Medical Laboratory Testing PDF

Department of Clinical and Chemical Pathology Medical Laboratory Testing  Medical Laboratory Testing  Around 70% of medical decisions are based on results of medical laboratory testing.  As a future physician, you will be using the medical laboratory services throughout your career...

Department of Clinical and Chemical Pathology Medical Laboratory Testing  Medical Laboratory Testing  Around 70% of medical decisions are based on results of medical laboratory testing.  As a future physician, you will be using the medical laboratory services throughout your career, that is why you need to understand how to use laboratory test ordering properly for better management of your patients and for cost effectiveness.  As a future physician, you must understand the importance and the effect of proper completion of request form as well as proper sample collection, handling and transportation on the accuracy of laboratory test results.  It is also very important to get used to communication with medical laboratory specialists for better patient care. Laboratory Testing Cycle (Laboratory Work Flow)  As a Future Physician You Must  Develop knowledge in the three phases of laboratory testing cycle (laboratory work flow cycle) including the pre-analytical, analytical and post-analytical phases.  Understand variables in each phase that may affect test results and interpretation.  Understand that most errors in laboratory test results are due to pre-analytical phase errors. Laboratory Testing Cycle  Most of you think that laboratory testing starts and ends in the lab after receiving the samples.  The truth is laboratory testing starts with the patient examination when appropriate tests are ordered and ends with improving patient outcome due to action taken based on the effectiveness of result reporting and interpretation.  The entire set of operations that occurs in laboratory testing is called the testing cycle or the work flow cycle. Laboratory Testing Cycle Laboratory Testing Cycle The Three Phases of Laboratory Testing  Pre-analytical Phase.  Analytical Phase.  Post-analytical Phase. Laboratory Testing Cycle The Three phases of Laboratory Testing Laboratory Testing Cycle  Most inaccurate results are due to errors in the pre-analytical phase. Laboratory Testing Cycle Percentage of Laboratory Errors Reported in Each Phase of Laboratory Testing Cycle Laboratory Testing Cycle  From the Patient to the Lab What Can ( and Does) Go Wrong ? Incorrect test ordering. Request form errors. Incorrect patient identification. Incorrect patient preparation: fasting, diet. Inaccurate sample timing. Sample poorly / incorrectly taken. Wrong type of sample. Incorrect containers. Under-filling or Over-filling. No labelling / Mislabelling of samples. Incorrect storage/ transport (temperature/delay). Loss, breakage and leakage. Laboratory Testing Cycle  Laboratory Tests Turnaround Time (TAT) Laboratory Tests Turnaround Time (TAT)  As a Future Physician you Must  Describe different methods for measuring turnaround time “TAT”.  Define laboratory tests turnaround time “TAT”.  Recognize the importance of assigning priorities to the requested laboratory tests by the requesting physician.  Differentiate between “STAT” and “Routine” testing.  Differentiate “TAT” from “STAT”  Recognize the importance of “TAT”. Laboratory Tests Turnaround Time (TAT)  Turnaround Time “TAT”  Turnaround time for laboratory tests is often considered the most significant measure of performance within a clinical laboratory.  There is a difference of defining the term “TAT” of a specific test among the clinicians and the laboratory personnel. Laboratory Tests Turnaround Time (TAT)  Turnaround Time “TAT”  For laboratory personnel, TAT includes the time from the receipt of sample in the laboratory to generation of report.  On the other hand clinicians consider TAT from the time of test requisition till the receipt of report. Laboratory Tests Turnaround Time (TAT)  Turnaround Time “TAT”  institutions should define TAT and what they are measuring Laboratory Tests Turnaround Time (TAT)  Turnaround Time “TAT”  Laboratory tests TAT differ between routine tests and tests ordered as STAT.  STAT laboratory tests are those that are needed immediately in order to manage medical emergencies.  STAT test requests are given the highest priority by the clinical laboratory for processing, analysis and reporting.  TAT for STAT tests is usually 30 minutes to 1 hour.  Do not confuse STAT with critical results.  The results of STAT could be within reference range. Laboratory Tests Turnaround Time (TAT)  Turnaround Time “TAT”  Why is Test turnaround Time (TAT) Important:  Laboratory support for patient –centered care.  