DOM 8250 Laboratory Exams-Part 1 2024 PDF

Laboratory Examinations (Tests) Part 1 DOM-8250 November 11, 2024 Rose Yin Geist, DDS, MS, FDS RCSEd Diplomate of The American Board of Oral Medicine  Biographic. Oral diagnostic process Demographic i...

Laboratory Examinations (Tests) Part 1 DOM-8250 November 11, 2024 Rose Yin Geist, DDS, MS, FDS RCSEd Diplomate of The American Board of Oral Medicine  Biographic. Oral diagnostic process Demographic information General appraisal Chief Complaint Initial history Physical examination CC Vital signs History of the Present illness HPI Nearly 90% of the diagnoses can be Extraoral exam established accurately by analyzing data dental history gathered from these two components medical history Intraoral exam Including Medication history Social history Diagnosis Supplementary exam Family history About 10% of the diagnoses Depending on the nature of the needs information gathered disease, examiner’s knowledge and experience, different diagnoses can be Review of systems from these two components established at different stage of examination Radiographic exams Medical or Specialized exam. Other Imaging exams Dental consultation Laboratory exams Biopsies  Laboratory Exams (Tests, test result reports) Laboratory examination is one of the specialized examinations and is the extension of the physical examination. It is also called laboratory tests and test reports. Blood, urine, tissue, and other specimens from the patient are used for biochemical, microbiol, histomorphological, histochemical ,immunological, or genetic exams to search further information for diagnosis.  Evolutional paradigm shift- use lab. tests judiciously and meaningfully to avoid misdiagnosis: New concepts and new technology Examples of how laboratory tests integrating with biopsy and imaging studies in diagnosis Examples of extension of traditional laboratory tests to include new tests or new calculation formula  Paradigm shift An important change that happens when the usual way of thinking about or doing something is replaced by a new and different way  Current diagnosis and classification of fibrosis and cirrhosis in chronic liver disease(CLD) Liver biopsy: e.g., Metavir fibrosis (F) scoring system-staging F0-F4 Blood tests: use biomarkers and special calculation formula – APRI: AST to platelet ratio index, – FIB 4:combination of patient age, platelet count, AST and ALT – Hepascore: bilirubin, gamma-glutamyltransferase, hyaluronic acid, alpha(2)- macroglobulin, age, and sex – Fibrotest (known as FibroSure in the USA): total bilirubin, gamma- glutamyltranspeptidase (gamma-GT), haptoglobin, alpha 2-macroglobulin, and apoliprotein A1. – FibroMeterVirus3G:prothrombin index, AST, ALT, Urea, GGT, alpha-2- macroglobulin and platelets. Imaging – MRI – Ultrasound based: FibroScan – Vibration controlled transient elastography (VCTE) » Measure liver stiffness correlated to fibrosis or cirrhosis – Controlled attenuation parameter (CAP) » To measure liver steatosis (alcoholic and nonalcoholic steatosis)  Metavir fibrosis (F) scoring system-staging F0-F4 Meta-analysis of Histological Data in Viral Hepatitis(Metavir) fibrosis (F) scoring system MRI Imaging of Liver Cirrhosis Ultrasound Image of Liver Cirrhosis FibroScan https://www.youtube.com/watch? v=YGTh1kMw4lc Meta-analysis of Histological Data in Viral Hepatitis (Metavir) score vs Fibroscan score Dentists do not order lab exams as often as they used to do Because: Dentists usually do not make diagnoses of systemic diseases. Costs, insurance policies. In majority cases they are non-applicable in dental practice The exception is oral tissue biopsy which is often ordered by dentists (biopsies are often separated from other lab exams).  Dentists do sometimes request the lab exam results- out of habit? Or for meaningful info? Questions: When are Lab. exam (test) results relevant to dental practice? Can you name a few lab. test results that are relevant to dental practice? And why?  