1.lab diagnosis

Lab DiagnosisLab Diagnosis
Dr. Bikesh Pandey

Diagnostic testDiagnostic test

• Any kind of medical test performed to aid
in the diagnosis or detection of disease.

• While interpreting test result doctor should
always consider sources of:
– Inaccuracy
and
– Imprecision

ContentContent
• Blood :
– Blood Routine Test (BRT)
– Bleeding time & Clotting time
– Others ….
• Bone marrow examination
• Urine :
– Urine Routine Test
– Renal Function Test (RFT)

ContentContent
• Liver Function Test (LFT)
• Stool Test
• Sputum
• CSF
• Serous Membrane Fluid
The normal range of particular test
depends upon the method used,
so its always better to consider the
reference range provided by particular lab.

Blood Routine TestBlood Routine Test (BRT)(BRT)

Blood Routine TestBlood Routine Test (BRT)(BRT)
CBC : Complete Blood Count
DC : Differential Count
Classically Five Items are Included :Classically Five Items are Included :
RBC count
Plt count
WBC count
DC
Hb

Differential CountDifferential Count
Absolute neutrophil count
• A measure of the number of neutrophil
granulocytes.

Absolute neutrophil countAbsolute neutrophil count
• Normal – ANC = 1500 - 8000 cells/µL
• Neutropenia - ANC < 500 cells/µL
• Neutrophilia – ANC > 8000 cells/µL.
– AKA "left shift"

PlateletPlatelet
• Normal range is 150,000 – 400,000 /µL.
• The ratio of platelets to RBC in adult is
1:10 to 1:20.
– Thrombocytopenia
– Thrombocytosis

HemoglobinHemoglobin
Normal Range (g/dL)Normal Range (g/dL)
Men 13.8 - 18.013.8 - 18.0
Women 12.1 - 15.112.1 - 15.1
Children 11 - 1611 - 16
Pregnant women 11 - 1411 - 14

HematocritHematocrit ((HtHt oror HCT)HCT)
• AKA “Packed cell volume
(PCV)” or “Erythrocyte
volume fraction (EVF)”
• It is the volume percentage
(%) of RBC in blood.
• It is normally 45% for men
and 40% for women.

Mean corpuscular hemoglobinMean corpuscular hemoglobin
• It is the average mass of Hb per RBC.
• A normal value is 27 - 31 pg/cell.
• HypochromicHypochromic:
– MCH < 27 pg/cell
• HyperchromicHyperchromic:
– MCH > 31 pg/cell

Mean corpuscular volumeMean corpuscular volume
• It is average volume of a RBC.
• The normal range is : 80-100 fL
• An elevated MCV is termed as Macrocytic & is associated with:
– Alcoholism
– Folic acid deficiency
– Vit B12 Deficiency
• A low MCV is termed as Microcytic & is also associated with:
– Iron deficiency
– Thalassemia
– Chronic disease

Mean corpuscular hemoglobinMean corpuscular hemoglobin
concentration (MCHC)concentration (MCHC)
• Calculated by dividing the hemoglobin by
the hematocrit.
Normal range :
• 32 to 36 g/dl

Reticulocytes CountReticulocytes Count
Normal “Reticulocyte Count” value = 1%Normal “Reticulocyte Count” value = 1%
of the red blood cell.of the red blood cell.
• Reticulocyte count can sometime be
misleading because it is not really a count
but rather a percentage

Corrected Reticulocyte CountCorrected Reticulocyte Count
• AKA “Reticulocyte index”
• AKA “Reticulocyte production index (RPI)”

Corrected Reticulocyte CountCorrected Reticulocyte Count
RIRI << 2.5% with anemia2.5% with anemia
Indicates loss of RBC, but decreased
production of reticulocytes.
i.e. Bone marrow is unable to
compensate
RIRI ≥≥ 2.5% with anemia2.5% with anemia
Indicates loss of RBC, with an
increased production of reticulocytes.
i.e. Bone marrow is able to
compensate

Red blood cell distribution widthRed blood cell distribution width
• RDW or RCDW
• Is a measure of the variation of RBC size (Volume)
• Standard size of RBC is 6-8 μm in diameter
• Higher RDW values indicate greater variation in size.
• Normal range is 11.5-14.5%

FISH – BONEFISH – BONE
A Way of representation

Test for HemostasisTest for Hemostasis

Plsminogen – Plasmin SystemPlsminogen – Plasmin System
The most notable subtype of fibrin
degradation products is D-dimer.D-dimer.

