Topics Covered Topics Covered Interpretation of Laboratory Tests - PDF document

7/24/2010 Topics Covered Topics Covered Interpretation of Laboratory Tests Interpretation of Laboratory Tests � BMP/CMP BMP/CMP � CBC CBC HIHIM 409 HIHIM 409 � Coagulation Studies Coagulation Studies � Urinalysis Urinalysis Fernando Vega, MD Fernando Vega, MD BMP vs. CMP BMP vs. CMP Sodium (Na) Sodium (Na) � BMP/Chem BMP/Chem- -7: 7: � CMP/Chem CMP/Chem- -12: 12: � Normally 125 Normally 125- -145 mmol/l 145 mmol/l – Sodium Sodium – Same as BMP plus: Same as BMP plus: � Collect in red top tube Collect in red top tube » AST AST – Chloride Chloride � Increased: Diabetes inspidius, exessive Increased: Diabetes inspidius, exessive » ALT ALT – Potassium Potassium » » Albumin Alb Albumin Alb i i sweating, Cushing’s syndrome sweating, Cushing’s syndrome – CO2/Bicarbonate CO2/Bicarbonate » Bilirubin Bilirubin – BUN BUN � Decreased: Excess body water (CHF, renal Decreased: Excess body water (CHF, renal » Alkaline Phosphatase Alkaline Phosphatase – Creatinine Creatinine failure, small cell lung cancer, brain failure, small cell lung cancer, brain – Glucose Glucose disorders), hypothyroidism, vomiting, disorders), hypothyroidism, vomiting, diarrhea, pancreatitis diarrhea, pancreatitis Chloride (Cl) Chloride (Cl) Potassium (K) Potassium (K) � Normally 97 Normally 97- -107 mEq/L 107 mEq/L � Normally 3.5 Normally 3.5- -5 mEq/L 5 mEq/L � Collect in tiger top tube Collect in tiger top tube � Collect in red or tiger top tube Collect in red or tiger top tube � Increased: Diarrhea, hyperalimentation Increased: Diarrhea, hyperalimentation � Hemolysis may falsely elevate level Hemolysis may falsely elevate level � Decreased: Vomiting, renal disease, Decreased: Vomiting, renal disease, � Increased: Renal failure, Addison’s disease, Increased: Renal failure, Addison’s disease, diabetic ketoacidosis diabetic ketoacidosis dehydration, ACE inhibitors, dehydration, ACE inhibitors, Spironolactone Spironolactone � Decreased: Diuretics, NG suctioning, Decreased: Diuretics, NG suctioning, vomiting, diarrhea, metabolic alkalosis vomiting, diarrhea, metabolic alkalosis 1

