tubes?
Collect Invert 8-10x Wait Centrifuge Analyze
Plain Red tubes yield ____ and are sent to (2) _____ testing areas of the lab
Serum
Chemistry/Serology
Red and Gray/Marble tubes yield ___ and are sent to what area of the lab for testing?
Serum
Chemistry
Purple top tubes yield _____ and are sent to what (2) areas of the lab for testing
Plasma
Hematology and Blood Bank
How does EDTA exert its effect within purple tubes?
Chelates Ca+
Best for preserving blood cell integrity
Purple top tubes are unacceptable for what type of analysis?
Ca+ or K
Lavender/EDTA tubes would be used for what 3 types of tests?
Chemistry- Ammonia, BNP, G6PD, lead
Hematology- CBC, Hct, Hgb, Manual differential, Sickle Cell
Microbiology- blood parasites
Which tube is used to preserve coagulation factors?
Light Blue Tube- Sodium Citrate
Light Blue tubes are unacceptable use for what two types of analysis?
Calcium
Sodium
What does green top tubes yield and what type of testing are they used for?
Plasma
Chemistry
What are green top tubes used for?
pH
Electolytes
Blood gas
Ionized calcium test
What specific type of green top tube is used for electrolyte tests?
Lithium
What type of additives are in gray top tubes?
Anticoagulant: potassium oxalate
Glucose preservative: sodium flouride
What type of sample do gray top tubes yield and for what type of testing area?
Plasma for glycolytic inhibition
Chemistry
What types of tests are gray top tubes used for?
Glucose testing
Blood alcohol
Lactate
Bicarbonate
What types of tests are dark blue tubes used for?
Special Chemistry: Trace metal studies
What are the big 3 types of unacceptable specimens?
Iceteric specimen
Lipemic specimen
Hemolyzed specimen
What are the SI prefixes below 10?
Deci -1 Centi -2 Milli -3 Micro -6 Nano -9 Pico -12 Femto -15 Atto -18
What part of the blood is being tested during a cardiac panel?
Plasma
What is the correct order of collection for blood obtained by skin punctures?
Serum tube
Heparin tube
EDTA
Examples of samples that require chilled specimen transport?
ACTH Acetone ACE Blood Ammonia Catecholamines Free FAs Lactic Acid Pyruvate Renin
Examples of samples that are light sensitive analytes?
Billirubin
Erythrocyte Protoporphyrin
Carotene
What colored tube is used for HLA/Paternity tests?
Yellow top
Acid Citrate dextrose
What color tube is used for coagulation tests?
Blue top
Sodium Citrate
What color tube is used for hematology tests?
Lavender top
EDTA
What color tube is used for transfusion service tests?
Pink top
EDTA
What color tube is used for serum testing?
Red top
What color tube is used for cardiac profiles?
Green top
Heparin
What color tube is used for glucose tests?
Gray top
Potassium oxalate
What type of anticoagulant may be found in royal/dark blue tubes?
None
EDTA
Heparin
What are the 5 areas that Pre-Analytical/Analytical causes of error can occur?
1: samples
2: operator
3: reagants
4: laboratory environment
5: measuring system
Where in the pre-analytical/analytical causes of error would instrument failure of inadequate instrument maintenance be found?
5- measuring system
6 examples of pre-analytical errors?
Wrong PT, time, tube, label, processing, sequence
5 examples of analytical errors?
Failure to notice instrument flags Disregard OOC QC results Wrong assay Wrong procedure No test but results produced
6 examples of post-analytical errors
Incorrect verbal reporting Incompatible instrument interface Confused reference ranges Wrong results reported Transposed results from manual entry Incorrect interpretation
What agency incorporated QA/Proficiency testing into lab procedures?
CLIA
Define Reliability
Consistency/reproducible
Considers random errors
“is it measuring something?
Define Validity
“is it measuring the correct sample? what conclusion can be obtained?”
What can effect validity?
Bias, a form of systematic errors
Safety, Acceptability, Cost
What are the four indicators most commonly used to determine the reliability/validity of a lab test?
