10/11/17. Labs What does that really mean? Objectives. Presenters

Transcription

1 Labs What does that really mean? 23rd Annual AONP Conference, MidWest City, Oklahoma 10/18/17, 4:30pm Jennifer Jameson, MT (ASCP) & Rochelle Colby (MLS) CM Objectives 1. Introduction 2. Laboratorians 3. Specimen Collection 4. General Laboratory (Blood Bank, Chemistries, Coag, Blood Gas, Point of Care (POC)) 5. Urinalysis 6. Microbiology 7. Hematology 8. Pathology 1 Presenters Jennifer Jameson MT(ASCP) 25 years of clinical experience 23 years in Microbiology 20 years at Cancer Treatment Centers of America Rochelle Colby MLS (ASCP)CM 7 years of clinical experience 3 years as Lead Hematology Tech 6 years at Cancer Treatment Centers of America 2 1

2 Who are we? Laboratorians MT/MLS/CLS/MLT Bachelor degree (MT/MLS/CLS) or associates (MLT) Medical Technologist, Medical Laboratory Scientist, Clinical Laboratory Scientist Medical laboratory scientist degree (Bachelor) programs are set up in a few different ways. In 3+1 programs, the student attends classroom courses for three years and complete a clinical rotation their final year of study. In 2+2 programs, students have already completed their lower division coursework and return to complete their last two years of study in a CLS program. In 4+1 program, students who have already completed an undergraduate program return to complete a year of medical laboratory training. The training is typically completed at a clinical site rather than a college. The core curriculum in medical technology generally comprises 20 credits in clinical chemistry, 20 credits in hematology, and 20 credits in clinical microbiology. Clinical Rotation Student experiences hands-on learning in each discipline of the laboratory and performs diagnostic testing in a functioning laboratory under supervision. With limited or no compensation, a student in the clinical phase of training usually works 40 hours per week for 20 to 52 weeks. National registry certification exam Administratively independent of the ASCP, the Board of Certification (BOC) has certified more than 450,000 people since it was founded in 1928 and represents the gold standard for certification of pathologists assistants and laboratory professionals 3 How do labs affect your diagnosis and treatment decisions? It is estimated that 70% of all health care decisions affecting diagnosis or treatment involve a pathology investigation. Decisions on an individual s diagnosis, treatment and subsequent therapeutic monitoring are often dependent on a range of pathology-based results. Lab and Pathology Results affect: 1. Imaging/Radiation 2. Pharmacy 3. Surgery 4. Nutrition 5. Oncology 6. Clinical Care Source Clin Biochem Rev Aug; 34(2): : 4 Ordering Lab Tests Order lab tests relative to patients clinical symptoms use to Rule out/rule in Correlate lab results with the clinical impression Use Positive Predictive Value the probability that subjects with a positive screening test truly have the disease Probability of False Positives - look at the whole picture 5 2

3 Lab Mantra Results are ONLY as good as the specimens that we get 1. Patient identification-- two identifiers 2. Source on specimen--write it on there and be specific 3. Date, time and collector s initials -- part of good technique 4. Transports/tube types a. tests can be temperature dependent b. some tests cannot have light exposure c. others need to be in preservative within minutes 5. Examples of what happens with poor collections 6. Redraws happen sometimes-- we want to make sure

4 Specimen Collection Importance of: Order of draw Transport media Timing Orders 9 General Lab - Chemistry **Methodologies are important** a.not all labs/tests are interchangeable for result comparison. Mar General Lab - Blood Bank Patient ID #1 (blood bank bracelets, scanning ID system) Most specimens only good for 72 hours Make sure to answer questions (past transfusions, pregnancy, transplants) 11 4

5 General Lab - Blood Gases sensitive specimens 12 General Lab - Point of Care 13 General Lab - Coagulation 14 5

6 Urinalysis 3 parts to UA a.physical Examination (Color, Clarity, etc) b.biochemical Examination (Blood, Leukocytes, Glucose, Protein etc.) c.microscopic examination (WBC, RBC, Bacteria, etc.) Urinalysis Collections Clean catch, cath, neph., suprapubic tap Contamination/obstructive analysis not properly collected/clean catch, sitting prior to analysis, drugs (pyridium) Differences between Macroscopic (dipstick) & Microscopic findings 17 6

