Therapetuics 1 Electrolytes and Lab Values.pdf

Variations in normal values for lab tests can be due to Techniques and Reagents, to Age, Gender, Weight, and Height. Potential causes of laboratory errors include technical error, improper calculation, inadequate specimen, incorrect sampling timing, medication interference. If a laboratory error is...

Variations in normal values for lab tests can be due to Techniques and Reagents, to Age, Gender, Weight, and Height. Potential causes of laboratory errors include technical error, improper calculation, inadequate specimen, incorrect sampling timing, medication interference. If a laboratory error is suspected, the test should be repeated. The first set of labs ordered on initial patient presentation are the Basic Metabolic Panel (BMP) and the Comprehensive Metabolic Panel. The basic Metabolic Panel consists of; Sodium, Potassium, Chloride, CO2, Glucose, Blood Urea Nitrogen, and Serum Creating. The Comprehensive Metabolic Panel includes; BMP, Albumin, Alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, total bilirubin, Calcium, Magnesium, and Phosphorous. The normal range for sodium is; 135 – 147 mEq/L. Sodium is the most prevalent cation in extracellular fluid, and is important in regulating serum osmolality, fluid balance, and acid-base balance. Sodium assists in maintaining the electrical potential necessary for transmission for nerve impulses. Hypernatremia is an excess in Sodium, and is caused by gastroenteritis, diabetes insipidus, hyperaldosteronism, and hypertonic saline. Hyponatremia is a decrease in Sodium, and is caused by heart failure, cirrhosis, chronic renal failure, SIADH, and severe burns. The normal range for potassium is; 3.5-5 mmol/L. Potassium is the main intracellular cation; thus serum concentrations are not always the most accurate indication. Potassium functions in the regulation of nerve excitability, acid-base balance, and muscle function. Hyperkalemia is caused by Metabolic or respiratory acidosis, renal failure, dehydration. Medications that cause hyperkalemia include ACE and ARB inhibitors, potassium supplements, potassium-sparing diuretics, drospirenone containing contraceptives, and Bactrim. Hypokalemia is caused by Severe diarrhea/vomiting, respiratory alkalosis, alcohol abuse, Cushing disease. Medications that cause hypokalemia include Thiazide/loop/osmotic diuretics, amphotericin B, insulin, albuterol, sodium bicarbonate. The normal range for Chloride 95-105 mEq/L. The function of chloride is the conduct a passive role in maintenance of fluid balance and acid-base balance. Hyperchloremia is caused by Metabolic acidosis, respiratory alkalosis, dehydration, diabetes insipidus, renal disorders. Hypochloremia is caused by Prolonged vomiting, metabolic alkalosis, heart failure, SIADH, use of acid suppressants (H2 blockers, proton-pump inhibitors). The normal range for CO2 is 22 – 28 mEq/L. CO2 represents measured H2CO3, which is the sum of dissolved CO2 and bicarbonate ion (HCO3), that exists in serum. The function of CO2 is the regulate physiologic pH. Hypercarbia is caused by Metabolic alkalosis (diuretics, primary aldosteronism, Bartter syndrome). Hypocarbia is caused by Metabolic acidosis (diabetic ketoacidosis, renal failure, lactic acidosis). Blood Urea Nitrogen has a normal range of 6 – 20 mg/dL The function of Blood Urea Nitrogen is to be a marker of renal function, and is the end product of protein catabolism. Increased Blood Urea Nitrogen is known as Azotemia, and is caused by Renal failure (shock, nephrotoxic medications), heart failure, GI bleeding, dehydration. Decreased Blood Urea Nitrogen is caused by Liver Failure. Creatine has a normal range of 0.6-1.2 mg/dl. Catabolic product of creatine phosphate used in skeletal muscle contraction. The function of Creatine is to be used as a tool to identify patients with renal