Terminology changes resulting from new knowledge and technology “Liver function tests” and “Liver panel” are no longer used, they are replaced by “Comprehensive metabolic panel” “Bleed time (BT)” test is no longer performed and BT no longer has clinical significance The new test “whole blood clotting assay- Thromboelastography (TEG)”, is currently used for major surgery bleeding risk assessment, in the operating room. Lab. operational changes Dear Dr._______ Mr._________is taking Eliquis for Afib. He needs a dental implant. Bleeding is most likely a complication. Please provide CBC and differential (need platelet count and bleeding time) Thank you. Faculty______________ This is a meaningless consultation and full of mistakes. Eliquis is a coagulation factor Xa inhibitor Dear Dr._______ Mr._________is taking Eliquis for Afib. He needs a dental implant. Bleeding is most likely a complication. Please provide CBC and differential (need platelet count and bleeding time) Thank you. Faculty______________ Eliquis is a coagulation factor Xa inhibitor Based on your knowledge of blood coagulation learned in the DS1 biomedical sciences courses, can you explain why this consultation is meaningless?  Dentists do sometimes request the lab exam results- out of habit? Or for meaningful info? Which of the following is the correct reason for Lab. examination? A. INR for patient on warfarin------ risk for prolonged bleeding* B. A1C of DM patient ------risk for SSI (surgical site infection) C. Metabolic panel of CLD†patient------risk for prolonged bleeding* D. INR for patient on plavix-----risk for prolonged bleeding* *Prolonged bleeding-active bleeding 24 hrs. after the procedure †Chronic liver disease When are lab test results relevant to dental practice? To support comprehensive oral health diagnosis e.g., Frequent aphthous ulcers in CNP(cyclic neutropenia), HIV related ANUG, OLP and HCV, mineral and bone disorders of orofacial complex in chronic kidney disease and others. Relevant to the concerns about treatment complications or treatment outcomes e.g., Concerns of prolonged bleeding after dental surgical procedures, SSI, Anemia patients need IV sedation, dental patient under antimitotic chemo therapy, DM patients’ periodontal treatment outcome, and others. When are lab test results relevant to dental practice? continued Relevant to the concerns about coordination and facilitation of medical treatment e.g.,cancer therapy. Relevant to the concerns about third party payment (insurance) e.g., verify patient’s adherence to HIV treatment when providing dental care to individuals living with HIV Relevant to interpretation of medical consultation responses  What current test results fulfill the needs mentioned in the previous slide? Once we got the test results, how to interpret the result? And how to apply them to patient care?  What are the principles of lab. test results (values) interpretation? Must know the basic terminology Must know why the test is being done Must know what is being tested Must know what the test result mean Must know the variations of the test result Must know the applicability of the test result (e.g., wrong test, questionable validity, etc.)  Factors affect the lab value, so called variations Analytical variations (Method, Machine and Agents): – performance specifications – within-laboratory precision Sample variations: – inter-individual variations---significant differences from one person to the next, such as gender, race, age, geographic location, and others. e.g., Hb, GFR, neutrophil count. – Intra-individual variations---- Factors affect the lab value, so called variations-continued Sample variations: – intra-individual variations--- The degree of variation can be increased under certain conditions, such as food ingestion, time of day (circardian), exercise, acute illness, or other physical stress. Analytical variations Each lab. has its own reference range  Example of inter-individual variations: GFR GFR is a calculation based on serum creatinine and other factors Standardized creatinine values are traceable to isotope dilution mass spectrometry (IDMS). Example of inter-individual variations: creatinine and GFR GFR (glomerular filtration rate) is a calculated number based on serum Creatinine and other factors. GFR is used to assess kidney function in general. J Am Soc Nephrol. 