INTERPRETATION OF COMMON LAB TESTS.pptx
- 1. INTERPRETATION OF COMMON LABORATORY TESTS Dr Bundi Karau Physician/Anatomist CME, Meru Teaching and Referral Hospital, 4th August 2021 1
- 2. Objectives • Be able to interpret a complete blood count, renal function test, liver function tests and glycemic tests • Case-based approach to interpretation of common lab tests • Take home message 2
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- 5. Steps in interpreting a full hemogram • Look at all the cell lines • Then look at the Hemoglobin (hb) and HCT (Remember rule of 3s) • If deranged Hb, look at the Mean Corpuscular Volume (MCV) and RDW 5
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- 8. HB%gm%(13-17gm%) HCT volume of blood occupied by RBCS(35-45%) MCV average volume of individual RBC.(80-100fl) RETIC % of immature RBCs in blood(1-2%) RDW (10-15%) RBCS. COUNT IS ADDITIONAL TO DIAGNOSIS RBCSX3=HBX3=HCT (If not -indicates micro or macrocytosis or hypochromia). depend on both total red cell mass and plasma volume BM activity Degree of anisocytosis 8
- 9. Evaluation of Hb • A higher Hct than 3Hb indicates dehydration, e.g if the Hct value is 34% when the Hb value is 9 g/dL, for example (34>3x9=27), this shows that the plasma of the blood is decreased, and may be a clue that the patient is dehydrated because of diarrhea or vomiting. • If the RBC count is 5.5 million when the Hb value is 9 g/dL, this indicates the presence of high RBC numbers but insufficiency of Hb, and this is usually observed in thalassemia trait (TT). 9
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- 16. LIVER FUNCTION TESTS DETECTION OF INJURY CHRONIC INFLAM MATION CHOLESTASIS -ALP -GGT -5’NT BIOSYNTHETIC FUNCTION -ALBUMIN -PT -HYALUR ONAN -IMMUNO GLOBULIN CAPACITY OF LIVER TO TRANS- PORT ANI- ONS AND METABOLISE DRUGS NECROSIS -AST -ALT -LDH -GDH -SERUM BILIRUBIN -URINARY BILIRUBIN -CERULOPLASMIN -FERRITIN -FIBROTEST -TRANSIENT ELASTOGRA 16
- 17. A 22 year old male with complain of jaundice, easy fatiguability and muscle pain for 6 months TEST PATIENT VALUE LAB VALUE SERUM BILIRUBIN (T) 5.84 0-1mg/dl SERUM BILIRUBIN(D) 2.24 0-0.25mg/dl AST(SGOT) 146 UPTO 40 IU ALT(SGPT) 57 UPTO 37 IU ALP 250 80-290 U/L GGT 45 MALE-7-32 U/L TOTAL PROTEIN 7.2 6.4-8.3 G/DL ALBUMIN 2.9 3.8-4.4 G/DL PROTHROMBIN TIME TEST-44 CONTROL-26 14-16 SEC INR 1.8 17
- 18. INTERPRETATION A case of indirect hyperbilirubinemia (direct<50% of total bilirubin) with 3 times elevation of AST, reduced albumin(ag reversal) and raised PT and INR suggestive of a chronic liver disease. AG reversal denotes Albumin/Globulin ratio < 1. 18
- 19. A 19 year old female with history of chicken pox 8months back developed jaundice, pale stool and pruritus gradually. TEST PATIENT VALUE LAB VALUE SERUM BILIRUBIN (T) 32.7 0-1mg/dl SERUM BILIRUBIN(D) 27.5 0-0.25mg/dl AST(SGOT) 181 UPTO 40 IU ALT(SGPT) 65 UPTO 37 IU ALP 914 80-290 U/L GGT 34 FEMALE-6-29 U/L TOTAL PROTEIN 5.7 6.4-8.3 G/DL ALBUMIN 2.2 3.8-4.4 G/DL 19
- 20. INTERPRETATION A case of direct hyperbilirubinemia with raised AST(6 times) and ALT (mild) and markedly raised ALP suggestive of a cholestatic picture with ongoing activity. Albumin also is low suggestive of liver disease. 20