• Platelet count
• Capillary resistance/ fragility test
• Bleeding time
• Clotting time
• Clot retraction test

• Prothrombin time (PT)
• Activated partial thromboplastin time
(APTT)
• Thrmobin time (TT)
• Tests for DIC

Platelet countPlatelet count
• Normal range is 150,000 – 400,000 /µL.
• The ratio of platelets to RBC in adult is
1:10 to 1:20.
– Thrombocytopenia
– Thrombocytosis

Capillary resistance/ fragility testCapillary resistance/ fragility test

Capillary resistance/ fragility testCapillary resistance/ fragility test
• Ideally No. of petechia should be < 10
• If > 10 it could be platelet abnormalities
or blood vessels abnormalities.

Bleeding timeBleeding time
• It is the duration of bleeding after a measured
skin incision.
• Three methods
– Template
– Duke
– Ivy

Clotting timeClotting time
• If done in Slide < 4 minutes
• If done in capillary 4 – 12 minutes
• Prolonged CT :
– Hemophilia and lack of factor I and II
– Over dosage of anticoagulant
– DIC
• Shortened CT :
– Hypercoagulable state

Clot retraction testClot retraction test
• The clot retraction test measures the amount of
time taken for the clot to retract from the sides of
a glass container by gently rimming the top of
the clot and is dependent upon normal platelet
count and function.
• Inspect at ½, 1,2,4 and 24 hours for signs of
retraction (separation of clot with expression of
serum)

Clot retraction testClot retraction test

Extrinsic Pathway
Prothrombin Time (PT)

• Measures the extrinsic pathway of
coagulation.
• PT measures factors
– I (fibrinogen)
– II (prothrombin)
– V
– VII
– X
Warfarin mainly blocks Vit K
dependent factors.
So, to determine the effect
of warfarin we need to test PT.

• Normal value: 12~14 s.
• While checking PT we should always
consider determination of International
Normalized Ratio (INR)

• PT varies due to variations between different batches of
manufacturer's tissue factor (III) used in the reagent to perform
the test.
• The INR was devised to standardize the results.
• Each manufacturer assigns an ISI value (International
Sensitivity Index) for any tissue factor they manufacture.
• The ISI is usually between 1.0 and 2.0.
• INR in absence of anticoagulation therapy is 0.8-1.2.
• The target range for INR in anticoagulant use (e.g. warfarin) is
2 to 3.

Intrinsic Pathway
Activated partialActivated partial
thromboplastin time (APTT)thromboplastin time (APTT)

Activated partial thromboplastinActivated partial thromboplastin
time (APTT)time (APTT)
• Normal value: 30~50 s
• Measures the intrinsic pathway of
coagulation.
• Also used to determine the effect of
Heparin.

Way of notation of coagulationWay of notation of coagulation
times in medical recordstimes in medical records

Thrmobin time (TT)Thrmobin time (TT)
• AKA “Thrombin Clotting Time (TCT) ”
• Procedure
– Plasma is separated from the whole blood by centrifugation.
– Bovine thrombin is added to plasma.
– Clot formation is detected .
– The time between the addition of the thrombin and the clot
formation is recorded as the thrombin clotting time.