2021 Dec 1;32(12):2994-3015. A Unifying Approach for GFR Estimation: Recommendations of the NKF-ASN Task Force on Reassessing the Inclusion of Race in Diagnosing Kidney Disease Factors affect the lab value, so called variations-continued Sample variations: – intra-individual variations--- The degree of variation can be increased under certain conditions, such as food ingestion, time of day (circardian, e.g., serum cortisol level), exercise, acute illness, or other physical stress. Example of intra-individual variation : Estimated Average Glucose and A1C Many factors influence the value of A1C Reference Intervals (range, limit) Reference range : defined by “healthy” population Reference limit: No range: one single number, e.g., Cholesterol (200mg/dl), fasting glucose (>126mg/dl), A1C; defined by health outcome ( based on a large number of clinical trial studies to define a health outcome)  Reference range Vs Normal range Reference limit Vs Normal limit Any lab. test result should be interpreted with context (background, conditions), e.g., specific physiologic condition, age and/or gender population. Number by itself can lead to misinterpretation Today, reference range or reference limit is used, not normal range or normal limit. WNL means We Never Looked. Hah Hah Reference range  Frequently requested lab Results and their application in dental treatment Complete Blood Count (CBC) with or without WBC differential (mainly RBC, WBC with differential, Hb, and platelet counts)- assessing validity of A1C, risk for post procedure prolonged bleeding Hemoglobin (often abbreviated as Hb or Hgb) Absolute neutrophil count (ANC)-evaluate the risk of SSI? the current evidence does not support this practice. International Normalized Ratio (INR) of prothrombin time (PT)- assessing therapeutic range of warfarin and evaluate risk of prolonged bleeding after surgery in patients who are taking warfarin UDM Corktown clinic provides chairside INR check in OS clinic.  Frequently requested lab Results and their application in dental treatment -continued Glycohemoglobin or glycated Hb, or HbA1c ( A1C)- assessing glycemic control of DM patients for the last 3 months.  Components of CBC Testing.com https://www.testing.com/wp-content/uploads/2021/07/CBC-sample-re port-with-notes_0.pdf  CBC with Differential Mean corpuscular volume Meancorpuscular Mean corpuscularhemoglobin hemoglobin Mean corpuscular hemoglobin concentration Red cell distribution width https://requestatest.com/includes/uploads/tests/CBC%20w%20diff.pdf  Comprehensive Metabolic Panel https://requestatest.com/includes/uploads/tests/Comprehensive%20Melabolic%2 0Panel.pdf  Components of CMP labcorp @2022 laboratory Corporation of America Holdings All Rights Reserved Enterprise Report Version 2.00 https://requestatest.com/includes/uploads/tests/comprehensive%20metabolic%20panel2.pdf  Red blood cells (RBC) RBC count – 4.2 - 5.9 million cells/mm3. Hct (hematocrit) % of RBC in the blood – 45 - 52% for men – 37 - 48% for women. Hb (hemoglobin) –relevant to patient’s A1C and oxygen saturation during IV sedation – 14 - 18 grams/dl for men – 12 - 16 grams/dl for women – Anemia- men Hb less than 13.5 gram/dl women Hb less than 12.0 gram/dl. Varies slightly between laboratories-analytical variations  Platelet count Reference range of 150,000 - 450,000/ mm3(150- 450K/uL) Platelet counts less than 150,000/mm3 (150K/uL) are termed thrombocytopenia. In mild thrombocytopenia, there may be no adverse effects in the clotting or bleeding pathways. Risk of prolonged bleeding is increased when platelet counts less than 50,000//mm3 (50K/uL) There is risk of spontaneous bleeding when platelet counts less than 20,000//mm3 (20K/uL) Varies slightly between laboratories  Clinical significance of thrombocytopenia Depends on the nature of thrombocytopenia the clinical significance varies and treatment also varies 1.Liver cirrhosis related thrombocytopenia 2.Idiopathic thrombocytopenia 3.Thrombotic thrombocytopenia 4.Vaccine-induced Thrombotic Thrombocytopenia, e.g., COVID-19 vaccine 5.Others  Thrombopoietin receptor agonits (TPO-RAs) Avatrombopag (Doptelet®) FDA approved at 6-27-2018 for chronic liver disease (CLD) patients who are scheduled for medical or dental surgery.  WBC count and differential : Total WBC count: 4.3×103 to 10.8×103 /mm3 4.3 -- 10.8 K/ mm3 or (4.3-10.8K/uL) Differential count: Neutrophils 55-70% Lymphocytes 20-40% Monocytes 2-8% Eosinophils 1-4% Basophils 0.5-1% ANC (absolute neutrophil count)—healthy, functional neutrophils: reported as # of cell/mm3 or # of cell/uL Reference range: 1.8-7.8 K cells/µL Neutropenia---ANC< 1500 cells/ mm3 Mild neutropenia (1000