7 Microbiology Step by Step overview MICs and more Blood Cultures Bacterial vs Viral Antibiotic Stewardship New tests/methodologies 18 Microbiology 19 Microbiology Setup 20 7

8 Microbiology Setup Incubate for 24 hours.. and you get.. 21 Microbiology Setup 22 Microbiology Setup 23 8

9 24 Microbiology Susceptibilities MIC = Minimal Inhibitory Concentration The lowest antimicrobial concentration that completely inhibits visible bacterial growth (this means the next well could have some tiny bit of growth). Given in units of mcg/ml. The amount of active drug in micrograms per amount of broth in milliliters (how the wand, bottle and panel all work together). This number is useful when the interpretation is Intermediate. If Susceptible, the drug can be used. If Resistant, it shouldn t be used. But Intermediate means if you can get the drug in a high enough concentration into the patient s system, you may be able to use the drug. But it isn t always safe to do this so consult with an ID expert or a Pharm D first (there s a whole other level of PK/PD and how drug diffuses throughout the body and a whole other lecture needed for that) Watching the MIC levels over time help us monitor resistance 25 Microbiology Susceptibilities MIC cont d Why do the MIC numbers vary? Depends on the bug AND the drug!! Example: A MIC of 8 for vancomycin versus Enterococcus is Intermediate. A MIC of <=32 for nitrofurantoin (Furadantin) versus Enterococcus is Susceptible. The MIC breakpoints (i.e. cut off values for S-I-R) are different for all the different classes of antibiotic. They are not comparable or interchangeable. Vancomycin is a glycopeptide and nitrofurantoin is in the class Nitrofurans. Example: To detect significant resistance to cefepime in Streptococcus pneumoniae, the dilution scheme uses a max concentration of 4 mcg/ml; however, to detect cefepime resistance in E coli, the required max concentration is 16 mcg/ml. Concentration of a drug level to detect resistance is different in each organism. 26 9

10 Microbiology Susceptibilities Kirby Bauer and Etest methods 27 Microbiology Blood Cultures Typically held 5 days total before final Contamination rates ideally should be at or below 3% (per CLSI guidelines) A contaminated culture costs both the hospital and the patient: with longer in-house stays greater antibiotic use increased diagnostic testing Should be calculated monthly to monitor the rate and to help educate those that draw them If you have a positive culture at 36 hours old, one bottle of 4, and gram stain shows Gram Positive Cocci. true positive? contaminant? Clinical symptoms and port vs peripheral draw tricky!!! CTCA s number one pathogen. coagulase negative Staphylococcus (we have a lot of VAD s and that means biofilm and that means colonization can turn to pathogen with immunosuppression) And don t forget fungus!! Yeast likes to live in plastic lines!! 28 Microbiology Bacterial vs Viral Flu season is coming up!! New guidelines coming out (compliance by Jan 2018) Culturing for viruses is almost obsolete. Best method is molecular (viruses are all DNA or RNA so easy to replicate them We ve seen viral throat infection that mimicked strep--beware!! 29 10

