Fundamentals of Nursing Laboratory Values PDF

Fundamentals of Nursing Laboratory Values Lecture Transcript Introduction: Hi Fundamentals students! Welcome to your lecture on Laboratory Values. I am Professor Richardson, and I am excited to be with you all today. I know it may seem a bit overwhelming to have to memorize lab...

Fundamentals of Nursing Laboratory Values Lecture Transcript Introduction: Hi Fundamentals students! Welcome to your lecture on Laboratory Values. I am Professor Richardson, and I am excited to be with you all today. I know it may seem a bit overwhelming to have to memorize lab values and know what it means if they are high or low, but hopefully, after this lecture, it will put your mind at ease. I will try to give you some easy ways to help you remember the lab values that my professors taught me when I was in nursing school. This is just part 1 of this lecture material, please refer to your Fundamentals calendar for the date and time for part 2. Part 2 will be a LIVE class activity with question and answer time to help you apply and really begin to understand the importance of learning lab values. So, what are we waiting for? Let dive right in! Slide 1: Laboratory Values Slide 2: One thing to remember, is this is an online presentation. This online presentation is for personal use only, so no sharing with classmates or future classmates. Transcripts of the presentation and/or the presentation itself is not to be posted in any format. Failure to follow these rules will be considered academic dishonesty and will be subject to the same consequences, including possible dismissal from the program. Slide 3: Your learning objectives for this lecture is to identify normal lab values and describe the function of the components of a Complete Blood Count (CBC) and Comprehensive Metabolic Panel (CMP). I would like you to also be able to describe common conditions that can alter a CBC and certain labs from a CMP, as well as being able to apply knowledge of the lab values, including abnormal results, and prioritization when choosing safe, patient centered, and collaborative interventions. Slide 4: The main concept we are going to cover today is homeostasis and regulation. Homeostasis is the body’s ability to maintain a stable equilibrium state through acid/base, fluid, and electrolyte balance. Living organisms need to maintain homeostasis constantly in order to properly grow, work, and survive. Overall, homeostasis is essential for normal cell function, and overall balance. So today, we are going to specifically talk about homeostasis through fluid and electrolytes. You will learn more about acid/base in a few mini-mesters when you are in Med/surg 1 class. Slide 5: Why do we need to know lab values? Almost every patient that walks through the doors of a hospital, whether it is a direct admission or through the emergency department, will most likely have labs drawn. Lab values measure several variables in a patient’s body and abnormal values can be a result of a patient’s illness and/or could be an indication of a complication. Lab value changes can also show that a patient’s condition is improving or worsening. Something to remember is that “normal” values can vary from hospital to hospital or institution to institution. For example, a normal Sodium level at UF health may be 135-145, where the normal value at North Florida is 136-146. The values that I have in this lecture are from your Mosby’s Diagnostic and Laboratory Test Reference, so for this course, study those lab values. Finally, lab values will most likely be on your NCLEX exam. The NCLEX wants to make sure you have competent knowledge in this area before you start working as a licensed nurse. On the NCLEX exam, you will be given lab values that are noticeably abnormal. For example, a normal Magnesium level is 1.3-2.1 mg/dL. On the NCLEX, it is highly unlikely they will ask you to choose an abnormal lab result of a Magnesium level that is 1.2mg/dL or 2.3 mg/dL because these results are way too close to normal. They will give you something you will notice like 3 mg/dL. Slide 6: The first lab we will discuss is a Complete Blood Count, which you will also hear referred to as a CBC. A CBC assesses and counts the number of cells in the blood and also helps us to diagnose, monitor and screen for a wide range of diseases, conditions disorders, and infections. A CBC includes red blood cells, white blood cells, hemoglobin, hematocrit, and platelets. Now let’s talk about each feature: Slide 7: Red Blood Cells, or RBC’s normal value for a male is between 