dysfunction. Creatine is released into the blood and excreted by glomerular filtration in the kidneys. An increase in serum creatine equals a diminished ability of the kidneys to filter creating/ Increased creatine is caused by Renal dysfunction, dehydration, urinary tract obstruction, hyperthyroidism, nephrotoxic medications. Decreased creatine is caused by Cachexia, elderly patients, comatose injury patients, spinal cord injury patients. The normal BUN/Creatine ratio range is 10-20:1 The ratio of BUN/Creatine suggest etiology for renal dysfunction. BUN/Creatine > 20 indicates intravascular depression or pre-renal cause (dehydration, GI bleeding) A normal range of BUN/Creatine ratio in the setting of renal dysfunction indicates intrinsic renal disease The normal fasting range for Glucose is 70 – 99 mg/dl The normal fasting diabetic range for Glucose is 80 - 130 mg/dl The normal postprandial diabetic range for Glucose is <180 mg/dl The function of glucose is to be an important energy source for most cellular function. Causes of hyperglycemia are diabetes mellitus, Cushing disease, sepsis, shock, trauma, myocardial infarction, corticosteroids. Causes of hypoglycemia are missing a meal, and medications such as insulin, and sulfonylureas The normal range for calcium is 8.5 – 10.5 mg/dL The function of calcium is to take part in Bone mineralization, Cardiac and skeletal muscle contraction, blood coagulation, nerve transmission. Total serum calcium is a measure of both free (ionized) and protein bound (albumin) calcium. Calcium levels are regulated by PTH, VitD, serum phosphate, intestine, kidney, skeleton. Hypercalcemia is caused by malignancy, hyperparathyroidism, thiazide diuretics and lithium Hypocalcemia is caused by Hypoparathyroidism, vitamin D deficiency, hyperphosphatemia, loop diuretics. 50% of serum calcium is bound to plasma protein such as albumin. Decreased albumin leads to decreased total calcium concentration and calcium may appear falsely low. Every 1 g/dL drop in serum albumin, measured serum calcium decreases by 0.8 mg/dL. Corrected Ca = reported serum calcium + 0.8 (4.0 – patient’s albumin) The normal range for Phosphorous is 2.5 – 4.5 mg/dL The function of Phosphorous is that it aids in the synthesis of phospholipids, and acts as a Cellular energy source for adenosine triphosphate (ATP). Causes of Hyperphosphatemia include Renal dysfunction, bone malignancy, hypoparathyroidism, increased vitamin D intake. Causes of Hypophosphatemia include Alcoholism, malnutrition, hyperparathyroidism, respiratory alkalosis, Aluminum and calcium containing antacids. The normal range for Magnesium is 1.5 – 2.4 mg/dL. The function of magnesium is to act as a Necessary cofactor in physiologic functions utilizing ATP, and to be Utilized in protein synthesis, carbohydrate metabolism, contraction of muscle tissue. Causes of Hypermagnesemia include Renal failure, Addison disease. Causes of Hypomagnesemia include Diarrhea, vomiting, malabsorption, alcoholism. The Complete Blood Count Panel includes; Hemoglobin, hematocrit, White Blood Cells, Red Blood Cells, Mean Corpuscular Volume, Mean Corpuscular Hemoglobin, Mean Corpuscular Hemoglobin Concentration. The normal range for hemoglobin in males is 13.5 – 16.5 g/dL. The normal range for hemoglobin in females is 12 – 15 g/dL. Causes of Increased Hemoglobin include Polycythemia, and COPD. Causes of Decreased Hemoglobin include Anemia, blood loss, increased fluid intake. The normal range for hematocrit in males is 41 – 50%. The normal range for hematocrit in females is 36-44%. The volume of blood that is occupied by RBCs is the Hematocrit Causes of Increased hematocrit include Polycythemia, and COPD. Causes of Decreased hematocrit include • Anemia, blood loss, cirrhosis, leukemia. The normal range for Red Blood Cells in Males is 4.3 – 5.5 x 106 cells/mm3. The normal range for Red Blood Cells