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63 Cards in this Set
- Front
- Back
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Specimens analysed in the chem path lab |
Whole blood, plasma , serum, urine, amniotic fluid, synovial fluid, peritoneal fluid, pericardial fluid, pleural fluid, buccal cells , saliva, feces, sweat, plasma |
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Use of skin puncture |
In young children to obtain a capillary sample |
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What are the steps for phlebotomy |
.. |
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Why should an arm with iv line not be used |
Cos it can cause lymphostasis |
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Gauges used In adults, kids and reasons for such gauge use?? |
Adults: 19-22 When large vol of blood is needed, 30-50ml In kids 23-25 because the higher the gauge the smaller the hole and large gauges might not (hit?) the vein |
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Skin at the back of the hand and anemia are less preferred in? |
Diabetes and those with circulating diseases |
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How to collect specimen in an arm containing canula or arteriovenous fistula ? |
Consent of the physician If the patient is being infused intravenously shut off the blood flow for 3 minutes before obtaining specimen . Make a note in patients chart and request form. |
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How to clean area to be punctured |
.... |
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If ethanol is to be tested what should be used as antiseptic for puncture? |
Benzoalkonium chloride |
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Why tourniquet shouldn't last more than 3 minutes |
Can cause stasis or changes in congestion of blood |
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Creatine kinase and aspartate transferase may be increased due to ? |
Hemoconcentration and slight trauma caused by venipuncture |
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Pumping fists should be avoided because? |
It can lead to release of analytes such as plasma k, PO4 (phosphate ion) and lactate concentration. Can cause decreased pH with increased ionised Ca concentration. Incorrect results |
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Stress associated with blood concentration can lead to increase in? |
Growth hormone and cortisol especially in young children. |
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How long is a patient supposed to hold a dry gauze pad over the punctured site with the arm raised? |
15 minutes |
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Where should tourniquet be applied and reasons? |
About 10-15cm above site To shut?? blood returning from heart and distend the veins. |
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What is/are Skin puncture equiment, indications for skin puncture and sites of skin puncture |
Lancet i) incase of damage to veins dur to repeated venepuncture ii) inability to access veins in situations like burns iii) small blood volume is needed iv) preservation of veins for chem and others Sites: fingertip, big toe of infant,heel, earlobe, phalanx of middle or ring finger. Capillary blood can be used for neonatal screening |
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Sites in order for arterial puncture and who performs it? |
Radial Brachial Femoral By a trained technician or physician. |
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Femoral artery is less preferred because? |
Leaks greatly especially in old people😗 (elderly ) Important structures around, give example More liable to hematoma |
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What are the sites of puncture in different ages where arterial puncture cannot be obtained? |
Catheterization of Umbilical artery(crosscheck with note page 8) in neonates. In young children- capillary blood, acceptable for PCO2 and Plt but not PO2 |
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Why use arterial blood as sample? |
ABG analysis and pH studies |
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Most widely used anticoagulant and mech of action |
Heparin- Inhibits fibrin formation from fibrinogen by accelerating the action of antithrombin III which neutralises thrombin. Inhibits EDTA binding of calcium |
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Mention anticoagulants and preservatives for blood. (7) |
Citrate, acid citrate dextrose, heparin, EDTA, Na fluoride, lithium salts and sodium iodoacetate. |
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EDTA(ethylenediamine tetraacetic acid) mechanism of action and uses |
Chelates calcium ... Prevents coagulation by binding calcium Inhibits CK and leucine aminopeptidase Prevents coagulation by binding calcium Dissolves dipotassium and tripotassium salts because it preserves the cellular component of blood.
Uses; Measurement of intracellular drugs in cyclosporine Isolation of genomic DNA HbAic analysis Haematological examination
P.s: not used for calcium collection/analysis |
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Na Fluoride. What is it, function, mechanism of action, preservation. How much and fast does glucose decrease without anticoagulant ? |
- it's a weak anticoagulant - it preserves glucose with another preservative K oxalate - it Inhibits enolase in the glycolysis pathway. - most specimens preserved at 25°for 24 hours and 4° for 48 hours - glucose decreases by 0.56mmol/L at 25° every hour -Decreases faster in newborns and leukemia patients Has delayed onset of action |
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What's the concentration of Na citrate soln for coagulation. Function. |
Used at conc 34-38g/L Chelates calcium Reversible by addition of calcium |
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Acid citrate dextrose function |
When Isolation of genomic DNA is required. Also for cytogenetic testing. (Diagnostic testing) |
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Oxalate Mechanism of action Enzymes it inhibits |
Na , k and lithium salts of oxalate Inhibit coagulation by formation of insoluble complexes with calcium ions. Inhibits Acid and alkaline phosphatase, amylase and LDH |
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Na iodoacetate. What's this fr? What're the functions? |
At conc 2g/L its an antiglycolytic agent and substrate for Na fluoride. Inhibits CK |
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Severe hemolysis causes increases in total- |
Acid phosphatase, ldh and isocitrate dehydrogenase |
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Venous vs capillary blood glucose |
Venous is lesser by 7mg/dL |
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Urine. What is it? Color? Ph? |
Fluid excreted from the kidney , passes through ureter and ends up in the bladder to be eliminated with the help of the urethra( my own def) Amber colored Slightly acidic |
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Use of random urine collection? |
Drug abuse detection |
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First morning specimen |
Most concentrated. For detection of abnormal protein constituents or gonadotropins. (hcg) Best for pregnancy I think |
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What to be avoided in timed specimens? What's the time for volume collection? |
Diet: no walnut,( cos it increases 5hydroxyindoleacetic acid), avocado's Plums, bananas. Certain drugs as well.