4.7-6.1 and for a female, 4.2-5.4. You may notice that for certain labs, there is a different number for male and female, so just make sure you keep that in mind. Red blood cells are round with a flattish, indented center, like doughnuts without a hole. Red Blood Cells carry oxygen to the tissues of your body, and RBCs are made inside your bones (in the bone marrow). If your body produces too many RBCs, it is called Polycythemia. Having Polycythemia can put one at risk for blood clots in the vessels or organs. If you have too many RBCs, they may clump together in the vessel and put a patient at risk for blood clots. The main cause of Polycythemia includes dehydration, chronic low oxygen levels, high altitude (such as living in the mountains), or significant heart or lung disease. If you have too few RBCs, it is called Anemia. There are many different types of anemia, that you will learn throughout this program. Anemia is where there is less oxygen getting to the tissues and organs since the RBC’s carry the oxygen. The main cause of Anemia includes excessive bleeding, iron deficiency, and chronic kidney disease. The body is automatically going to respond to increase making red blood cells to try and get those oxygen levels up and to those cells. However, your body can then make too many RBCs in response, and that is what causes the blood clots or Polycythemia. Slide 8: The two biggest measurements that go along with red blood cells is hemoglobin and hematocrit. The normal value for hemoglobin in a male is 14-18g/dL and for a female is 12- 16mg/dL. The way I remember this, is that females usually mature sooner than males, so a female mature around 12-16 years old, and a male matures around 14-18 years old. Hemoglobin is the oxygen-carrying protein in red blood cells. Hematocrit (or you may hear called “crit”), is the percentage, by volume, of how much of your blood contains red blood cells. The normal value for a male is 42-52% and for a female is 37-47%. A hematocrit test (which is part of a CBC) is needed to check for the proportion of red blood cells. A low red blood cell count, or low hematocrit, indicates anemia. Suspected anemia is the most common reason for hematocrit testing. Slide 9: Another factor in a CBC is the White Blood Cells or WBCs. The normal value of white blood cells is 5,000-10,000/mm3. White blood cells are part of the immune system that help your body to fight off viruses, bacteria, and other foreign invaders. When you get sick, your WBCs rush in to help destroy the harmful substance and prevent illness. White blood cells are also made in the bone marrow. If one’s WBCs are too high, it could be indicative of an infection, stress, or leukemia, because your body is responding, and the white blood cells are rushing to that area to “fix” the problem. You will learn more about Leukemia in Pediatrics and/or Med surg courses. White blood cells also may be decreased if one has drug toxicity, an overwhelming infection such as HIV. If an infection has been going on and on, your white blood cells may deplete, or if you have a bone marrow disorder, such as Lymphoma. Your body cannot effectively make WBCs if the bone marrow, as it is packed with cancer. Slide 10: There are actually five different types of white blood cells, Neutrophils are the first to respond to a virus or bacteria, Basophils are known for their role in asthma, Eosinophils are known for their role in allergies, Lymphocytes fight infections by producing antibodies, and Monocytes clean up all the dead cells. The Neutrophils are our main type of white blood cell that you may see, as its function is to fight bacteria. So, if you have step throat, the bacteria involved is streptococcus, the neutrophils are going to rush into your throat, which is why, if you had labs drawn, you would see a higher number of white blood cells. The normal number of Neutrophils is 45-75% of your total white blood cells, the Neutrophils do most of the work at fighting off bacterial infections. When the Neutrophils reach 80%, we get concerned, because that tells us that there is an overwhelming infection going on. Because these Neutrophils are coming into play, we will see a left shift of the white blood cells (A “left shift” is a phrase used to note that there are young/immature white blood cells present. Most commonly, this means that there is an infection or inflammation present, and the bone marrow is producing more WBCs and releasing them into the blood before they are fully mature. This is a natural immune response to infection and inflammation); therefore, the