TAT is a cornerstone in measuring laboratory performance.  It is the most important factor that leads to patient and physician satisfaction.  Delays in laboratory test TAT is a major source of complaints from laboratory service users.  TAT is a key performance indicator of laboratory services. Laboratory Tests Turnaround Time (TAT)  Laboratory Test Ordering Pre-analytical phase 1st step : Laboratory Test Ordering  As a Future Physician you Must  Develop knowledge and skills in the appropriate ordering of laboratory tests and their effective utilization for optimal patient care.  Recognizes the rationale of requesting a laboratory test only if it contributes to patient care: diagnosis, prognosis, treatment and/or disease screening – the right test at the right time.  Select the appropriate test for clinical evaluation desired.  Describes and explains how clinical information guides clinical pathologists activities and recognizes the need for adequate clinical information on a request form.  Completes a request form accurately. Pre-analytical phase 1st step : Laboratory Test Ordering   Why am I ordering the test?  How do I order it? Pre-analytical phase 1st step : Laboratory Test Ordering  Indications For Ordering Laboratory Tests  To confirm diagnosis.  To help in differential diagnosis.  To evaluate prognosis.  To monitor therapy.  To screen for a disease. Pre-analytical phase 1st step : Laboratory Test Ordering Proper Completion of Laboratory Request Form   The request form MUST contain:  Patient full name.  Age or date of birth.  Gender (male/female).  Medical record number.  Date of request.  Clinical diagnosis.  Ordered tests.  Physician signature. Pre-analytical phase 1st step : Laboratory Test Ordering  Incomplete Request Form Will not be Accepted Pre-analytical phase 1st step : Laboratory Test Ordering  Sample Collection Pre-analytical phase 2nd step : Sample Collection  As a Future Physician you Must  Provide quality and safe patient centered care by knowing and applying proper patient identification.  Recognize the importance of using correct timing of sample collection, transport and storage.  Recognize the proper procedure for sample collection.  Describe the use of sample tubes with various colored tops.  Recognize the correct sample container/tube for specific tests. Pre-analytical phase 2nd step : Sample Collection  As a Future Physician you Must  Recognize the importance and criteria of proper sample labeling and how incorrect labeling may contribute to diagnostic errors.  Recognize the importance of correct pairing of the sample identifiers with the accompanying requisition form.  State the criteria of appropriate sample handling and transportation.  Recognize criteria of sample rejection. Pre-analytical phase 2nd step : Sample Collection  Proper Patient Identification  The initial step in sample collection is patient identification.  Proper patient identification is an international patient safety goal.  The patient identifiers commonly used are the patient full name, age or date of birth (DOB) and medical record number.  At least 2 patient identifiers should be used.  Positive identification of the patient is essential, always ask the patient “what is your name?” not “is your name Mr.…?” Pre-analytical phase 2nd step : Sample Collection  Proper Sample Collection  General considerations : Patient instructions must be followed e.g. fasting in certain tests. Sampling timing must followed for certain tests e.g. cortisol. A free vein must be chosen (not from the cannula arm). A vein not from cancer breast side arm must be chosen. Infection control procedures must be followed. Short tourniquet time must be followed (< 1 minutes). The correct tube for the ordered test must be used. The tube must be labeled in presence of the patient. And by the person who took the sample. Pre-analytical phase 2nd step : Sample Collection Pre-analytical phase 2nd step : Sample Collection  Proper Sample Collection  Prepare, collect and label samples for one patient at a time. Pre-analytical phase 2nd step : Sample Collection  Proper Sample Collection  Put the blood sample in the tube suitable for the requested test Type of tube Top color Additive Mode of action Uses Blood culture bottle Broth mixture Preserves viability of microorganisms Microbiology Sodium citrate Sodium citrate Forms calcium salts to remove calcium Coagulation tests (PT, PTT) (light blue top) Requires full draw No additive Blood clots and the serum is separated Chemistries, immunology (red top) by centrifugation and serology Sodium heparin Sodium heparin or Inactivates thrombin and STAT chemistry ( green top) lithium heparin thromboplastin EDTA EDTA Forms calcium salts to remove calcium Hematology e.g. CBC (lavender top) Requires full draw Oxalate/fluoride Sodium fluoride Antiglycolytic agent preserves glucose Glucoses (light grey top) and potassium up to five days Requires full draw oxalate Pre-analytical phase 2nd step : Sample Collection  Color Coded Collection Tubes Pre-analytical phase 2nd step : Sample Collection  Proper Sample Collection  Fill tubes to the fill mark  Inappropriate filling leads to wrong results Pre-analytical phase 2nd step : Sample Collection  Proper Sample Collection  Gently invert the tube 5-8 times for proper mixing.  