11 Microbiology Antibiotic Stewardship Here s some scary statistics about microbiology and antibiotic usage: An estimated 50% of antibiotic use in humans is unnecessary and inappropriate. Antibiotic-resistant bacteria cause over 2 million illnesses and 23,000 deaths annually in the US (as of 8/14/17). Antimicrobial resistance is an increasingly serious threat to health at the patient, community and global level. Prescribing of second-and third-choice drugs due to resistance of first-choice drugs resulting in less effective, more toxic and more expensive drugs being used. At current rates of antimicrobial resistance, we estimate that 2.5 million people will be lost to drug-resistant superbugs in 2020; 5.9 million will be lost in 2030; 15 million will be lost in The rate of resistance is increasing faster than new antimicrobials are being discovered (Methicillin introduced in 1960, resistance detected in 1962; Levofloxacin introduced in 1996, resistance detected in 1996). Source: and 30 Microbiology Antibiotic Stewardship This topic was important enough to be mentioned in the 2014 Presidential State of the Union address. By March of 2015, a National Action Plan, that charged key federal departments and agencies, was created to combat the rise of antibiotic-resistant bacteria. Most hospitals, by now, have implemented an Antibiotic Stewardship Program (ASP). This is usually led by Pharmacy and includes clinicians, Quality, Infection Prevention and Laboratory departments. What can you do to help? Get involved with your ASP and get educated (and educate your patients, too) Check culture results to make sure bug-drug combo is working D/C drugs that aren t needed Ask to see your lab s antibiogram (a chart that summarizes the percent of pathogens susceptible to different antibiotics; done retrospectively) 31 Microbiology Newer Methodologies 1. Stool lactoferrin -- replaces stool for polys 2. Cryptococcal Antigen -- replaces India Ink test 3. EIA/ELISA methods-- for common parasites 4. Chromogenic agar -- selective for certain organisms and will turn color when that organism grows 5. PCR/molecular -- best way to detect viruses, toxins, harder to grow organisms a. C difficile (need to be doing a 2-step algorithm--best practice) b. Respiratory pathogens c. Stool pathogens d. CSF pathogens 6. MALDI TOF -- Matrix-Assisted Laser Desorption/Ionization Time Of Flight-- basically a mass spectrometer with pulsing lasers and ion mirrors and electric fields that give you an organism identification (no susceptibility yet) in about 10 minutes!! The more that are put into use, the larger the database grows and the more reliable it becomes. In use around the country especially being placed into Health Depts 7. Check sensitivity and specificity before implementing a new system-- may not be the best choice for what your facility needs 32 11

12 Hematology 33 Hematology Top vs. Bottom instrument vs. manual diff - indications for manual Flow Cytometry - technology that is used to analyze the physical and chemical characteristics of particles in a fluid as it passes through at least one laser. Cell components are fluorescently labelled and then excited by the laser to emit light at varying wavelengths Top (Hemogram) Bottom (Differential) Suspect Flags (Manual Differential) Flow Cytometry - Differential Scattergram 35 12

13 36 Suspect flags from flow cytometry = manual differential review/differential 37 Possible Peripheral smear from previous scattergram Figure 1. Chronic phase of chronic myelogenous leukemia. The peripheral blood smear is characterized by an elevated white blood cell count showing a left shift in granulocyte maturation, with increased myelocytes. Eosinophilia and basophilia are characteristic (Wright- Giemsa stain, X 100) Source:

14 Hematology Left shift particular population is shifted towards more immature precursors (ie bands, metamyelocytes, myelocytes etc). Right Shift - Neutrophil count will be higher than normal range (predominant cell w/higher than normal absolute value) without the presence of immature cells (bands, metas, myelos) Source: 39 Hematology Toxic Changes: Matters for distinction of infection especially in leukopenic patients. 1. Will be noted on the manual differential 2. Dohle Bodies 3. Toxic Granulation 4. Vacuoles 40 Pathology Specimens in Pathology flow overview 1. Specimens received in the pathology lab 2. Specimen Macroscopically Examined "grossing" is the process by which pathology specimens are inspected with the bare eye to obtain diagnostic information, while being processed for further microscopic examination. Gather diagnostically critical information in this stage of processing, including the stage and margin status of surgically removed tumors 3. Specimen is then sectioned and processed (overnight process) 4. Once processed it is then thinly cut and placed on slide for microscopic evaluation 5. May need special stains identify organisms/diagnosis (add 1-2 days) 6. May be sent out for additional testing (add 1-2 days) 7. If Cancer and needs molecular testing it is sent out (add 1-2 weeks) **Note: Benign FNA or Biopsy does not rule out Cancer Examples of why: May have missed the spot when performing procedure, QNS sample for adequate processing, overwhelmed with inflammation so unable to accurately diagnose. Use Positive Predictive Value and clinical picture to decide if to re-biopsy 41 14

15 Questions? 42 15