Precision/Accuracy- how well the test performs day to day
Sensitivity/Specificity- How well test is able to distinguish disease presence from disease absence
Define Sensitivity
Test ability to correctly ID those w/ a disease/condition
More sensitive a test, fewer false-negative results
Define False Negative
100 people with disease
90 tested positive
10 shown as normal
Negative test result is used by a provider in what manner?
SnOut, rules out disease/diagnosis
Define Specificity
Tests ability to correctly exclude those who do not have a disease
More specificity= fewer false positives
Define False Positive
100 healthy
90 ID’d as normal
10 shown as “positive”
What are the two types of microscopes and the two types of lens they have?
Simple or compound
Ocular or objective
How do you get the total magnification power of a microscope?
Ocular x objective lens
What kind of microscope is the most commonly used in the lab?
Light/Bright Field Microscope
Light/bright field microscope has a _____ magnification power and a ____ resolution
High magnification
Low resolution
When is phase contrast microscopes preferred?
High magnifications needed 400x, 1000x
Colorless specimen
Detailed so fine colors don’t show
What part of microbes is phase contrast microscopy effective for observing?
Cytoplasmic streaming
Motility
Organelles
Define Birefringence
Objects/Crystals w/ ability to rotate or polarize light for viewing through a cross polarizing filter
What if Polarizing Light microscopy used to distinguish between?
Gout and pseudo gout
Monosodium urate vs calcium pyrophosphate dihydrate
How does Dark-Field Microscopy work?
Enhances contrast in unstained samples
Illuminates sample with light that won’t be collected by objective lens
Dark Field Microscopy is used for viewing what type of microbe?
Spirochetes (syphilis)
Unfixed, unstained specimens
When is fluorescence microscopy used?
Infectious diseases diagnosis
Identify specific Abs in response to Ags
What are the two types of Electron Microscopes?
Transmission Electron Microscope- high resolution, e- passes through thin sample
Scanning Electron Microscope- bounces e- off of surface of specimen to form 3D image
What are wet mounts used to detect the presence of?
Bacteria
Fungi
Parasites
Human Cellular elements
What are KOH slides used to detect?
Fungal elements
What is Urine Sediment tests used to identify?
Hematuria- UTI/systemic infection Pyuria- infection Casts- formed elements of urine Crystals Microbes
What do epithelial cells in urine sediment exams mean?
Squamous type= insignificant
Renal epithelial= significant
What types of conditions cause the formation of crystals?
pH
Temp
Urine concentration
What types of crystals are in normal acid urine?
Uric acid
Calcium Oxalate
What types of crystals are in normal alkaline urine?
Calcium/Magnesium phosphate
Calcium carbonate
Ammonium biurate
What types of crystals are in abnormal urine?
Cystine Tyrosine Leucine Sulfonamide Ampicillin
What are Saline Wet Prep wet mounts used to detect?
Trichomonas baginalis- clue cells
Yeast- vaginitis
What type of microscopy is often performed after a saline prep slide?
KOH Prep
Why is a Fern Test conducted?
Determines if rupture of fetal membrane has occurred before the onset of labor
Amniotic fluid appears “fern-like”
Why is a postcoital test conducted?
Evaluates infertility
Nasal smear eosinophilia is used to make what diagnosis?
Allergic rhinitis
Fecal leukocytosis is an infection of what microorganism infection?
Salmonella
Shigella
Semen analysis study focuses on what 3 areas?
It is used to determine what 3 things?
Motility
Morphology
Sperm count
Infertility
Post-Vesectomy
Vesectomy reversal
What is the function/use of POCTs?
Shortened turn around time for critical results to enhance convenience
What lab oversights are required for POCT?
Method validation
Training
Policies/procedures
Responsibilities
What are the limits of POCT?
Technology Knowledge/training QA Accountability Cost
What are 3 Hematology POCTs?
Hg
Hct
Coagulation test
What are 4 Chemistry POCTs?
Glucose
Urine dipstick
Creatine/cardiac markers
Pregnancy
What are the microbiology PPM tests available?