Do not shake the tube. Pre-analytical phase 2nd step : Sample Collection  Proper Sample Labeling  The sample tubes must be labeled by bar codes immediately after the sample has been taken, by the person that took the sample and in front of the patient.  If tubes are labeled manually, the sample label must contain a minimum of two points of identification : 1- Full name. 2- Age or date of birth (DOP) and/or medical record No. Pre-analytical phase 2nd step : Sample Collection  Finally you have the correctly collected and labeled sample from the correctly identified patient Now what?  Proper Sample Transportation  Put the samples in the biohazard transport box.  Transport the sample immediately to the laboratory along with the request.  Do Not carry the sample in your hand or in your pocket. Pre-analytical phase 3rd step : Sample Transportation  Laboratory Sample Delivery  The laboratory checks sample to ensure that the following have been met:  Tube is firmly covered.  Label information is complete.  Label information matches the request.  Sample volume is suitable.  Sample quality is suitable.  Sample type is suitable for tests requested. Laboratory Sample Delivery  Sample rejection Criteria Unlabeled or partially labeled samples. Label not matching requisition form. Insufficient volume. Unsuitable sample. Hemolyzed specimen. Wrong tube drawn. Inadequate volume for the amount of preservative. Prolonged transport. Will Not Be Received Must Be Recollected Sample Rejection Criteria  Laboratory Test Results Interpretation Post-analytical phase: Interpretation of Laboratory Results  As a Future Physician you Must  Recognize that laboratory results must be interpreted on a background of a reference value that is used to distinguish between health and disease.  Recognize the different types of reference values.  Recognize that reference intervals may vary according to age, sex, race, clinical state (e.g. pregnancy), or other factors.  Recognize the concept of variability in repeated measurements, as well as variability within and between individuals.  Explain how sources of variability relate to clinical interpretation of changes in test results.  Recognize how to establish diagnosis based on test results. Post-analytical phase: Interpretation of Laboratory Results  Reference Values Interpretation of laboratory results is based on reference values. Types of reference values:  Reference interval (range) e.g. creatinin test.  Decision cut off as positive and negative e.g. hepatitis markers test.  Therapeutic range e.g. INR or drug level test. Reference intervals may vary by age, sex, race, clinical state such as pregnancy or different methodology used. Post-analytical phase: Interpretation of Laboratory Results  Reference Intervals Why laboratory test results from healthy individuals might fall outside the reference ranges?  Reference intervals are most commonly defined as the range of values into which 95% of non diseased individuals will fall.  5% of non diseased individuals can have laboratory results outside the reference range.  It is possible to have laboratory results different from the reference range even though nothing is wrong. Post-analytical phase: Interpretation of Laboratory Results  Variability of Laboratory Test Results  Differences in laboratory test results between different laboratories using different methodologies should be expected when evaluating test results.  Biological, pre-analytical, analytical and post-analytical factors may contribute to variability in test results.  The clinician must evaluate the result from the knowledge of biological variation and be aware of the potential risk of false interpretation. Post-analytical phase: Interpretation of Laboratory Results  Variables Affecting Test Results Post-analytical phase: Interpretation of Laboratory Results  How to Establish Diagnosis Based on Laboratory Test Result?  Sometimes a laboratory test is performed to support a clinical decision or answer a clinical question, interpretation would be easy and straight.  For example performing prothrombin time/ INR test for monitoring of oral anticoagulant therapy, you will get the INR and you have the expected therapeutic ranges according to guidelines, so you will use results to adjust dose.  