Thrmobin time (TT)Thrmobin time (TT)
• Normal value: 16~18s
• Highly Inaccurate

Tests for DICTests for DIC
Laboratory markers consistent with DIC areLaboratory markers consistent with DIC are:
• Prolongation of prothrombin time (PT)
• Prolongation of activated partial thromboplastin time (aPTT)
• A rapidly declining platelet count
• Fibrinogen is an acute phase reactant, it will be elevated due to the
underlying inflammatory condition.
– Normal (or even elevated) level seen in 57% of cases.
– However, Low level is more consistent with the consumptive process of DIC.
• High levels of fibrin degradation products
– D-dimer
• The peripheral blood smear may show fragmented RBC (schistocytes)

Tests for DICTests for DIC
• Severe liver disease can essentially have the
same laboratory findings as DIC so
Characteristic history is important
• International Society of Thrombosis and
Haemostasis has proposed a diagnostic
algorithm.
• This algorithm appears to be 91% sensitive and
97% specific for the diagnosis of overt DIC.

Algorithm by ISTH for DICAlgorithm by ISTH for DIC

Algorithm by ISTH for DICAlgorithm by ISTH for DIC
• A score of 5 or higher is compatible with
DIC and it is recommended that the score
is repeated daily,
• While a score below 5 is suggestive but
not affirmative for DIC and it is
recommended that it is repeated only
occasionally

Bone Marrow TestBone Marrow Test
Dr. Yahya Ibn IliasDr. Yahya Ibn Ilias

Cells in bone marrowCells in bone marrow

BONE MARROW EXAMINATION:BONE MARROW EXAMINATION:
• Type of examination-
– Bone marrow aspiration.
– Trephine biopsy.

Site forSite for bone marrowbone marrow aspirationaspiration
– Sternum.
– Posterior superior iliac spine.
– Spinous process of
vertebrae.
– Shin of tibia ( <2 years of
age).
– Anterior superior iliac spine

Causes of failure of aspirationCauses of failure of aspiration
• Dry tap
– Failure to aspirate any material at all is referred to as dry
tap.
• Blood tap
– Aspiration of blood without any marrow particles is referred
to as blood tap.
(A) Faulty technique.

Pathological factorsPathological factors for Blood tapfor Blood tap
1. Increased connective tissue in bone marrow
– Myelofibrosis.
– Hairy cell leukaemia
– Other myeloproliferative disorders.
– Lymphoma.
– Metastatic carcinoma.
– Tuberculosis.
2. Bone marrow hyperplasia
3. Localization of needle tip in neoplastic tissue
– Metastatic carcinoma.
– Lymphoma.
– Multiple myeloma.
4. Idiopathic.

BONE MARROW EXAMINATION:BONE MARROW EXAMINATION:
RoutineRoutine
– Cellularity
– M:E ratio- Normal is 3-4:1
– Erythropoietic tissue
• Erythropoiesis
– Leukocpoietic tissue
• Types
• Morphology
• Number
• Megakaryocytes
• Number

Cellularity of Bone MarrowCellularity of Bone Marrow
 Hypercellularity
 Normal cellularity
 Hypocellularity

Normal bone marrowNormal bone marrow
• Haemopoietic cell
– Granulocytes and precursors- 60%.
– Erythroid precursors- 20%.
– Lymphocytes, monocytes and their precursors-
10%.
– Unidentified or disintegrating cell- 10%.
• M:E ratio- 3-4:1.

Cell composition of aspirated normal adultCell composition of aspirated normal adult
bone marrowbone marrow
• Granulocytes
– Myeloblast 0.1–3.5%
– Promyelocytes 0.5-5 %
– Myelocyte5-23 %
– Metamyelocyte 7-27 %
– Band form 9-18 %
– Segmented form 4-28 %
• Erythroid series
– Pro-erythroblast 0.1-1.1%
– Basophil 0.4-2.4%
– Polychrmatic 2-30%
– Orthochromatic 2-10%
• Lymphocytes 5-24%
• Plasma cells 0-3.5%
• Monocytes 0-0.6%
• Macrophage 0-2%
• Megakaryocytes 0-0.5%

Tests for Urinary SystemTests for Urinary System

Tests for Urinary SystemTests for Urinary System
• Urine Routine Test
• Renal Function Test (RFT)

