hey guys so we're here in part two of labs we're going to talk about some more specialized specialty laboratory tests first we're going to talk about cardiac enzymes um cardiac enzymes or troponin levels are the preferred test to diagnose a heart attack or myocardial infarction because they are unique to heart muscle as opposed to other types of muscle so they're specific for heart muscle these enzymes are released as early as one to three hours after any heart muscle damage which occurs in um injury to the muscle in a heart attack um the enzymes peak at 12 to 24 hours and they slowly return to normal and will show negative levels in five to seven days so even after a heart attack the levels are going to come back to normal because they're specific to that injury process um these enzymes can even detect heart damage when an ekg is not showing an mi um because these are very sensitive and specific indicators to cardiac damage so when a patient contains it complains of chest pain they'll do serial sampling of this troponin because it's because of the way that it elevates and is released uh usually done upon admission or presentation and at 4 8 and 12 hours after chest pain to rule out an acute mi so it may not be initially elevated when they first present to the er or wherever but it may start to elevate so that's why they do those serial tests so they'll continue to test for those troponin levels there's no special preparation or fasting or anything needed for these cardiac enzymes should be noticed some cardiac enzymes not so much troponin but some of the other ones such as ck you can get a false elevation false positive in chronic muscular disorders kidney disease things like that so it's used as part of a big picture um along with the symptoms that the person is having to evaluate for uh mi and patients with chest pain okay so moving on to digoxin levels or gauge level so we sometimes need to draw labs to monitor actual drug levels to make sure they're in a therapeutic range there's a few different medications that would require this theophylline lithium vancomycin gensomyosin and digoxin are some examples of some medications that require lab monitoring so digoxin is a medication for cardiac dysrhythmias so we would only do this if the patient is taking digoxin so uh this there's a risk of toxicity with digoxin so that's why we need to evaluate it and monitor it the only preparation for this lab is to know when the patient took their last dose of the medication and to plan to draw the blood prior to the next scheduled dose so it could be facility you would be following the facilities policy but uh the norm is 30 minutes to an hour prior to the next dose being due you would draw this level um if the patient's level is too low their digoxin level is too low they may have abnormal rhythms so that they aren't getting enough of the medication to address those dysrhythmias or if the patient's level is too high they can experience symptoms of toxicity and they can get nausea vomiting anorexia and visual distortion green yellow visual distortion so here's an important note you always want to take the apical pulse before administering digoxin if the apical pulse is below 60 never administer you hold the medication in that case so always for digoxin requires an apical pulse being taken so p t ptt and inr these are coagulation studies and so these are studies about the clotting of the blood or the clotting ability or time that it takes so [Music] ptt partial thromboplastin time we use this to monitor the overall ability of the blood to clot normal range is 21.0 to 35.0 seconds a ptt is used when the patient is on heparin the medication heparin which is considered a direct anticoagulant the next one there is pt or prothrombin time so prothrombin is a protein produced by the liver for clotting of our blood and measures the function of the second stage clotting factors normal range is 11.0 to 13.0 and pt is monitored on patients who are receiving coumadin the medication coumadin or warfarin it's also called which is an uh considered an indirect anticoagulant an inr or international normalized ratio blood test was established for accuracy ensure the accuracy and compare pt readings across the board it's a calculation made to standardize prothrombin time so why would a person be on needing a coagulation study as you can imagine your bleeding time and ability to clot would be important information especially if you're preparing to have surgery we can also assess these levels to monitor therapeutic range for anticoagulation medications so if you're preparing for surgery we want to make sure that you're not going to bleed out on the table um so we want to check that out before surgery and also if someone is taking a medication that can affect the clotting of the blood um you would need that assessed such as if you're taking coumadin you need to check that out make sure you're in the right range if the patient has some sort of liver damage since some of these these proteins are produced in the liver their ability to clot may be affected so you might it might reveal some liver complications when a patient has a blood clot they usually initially receive heparin in the hospital and then they are switched to oral anticoagulants to go home on so they'll be getting iv heparin in the hospital if they have a blood clot somewhere to thin the blood basically and um when they're getting ready to go home there's typically a period of overlap because it takes coumadin a couple of days to be therapeutic so if a patient has a disorder that affects the blood coagulation these studies can be irregular it says do you ever want prolonged bleeding time so you can think about that a little bit is there a scenario where you would want the blood to be a little bit um thinner or not coagulate as much um you can think about that a little bit um prep for the test there's no prep needed for coumadin tests or excuse me coagulation studies they require no preparation or fasting just a list of current medications you should