In other conditions interpreting laboratory result is not that simple, as when you use laboratory test to establish diagnosis. Post-analytical phase: Interpretation of Laboratory Results  How to Establish Diagnosis Based on Laboratory Test Result?  Pattern recognition: several laboratory tests (panels) that have been determined previously to provide excellent power in discriminating closely related conditions. Post-analytical phase: Interpretation of Laboratory Results  How to Establish Diagnosis Based on Laboratory Test Result?  Hypothesis deduction: establishing differential diagnosis based on clinical evaluation, then selecting the test most likely to exclude or confirm. Example: A four years old child with upper respiratory tract infection and generalized seizures, the differential diagnosis includes febrile convulsions or meningitis. CSF examination if normal will exclude meningitis. Post-analytical phase: Interpretation of Laboratory Results  How to Establish Diagnosis Based on Laboratory Test Result?  Medical algorithm (decision tree or logic sequential testing) Example: medical algorithm for anemia evaluation. Post-analytical phase : Interpretation of Laboratory Results Critical Results Critical Results  As a Future Physician you Must  Define critical values.  Recognize the clinical importance of critical values and why they should be reported directly to the health care provider for immediate action.  Identify critical values and give examples of test results that represent critical values.  Describe the proper procedure of reporting critical values.  State how to give and receive a result over the phone and act upon it appropriately. Critical Results  Critical Laboratory Values  Critical results are test results falling significantly outside the normal range and may represent life- threatening values.  Critical results require immediate communication of results to the responsible care giver.  Don’t wait for results of other tests requested for the patient to report the critical result.  Don’t wait for the requesting department to come and pick up the results.  A delay in taking action responding to the result may result in a serious adverse outcome for the patient. Critical Results  Critical Laboratory Values  Examples of critical results: Test Critical Value Unit Glucose < 50 or > 450 mg/dL Hemoglobin < 7 or > 20 g/dL Platelets < 40,000 or > 1,000,000 /dL INR >5 Critical Results  Critical Laboratory Values Read back of critical values:  I'm calling to inform you of a critical result for a laboratory test for patient ( full name/Medical record number.  To ensure patient safety and verification of the correct test result, we require that you write down and read back the laboratory test result you are about to receive. Critical Results Department of Clinical and Chemical Pathology  As a Future Physician you Must  Identify different parameters of CBC.  Identify normal adult ranges. Recognize classifications of anemia according to RBCs indices. Recognize laboratory evaluation and differential diagnosis of anemia. Complete Blood Count (CBC) /Anemia What is a Complete Blood Count (CBC)?  It is a routine hematology laboratory test that measures all the blood cells and can propose a provisional diagnosis on a variety of health conditions depending on the different cells involved.  Our blood is composed of a plasma compartment and a cellular compartment including the red blood cells (RBCs), white blood cells (WBCs) and platelets (PLTs). Complete Blood Count (CBC) /Anemia Parameters of CBC: Hemoglobin Hematocrit RBCs count RBCs Indices WBCs total count WBCs differential count Platelet count Complete Blood Count (CBC) /Anemia  Normal Adult Red Cell Values  Hemoglobin concentration: Men: 13-17 g/dl. Women: 12-15 g/dl. ( Reduced in anaemia, increased polycythemia).  PCV or Hct. : Men: 40-50% , Women: 36-46% (reduced in anaemia, increased in polycythemia)  RBCs Men : 4,500,000 - 5,500,000/dl (reduced in anaemia, increased RBCs is erythrocytosis).  RBCs Women: 3,800,000 - 4,800,000/dl.  MCV men and women : 83-100 fl.  MCH men and women: 27-32 pg.  MCHC men and women: 31.5- 34.5 g/dl.  RDW (CV): 11.6 %- 14.0 %. Complete Blood Count (CBC) /Anemia  Red Blood Cell Indices  MCV (mean cell volume): microcytosis and macrocytosis.  MCH (mean cell hemoglobin): hypochromia.  MCHC (mean cell hemoglobin concentration): Hypochromia.  RDW (red cell distribution width): anisocytosis (variation in cell volume).  These provide the basis for classifying anaemias and in various combinations have been useful in the distinction between iron deficiency and thalassemia. Complete Blood Count (CBC) /Anemia  Normal Adult WBCs Values  Total WBCs : minimum 4000 maximum 10,000- 11,000/dl (reduced count is leucopenia, increased count is leucocytosis).  