Download Blood samples collection and handling

CLINICAL PATHOLOGY ‫ المرحلة الرابعة‬//
CLINICAL CHEMESTRY
‫ احمد نعمان‬.‫م‬
Clinical chemistry
Chemical
measurement of various constituents of body fluid especially blood
plasma or serum .one test commonly not enough to diagnosis a disease condition ,so its
often need group of tests that gathered to analyze results and must be combined with
other laboratory procedures (full hematology , bacterial culture , serology -----) , history ,
and physical examination . the clinician must have complete knowledge of the normal
values .
Blood samples collection and handling :
Blood Samples Obtained For Clinical Chemistry Should Be Taken:
①carefully to avoid and minimize trauma either physical or psychological ,excitement and apprehension
or exercise of animal that may cause hyperadrenalized .
②avoid contaminating the blood or the animal patient . by use sterile equipment , skin must be
cleansed and disinfectant , using plastic disposable syringes and needles (if available vacutainers
with or without anticoagulants ) , the anticoagulant of choice ( heparin , oxalate , citrate ,or EDTA) .
③needle should be removed due to forcing blood through a small gauge needle may disrupt
erythrocytes ,also over shaking in mixing blood .
④chemical analyses of blood should made as soon as practical (within one hour following collection ) ,
can refrigerated immediately . the serum should be separated quickly as possible , coagulate at
room temperature for max 30 minutes and clot gently removed from the sides of the tube by using
wooden stick . then centrifuged and collected into clean tubes .plasma can be immediately
separated by centrifugation ( care be taken not to over centrifuge the blood or at high speed ).
Blood Samples Acceptable For Clinical Chemistry If Following Precaution Are Taken:
1- Avoid hemolysis by:
a- Care in collection as in ①②.
b- Carful transfer of blood as in ③.
c- Separation of the blood as in ④.
2- Avoid volume changes due to dilution or evaporation .
a- Avoid wet syringe .
b- If possible not use liquid anticoagulant .
c- Open container .
3- Avoid composition changes :
a- Bacterial alteration . by ②④.
b- Enzymatic alteration . by ②④.
c- Blood gas changes .( reduced by filling the chamber nearly to capacity and keeping it tightly
closed).
d- Cell liquid interchanges .by ③④.
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Coles , Embert H. (1986) "Veterinary clinical pathology" 4th ed. W.B .Sauenders
CLINICAL PATHOLOGY ‫ المرحلة الرابعة‬//
CLINICAL CHEMESTRY
‫ احمد نعمان‬.‫م‬
All samples submitted must record owner's name , the case or accession number , date, specimen
number , patient identification ,and test required .
First must use best grade volumetric glassware ( national bureau of standards :
including pipettes , flasks , burets ,and graduate cylinders ), special kits (developed for
animal, not outdate , good storage) , and standardized capillary micropipette .
Instruments :
Must calibrated every time to diagnosis incompletely accuracy or problems by Pre calibrated scale
Provide by manufacturing of test kit or instrument standard solution .
Colorimetry :
Its quantitative analysis in clinical chemistry . by converted body fluid ( such as blood) into colored
solution by adding chemical reagents . then estimate intensity of color and compared to standards and by
adding dilution until reaching similar color ( by photoelectric colorimetry that measure transmission light
(%T) or absorbance light ). When reach similar color measure volume of diluents .
Spectrophotometer :
Widely used . by fixing desired wave length by using filters between 350-1000 nm. .after adding
reagents measured difference of transmittance or absorbance light between sample and standard
solution .
Flame Photometry :
Same Spectrophotometer but solution have metal ion released light when burned .
Atomic Absorption Spectrophotometer :
Same Flame photometry but it will measured light absorbed by ground state atoms rather than the
light emitted by atoms .
Multiple Channel Auto Analyzer
Reflotron :
a dry reagent method , it's using already added reagent strips that exactly calculated concentration ,
and measured sample kinetically .
Enzymology
Enzymes is protein products inside tissue cells act specific action of energy and different in each
tissue . its present in blood due to 1- leakage (as result of cell damage ). 2-induced (when increased cell
production due to several effects ).
2
Coles , Embert H. (1986) "Veterinary clinical pathology" 4th ed. W.B .Sauenders
CLINICAL PATHOLOGY ‫ المرحلة الرابعة‬//
CLINICAL CHEMESTRY
‫ احمد نعمان‬.‫م‬
Kidney Function
The kidneys are the chief organs regulating the internal environment of the body .
Urine is a byproduct of these regulatory activates .(maintaining extracellular, and
lesser intracellular fluid).
involved :
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Elimination of water formed or introduced to body at normal amount required .
Eliminate of inorganic elements according to the need of the body.
Eliminate of non volatile end products of metabolic activity .
Eliminate of foreign toxic substances.
Retention required substances ( amino acids , hormones , vitamins , plasma
portions , glucose ----) .
6- Formation and execration of substances as hydrogen ions and ammonia .
So it play important role in the regulation of water , electrolyte , and acid – base
balance . the Functional unit is Nephron , which consists of 2 units :
❶ Glomerulus . ( Filtration unit ) .