always hold manual pressure and monitor the patient a little longer after the stick after the venipuncture why because they're going to tend to bleed they're taking a blood thinner they're taking something that's affecting their blood's ability to clot they don't want the reason they're taking it is because you don't want that blood to be overly clotting probably because they have a risk for um some type of ischemic problem or risk of some sort of clot maybe they've had a blood clot maybe they're at risk for a stroke um a risk for some some kind of condition um where they could get a clot and have a pulmonary embolism or something like that so we want to watch bruising and after they get uh the venipuncture we want to hold pressure and watch them a little bit longer than maybe um somebody else that's not taking these medications because they tend to bleed a lot because they're taking a medication that lessens the blood's clotting abilities some diet teaching for patients on coumadin um they need to limit green leafy vegetables such as kale spinach brussels sprouts parsley collard greens because all of them are rich in vitamin k and vitamin k enhances clotting so vitamin k increases the blood's ability to clot so for someone that's already prone to quads that's taking coumadin to prevent that if they take taking a lot of these foods containing vitamin k it's going to counteract the coumadin basically and cause them to be more risk for clots so when you get these uh results we want to know what we need to do with them if the reason for them is if they need a higher or lower adjustment on their dose are the is their blood too thin we want it to be somewhat thin but you don't want it to be overly thin because you don't want them to bleed out but you also don't want it to be too much clotting and cause a risk for a blood clot so persons on anticoagulation therapy need education on the diet and then as well im injections avoid those avoid contact sports many providers caution them to use an electric razor instead of a standard razor so just some patient teaching there to be aware of okay a d dimer d dimer is a test it's called um it's basically a degradation prop degradation product of fibrin when a clot is degraded the products are released into the bloodstream and can be measured so an elevation of a d-dimer is an indication of some type of thrombosis meaning some type of clot formation a dvt which is a deep vein thrombosis a pulmonary embolism etc positive d dimer indicates um that both thrombin and plasma generation have occurred elevated d-dimer indicates a thrombosis somewhere and is often used as a tool to diagnose as with other labs you can have false positives so again it's a tool used along with other factors symptoms etc to help diagnose so a negative d dimer definitively rules out a thrombosis and therefore its main use is to rule it out a positive d-dimer can be elevated in other conditions such as malignancy pregnancy pulmonary embolism surgery mi dvt thromboembolic embolic event so it could indicate um a clot process it could indicate something else a negative rules it out a positive means it could be and we need to evaluate it along with other symptoms and the the big picture basically a lot of these labs you'll find um you're looking as part of a big picture it's a clue that helps us figure out what's going on with our patient okay bnp uh b type juridic peptide is a hormone produced by the ventricles of the heart and levels increase in response to ventricular volume expansion and pressure overload it's useful in diagnosing congestive heart failure ideally this is drawn fasting and after holding cardiac medications but it's often tested non-fasting in the emergency room and so forth normal range is less than 100 levels tend to increase as one gets older and are normally higher in women than men so it is useful in diagnosing and assessing severity of congestive heart failure so if the heart is overloaded with pressure or it's failing basically this increases this hormone increases it's produced by the ventricles of the heart so preparation for the test if in the er setting then we're not gonna have a chance for any preparation if the patient is scheduled for a bnp then they need to fast usually after midnight day before usually cardiovascular meds are held per the physician's order so when i see an accurate picture of what it looks like without um the medications assistance or effect normal range less than 100 post-test continue meds and diet per physician's orders okay test for autoimmunity and systemic rheumatic disease so these are some tests that's going to test for like some autoimmune disorders the antinuclear antibody test is most commonly performed for auto antibodies in patients suspected of having a systemic rheumatic disease these are also called connective tissue diseases or collagen diseases for example rheumatoid arthritis is probably one that you've heard of before lupus systemic lupus scleroderma these are some examples of these autoimmune disorders a systemic rheumatic disease pre-test no preparation except for explaining the purpose of the test of the patient post-test results will be addressed by the doctor and based upon the diagnosis will determine the care the patient needs a positive result does not confirm a disease however it gives reason for to further investigate into the patients along with the patient's clinical signs and symptoms results are either negative or positive so again taken as part of a big picture and compared taking this part with the information of the patient's symptoms and things that they're experiencing as well and so that is your anti-nuclear antibody test rheumatoid factor test rheumatoid factor is an antibody that is found in higher concentrations in patients with rheumatoid arthritis but it can be found in patients with other diseases as well such as lupus endocarditis tb syphilis cancer viral infections and diseases affecting the liver lung or kidney it's a diagnostic tool along with patient symptoms that can point the