Neutrophils: 2000 -7000 (40-80%).  Lymphocytes: 1000- 3000 (20- 40%).  Monocytes: 200-1000 (2-10%).  Eosinophils: 200-500 (1-6%).  Basophils: 20-100 ( 2000 mL/ day: polyurea as in diabetes millitus, diabetes incipidus, high protein in diet and increased water intake. < 500 mL / day: oliguria as in urinary obstruction by stones, heart failure. < 125 mL/ day: anurea as in urinary tract obstruction. Urinalysis  Physical Examination - odor  Normal odor :  Urineferous odor (faint aromatic odor).  Due to presence of volatile aromatic acids.  Abnormal odor: Fruity odor: Acetone in urine as in diabetes ketoacidosis. Ammonia odor: release of ammonia by bacterial action on urea as in bacterial infection or long standing sampls. Urinalysis  Physical Examination - Color  Normal color :  Pale yellow (amber yellow).  Due to presence of traces of urobilin or urobilinogen  Abnormal color : Colorless: chronic renal failure, diabetes insipidus. Pale yellow: diluted. Orange: concentrated or ingestion of carotenoids (vitamin A). Yellowish brown: billirubin in obstructive or hepatic jaundice. Red: hematuria as in infection, tumors, stones. Black: Malignant malaria, methemoglobine. Urinalysis  Physical Examination - Aspect  Normal aspect :  Clear, transparent.  Due to presence of traces of urobilin or urobilinogen  Abnormal aspect : Turbid: due to pus cells (pyurea). Turbid: due to crystals (crystalourea). Turbid: due to chyle (lymph and emulsified fat) [chylurea]. Turbid: due to protein. Smokey: due to hematuria (RBCs or hemoglobine). Urinalysis  Physical Examination - Specific gravity  Normal specific gravity :  1015 - 1025.  The density of urine compared to density of water.  Due to presence of dissolved solids e.g. urea, sugar, uric acid.  Abnormal specific gravity : Increased: due to acute nephritis, dehydration. Decreased: due to chronic nephritis, diabetes insipidus, high fluid intake. Urinalysis  Physical Examination - pH  Normal pH:  Acidic (5 - 6.5).  Due to conversion of basic phosphate to acidic phosphates in the distal convoluted tubules of the kidney.  Abnormal pH: Increased: potassium depletion in alkalosis, after meals, medication, long standing samples. Decreased: due to metabolic and respiratory acidosis, urinary tract infection with E coli. Urinalysis Chemical Examination of Urine Urinalysis  Chemical Examination of Urine  Dipstick test is often used to detect the chemical properties of urine.  Each small square represents a component of the test used to interpret urinalysis.  Colors generated are visually compared against a range of colors on brand-specific color charts  The entire strip is dipped in the urine sample and color changes in each square are noted.  The chemical strips change color if certain substances are present or if their levels are above typical levels. Urinalysis  Chemical Examination of Urine  The squares on the dipstick represent the following components in the urine:  Glucose: may indicate diabetes millitus.  Bilirubin: may indicate liver disease or RBCs break down.  Ketones: may indicate diabetes or starvation.  Specific gravity: may indicate dehydration  Blood: may indicate infection, stones or tumors.  pH: may indicate kidney or urinary tract infection.  Protein: may indicate kidney disease.  Urobilinogen: may indicate liver cell damage.  Nitrite: may indicate urinary tract infection.  Leucocyte estrase: may indicate urinary tract infection. Urinalysis Microscopic Examination of Urine Urinalysis  Microscopic Examination of Urine  Microscopic examination of urine is performed on 10 mL of a midstream, clean-catch specimen that has been centrifuged for 10 minutes at 2000 rpm or for 5 minutes at 3000 rpm.  The top part (supernatant) is discarded.  The sediment is re-suspended, placed on a glass slide, covered with glass slip and examined under high power magnification. Urinalysis Microscopic Examination of Urine 1 2 Centrifugation Discard supernatant 3 Examination of the sediment under the microscope Urinalysis  Microscopic Examination of Urine  A variety of normal and abnormal cellular elements may be seen in urine when looked at under a microscope, including:  Red blood cells  White blood cells  Epithelial cells  Crystals  Bacteria Urinalysis Microscopic Examination of Urine Urinalysis  Microscopic Examination of Urine  Microscopic Examination of normal urine:  RBCs: Negative or rare.  Pus cell : Negative or rare.  Crystals: Negative or rare.  Epithelial cells: Negative or rare.  Casts: Negative. Urinalysis  Microscopic Examination - RBCs  Hematuria is the presence of blood in urine.  There are 2 Types of hematuria:  Gross hematuria means that the blood can be seen by the naked eye. The urine may look pinkish, brownish, or bright red.  