檢驗數據判讀
莊子儀醫師
胸腔內科
內科加護病房主任
Why do you need to check lab?
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How do you evaluate a patient?
Interrogation
 Physical examination
 Blood examination
 Image examination
 Special examination
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Classification of lab work
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Hematology test
Blood biochemistry
Serology
Body fluid
Urine and stool
Bacteriology and virology
Histopathology
Hematology test
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What kind of patient do you need to check
hematology test?
Symptoms and signs of blood loss, inadequate blood
production
 Symptoms and signs of infection, inflammation and
malignancy
 Symptoms and signs of coagulopathy
 Routine
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Complete Blood Count (CBC)
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Hemoglobin (Hb)
Hematocrit (Hct)
Red blood cells (RBCs)
Hct  1000
MCV 
Mean cell volume (MCV)
RBC ( in millions / uL )
Mean cell hemoglobin conc. (MCHC)
g / dL )
White blood cells (WBCs) MCHC  Hb ( inHct
Differential count
Platelet count
CBC
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What do you expect if patient has blood loss?
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Macrocytic, normocytic or microcytic anemia?
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MCV, RBC increase or decrease
Normochromic, or hypochromic anemia?
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Hb, Ht decrease
MCH, MCHC normal or decrease
Acute or chronic?
Reticulocyte count
WBC
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What do you expect if patient has infection,
inflammation or malignancy?
WBC increase or decrease
 Leukocytes shift to left
 Monocytes increase
 Abnormal or immature WBC
 Thrombocytopenia
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PLT
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What do you expect if patient has coagulopathy?
Thrombocytopenia
 PT, aPTT increase
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Pancytopenia
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CBC, WBC, PLT decrease
Severe infection
 Malignancy
 Drug effect
 Liver cirrhosis, uremia etc.
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Blood biochemistry
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Liver function
Renal function
Cardiac enzymes
Diabetic test
Liver function
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Albumin, bilirubin, PT
AST, ALT, ALP, rGT
Albumin
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Produced by the liver and contributes
approximately 80% of serum colloid osmotic
pressure
T1/2 of albumin is about 20 days
Lost directly from the blood because of
hemorrhage, burn, or exudates, or it may be lost
into the urine or stool because of nephrotic
syndrome and chronic diarrhea
Bilirubin
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Breakdown product of Hb
Exceeds 0.2-0.4 mg/dL, bilirubin will begin to
appear in the urine
Conjugated bilirubin: water soluble, measured as
D-bil
Unconjugated bilirubin: water insoluble, bound
to serum albumin, measured as T-bil – D-bil
Bilirubin
Increased direct (conjugated): hepatocelluar
injury, biliary obstruction/cholestasis
(gallstone, tumor, stricture, drug-induced)
 Increased indirect (unconjugated): so-called
“hemolytic jaundice” caused by any type of
the hemolytic anemia, newborn jaundice
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Prothrombin time
Direct measurement of activity of clotting
factors VII, X, prothrombin (factor II), and
fibrinogen
 The INR is the PT ratio that would result if
WHO’s international reference
thromboplastin were used to test the pt’s
blood sample
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Aspartate Aminotransferase
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Abundant in heart and liver tissue and
moderately present in skeletal muscle, the kidney,
and the pancreas
Evaluate myocardial injury and to diagnose and
assess the prognosis of liver disease resulting
from hepatocellular injury
Higher than that of ALT in cirrhosis
Alanine Aminotransferase
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Relatively more abundant in hepatic tissue,
more liver-specific enzyme
ALT>AST in viral hepatitis, AST >ALT in
alcohol hepatitis
Alkaline Phosphatase
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Different physiochemical properties and
originate from different tissues: liver, bone,
placenta, intestine
The presence of early bile duct abnormalities
can result in ALP before bilirubin are
observed.
Alkaline Phosphatase
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Drug induced cholestatic jaundice (eg.,
chlorpromazine or sulfonamides) can ALP.
ALP is an excellent indicator of spaceoccupying lesions in liver because of disruption
of biliary canaliculi within liver.
-Glutamyl Transferase
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Major clinical value for hepatobiliary disease.
GT is a sensitive indicator of recent alcohol
exposure (GT/ALP>1.4).