provider toward the diagnosis there are specific clinical criteria for diagnosing rheumatoid arthritis but the lab is used with the symptoms to support the diagnosis no specific interventions for pre-test or post-test c-reactive protein crp this is an abnormal protein that appears in the blood in response to an inflammatory process in the body it's not normally found in healthy patients increased levels are seen in inflammatory processes such as severe trauma bacterial infections inflammation surgery neoplastic proliferate which essentially is um for example a tumor some type of cells that are um dividing very quickly think of maybe a cancer process or a tumor process disease processes such as autoimmune disorders transplant rejections etc crp tends to increase before rises in antibody titers and esr levels occur which we will talk about esr in just a moment it's preferred that the patient is fasting for this and it's useful in monitoring disease activity and successful treatment so fasting preferred water may be taken positive results indicate inflammation but does not identify the cause so if we have a positive c-reactive protein that means we have an inflammatory process going on somewhere but it doesn't identify where it just says that there is an inflammatory process happening so this test can also be performed to monitor a patient's response to medications such as those for ra or lupus so if they're prescribed a medication for these conditions and they go back and have this lab done that can evaluate if the medication has been effective so that's your c reactive protein your esr or your erythrocyte sedimentation rate is the rate at risk at which erythrocytes settle after an intensive centrifugation for an hour normal erythrocytes settle slowly but in the presence of inflammatory or necrotic processes blood proteins become heavier and settle faster the faster the settling of cells the higher the esr or sedimentation rate it determines body inflammation though it cannot tell us the reason for it it tells us there's something going on somewhere that needs to be evaluated esr will decrease with resolution of the disease process there's no specific pre-test or test preparation esr is increased in conditions such as anemia rheumatic fever thyroid malfunctioning kidney disease arthritis and pregnancy um there are some diseases that have no increase such as ca c hf and sickle cell so moving on to some iron studies uh ferritin levels ferritin reflects the body irons bodies iron stores and is the most reliable indicator of total body iron status only better test is a bone marrow examination so it's more specific and more sensitive than iron concentration or tibc which is total iron binding capacity um more specific for diagnosis of iron deficiency ferritin levels decrease before anemia and other changes occur normal range is 18 to 270 for males 18 to 160 for females so if the person is having an iron deficiency it can lead to iron deficiency anemia where they're not getting enough oxygen to their cells um so this ferritin level will decrease before that happens and before that anemia process starts to happen you can detect this low iron this low ferritin level prior to that so no fasting necessary no radioactive medication three to four days before test no alcohol no special care after the test um folks that eat red meat and those with increased age may have increased levels vitamin b12 also called cobalamin is necessary for production of red blood cells so this is something that's necessary to make our red blood cells range is 280 to 1500 it requires overnight fasting nothing special for a post-test um b12 is mostly found in animal sources so strict vegetarians may need supplements for this vitamin um something to note here to absorb b12 vitamin b12 your body has to have in something called intrinsic factor an intrinsic factor is produced by the gi tract so if a person is not having a normally functioning gi tract if they've had some sort of gi tract surgery a lot of times will cause this there will be a reduction in intrinsic factor produced by the body and therefore the body can't absorb the vitamin b12 even if the person is in taking enough of it if their body isn't creating this intrinsic factor to absorb it it's not doing them any good um so any kind of gi tract surgery puts the person at a risk for a malabsorption syndrome or a malabsorption of this vitamin b12 so that can lead to something called pernicious anemia so deficiencies of vitamin b12 can cause decreased mental function leg aches numbness and tingling and things like that folate folic acid folate folic acid is needed for several reasons energy production formation of red blood cells immunity aiding in white blood cell functioning protein metas metabolism it's found in eggs milk leafy vegetables yeast liver fruits you'll see decreased levels in folks with inadequate dietary intake such as our folks with alcoholism chronic disease malnutrition anorexia small bowel disease certain anemias liver disease cancers crohn's or alternative colitis you'll see increased levels in pernicious anemia and b12 deficiency so um that is your folic acid and it needs to be done fasting to see the accuracy of the test and finally vitamin d deficiency shows us their vitamin d milk carton vitamin d is required for the absorption of calcium so vitamin d and calcium are best friends and they need to go together um for proper absorption calcium needs vitamin d to be absorbed properly um also it's necessary for phosphorus absorption it's necessary for normal development of bones and children it protects against muscle weakness regulates the heartbeat important in treatment of osteoporosis and hypocalcemia which is low calcium for accuracy it needs to be drawn fasting decreased levels are seen in patients on anti-convulsants anti-seizure medications poor diet inadequate exposure to sunlight which could also be the elderly liver disease and malabsorption syndromes so that concludes our part two lecture on some specialty labs that you might see drawn