LABCON_PACHUCHI

8/13/2019 LABCON_PACHUCHI

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MAIN OBJECTIVE

To illustrate the renal response to fluid

deprivation,water loading and isosmoticfluid expansion

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To determine urine volume, flow rate, specificgravity and sodium concentration on all urinesamples


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A.urine sample was collected andDiscarded. Time of collectionwas noted

RATIONALE:This is done to ensure that thefollowing urine samples are notcontaminated by previous water orfood intake

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B. First urine sample was takenwhich was labeled PREINGESTION.

The sample was analyzed for: Volume and Flow Rate Specific Gravity Sodium Concentration

RATIONALE: this specimen serves 4


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C.Immediately after the collection,the subject rapidly drinks either:

GlucoseWater0.9% NaClNone

RATIONALEThe ingestion of fluid serve as INTERVENTION.Glucose,water and 0.9% Isotonic NaCl have differenttonicities that would alter urine volume and sodiumconcentration

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D. Urine Sample was collected

every 30 minutes for 3determinations

This was subjected tospecific gravityUrine volumeFlow rateAn aliquot of urine was prepared

for Na concentration using the 6


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WHAT IS RENAL CLEARANCE


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It i s the vo lum e of p lasm a passingthrough the kidneys th at has b een tota l lycleared o f a so lute



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Rate atwhich thatsolutedisappearsfrom the

body byexcretion



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Albumin

Glucose

Na+Cl

Inulin

Creatinine


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Clearance Is a Noninvasive Way

to Measure GFR

Clearance Helps Us DetermineRenal Handling


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Clearance (mL/min)Urineconcentration of asubstance

(mg/ml)

Plasma concentration of asubstance(mg/ml)

Urine Flow Rateper minute(ml/min)


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Plasma ConcentrationUrinary Excretion Rate

For a given plasma Concentration, renal clearanc e of asubstance increases as the urinary excretion increases.

Renal Clearance =


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WHAT IS AN IDEAL SUBSTANCE USED IN RENALCLEARANCE?

WHAT IS AN IDEAL SUBSTANCE USED IN RENAL


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CLEARANCE?

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FREELYFILTERED

NOTREABSORBED

NOTMETABOLIZED

INERT

NOT SECRETED


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INULIN Ideal

substancethat measureGFR

Not clinicallyused

Intravenous

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Used Clinically Endogenous End product of muscle

metabolism 10 % Secreted in the

Proximal Tubule Amount

filtered=amountexcreted


CLEARANCE?

CREATININE


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Discuss the physiologic basisfor the mathematical formulaused for the computation of

the creatinine clearance

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FICKS PRINCIPLE

Pxa x RPFa = ( Pxv x RPFv) + ( Ux X

V)

Concentration in theRENAL

ARTERY

FLOW

RATEin Artery

INPUT

FLOW

RATEin Vein

Concentration in theRENAL

VEIN

Concentration of

substance inURINE

URINE

FLOWRATE

OUTPUT


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VOLUME OF PLASMA FROM WHICH ALLTHE CREATININE HAS BEEN REMOVED AND EXCRETED INTO THE URINE PER

UNIT TIME.


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What is the relationshipbetween Creatinine

Clearance and GlomerularFiltration Rate GFR?

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Creatinine Clearance is used

for routine assessment ofGFR

in hospitalized patients

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BOTH MEASURE THE FILTERING CAPACITY

GFR CreatinineClearance

Describes how manymilliliters of Plasma

passing into theBowman capsule perunit time

Inulin Clearance isaccurate butexpensive

Describes how manymilliliters of plasma

passing through thekidneys that havebeen totally clearedof a solute in a givenperiod of time

Overestimates GFR

but is inexpensive 26


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PLASMA CREATININE AND GFR

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LABCON_PACHUCHI