white blood cells will increase as a reaction to the Neutrophils increasing, due to an infection. Slide 11: The final attribute of a CBC is platelets (or Thrombocytes). The normal value for platelets is 150,000-400,000/mm3. A blood clot forms when the platelets get activated when the blood vessels are damaged. Platelets control bleeding in our bodies, so they can be essential to surviving surgeries such as organ transplant, as well as fighting cancer, chronic diseases, and traumatic injuries. Donor platelets are given to patients who don’t have enough of their own, a condition known as thrombocytopenia, or when a person’s platelets aren’t working correctly. Raising the patient’s blood platelet count reduces the risk of dangerous or even fatal bleeding. Platelets are made in our bone marrow, which is the sponge-like tissue inside our bones. Bone marrow contains stem cells that develop into red blood cells, white blood cells, and platelets. When a blood vessel is “broken, the platelets are activated and become “sticky” to “seal” the cut or area needing clotting. If a patient has an increased number or platelets, it is called Thrombocytosis. The main cause is from cancer or malignancy, polycythemia (which is too many red blood cells) or anemia. Having too little of platelets is called Thrombocytopenia, these patients are more vulnerable to bleeding. The main causes of thrombocytopenia can be caused from leukemia, chemotherapy, inflammatory conditions, and/or sepsis. Slide 12: This picture shows that when a blood vessel is damaged, the platelets are activated to become “sticky”, and therefore, “clot” off the vessel. A patient who is bleeding has many platelets becoming activated, therefore, showing a lesser amount of platelets on a CBC. Slide 13: That concludes our talk about what is involved in a complete blood count (CBC), so now, lets talk about a chemistry panel, or basic metabolic panel (BMP) and comprehensive metabolic panel (CMP). The main lab values that we are going to focus on for a BMP, and that you need to know for your NCLEX are starred. They include Chloride, Sodium, Potassium, Calcium, Magnesium, Blood Urea Nitrogen (BUN), Creatinine, Glucose and Carbon Dioxide. A CMP or a Comprehensive Metabolic Panel includes all the same lab tests as a BMP, but they do add a few. Included in a CMP are albumin, total protein and bilirubin, (which you do not have to memorize), and also, Alanine amino transferace (ALT) or Aspartate amino transferace (AST). ALT and AST are also part of the Liver Function Tests and you want to know these for this lecture and before reviewing for the NCLEX. I will also point out the major lab values and the importance about each one. Slide 14: The first electrolyte we are going to talk about is Sodium. Sodium is one of those major electrolytes that you need to know. The normal values for sodium are 136-145 mEq/L. Sodium helps to keep the body fluids in normal balance, so if we do not have enough or if we have too much sodium in our body, we can get out of homeostasis. Sodium also plays a key role in normal nerve and muscle function by transmitting nerve impulses. If someone has a rise in serum sodium concentration (greater than 145 mEq/L), that is called hypernatremia, which is indicative of dehydration. Hypernatremia is considered a “water problem”, not a problem with sodium homeostasis. Some conditions that can cause high levels of concentrated sodium include not drinking enough water, diarrhea (because you are getting rid of water in your body and therefore, causing a concentration of sodium), and also kidney dysfunction, which you will learn more about in your med/surg courses. The opposite of hypernatremia is hyponatremia, which is when your sodium level is below 136 mEq/L. Hyponatremia is when there is an increase of water in the body and causes the sodium to become diluted. The main causes of this are certain medications, like diuretics (if a patient is on diuretics, it is because they have an excess amount of water in their body, you will also learn more about diuretics in Pharmacology next mini- mester), excessive water intake, or if a patient has a heart and/or liver dysfunction (which can cause a chronic problem of low sodium). Sodium is also “best friends” with Chloride, they tend to usually move together, so when you put them together, they become “Sodium-Chloride” which is actually salt. Slide 15: Speaking of Chloride, this is another electrolyte collected in a BMP or CMP. Chloride is influenced by the extracellular fluid balance and acid-base balance. The normal value for