Strep Flu Malaria Fecal occult Mono Pylori S. pneumoniae Lyme HIV Respiratory Syncitial virus Trichomonas Adenovirus Bacterial vaginosis
What is the PURPOSE of TDM?
Measuring the concentration of a drug/metabolite to aid in the correct dosing and to assess PT compliance
What is the GOAL of TDM?
Increase likelihood of therapeutic effect and avoide adverse effects
What are 5 indications to start TDM?
Rx has low margin for safety Eval PT compliance Difficult to distinguish S/Sx from toxicity Not a measured end point Pharmacokinetic variability
Define Unpredictable Dose Response
When same dose produces therapeutic effect in one PT and toxic effects in another
What part of blood is tested during TDM?
Serum or Plasma
What are the 4 steps of pharmacokinetics?
Absorption
Distribution
Metabolism
Excretion
Drugs administered orally must have what two characteristics?
Withstand gastric pH
Transportable across lipid membrane
When are suppositories usually used/prescribed?
Infants when oral form is not available
What are the 3 forms of parenteral drug administrations?
IV
IM
Sub-C
What do insoluble drugs require in order to enter the body’s systemic system?
Protein carries
What are the two most common carrier proteins and where are they produced?
Albumin
A-Acid Glycoprotein
Liver
Presence of any liver disease will increase what in a drugs presence in the body?
Free fraction
Define Free Fraction
Therapeutically active fraction of a drug that is non-protein bound
Most laboratory assays measure the total drug concentration which is what two measurements?
Free and bound medications
Define Therapeutic Range
Drug concentration with the highest probability of desired response and the lowest probability of an unacceptable toxicity
Define Minimum Effective Concentration and Minimum Toic Concentration
MEC- below this level, therapeutic effect is not reached
MTC- above this level cause symptoms of toxicity to occur
Define Trough Value and when is it present?
Lowest therapeutic concentration during dosing cycle
Occurs before next dose and should remain above the MEC of a drug
Define Peak Value and when does it normally occur?
AKA Toxicity risk
Highest therapeutic concentration level of dosing cycle but should be below minimum toxic concentration
When/how is Steady-State Concentration achieved?
When rate of drug entering body is equal to rate of drug elimination from body
Steady state occurs after how many half lives?
5 - 7
Drug metabolism changes non-polar lipophilic drugs how?
Into polar water soluble compounds that can be eliminated
What is the primary site for drug metabolism?
Liver
Polar, non-lipophilic drugs are primarily eliminated through the urine and is dependent on what factors?
Renal function
Renal blood flow
Urine pH
Drug molecule size
Define Drug Clearance
Volume of plasma that is completely cleared of a drug per unit of time
Drug Clearance is the sum of what 3 elimination mechanisms?
Hepatic
Renal
Biliary
What are the key processes involved in drug disposition?
Liberation Absorption Distribution Metabolism Excretion LADME
What 4 factors influence drug distribution?
Age
Weight
Gender
Race
Decreased carrier protein levels result in what effect on drug distribution?
Increased free fraction
Increased physiological effect
What procedural factors can effect drug distribution?
PT compliance
Wrong specimen draw time
Lab test methodology
What are 3 clinical benefits of TDM?
Recognizing PT non-compliance
Unusual drug disposition characteristics
Adjustments of prolonged therapeutics
What tube is used for TDM specimens?
Red top serum
Definition of chronic ingestion of analgesics/aspirin?
100 mg/kg/day x 2 days
What are the indications for monitoring of aspirin?
Suspected toxicity
What is the timing requirements for analgesic monitoring?
No less than 6hrs post-ingestion
No more than 60hrs post ingestion
Draw serial values to prove declining values
Estimations of toxicity are used using what type of chart?
Done nomogram for acute ingestion
Define Toxicology
Study of poisons, their actions/detection/treatment of conditions caused by them
What are the make ups of toxicology cases seen?
50% attempted suicide
30% accidental
20% occupational exposure/homicide
What are some of the common drugs and toxins tested for?
Acetaminophen CO Ethanol Salicylates Drugs of abuse Lead
What 3 factors determine the best specimen for toxicology specimens?