in Males is 4.0 – 4.9 x 106 cells/mm3. The causes of Erythrocytosis is Polycythemia, high altitudes, strenuous exercise. The causes of Decreased Red Blood Cell is Anemia, blood loss, leukemia. The normal range for the Mean Corpuscular Volume is 80 – 100 um3/cell. Causes of Macrocytic MCV is Folate deficiency, B12 deficiency, chronic liver disease. Causes of Microcytic MCV is Iron deficiency anemia, hemolytic anemia. The normal range for Mean Corpuscular Hemoglobin is 26 – 34 pg/cell. Causes of Hyperchromic MCH is Folate deficiency, B12 deficiency. Causes of Hypochromic MCH is Iron deficiency anemia. The normal range for Mean Corpuscular Hemoglobin Concentration is 31 – 37 g/dL. Causes of Increased Mean Corpuscular Hemoglobin Concentration is hereditary spherocytosis. Causes of Decreased Mean Corpuscular Hemoglobin Concentration is Iron deficiency anemia, hemolytic anemia. The normal range for reticulocytes is 0.1 – 2.4% of RBC. Reticulocytes reflects immature RBCs formed in bone marrow (increase indicates increase in RBC production). Causes of reticulocytes include Hemolytic anemia, hemorrhage, s/p anemia treatment. Causes of decreased reticulocytes include Iron deficiency anemia, renal disease, bone marrow suppression. The normal range for White Blood Cell is 4,000 – 11,000 cells/mL. Causes of Leukocytosis include infection, Leukemia, trauma, corticosteroid use, emotion, stress. Causes of Leukopenia include Viral infection, bone marrow, depression due to chemotherapy. The normal range for neutrophil segments is 54 – 62%. The normal range for neutrophil bands is 0 – 5%. Band Neutrophils are immature neutrophils, and an Increased *”left shift” can indicate infection or leukemia. Causes of neutrophilia include infection, stress, emotion.n and corticosteroids. Causes of neutropenia include viral infection, and chemotherapy agents. The Absolute Neutrophil Count formula is Total number of circulating segs and bands. Formula for Absolute Neutrophil Count is ANC = WBC x (% segs + % bands)/100 . Risk of infection increases dramatically as the ANC decreases. ANC < 500/mm3 is associated with substantial risk of infection. Normal range for Lymphocytes is 24 – 44%. Lymphocytes are important in the immune response to foreign antigens. Causes of lymphocytosis include Hepatis, herpes simplex, herpes zoster, other viral infections. Causes of Lymphopenia include Acute infections, HIV, lupus, lymphoma. Normal range for monocytes is 3 – 7% Monocytes are Synthesized in the bone marrow, and released into the circulation. Monocytes Migrate into lymph nodes, spleen, liver, lung, and bone marrow. In the tissues, monocytes mature into macrophages and served as scavengers for foreign substances. Causes of monocytosis include Tuberculosis (TB), syphilis, malaria. Causes of monocytopenia include Bone marrow suppression agents, severe stress. The normal range for eosinophil is 1-3% Eosinophils are phagocytic White Blood Cells that assist in the killing of bacteria and yeast. Eosinophils are predominantly found in the intestines and lungs. Eosinophils are involved in allergic reactions, and immune responses to paracytes. Causes of eosinophilia include allergic disorders, and allergic drug reactions. Causes of eosinopenia include adrenal steroid production. The normal range for Basophils 0 – 0.75%. Basophils are Phagocytic WBCs, present in small numbers. Basophils contains heparin, histamine and leukotrienes. Basophils are more likely associated with hypersensitivity reactions. Causes of Basophilia include Hypersensitivity reactions to food or medications, leukemias. The normal range for platelets is 100,000 – 450,000/uL. Risk of bleeding is low unless platelets fall below 50,000/uL. Causes of thrombocytosis include Infection, malignancies, chronic inflammatory disorders. Causes of Thrombocytopenia include Radiation, chemotherapy, use of heparin.