Chloride is 98-106 mEq/L. I mentioned that Chloride and Sodium are besties, so usually, chloride levels will increase and decrease as sodium increases and decreases. If you look at the little cartoon on your screen, it really depicts the relationship between the two. High levels of chloride can mean that your kidneys are not filtering enough acid from your body. Abnormal levels rarely occur alone and are usually part of sodium or bicarbonate shifts. Slide 16: The next electrolyte is Potassium. Potassium is a big one and a very important lab to remember. The normal values for Potassium are 3.5-5 mEq/L. The way I remember this one, is potassium comes from bananas, and most bananas come in about 3-5 per bunch, and I love to buy my bananas ½ off, so 3.5-5 is important to remember as it does have a narrow range. Even the slightest increase or decrease can cause big problems for a patient. Potassium is crucial to the function of the heart and for skeletal and smooth muscles to contract. If we do not have enough or too much potassium, our hearts are not going to function properly. An increased level of potassium is called Hyperkalemia, increased levels could be caused from kidney dysfunction, meaning your kidneys are not working correctly and they are not going to be able to get rid of the potassium in a normal fashion, which can cause the potassium to build up. Another reason a person can have hyperkalemia is if they have hemolysis, or red blood cell destruction. When a red blood cell is destroyed, they can release too much potassium into our blood stream, and lastly, hyperkalemia can be caused from dehydration. If our patient is dehydrated, the potassium will become concentrated in the body, and therefore, cause an increase in the number. Hyperkalemia can cause nervous transmission defects and muscle contraction defects that can affect the heart and will show up on an EKG. Hypokalemia is when there is not enough potassium, so a value less than 3.5 mEq/L. Hypokalemia can also be caused from kidney dysfunction, as the kidneys are not filtering the potassium correctly. It can also be caused from any type of GI losses, such as an NG tube, if a patient has suction to the NG tube, it can be pulling out potassium, if a patient has extreme vomiting or diarrhea, that may cause the patient to excrete too much potassium, as well as being on diuretics. If potassium is too high or too low, it can cause cardiac issues, so when you think of potassium, think about the heart. The potential for life threatening cardiac arrhythmias makes altered potassium values very concerning. You will also learn much more about EKG’s and what affects the heart in your med/surg courses. Slide 17: Now let’s talk about Calcium. Calcium is another major electrolyte that you need to be sure to know. The normal value for Calcium is 9-10.5 mg/dL. Calcium is also important for heart function, muscle contraction, nerve signaling, blood clotting, and bone metabolism. Only about 0.5% of the body’s total calcium is found outside of the bones. If a patient has an increased number of calcium, it is called Hypercalcemia. This can be caused from a patient who has metastatic tumors, bone disease, or prolonged immobilization. If a patient has an increase in calcium, it can cause the patient to have a seizure, irritability or anxiety, heart failure, muscle cramps or a bronchospasm. If a patient has a decreased amount of calcium, it is called hypocalcemia. Hypocalcemia can be caused if the patient has a parathyroid dysfunction, a renal dysfunction, or a Vitamin D deficiency. Patients who have low levels of calcium, can have confusion, heart arrhythmias, bradycardia (low heart rate), muscle weakness or even cause coma and death. You do not need to memorize all the issues hyper, and hypocalcemia can cause, just know that it can affect the central nervous system and cardiovascular system because of the muscle contraction. Slide 18: Next is Magnesium. The normal value for magnesium is 1.3-2.1 mEq/L. Magnesium is a critical electrolyte in nearly all metabolic processes of the body and most organ functions, including cardiac and neuromuscular depend on magnesium. A patient with low levels of magnesium can have an increase in cardiac irritability and aggravate cardiac arrhythmias. So, if a patient is admitted and has low levels of magnesium, they will most likely be on continuous cardiac monitoring. Increased levels of magnesium are called hypermagnesemia, and the main causes are if a patient has Hepatitis or Addison’s disease (again, you will learn about these later on in Med/surg). A