Urine Routine Test (URT)Urine Routine Test (URT)
Sample collection
• The first voided morning urine (most concentrated)(most concentrated)
– Most accurateMost accurate
• Random urine (routine)
• 24hrs sample- quantitative
• Mid-stream clean catch (MSCC)
• Post prandial sample-D.M
Need to be examined within 1 hour of collection of sample

Content of URTContent of URT
• General properties
• Chemical tests
• Microscopic examinations

URT - General propertiesURT - General properties
• Urine volume
• Appearance (color)
• Urine pH
• Specific gravity
• Osmotic pressure

Urine volumeUrine volume
• Generally 1.5 L urine is produced a day.
• Polyuria : >3L/24hr
• Oliguria : <400ml/24hr
• Anuria : <100ml/24hr

Appearance (color)Appearance (color)
• Normal, fresh urine is pale to dark yellow.
• Abnormal appearance;
– Hematuria
– Hemoglobinuria
– Pyuria
– Bilirubinuria
– Crystalluria

Hematuria
• Macroscopic Hematuria
– Frank blood in the urine.
• Microscopic Hematuria
– RBC is seen only by the help of microscope.

• Hemoglobinuria
– Color is like strong tea or
wine due to presence of
free Hb.
• Pyuria
– Presence of WBCs. (>5
WBCs /HP)
– Cloudy.
– Eg. UTI.

• Bilirubinuria
– Presence of direct bilirubin.
– Dark yellow color.
• Crystalluria
– Presence of salt crystals.
– Cloudy.

AppearanceAppearance
• We can also see for urine clarity.

Urine pHUrine pH
• Normal urine pH: 6 - 6.5
• Aciduria :
– Gout ,DM, meat consumption.etc.
• Alkaluria :
– UTI ， RTA.etc.

Specific gravitySpecific gravity
• Specific gravity
– Ratio of the density of a substance to density of a
reference substance (H2O).
– Directly proportional to solute concentration of urine.
• Normal specific gravity: 1.003-1.03
• Lower SG:
– Chronic renal failure, diabetes insipidus.etc.
• High SG:
– Acute nephritis, diabetes mellitus.etc.

Osmotic pressureOsmotic pressure
• Normal value – 250mosmol – 300mosmol

URT - Chemical testsURT - Chemical tests
• Urine protein
• Urine glucose
• Urine ketone

Urine proteinUrine protein
• Normal :
– (-) or 20-80 mg/24 hrs
• Abnormal :
– (+ ) or > 150 mg / 24 hrs

Urine glucoseUrine glucose
• Normal :
• (-) or <15mg/dL
Urine ketoneUrine ketone

URT-Microscopic examinationsURT-Microscopic examinations
• Cells
• Casts
• Crystal bodies
• Pathogen

Microscopic examination of the urine
Finding Associations
Casts
• RBC Glomerulonephritis, Vasculitis
• WBC Interstitial nephritis, Pyelonephritis
• Epithelial cell ATN, Interstitial nephritis, Glomerulonephritis
• Granular Non-specific
• Waxy Advanced renal failure
• Hyaline Normal finding in concentrated urine
• Fatty Heavy proteinuria
Cells
• Red blood cell UTI
• White blood cell UTI

Crystal bodiesCrystal bodies
Calcium Oxalate CrystalsCalcium Oxalate Crystals

Phosphate CrystalsPhosphate Crystals

Urate CrystalsUrate Crystals

Cystine CrystalsCystine Crystals

PathogensPathogens
Yeast

Renal Function TestRenal Function Test

• AKA “Kidney Function Test”
• Kidney function test is a collective term for a
variety of individual tests and procedures that
can be done to evaluate how well the kidneys
are functioning.