2hours 1L 12 hours 2L 24 hours 3/4L |
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24 hours specimen. What dyou know about this ?? |
For detection of bacteria in urethritis, use the first 10ml MSU for bladder disorder investigation Specimen must be collected during or immediately after symptoms |
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______ occur early in the morning urine |
Catecholamines and 17 hydroxy steroids |
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Define double voided specimen. |
Urine exerted during a timed period after completely emptying the bladder eg during glucose tolerance test |
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What is the catheter specimen? |
This is specimen collected after insertion of the catheter into the urethra. Used for bladder obstruction |
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What Is the suprapubic specimen? |
Used in infants to know if there's bacteria in the bladder. |
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Steps for urine preservative and preservative example. |
Refrigerated at 2-8°c or frozen -24 to -16°c Examples- HCl, acetic acid, boric acid, thymol, Na2CO3, HNO3, toluene. |
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Ps: urine can be used for molecular testing for infections example; chlamydia |
Yeahhhh |
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Use of feces |
For detection of occult blood in ulcers or malignancy |
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Hpw do you access severity of malabsorption in feces? |
By measurement of fecal nitrogen and fat in 72 hours |
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Hpw do you access severity of malabsorption in feces? |
By measurement of fecal nitrogen and fat in 72 hour specimen. Usually no preservative is used but specimen is refrigerated throughout ollection period |
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Normal amniotic fluid amount and method of obtaining it. Its uses. |
500-1500 ml. Obtained from the 13th week Obtained by amniocentesis Prenatal diagnosis of fetal lung maturity To access fetal lung maturity To check for intrauterine infection Congenital abnormalities eg neural tube defects. Behind the neck of the fetus below it's head.
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What do you know about saliva? |
It's alkaline. Used for dna saming and drug abuse About 0.8-1.2L produced daily. Produced by parotid gland, sub maxillary gland, sublingual and smaller mucus glands. |
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Why are buccal cells useful? |
Better for genomic DNA or DNA sampling In patients that have undergone blood transfusion or bone marrow transplant. |
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Solid tissue eg breast tissue and liver .uses |
Breast tissue is used for oestrogen and progesterone receptors??? Liver tissue is used for measurement of iron and copper content to assist diagnosis related to hemochromatosis or Wilsons disease. Other uses- for toxicology and elemental analysis. |
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Indications for csf |
Total volume of CSF produced is about 150ml. About 20ml can be collected safely Blood in csf may be due to subarachnoid hemorrhage or traumatic tap. Indications- infections like meningitis, malignancy, hemorrhage. |
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Plasma should be collected ____ hours prior to the tap. |
2-4 hours |
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Causes of low csf glucose (hypoglycorrhachia) |
1-Hypoglycemia 2-Infection- increased glucose metabolism 3-Falsely low values due to lack of preservation in fluoride bottle 4- may be low in pyogenic meningitis or TB meningitis |
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Indications for synovial fluid |
Lubricants for joints Transport for nutrient deliveryRemoval of cell waste Fluid volume rarely exceeds 3mL. |
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SF/p glucose ratio ??(synovial fluid to glucose ratio) |
0.9-1. Decreased ratio in Inflammations eg gout , rheumatoid arthritis Septic conditions |
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Abg analysis storage |
In ice slosh |
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When to obtain Placental tissue ? |
At 9th week |
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Gamma glutamic transferase in increased in ? |
Alcoholics |
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Cortisol and glucose is increased in? |
Smokers |
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What to do when sample first comes to the lab |
1- Read the request form. Name, time of sample collected , time released , signature of person analysed in the result, etc Check if sample is enough |
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Chain of custody?? |
For laboratory tests related to crime and accidents. It means that any individual in contact with the sample most document it's receipt condition, day and time it was received |
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What's point of care testing? |
Tests carried out where the patient is receiving medical care. Also called close patient testing or bedside testing . |
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Advantages of point of care testing ; |
- rapid - used in emergency and ICU - Helps doctor make faster decisions - prevents mix up with other samples of patients |
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Disadvantages of point of care testing |
Issue of performance and standardisation Some machines are expensive Limited range of parameter |
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Examples of point of care tests |
Bilirubin Blood gas analyser Glucometer Digital sphygmomanometer |