decreased amount of magnesium is called hypomagnesemia. Hypomagnesemia can be caused from excessive GI losses, excessive diuresis, alcoholism, or chronic kidney disease. So, if we lose too much magnesium in our bodies, it can cause changes to the heart and be seen on an EKG. Slide 19: Blood Urea Nitrogen, or you may hear it called BUN is another important electrolyte in a BMP. The normal value for BUN is 10-20 mg/dL. Now, the way I remember this is if you go to a restaurant (a nice one, not McDonalds) and you order a cheeseburger (think about a bun), it will most likely cost you about $10-20 dollars. A BUN measures the amount of urea nitrogen (which is waste products) in the blood and is directly related to the function of the liver and the excretory (or eliminating) function of the kidney. If a patient has an increased level of BUN, it could be caused from a kidney disease (the kidneys are not able to get rid of those waste products), heart failure, dehydration, or a ureteral/bladder obstruction. If your patient has a decreased level BUN, it could be caused from not getting enough protein in their diet, if they have a liver condition, or if they are fluid overloaded (it may dilute the number of BUN). Slide 20: Another major electrolyte to need to know is Creatinine or serum creatinine. You can have a urine creatinine, but today, we are going to talk about the creatinine in your blood, which is serum creatinine. Male and female have slightly different levels, the normal level for a female is 0.5-1.1 mg/dL and the male is slightly higher at 0.6-1.2 mg/dL. Creatinine is a by-product of muscle metabolism. The amount of creatinine produced per day is constant and dependent upon the body’s muscle mass. It is freely filtered so that production should equal excretion. Because of this, measuring one’s serum creatinine is a very reliable indicator of renal function, which is how we assess kidney function. Serum creatinine is also used as an approximation of the glomerular filtration rate or GFR, basically tells us how well your kidney output is. If a patient comes in with a creatinine level of 2 mg/dL, that is double the amount of creatine and that tells us that there is a 50% decrease of how their kidneys are working. If a patient has an increased level of creatinine, it can be caused from kidney disfunction, reduced renal blood flow and nephrotoxicity due to drugs. If there is a decreased level of creatinine, that can be caused from a decrease in muscle mass, decreased activity or a spinal cord injury, because remember, creatine is a by-product of muscle metabolism. Slide 21: Now the next one is Glucose, this is another important electrolyte to know, so make sure you star this one as well. You may see different “normal” levels, depending on if the patient is fasting or not. A normal, fasting or pre-meal glucose level is 74-106 mg/dL. Glucose is important as it supplies energy to the cells and is stored in the body as glycogen. Our glucose is controlled by insulin and glucagon working together, but we all know not everyone, or everything can get along, so when they are not working together, we get an elevation in our glucose, which is indicative of Diabetes. You will be learning how to use a glucometer and I am sure when you are in clinical, you will be collecting many patients blood sugar as many patients have high blood sugar or a history of diabetes. An increased level of glucose is called Hyperglycemia, which can be caused by Diabetes, a response to stress, if a patient is on steroids, it can increase your blood sugar, as well as being on diuretics. Hypoglycemia is when your blood sugar is low, and the main causes for that is starvation, extensive liver disease, if they receive too much insulin or through strenuous exercise. It is important to know the signs and symptoms of both hyper and hypo glycemia, as both can be commonly seen in a hospital or acute care setting. If a patient has low blood sugar, they may feel anxious, dizzy, tired, have a headache, fast heartrate, blurry vision, shakiness, and irritability. Signs of hyperglycemia include stomach pain, excessive thirst, the need to urinate often (this is due to fluid shifts) and, may have irritability. If a patient is a diabetic and has symptoms of low blood sugar, it is important to offer them juice or glucose paste of some sort…but you will learn a lot more about diabetes in med/surg. Slide 22: We are getting close to the end, the next electrolyte we are going to discuss is serum Carbon Dioxide. The CO2 level is related to the respiratory exchange of carbon