Renal Blood SupplyRenal Blood Supply

Physiology of Urine ProductionPhysiology of Urine Production
Urine production DependsUrine production Depends
uponupon
Glomerular Filtration
Tubular Reabsorption
Tubular Secretion

Physiology of Urine ProductionPhysiology of Urine Production
• Glomerular Filtration Rate (GFR) = 125 ml/min
= 180 L/Day
• Tubular Reabsorption Rate (TRR) = 124 ml/min
= 178.5 L/D
So, Generally 1.5 L urine is produced a day.

• Can be divided into two categories:
– Test for function of Glomerulus
• GFR
– Test for Function of Tubule
• Reabsorption &
• secretion

Creatinine Clearance Rate (Ccr)Creatinine Clearance Rate (Ccr)
{eGFR}{eGFR}

Renal ClearanceRenal Clearance
• Renal clearance of a substance is the
volume of plasma that is cleared of the
substance by the kidneys per unit time.
• It is the measurement of the renal
excretion ability.

Substances used for EstimatingSubstances used for Estimating
Kidney conditionKidney condition
• Inulin - eGFR
• Creatinine - eGFR
• PAH - RPF

InulinInulin
• Inulin Clearance Can Be Used to Estimate GFR
(eGFR)
• Inulin is :
– Freely filtered
– Neither reabsorbed
– Nor secreted
• Whatever, inulin is filtered, all of it is excreted in
the urine.

CreatinineCreatinine
• Creatinine Clearance Can Be Used to
Estimate GFR.

CreatinineCreatinine
• It is not practical to measure urine
creatinine level to estimate GFR, so many
scientist has given many ways to calculate
GFR by being based upon only blood
creatinine.
• Widely accepted is :

Let’s TryLet’s Try
• A 36 year old man comes to the
hospital with severe abdominal and
back pain. On examination you find he
might have some renal disorder. You
order for a serum creatinine level
which is 2.7mg/ dL. His weight is
72kg. What is his GFR?

Let’s TryLet’s Try
• A 55 yrs old African female is brought
to ER with a C/O inability to pass
urine since last 3 days. You suspect
renal failure. Her blood creatinine is
0.85 mg/dL. Her weight is 72 Kg. What
is her GFR?

eGFReGFR
• Also, used to stage the Chronic Kidney
Disease (CKD)

Serum Creatinine (Cr)Serum Creatinine (Cr)

Serum CreatinineSerum Creatinine
Normal range ( Highly Variable)
0.5 to 1.0 mg/dl
If, GFR < 50% normal, Scr will increase
markedly
Is Scr an early diagnosis marker?
NO

Blood Urea NitrogenBlood Urea Nitrogen

• ADA “BUN”
• The normal range is 6 - 20 mg/dL.
• Increased BUN
– Azotemia
– Uremia
• Azotemia is used when the abnormality can be
measured chemically but is not yet so severe as to
produce symptoms. Uremia is the pathological
manifestations of severe azotemia.

• BUN increased in:BUN increased in:
– Renal failure
– Urinary tract obstruction
– Nephrotoxic drugs
– Shock, Burn, GI bleeding, Dehydration
• BUN decreased in:BUN decreased in:
– Hepatic failure
– NS
– Cachexia (low-protein and high-carbohydrate diets)

BUN : CrBUN : Cr RatioRatio
• Normal 12-20
• The principle behind this ratio is the fact
that both urea (BUN) and creatinine are
freely filtered by the glomerulus, however
urea reabsorbed by the tubules can be
regulated (increased or decreased) whereas
creatinine reabsorption remains the same
(minimal reabsorption).

BUN : CrBUN : Cr Ratio in Acute KidneyRatio in Acute Kidney
InjuryInjury

Concentration Dilution TestConcentration Dilution Test
(CDT)(CDT)
• AKA “3 Hrs Urine Test”
• AKA “ 3 Hrs Specific Gravity Urine Test”
• As the name the specific gravity of urine is
tested evry 3 hrs.
• It shows the concentrationg ability of
kidney.

Phenolsulfonphthalein (PSP)Phenolsulfonphthalein (PSP)
Excretion TestExcretion Test
• Estimates the overall blood flow through the
KIDNEY.
• This test is rarely used these days.