More responsive to biliary obstruction (5-50
times of upper limit of normal)
Useful in the diagnosis of obstructive jaundice,
intrahepatic cholestasis
Case discussion
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24歲男性病人，主訴疲倦，深棕色尿，身體
檢查呈現黃疸，lab data如下：
AST (IU/L): 1543 (5-40)
 ALT (IU/L): 2230 (15-40)
 T-Bilirubin (mg/dl): 16 (0.2-1.3)
 D-Bil. (mg/dl): 11.1 (0.1-0.4)
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Renal function
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BUN, creatinine, electrolytes
Blood gas, lactic acid
Urine analysis
Blood Urea Nitrogen
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End-product of protein metabolism
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Azotemia (elevation of BUN)
Dehydration
 Blood loss
 Steroid
 Renal failure
 Heart failure
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Creatinine
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Derived from creatine and phosphocreatine,
major constituent of muscle
Ccr reflects the glomerular filtration rate (GFR)
(140  age) (body wt in kg)
for males
( SrCr )( 72)
If for females  0.85
Clcr ( ml / min) 
Creatinine
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BUN:Cr ratio
BUN/Cr >20 in prerenal and postrenal azotemia
 BUN/Cr <12 in acute tubular acidosis
 BUN/Cr between 12 and 20 in intrinsic renal
disease
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Urine
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Normal are not present (eg., glucose, blood, ketone, and
bile pigments)
 Appearance: slightly yellow, clear
 pH: 5.0~8.0
 Specific gravity : 1.005~1.030
 Occult blood (O.B): not present
 Sugar : not present
 Protein : not present
 Bilirubin/urobilinogen
 Nitrite/leukocyte esterase
 Microscopic examination: RBC(0-2)HPF, WBC(0-6), cast(0-2),
yeast, crystals(0-3), and epithelial cells(0-5)
Blood gas
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Step 1
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Step 2
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pH = ?  Acidosis / Alkalosis
HCO3- or PCO2 ?  Metabolic or Respiratory
Step 3
Well compensation ?
 Mix ?
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Blood gas
PH
HCO3
Metabolic acidosis
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Respiratory acidosis
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Metabolic alkalosis
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Respiratory alkalosis
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PCO2
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Blood gas
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Metabolic acidosis: PCO2= 1.5x HCO3- +(8 ± 2)
Metabolic alkalosis: HCO3-  1 nmol/L  PCO2 
0.6~0.7 mmHg
Respiratory acidosis
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Acute : PCO2  10 mmHg  HCO3-  1 nmol/L
Chronic : PCO2  10 mmHg  HCO3-  4 nmol/L
Respiratory alkalosis
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Acute : PCO2  10 mmHg  HCO3-  2 nmol/L
Chronic : PCO2  10 mmHg  HCO3-  5 nmol/L
Blood gas
PH
HCO3
PCO2
Metabolic acidosis
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Respiratory acidosis
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Metabolic alkalosis
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Respiratory alkalosis
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Case discussion
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22歲男性病人主訴有下肢水腫，五年前有急
性腎絲球腎炎病史及輕微的蛋白尿。血壓
130/84mmHg，實驗室檢查結果如下:
RBC in urine (0~1) :8~10/HPF
 Albumin in urine (neg) : 4+
 24-hrs urine protein(0~150) : 829 mg/24hr
 Serum total protein (6~8) : 7.6 gm/dL
 Serum albumin (3.5~5.0) : 2.0 gm/dL
 Serum total cholesterol (125~200) :483 mg/dL
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Cardiac enzymes
CKtotal
CK-MB
SGOT
LDH
total
LDH-1
Creatine Kinase
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Suspected MI or muscle disease, heart, skeletal
muscle, and brain with high levels.
Total CK can be increase by strenuous exercise,
IM injections of drugs that are irritating to
tissue (eg., diazepam, phenytoin), acute
psychotic episodes or myocardial injury.
Creatine Kinase
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CK-MB: myocardium,(3-10 U/L) increased in
acute MI (begin in 2-12hrs, peak at 12-40 hrs,
returns to normal in 24-72 hrs), pericarditis with
myocarditis, rhabdomyolysis, crush injury,
Duchenne’s muscular dystrophy, polymyositis,
malignant hyperthermia, and cardiac surgery.
CK-MB level >25 U/L usually are associated
with a MI, the absolute amount may vary
depending on the assay technique used.
Troponin-I
The detection of the presence of troponin T
and I is more specific and sensitive indicator
of myocardial damage.
 Troponin  within 4hrs of AMI, enabling
clinicians to initiate appropriate therapy very
quickly following presentation to the ED.
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Diabetic test
Glucose AC/PC
 HbA1c
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Glucose AC/PC
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The fasting plasma glucose and 2hrs postprandial glucose tests commonly are used for
evaluating glucose homeostasis.
Diagnosis of DM:
Fasting blood glucose>126 mg/dL
 Symptoms of diabetes plus a random plasma
glucose  200 mg/dL
 Plasma glucose  200 mg/dL at 2hrs following a 75g
glucose load
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HbA1c
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Measurement of HbA1C (normal range 4.66.5% ) indicative of glucose control during the
preceding 2-3 months.
Normal Values
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Abnormal laboratory values are not always of
diagnostic significance and normal values
sometimes can be interpreted as being abnormal in
some disease.
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Various factors (eg., age, gender, weight, height,
time since last meal, drugs) can affect the range of
normal values for a given test.
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Each laboratory has its own set of normal value.
Laboratory Error
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Spoiled specimen
Specimen taken at wrong time
Incomplete specimen
Faulty reagents
Technical errors
Diagnostic and therapeutic procedures
Diet
Medication
Thank You for Your Attention