dioxide in the lungs and is part of our bodies buffering system. Generally, when used with the other electrolytes, it is a good indicator of acidosis and alkalinity. The total carbon dioxide level is determined by acidifying serum to convert all of the bicarbonate present to carbon dioxide. Then, the total carbon dioxide content is determined. Since 95% of total serum carbon dioxide is made of converted bicarbonate, this lab test is actually a measure of bicarbonate concentration in our blood. The normal values for carbon dioxide are between 23-30 mEq/L. Carbon dioxide is important for evaluating acid-base status and electrolyte and are regulated by the kidneys. It is important to understand that this value represents bicarbonate, the end product of the carbonic acid/bicarbonate buffer system, it does not measure the acid content in our blood. Some reasons a patient may have increased levels are if they have severe diarrhea or vomiting, metabolic alkalosis, which is too much of a buffer, or if a patient has a G or NG tube to suction. If a patient has a decreased amount of carbon dioxide, this may be caused by kidney failure, metabolic acidosis, shock, or low blood pressure. Slide 23: The last two electrolytes we are going to discuss are our liver function tests. These tests will not be collected if just a Basic Metabolic Panel or BMP is collected, but will be on a CMP, or Comprehensive Metabolic Panel. The two liver function tests we are going to discuss is AST and ALT. AST is a hepatocellular enzyme (hepato means liver), and the normal value for AST is 0-35 units/L. When the liver cells get damaged, AST leaks out into the bloodstream and the level of AST in the blood becomes higher than normal. Increased levels may indicate liver dysfunction, skeletal muscle disease or hemolytic anemia, which is where the red blood cells are destroyed, and that can happen in patients with liver disease. ALT is the other enzyme found in the liver and its normal values are between 4-36 units/L. If a patient has an injury or disease affecting the liver, there can be a release of this enzyme, causing an increased level of ALT. If a patient has in increased level, it could be due to liver disease, muscular disease, or a myocardial infarction, which is a heart attack. A low level of AST or ALT is normal. Slide 24: That wraps up all the different important lab values that I want you to know for this lecture. It is neat to see what can be going on in a patient’s body, just by looking at a sample of their blood and being able to diagnose and treat certain diseases or problems. Now let’s look at some key nursing diagnosis that we may see in patients with abnormal lab values. The first one is “Risk for Electrolytes”, this could be due to abnormal levels, such as Sodium, Potassium, Magnesium, and/or Calcium. “Risk for Bleeding” could be due to a low platelet count. One nursing diagnosis that you may be able to use for many patients could be “Risk for Unstable Blood Glucose Levels” now this could be due to hyper or hypoglycemia, and/or Diabetes. Finally, you may be able to use this one quite a bit as well, “Risk for Infection” due to an increase in a patients White Blood Cells. These are just a few, there are many more Nursing Diagnosis related to an imbalance in electrolytes and/or an abnormal CBC. Slide 25: This is just a chart that shows the main labs that I went over with the normal lab values, what levels would consider them critical, and what a critical value may result in. There is also another chart that I have put up in Canvas under this lecture that has all the normal lab values listed as well. Slide 26: A little helpful hint to remember about lab values and what they affect is listed here: So, when you think about infection, think about WBCs or a WBC with differential. If you suspect Anemia, you will want to pay attention to the patient’s RBCs, hemoglobin, and hematocrit. If you are worried about a patient’s kidneys or kidney function, remember BUN and creatinine and finally, our liver tests, AST, and ALT. Slide 27: Well, this concludes our recorded lecture on Lab Values, I know if may seem like a lot to remember, but hopefully, after this lecture and after our in-class activity, it will really help you to be able to connect the dots. I have also posted in this lecture on Canvas, a few YouTube video’s that may help you remember these lab values and key things to remember. Don’t forget to come prepared and ready to apply the knowledge you learned today, in our LIVE, Part 2 session. It will be a lot of fun; you won’t want to miss it!