ProcedureProcedure
• A specific dose of the PSP dye is injected
• Its recovery in the urine is measured at successive 15,
30, 60, and 120minute intervals.
• The kidney secretes 80 percent of the PSP dye.
• The recovery value at 15 minutes after injection is
normally about 25–35 %

InterpretationInterpretation
• even a damaged kidney may be able to
remove the PSP dye from circulation given
a longer time to do so.
• PSP excretion is decreased in most
chronic kidney diseases and may be
increased in some liver disorders.

COCO22 Combining PowerCombining Power (CO(CO22 CP)CP)
• A measurement of the total CO2 that can bind as
HCO3 -at a PCO2 of 40 mmHg at 25°C by serum,
plasma, or whole blood.
• Normal range is 25-31 mmol / L
• Elevated : Met. Alkalosis / Resp. Acidosis
• Decreased : Resp. Alkalosis / Met. Acidosis

Liver Function Test (LFT)Liver Function Test (LFT)

Liver Function Test (LFT)Liver Function Test (LFT)
• LFT gives information about the state of a liver.
LFTLFT
• True LFTs
– Prothrombin Time (PT/INR)
– aPTT
– Albumin
– Bilirubin (direct and indirect)
• Liver injury related LFTs
– Liver transaminases
• Aspartate transaminase (AST) or Serum glutamic oxaloacetic
transaminase (SGOT)
• Alanine transaminase (ALT) or serum glutamate-pyruvate transaminase
(SGPT)

AlbuminAlbumin
• Albumin is a protein.
• Albumin contributes 80 % of osmotic pressure of
human body.
• Albumin works mainly as a carrier protein.
• Albumin levels are decreased in chronic liver
disease, nephrotic syndrome.

BilirubinBilirubin
Normal range
• Highly variable
• Normal adult has Total Bilirubin < 17µmol/L
(1mg/dl)
• Out of which, around 30% is Direct bilirubin
– Normal Direct Bilirubin < 5.1µmol/L (0.3mg/dl)

Liver transaminasesLiver transaminases
• Transaminase or Aminotransferase is
enzyme that plays important role in
metabolism of amino acids.
• Important transaminase enzymes are,
– AST (aspartate transaminase)/ (SGOT)
– ALT (alanine transaminase)/ (SGPT)
• Elevated transaminases can be an indicator
of liver damage.

Liver transaminasesLiver transaminases
• Normal ranges  8-40 U/L (Both ALT and AST)
• Mild transaminesemia if reaches to 250 U/L.
• Acute  increased transaminases for <6 months
• Chronic  persist for >/= 6 months
• Eg of elevated transaminase,
– Drug-induced (isoniazid) increases of 100 U/L or less.
– Liver Cirrhosis increase to >1000+ U/L range.

How ALT or AST increase?How ALT or AST increase?
Liver damage
Hepatocytes become
more permeable
Enzymes leak in blood
ALT is primarily localized to the liver and is
considered a more specific test for liver damage.

ALTALT
• Female ≤ 34 IU/L
• Male ≤ 52 IU/L
• Formerly known as serum glutamate-
pyruvate transaminase (SGPT).

ASTAST
• Male 8 - 40 IU/L
• Female 6 - 34 IU/L
• Formerly known as serum glutamic
oxaloacetic transaminase (SGOT).

AST/ALT ratioAST/ALT ratio
• AKA, "De Ritis Ratio"
• Specially used for alcoholic liver disease.
• It is AST to ALT ratio of 2:1 or greater,
particularly with increased Gamma-Glutamyl
Transferase.

Lactate dehydrogenaseLactate dehydrogenase
• Found in many body tissues, including the liver.
• Elevated levels of LDH may indicate liver damage.
• Elevated LDH maybe due to,
– Cancer
– Meningitis
– Encephalitis
– Acute pancreatitis
– HIV

Alkaline PhosphataseAlkaline Phosphatase
• Normal  ~20 to 140 IU/L
– Although higher in children and pregnant.
• Concomitant increases of ALP with GGT
should raise the suspicion of hepatobiliary
disease.