Microscopic hematuria means that the urine is clear, but blood cells can be seen under a microscope. Urinalysis Urinalysis  Microscopic Examination - RBCs  Microscopic hematuria is defined as > 5 red blood cells per high powered field (rbc/hpf) on a single specimen.  Due to: a. Glomerular damage. b. Tumors. c. Urinary tract stones. d. Upper and lower urinary tract infections. Urinalysis  Microscopic Examination - WBCs  Pyurea is defined as > 5 white blood cells per high powered field (rbc/hpf) on a single specimen.  Usually the WBCs are granulocytes.  Due to upper and lower urinary tract infection or with acute glomerulonephritis. Urinalysis  Microscopic Examination - Epithelial cells  Renal tubular epithelial cells, which contain large round or oval cells, normally slough into the urine in small numbers.  Few cells are usually in the normal range.  The number of sloughed renal tubular cells increase with nephrotic syndrome and conditions leading to tubular degeneration.  Columnar and transitional squamous cells are derived from kidneys, ureters or bladder due to infection.  Squamous epithelial cells are present in the urine as a contamination from the vagina or urethra. Urinalysis Microscopic Examination - Epithelial cells Squamous Cells Transitional Cell Renal Tubular Cells Pus cells Urinalysis  Microscopic Examination - Crystals  As oxalates, urates and phosphates. Urinalysis Microscopic Examination- Crystals Urinalysis  Microscopic Examination - Casts  Cylindrical structures formed basically from mucoprotein formed in the distal convoluted tubules and collecting ducts of the kidney and are present in urine in certain disease states.  Because they are loose structures, they dislodge and pass into the urine. Where they can be detected by microsopy.  Urinary casts may be made up of cells (such as white blood cells, red blood cells, kidney cells) or substances such as protein. Urinalysis  Microscopic Examination - Casts  Hyaline casts: they are composed primarily of a mucoprotein (Tamm-Horsfall proteins) secreted by tubule cells forming a hyaline cast in the collecting duct. Hyaline casts can be seen even in healthy people.  Red blood cells casts: RBCs may stick together and form red blood cell casts. Such casts are indicative of glomerulonephritis, with leakage of RBC's from glomeruli  White blood cells casts: they may also be present with glomerulonephritis. Their presence indicates inflammation of the kidney, because such casts will not form except in the kidney. Urinalysis  Microscopic Examination - Casts Hyaline Casts RBCs Cast Appear Transparent Urinalysis Microscopic Examination - Casts WBCs Cast Urinalysis Department of Clinical and Chemical Pathology  As a Future Physician you Must  Define point of care testing “POCT”.  Appraise its indications and limitations.  Identifies point of care tests.  Perform and interpret basic bedside laboratory tests e.g. urine dip stick, pregnancy and glucometer.  Recognise that values generated using POCT methods may differ from values generated in the clinical laboratory.  Recognize laboratory role in POCT. Point of Care Testing (POCT) Point of Care Testing (POCT) (Bedside Testing) Point of Care Testing (POCT)  What is Point of Care (POC) Tests? Diagnostic tests designed to be:  Available at or near the site where the patient is located.  Do not require permanent dedicated space.  Performed outside the physical facilities of clinical laboratories. CAP, 2009 | Point of Care Testing (POCT) 1/06/2024 127  What is Point of Care (POC) Tests?  At or near the patient side: | Point of Care Testing (POCT) 1/06/2024 128  What is Point of Care (POC) Tests?  Do not require permanent dedicated space: | Point of Care Testing (POCT) 1/06/2024 129  What is Point of Care (POC) Tests?  Performed outside the laboratory:  Home  Physician office  Emergency Room (ER)  Intensive Care Unit (ICU)  Operating Room (OR)  Admissions Unit  Wards  Outpatient Clinic | 1/06/2024 Point of Care Testing (POCT) 130 Types of Point of Care Tests (POCT) Point of Care Testing (POCT)  Advantages of Point of Care Testing (POCT)  Reduction of the administrative work associated with the test requesting  Minimization of delays associated with sample collection and sample requirements.  Reduction in the time delay resulting from the transport of the sample to the testing lab. | 1/06/2024 Point of Care Testing (POCT) 132  Advantages of Point of Care Testing (POCT)  Reduction in the time delay resulting from having to log in (register) the sample.  