When
How
Mode of exposure
Blood draws for toxicology reports are best for testing for ?
Acetaminophen CO Ethanol Salicylates Pesticides Lead
Urine samples for toxicology are taken for testing for ?
Arsenic
Mercury
Drug abuse
Acetaminophen overdose is associated with ?
Why is this?
Hepatotoxicity
High protein binding affinity
What part of the blood is NOT reliable for testing for acetaminophen levels?
Serum
What is a Rumack-Matthew nomogram used for and what info is used when using it?
Serum acetaminophen level
Known time since ingestion
Predicts if toxic levels of meds were ingested
What are the 3 POCT methods for drug abuse?
Rapid ID for agent
Urine
Oral fluid
UA sample that tests positive for drugs has be subjected to what tests?
Screening
Re-screening
Confirmation
The term “serous fluid” is an encompassing term for what 3 fluids?
Pleural
Pericardial
Peritoneal
CSF has what 5 functions?
Transportation (nutrients/waste)
Buoyancy
Sudden change protection
BBB
What does healthy/normal CSF look like?
What 3 areas does it bathe?
Clear
Colorless
Sterile
Ventricles
Subarachnoid
Spinal cord
How much CSF is produced/replaced each day?
Produce 500ml/day
Normal volume- 90-150ml
Turned over every 5-7hrs
Where is CSF made and where is it reabsorbed?
Choroid plexus
Arachnoid villi
What happens with CSF flow with varying pressures of CSF and blood pressure?
Inc CSF, Dec venous= CSF-> blood stream
Dec CSF, Inc venous= blood does NOT pass into ventricular system
3 functions of BBB
Protection from:
Foreign substances
Hormone/neurotransmitters
Environment maintenance
What effect does BBB have on ions and molecules?
Large- don’t pass
Lipid insoluble don’t cross
Lipid soluble pass
Highly charged molecules are slowed
4 indications that require a STAT CSF test?
Meningeal infection
Brain hemorrhage
Primary/Secondary malignancy
Neurological
List the S/Sx of meningitis
Sudden fever Severe headache N/V Double vision Stiff neck Photophobia
List the S/Sx of encephalitis
Fever Seizure Behavior changes Confusion Disorientation
Majority of infectious encephalitis cases are caused by ?
Viral infections
Characteristics of bacterial, viral, fungal, and parasitic meningitis?
Bacterial- life threatening w/ vaccine avail
Viral- self-limiting
Fungal- AIDS
Parasitic- free living amoeba and is 99% fatal
What microbes cause bacterial encephalitis?
Listeria
Leptospira
Borrelia
Treponema
What is the most common cause of encephalitis?
Viral Herpes Enterovirus Arbovirus Rabies
What causes fungal encephalitis?
Histoplasma
Cryptococcus
What causes parasitic encephalitis?
Toxoplasma
Taenia
Define subarachnoid hemorrhage
Bleeding in subarachnoid space from aneurysms and head trauma
Define Intra-cerebral hemorrhage
Ruptures of small vessels in the brain from chronic high BP
Define Cerebral Infarct
Blockage of blood flow to brain
What are the 3 types of malignancy associated w/ CSF?
Leukemia
Lymphoma
Metastatic carcinoma
What neurological diseases are associated with CSF?
MS
Demyelinating disorders
Guillain-Barre syndrome
What is normal opening pressure during a LP?
5-20cm of water
How much CSF is collected during an LP?
10 drops per tube
20ml total
What is the sequence of collection during an LP?
1- chemical/serologic (glucose/proteins)
2: micro (gram stain/culture)
3: hematology (Cell count/differential)
4: micro w/ further exclusion of skin contaminants/better serological tests
What are the storage requirements for Hematology/Micro/Chemistry CSF tubes?
Hematology- refrigerated
Micro- room temp
Chem- frozen
Routine exam of CSF samples contain what examinations?
How quickly are results returned?
Gross appearance Red/white cell counts Morphology Chemistry Micro Serology
All tests except micro returned w/in 1 hr
CSf gross appearance can include what 3 things?