CSF valuesCSF values
Normal RangeNormal Range
PressurePressure 7 – 15 mmHg
OsmolalityOsmolality 280 – 300 mmol/L
ChlorideChloride 115 – 130 mmol/L
RBCRBC 0 cells/mm3
WBCWBC 0 – 3 cells/mm3
Glucose 50 – 80 mg/dL
Protein 15 – 40 / 45 mg/dL

LPLP
• Most accurate test is culture.
• Most sensitive test for acute bacterial
meningitis is elevation of protein in CSF.
(Not elevated protein Rules out Acute bacterial meningitis)
• Increase in WBC is the indicator to start
treatment.

Serous Membrane FluidSerous Membrane Fluid

Transudate Vs ExudateTransudate Vs Exudate
• Transudate
– It is extravascular fluid with low protein content and a low
specific gravity (< 1.012).
– It results from increased fluid pressures or diminished colloid
oncotic forces in the plasma.
• Exudate
– It is a fluid emitted by an organism through pores or a
wound, a process known as exuding.
– Composition of an exudate varies, but generally includes
water and the dissolved solutes of the main circulatory fluid
such as sap or blood.

Stool TestStool Test
• Appearance
• Consistency
• Odor
• Chemical tests
• Microbiology tests
• Fecal Occult Blood Test

Stool TestStool Test (Appearance)(Appearance)
• Normally is a
light to dark
brown
coloration.
Stool ColorStool Color DiseaseDisease
Yellow Giardiasis
Pale or Clay Decreased Stercobilin
Black or Red
GI Bleeding
Iron
Bismuth
Beetroot
Blueberry …….
Blue Radiation
Thallium poisoning
Grape soda……
Silver (Clay stool with blood)
Ca ampulla vater
Green (Due to unprocessed bile)
Intake of large quantity of
sugar
Violet or Purple Porphyria

Stool TestStool Test (Consistency)(Consistency)
• Normally it is semisolid, with a mucus
coating.
• Hard in constipation, dehydration.
• Loose in diarrhea.
• Stickness increased in shigella.

Stool TestStool Test (Odor)(Odor)
• Feces odor vary according to diet.

Stool TestStool Test (Chemical test)(Chemical test)
• Fecal pH test
– Used to determine Steatorrhea:
» lactose intolerance
» Infection
• Faecal elastase levels
– For pancreatitis
– These days is the mainstay diagnosis of
pancreatitis.

Stool TestStool Test (Microbiology test)(Microbiology test)
• Stool is examined under a microscope for
the presence of:
– Parasites
– Larvae or Eggs
– Toxins
• Eg: Toxin of Clostridium difficile
– Viruses through EM

Stool TestStool Test (Microbiology test)(Microbiology test)
Hanging Drop test
• Is done to test Bacterial Motility.

Darting motility –Darting motility – Vibrio choleraVibrio cholera

Stool TestStool Test (Fecal Occult Blood Test)(Fecal Occult Blood Test)
• Stool Guaiac TestStool Guaiac Test

SputumSputum
• Mucus coughed up from the lower airways
is called as sputum.
• Phlegm: Same sputum when it is within
body.

SputumSputum
• Appearance
• Microbiological investigations
– Staining / culture
• Cytological investigation

SputumSputum
• Sputum can be:
– Bloody(Hemoptysis)
• lung cancer;
• Alveoli
• Pulmonary TB
• Lung abscess
• Bronchiectasis ……………………..
• Rusty colored - pneumococcal bacteria
• Greenish colored – Pseudomonas
• Purulent - containing pus.
– Thick purulent : staphylococcus
– Thin purulent : Streptococcus pyogenes
• Frothy pink - pulmonary embolism

1.lab diagnosis

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (13)

Similar to 1.lab diagnosis

Similar to 1.lab diagnosis (20)

Recently uploaded

Recently uploaded (20)

1.lab diagnosis