Reduce the turnaround time (TAT)  Reduction of the risk of a disconnection between the process of testing and clinical decision making. | 1/06/2024 Point of Care Testing (POCT) 133 Advantages of Point of Care Testing (POCT) | 1/06/2024 Point of Care Testing (POCT) 134 Advantages of Point of Care Testing (POCT) Point of Care Testing (POCT) Advantages of Point of Care Testing (POCT) Point of Care Testing (POCT) Disadvantages of Point of Care Testing (POCT) Point of Care Testing (POCT) Department of Clinical and Chemical Pathology  No laboratory test should ever be ordered unless it is medically necessary Laboratory Test Panels  As a Future Physician you Must  Enumerate common laboratory test panels  Mention tests included in every panel  Explain uses of each panel Laboratory Test Panels  Laboratory Test Panels  Test panels are groups of tests that are routinely ordered to determine a person’s general health status.  They help evaluate, for example, the body’s electrolyte balance and/or the status of several major body organs.  Some of the number and type of tests contained in specific panels, and the names of the panels, have been standardized internationally. Laboratory Test Panels  Laboratory Test Panels  Examples of common chemistry panels include:  Basic Metabolic Panel (BMP): usually contains 8 tests. It provides information about the current health of kidneys and respiratory system as well as electrolyte and acid/base balance and level of blood glucose.  Comprehensive Metabolic Panel (CMP): usually includes 14 tests. It provides the same information as the BMP with the addition of the health of liver and important blood proteins. Laboratory Test Panels  Laboratory Test Panels  Examples of common chemistry panels include:  Electrolyte Panel: helpful for detecting a problem with the body’s fluid and electrolyte balance.  Lipid Panel: used to assess a person’s risk of developing cardiovascular disease.  Hepatic Panel (Liver Function Tests): used to screen for, detect, evaluate and monitor acute and chronic liver inflammation (hepatitis), liver disease and/or damage.  Renal Panel (Kidney Function Tests): contains tests to evaluate kidney functions.  Thyroid Panel ( Thyroid Function Tests): to help evaluate thyroid gland function and to help diagnose thyroid disorders. Laboratory Test Panels  Laboratory Test Panels  Examples of common chemistry panels include:  Electrolytes Panel: helpful for detecting a problem with the body’s fluid and electrolyte balance.  Lipid Panel: used to assess a person’s risk of developing cardiovascular disease.  Hepatic Panel (Liver Function Tests): used to screen for, detect, evaluate and monitor acute and chronic liver inflammation (hepatitis), liver disease and/or damage.  Renal Panel (Kidney Function Tests): contains tests to evaluate kidney functions.  Thyroid Panel ( Thyroid Function Tests): to help evaluate thyroid gland function and to help diagnose thyroid disorders. Laboratory Test Panels  Electrolytes Panel  Electrolytes are minerals found in body tissues and blood in the form of dissolved salts.  As electrically charged particles, electrolytes help move nutrients into and wastes out of the body’s cells, maintain a healthy water balance, and help stabilize the body’s acid/base (pH) level.  The electrolyte panel measures the blood levels of the main electrolytes in the body:  Sodium  Potassium  Chloride  Bicarbonate  Lipid Panel A lipid panel includes the following measurements:  Total cholesterol: This measures overall cholesterol level.  Low-density lipoprotein (LDL) cholesterol: This type of cholesterol, known as “bad cholesterol,” can collect in blood vessels and increase risk of cardiovascular disease.  High-density lipoprotein (HDL) cholesterol: This type of “good cholesterol” helps reduce the buildup of LDL.  Triglycerides: Excess amounts of this type of fat are associated with cardiovascular disease and pancreatic inflammation. Laboratory Test Panels  Hepatic Panel (Liver Function Tests)  In most cases, a liver panel includes the following measurements:  Aspartate aminotransferase (AST)  Alanine aminotransferase (ALT)  Alkaline phosphatase (ALP)  Bilirubin  Albumin  Gamma-glutamyl transferase (GGT)  5’ nucleotidase (5’-NT)  Total protein:  Globulins:  Prothrombin time  Lactate dehydrogenase (LDH)  Renal Panel (Kidney Function Tests)  The common components tested in most renal panels:  Glucose.  BUN.  Creatinine.  Potassium.  Sodium.  Phosphorus.  Calcium.  Chloride.  Bicarbonate.  Albumin. Laboratory Test Panels  Renal Panel (Kidney Function Tests)  The purpose of a renal panel test is to find or rule out potential kidney impairment or disease. Depending on the circumstances, it may be used for diagnosis, screening, or monitoring.  