❷Tubules which lined by epithelial cell (execration , reabsorbtion, and other ) urine.
Analysis of this end product of kidney function will often reveal alterations typical of
diseases of that organ , with addition may provide information of other physiologic
processes in the body .
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URINALYSIS .
RENAL FUNCTION TESTS .
BACTERIAL CULTURE .
RENAL BIOPSY.
THE HEMOGRAM IN RENAL DISEASE.
RENAL FUNCTION TESTS
Renal function tests do not reveal the definitive cause of disease , wither the
disease is in an acute or chronic stage . its more accurate done by periodic assessment.
3
Coles , Embert H. (1986) "Veterinary clinical pathology" 4th ed. W.B .Sauenders
CLINICAL PATHOLOGY ‫ المرحلة الرابعة‬//
CLINICAL CHEMESTRY
‫ احمد نعمان‬.‫م‬
Measurements can be made of the renal blood flow , the glomerular filtration , and
the renal tubule excretion and reabsroption . its done by :
① urine specific gravity (SG) . ② estimation of nonprotein nitrogen (NPN) levels
in the blood . ③ studies of the ability of the kidney to execrate certain dyes . ④ test
based on the clearance concept.
② estimation of nonprotein nitrogen (NPN) levels in the blood:
Its nitrogen – containing components of serum or plasma that are not associated with
protein . including : Urea , Creatinine , Uric Acid , Ammonia , Amino Acids , and
Undetermined Nitrogen . ( when all increased together termed Azotemia the Urea , and Creatinine
is most used in veterinary medicine )
Urea Nitrogen (UN) :
Urea is formed in liver and represents end product of protein catabolism . its no
useful function in the body , and almost excreted by kidneys. The glomerulus filters urea
and 25-40% reabsorbed through tubules . ( when it sever increased termed Uremia )
Indication for testing : 1- when suspected decreased kidney function. 2- measuring
peripheral perfusion of tissues in hypovolemic shock or blood pressure . 3- routine pre
surgical laboratory screening .
UN increased normally with dietary  in protein . and  when  dietary protein.
UN  in case of:
❶ catabolic breakdown of the tissues as a consequence of Fever ,Trauma , Infection ,
or Toxemia .
❷ Hemorrhagic into gastro intestinal tract .
❸drug increase protein catabolism [ corticosteroids , thyroid compounds].
❹drugs decrease protein anabolism [tetracycline ].
❺anything that reduces the glomerular filtration rat (GFR).
❻decreased plasma water .
Azotemia may be prerenal , renal , or post renal . prerenal when blood flow though
kidney (also blood pressure) as in [ shock , dehydration , cardiac diseases , and
hypoadrenocortictism ]. Postrenal as[ blocked urethra , rupture bladder ].
UN  in case of : gross sepsis , hormonal effect , liver failure , or portosystemic shunt .
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Coles , Embert H. (1986) "Veterinary clinical pathology" 4th ed. W.B .Sauenders
CLINICAL PATHOLOGY ‫ المرحلة الرابعة‬//
CLINICAL CHEMESTRY
‫ احمد نعمان‬.‫م‬
Creatinine (Cr)
Formed during muscle metabolism of creatin and phosphocreatin . also its excreted
by The glomerular filtration and reabsorbed through tubules. Factors affect (Cr) similar to
(UN) except : 1-criatinine not influenced by diet . 2- daily production from muscle is
relatively constant . 3-not affected by catabolic factor [like fever ---].
Other blood chemistry determinations :
Electrolytes :
Potassium: hyperkalemia in oliguric , anuric .
Sodium : in chronic renal diseases with polyurea and water loss Na to maintain body isotonicity.
Chloride : follow Na.
Bicarbonate : in advanced renal diseases .
Phosphate :hypophosphatemia when GFR is reduced .
Calcium:hypocalecmia in chronic renal diseases .
Nonelectrolytes :
Blood pH : acidosis in renal failure .
Serum protein : total serum protein reflect state of hydration . hyperproteinemia in dehydration .
renal diseases  protein urea hypo albuminemia (with edema) due to osmotic pressure .
③Dye Excretion Tests
studies of the ability of the kidney to execrate certain dyes :
By injected phenolsulfonphthalein (PSP) that removed from plasma by tubular excretion . (Dogs)
④ Renal Clearance Tests
test based on the clearance concept. By measuring clear blood of some constituents in one minute
. its depend on 1- glomerular filtration . 2- filtration plus tubular excretion. 3- filtration plus tubular
reabsorption.
Azotemia =  UN +  Cr
Urine S.G :
Concentrated pre renal (Pcv ,Alb. ----)in [ ADH ,Ca ,steroids , or pyometra)
Non Concentrated Renal
history
(weeks , weight loss ) chronic (Pcv ,Alb )
( hours , good body condition ) Acute (Pcv ,Alb.)
Urinalysis :
 protein = glomerular casts = tubular Chronic = interstitial casts , WBC, RBc ,bacteria = pelvis
Na : K
>27 primary poly uric renal failure
<27 hypoadrenocortictism renal failure
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Coles , Embert H. (1986) "Veterinary clinical pathology" 4th ed. W.B .Sauenders