- 21. A 32 year old male a chronic alcoholic and known case of DCLD, with history of alcohol intake 3 days before admission. TEST PATIENT VALUE LAB VALUE SERUM BILIRUBIN (T) 38.63 0-1mg/dl SERUM BILIRUBIN(D) 31.4 0-0.25mg/dl AST(SGOT) 54 UPTO 40 IU ALT(SGPT) 19 UPTO 37 IU ALP 211 80-290 U/L GGT 78 MALE-7-32 U/L TOTAL PROTEIN 7.8 6.4-8.3 G/DL ALBUMIN 2.5 3.8-4.4 G/DL PROTHOMBIN TIME TEST-34 SEC CONTROL- 22SEC 14-16SEC 21
- 22. INTERPRETATION A case of direct hyperbilirubinemia with mild elevated ST and AST/aALT~ 3:1 and GGT raised suggestive of alcoholic liver disease with ongoing activity. Ag reversal suggestive of chronic liver disease. The liver enzymes are not elevated much as the liver has already undergone cirrhosis. 22
- 23. A 40 year old male asymptomatic came, after routine master health check up. TEST PATIENT VALUE LAB VALUE SERUM BILIRUBIN (T) 0.8 0-1mg/dl SERUM BILIRUBIN(D) 0.15 0-0.25mg/dl AST(SGOT) 125 UPTO 40 IU ALT(SGPT) 80 UPTO 37 IU ALP 190 80-290 U/L GGT 30 MALE-7-32 U/L TOTAL PROTEIN 8.0 6.4-8.3 G/DL ALBUMIN 4.0 3.8-4.4 G/DL 23
- 24. INTERPRETATION A case of mildly elevated transaminases with no other abnormality. Has to be workedup further for any occult liver problem. May need hepatitis serology testing-Hepatitis B surface antigen and Hepatitis C antibodies 24
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- 26. Hyperbilirubinemia LFT Hepatocellular disease. Cholestatic disease. Bilirubin levels Usually variable Usually < 5mg/dL Usually high consistently > 5 mg/dL Aminotransferases Variable, depending on the underlying disease Mild to mod Usually < 400 IU/mL Alkaline phosphatase Usually Normal - mild Usually > 3 times (N) 26
- 27. Causes of elevated aminotransferases ALT > AST AST > ALT α -antitrypsin deficiency 1 Autoimmune hepatitis Chronic viral hepatitis (B, C, and D) Hemochromatosis Steatosis and steatohepatitis Wilson disease medication and toxins NON HEPATIC CAUSES Celiac disease Hyperthyroidis m ( Acute severe>20 fold ) Acute bile duct obstruction Acute Budd- Chiari syndrome Acute viral hepatitis Autoimmune hepatitis Ischemic hepatitis Medications/toxin s Wilson disease ( Chronic, Mild < 5 fold ) HEPATIC CAUSES (Chronic, Mild < 5 fold) Hepatic Causes Alcohol-related liver injury Cirrhosis. Nonhepatic Causes Hypothyroidism Myopathy Strenuous exercise ( Acute severe>20 fold ) Hepatic Cause Medications or toxins in a patient with underlying alcoholic liver injury Nonhepatic Cause Acute rhabdomyolysis 27
- 28. KEY CONCEPTS • Elevations in serum levels of ALT and AST are nonspecific indicators of hepatocellular damage except that AST/ALT ratio(de riti’s ratio)greater than 2 suggests alcoholic liver disease. • Elevation of serum level of ALP in liver injury is caused by regurgitation of alkaline phosphatase from damaged hepatocytes into the serum. • The rate-limiting step in hepatic bilirubin production is excretion of conjugated bilirubin into canalicular bile- explains why patients having hepatocellular dysfunction have a predominantly conjugated fraction in hyperbilirubinemia. 28
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- 37. TAKE HOME MESSAGE Proper interpretation of tests depends on • Comprehensive history and examination • Proper knowledge of the tests and their implications • Always look at the test as a whole, not just one part • When the test indicates new findings not anticipated in history, you can go back and re-evaluate the patient 37