Diagnosis is the identification of a health problem after signs or symptoms have started. A renal panel may be ordered if the doctor believes that symptoms could be related to an issue affecting the kidneys. Laboratory Test Panels  Renal Panel (Kidney Function Tests)  Screening is testing with the goal of early detection of a problem. Screening tests are done before any symptoms have occurred. For people who are at higher risk of developing kidney disease, a renal panel may be prescribed to try to reveal problems at an earlier stage.  Monitoring is how a patient’s situation can be tracked over time. Repeat testing with a renal panel can show if the condition of the kidneys is getting better or worse. This monitoring may be done after treatment for kidney disease. It can also be used to watch for changes to kidney function when taking medications that can cause kidney impairment. Laboratory Test Panels  Thyroid Panel  Three hormones are part of a standard thyroid panel:  TSH (thyroid-stimulating hormone)  Free T4 (thyroxine)  Free T3 or total T3 (tri-iodothyronine)  By measuring levels of thyroid hormones in the blood, the thyroid panel can help diagnose thyroid disorders and disrupted thyroid function.  A thyroid panel can also be used to monitor the treatment of hyperthyroidism and assess patients receiving levothyroxine therapy. Levothyroxine therapy replaces or supplements thyroid hormones that are reduced or absent due to hypothyroidism, thyroid cancer, thyroid nodules, and goiters. Laboratory Test Panels Department of Clinical and Chemical Pathology  Infection Control  Infection control refers to a range of practices and procedures designed to minimize the risk of infection spreading; especially in hospitals and health care facilities. Infection Control  Hospital-acquired Infection  A hospital-acquired infection is an infection that a patient acquires while in hospital; and was neither present nor incubating at the time of the patient’s admission to hospital. Infection Control Chain of Infection Infection Control Infection Control Chain of Infection Infection Control Standard Precautions Infection Control The most common way of spreading infection in a healthcare environment is via hands of healthcare staff Infection Control Standard Precautions: Hand Hygiene Infection Control Standard Precautions: Hand Hygiene Infection Control  Personal Protective Equipment “Specialized clothing or equipment worn by an employee for protection against infectious materials” (OSHA) “provides a physical barrier between micro- organisms and the wearer ” (WHO) Infection Control Department of Clinical and Chemical Pathology  Learning Objectives  Describe the adverse problem of antibiotic misuse.  Define the meaning of antibiotic stewardship.  Recognize the antibiotic stewardship team.  Illustrate the role of the physician. Laboratory Testing Cycle  Antimicrobial Stewardship  Is a rational, systematic approach to the use of antimicrobial agents in order to achieve optimal outcomes of the patient and the larger population.  Optimal outcome of the patient:  Achievement of cure.  Avoidance of toxicity and other adverse effects.  Optimal outcome of the larger population:  Avoidance of emergence of antimicrobial resistance. Antimicrobial Stewardship  Antimicrobial Stewardship Program  A program that encourages: organism patient Antibiotic Less Best clinical Optimum Resistance outcome Selection Minimal Optimum toxicity Dose Optimum Duration Antimicrobial Stewardship  The Goals of Antibiotic Stewardship  Optimize Patient Safety by:  Increasing infection cure rate.  Reducing treatment failures.  Preventing adverse effects.  Reducing antibiotic resistance.  Control cost (Saving hospitals money). Antimicrobial Stewardship  Misuse of Antibiotics  Treating viral infections with antibiotics.  Prescribing antibiotics for patient satisfaction.  Using wrong antibiotic dose and duration.  Using broad spectrum antibiotics. Antimicrobial Stewardship Misuse of Antibiotics Antimicrobial Stewardship  Misuse of Antibiotics  Emergence of multi-drug resistant bacteria:  Treatment failure.  Increase morbidity and mortality.  Increase length of hospital stay.  Need for more expensive broad spectrum antibiotics (vicious circle). Antimicrobial Stewardship  Misuse of Antibiotics  Super infection with Clostridium difficile:  Antibiotic exposure is the main risk factor.  Up to 85% of patients with Clostridium difficile infection had previous antibiotic exposure. Antimicrobial Stewardship Antimicrobial Stewardship  Role of the Physician  Obtain appropriate cultures before starting antibiotics in case of suspicion of infection and communicate.  Start empirical antibiotics according to stewardship program.  Stop antibiotics in patients with non infectious diagnosis.  Optimize the dose and duration of antibiotic therapy. Antimicrobial Stewardship  A Message to Take Home Conserve Antibiotics by Antimicrobial Stewardship Antimicrobial Stewardship