Introduction part B How does clinical biochemistry help in patient health care?. Different categories of biochemical test. Sample’s tubes and types. Request form. (& types of biochem. Tests) 2. Sample obtained. ( & examples of errors) 3. Transit to Lab. 1. 4. Reception. 5. Analysis. 6. Quality control. 7. Collation and reporting. 8. Interpretation. Blood Specimens Plasma Blood collected into a tube containing anticoagulant. A sample undergoes centrifuging process, a supernatant is called PLASMA. Serum Blood collected into a plain tube and allowed to clot. After a sample undergoes centrifuging process, a supernatant is called SERUM. Whole blood Blood collected into a tube containing an anticoagulant with no further handling. • Normal appearance of plasma and serum is CLEAR PALE YELLOW COLOR. • Abnormal appearance may be due to disease or improper handling of the sample. - RED-colored : RBCs destruction. - DEEP YELLOW OR OGRANGE ( ICTERUS ) : presence of bilirubin. - MILKY OR TURBID : presence of fat. Wrong technique May lead to false results as false hemolysis or high potassium. Prolonged stasis in venipuncture This causes diffusing of plasma from blood vessels into interstitial space leading to false high results of plasma proteins such as calcium and thyroid hormones. Inaccurate timing Common in 24-h urine sample. Wrong container - Blood samples for lipid tests collected into tube with anticoagulant - Blood sample for a glucose is collected into a tube containing fluoride. - Obtain a new sample if the original one were put in a wrong container. Inappropriate sampling site - No sample should be taken from DOWNSTREAM an IV drip/ - - An arm in which 5% glucose is infused, must spared. Inappropriate storage Generally, a blood sample should not stored overnight to avoid leakage of RBCs components ( false high K. PH, LDH-ase ) A blood sample should be transferred IMMEDIATELY to lab to be processed properly. Other specimen may require specific precautions . Any new sample received by lab reception will get specific serial number and bar code. Many of biochemistry lab tests are done in automated manners. Biochemical measures vary for two reasons: A) Analytical variation. B) Biological variation. Quality monitored in two levels: Internal quality control. External quality control . Once the results are available they are collated and report is issued. The laboratory report should include : Patient information. Results of analysis. Normal values ( references ) Normal values “ reference “ represent the normal healthy state. A person not having any disease with abnormal lab result is a FALSE POSITIVE. A person has a disease but normal lab result is a FALSE NERGATIVE. Clinician should follow both absolute value and accumulative value. If test’s results is unexpected or can not be explained, a decision to repeat the test is made after discussion with the office. Sex e.g. serum creatinine Stress and anxiety. is higher in men Age e.g. ALK enzyme is higher in children Diet e.g. TG should measured after 14-h. Time e.g. certain hormones has a peak tendency. Exercise posture Medical condition. Pregnancy Menstrual cycle Drug history After interpretation of the results, the answer for a clinical question is reached. 1. Core biochemical test Na, K, Urea, creatinine, HCO3, Ca, Ph, Alb, Total protein, Bilirubin, ALK, ALT, AST, T4, T3, TSH, γGT, CK, blood gases, glucose, amylase. Specialized tests Vitamines, Drugs, Lipids, DNA analyses, Trace element, Hormons. 2. Emergency test Urea and electrolyte, Blood gases, glucose, amylase, Ca, paracetamole. 3.