Turbidity= WBC, bacteria, protein, lipid Clots= protein, traumatic tap Color= clarity should increase as collection increases
Define Xanthochromia
Pale pink/orange/yellow collor of CSF samples
Subarachnoid hemorrhage will have what presentation during an LP/CSF test?
Elevated opening pressure
RBCs
Xanthochromia
What is the normal WBC count for a CSF sample?
0-8/uL
Morphologic examination of CSF samples include what 3 things?
Cytocentrifugation
Smears
Differential
What doe protein levels in CSF tests mean?
Inc= meningitis, hemorrhage, MS Dec= CNS leakage
What do glucose levels in CSF tests mean?
Dec= bacterial meningitis
Where is the LP performed?
Lumber L3 and L4
What does increased lactate in CSF tests mean?
Bacterial, fungal or tubercular meningitis
Lactate greater than 25mg is more consistent than dec glucose
Lactate levels in CSF that are +35= ?
Below 25= ?
Bacterial meningitis
Viral meningitis
Microbial CSF is normally sterile w/ Gram Stain completed in less than ___ and a culture in ___
GS= 1 hr
Culture- 72hrs
Micro exams of CSF test for what 2 Ags?
Bacterial Ag
Cryptococcal Ag
When is a serology testing of CSF useful?
When PCR is negative, typically for neurosyphyllis
Veneral Disease Research Lab can onbly be used for what work up?
CSF- non treponemal test (similar to RPR)
What are 6 pathogens that can be tested via serology tests of CSF?
Measles Rubella West Nile Toxoplasma Herpes Varicella
What are the two types of effusions?
Transudate- systemic disorder disrupting the filtration/re-absorption process
Exudate- produced by conditions directly involving membrane of a particular cavity (local accumulation)
What are the most common causes of pleural effusions in adults and children?
Adult= Heart failure, malignancy, pneumonia, TB, PE
Children- pneumonia
PT S/Sx that would lead you to order an analysis of pleural fluid?
Chest pain that inc w/ deep breathing Coughing SOB Fever/chills Fatigue
What are the most common causes of pleural effusions?
CHF Kidney failure Malignancy PE Hypoalbuminemia Cirrhosis
What are the most common causes of pericardial effusions?
Infection Autoimmune Malignancy Kidney failure Inflammation Trauma
PT S/Sx that would lead you to order an analysis of pericardial fluid?
Chest pain relieved by bending forward Couch SOB Arrythmia Enlarged heart Abnormal echo
What are the most common causes of peritoneal effusion?
Infection Autoimmune Malignancy Cirrhosis Inflammation Pancreatitis
When/why would an analysis of peritoneal fluid be ordered?
Ascites of unknown origin
Abdominal pain
Intestinal perforation
Intra-abdominal malignancy
Upon gross appearance, clotting in a serous fluid samples indicates?
High protein level
What are the 3 chemical analysis of serous fluid exams?
Protein
Lactate dehydrogenase
Glucose
What is an abnormal visual appearance of seroud fluid analysis?
Turbid- high WBCs
Viscous- clotting/hydrolyzed
Colored- red/pink= blood
Transudate fluid summary info
Low Protein
Low Spec Gravity
Non-inflammatory
Exudate fluid summary info
High protein High Spec Gravity Hyperprotein Inflammatory Decreased glucose
What chemical finding in synovial fluid differentiates it from all other bodily fluids?
Mucopolysaccharide hyaluronic acid
What are the 4 classifications of synovial fluid joint disease?
1- Non-Inflammatory- degenerative (OA)
2- Inflammatory- immunologic disease
3- Infectious- bacterial infection
4- crystal induced- gout
What does abnormal synovial fluid that is yellow, green cloudy or red mean?
Dark yellow- inflammation
Green- bacteria
Cloud- WBCs, crystals
Red- RBCs
What type of microscopy is used for synovial fluids?
Bright field/Phase Contrast
Polarized- gout
Why do all synovial fluids have a culture and gram stain performed?
Acute bacterial arthritis is the most rapid destructive disease to joints