7/24/2010 Carbon Dixoide (CO2) Carbon Dixoide (CO2) Blood Urea Nitrogen Blood Urea Nitrogen � Normally 23 Normally 23- -29 mmol/L 29 mmol/L � Normally 5 Normally 5- -20 mg/dl 20 mg/dl � Collect in tiger tube top; don’t expose to air Collect in tiger tube top; don’t expose to air � Collect in tiger top tube Collect in tiger top tube � CO2 excreted into blood as bicarbonate CO2 excreted into blood as bicarbonate � Increased: Renal failure, CHF, Increased: Renal failure, CHF, aminoglycosides aminoglycosides � Increased: COPD, severe vomiting Increased: COPD, severe vomiting � Decreased: Starvation, liver failure Decreased: Starvation, liver failure � Decreased: Starvation, diabetic Decreased: Starvation, diabetic ketoacidosis, diarrhea, dehydration ketoacidosis, diarrhea, dehydration � BUN:Creatinine >20 suggests dehydration BUN:Creatinine >20 suggests dehydration � BUN:Creatinine >30 suggests GI bleed BUN:Creatinine >30 suggests GI bleed Creatinine Creatinine Glucose Glucose � Normally <1.1 mg/dl Normally <1.1 mg/dl � Normally 80 Normally 80- -140 mg/dl 140 mg/dl � Collect in tiger or red top tube Collect in tiger or red top tube � Collect in red or tiger top tube Collect in red or tiger top tube � Measures blood flow through kidneys Measures blood flow through kidneys � Slight increase normal with aging Slight increase normal with aging � Increased: Renal failure, false positive seen Increased: Renal failure, false positive seen � Increased: DM, Cushing’s syndrome, Increased: DM, Cushing’s syndrome, in diabetic ketoacidosis in diabetic ketoacidosis pancreatitis, thiazide diuretics pancreatitis, thiazide diuretics � Decreased: Muscle wasting, liver disease Decreased: Muscle wasting, liver disease � Decreased: Liver disease, malnutrition, Decreased: Liver disease, malnutrition, sepsis, endocrine tumors sepsis, endocrine tumors AST/ALT AST/ALT Albumin Albumin � Aspartate Aspartate � Alanine Alanine � Normally 3.5 Normally 3.5- -5 g/dl 5 g/dl Aminotransferase: Aminotransferase: Aminotransferase: Aminotransferase: � Collect in tiger top tube Collect in tiger top tube – Normally 7 Normally 7- -42 IU/L 42 IU/L – Normally 1 Normally 1- -45 IU/L 45 IU/L � Best lab test for measuring protein Best lab test for measuring protein – Increased: Liver Increased: Liver – Increased: Liver Increased: Liver disease, muscle disease, muscle disease, billary disease, billary � Decreased: Malnutrition, nephrotic Decreased: Malnutrition, nephrotic trauma, burns trauma, burns obstruction obstruction syndrome, alcoholic cirrhosis, inflammatory syndrome, alcoholic cirrhosis, inflammatory – Decreased: Vitamin Decreased: Vitamin – ALT>AST in viral ALT>AST in viral bowel disease, metastatic cancer, leukemia, bowel disease, metastatic cancer, leukemia, B6 deficiency, dialysis B6 deficiency, dialysis hepatitis hepatitis Hodgkin’s disease Hodgkin’s disease – AST>ALT in alcoholic AST>ALT in alcoholic hepatitis hepatitis 2

7/24/2010 Bilirubin Bilirubin Alkaline Phosphatase Alkaline Phosphatase � Normally 0.3 Normally 0.3- -1 mg/dl 1 mg/dl � Normally 25 Normally 25- -160 IU/L 160 IU/L � Collect in tiger top tube Collect in tiger top tube � Collect in tiger top tube Collect in tiger top tube � Increased: Liver damage, hemolysis, billary Increased: Liver damage, hemolysis, billary � Increased: Liver disease, billary Increased: Liver disease, billary obstruction obstruction obstruction, bone tumors, healing fracture, obstruction, bone tumors, healing fracture, hyperparathyroidism, hyperthyroidism hyperparathyroidism, hyperthyroidism � Decreased: Malnutrition, excessive vitamin Decreased: Malnutrition, excessive vitamin D intake, pernicious anemia, zinc deficiency D intake, pernicious anemia, zinc deficiency Complete Blood Count Complete Blood Count White Blood Count White Blood Count � WBC, H&H, Platelets most important WBC, H&H, Platelets most important � Normally 4500 Normally 4500- -11,000 11,000 � Collect in purple top tube Collect in purple top tube � Differential provides more clues to cause Differential provides more clues to cause than overall count does than overall count does � Capillary sample will decrease hematocrit Capillary sample will decrease hematocrit � Increased: Infection, inflammation, Increased: Infection, inflammation, � Platelets normally 150,000 Platelets normally 150,000- -450,000 uL 450,000 uL leukemia leukemia � Decreased: Bone marrow failure, vitamin Decreased: Bone marrow failure, vitamin B12 deficiency B12 deficiency Cause of Increased Differentials Cause of Increased Differentials H & H H & H � Basophils: Leukemia, s/p spleenectomy Basophils: Leukemia, s/p spleenectomy � Hematocrit: ~40 Hematocrit: ~40- -50% (lower in women, 50% (lower in women, higher in men) higher in men) � Eosnophils: Allergies, asthma, parasites Eosnophils: Allergies, asthma, parasites � The percentage of blood that is RBCs The percentage of blood that is RBCs � Lymphocytes: Viral infections, leukemia Lymphocytes: Viral infections, leukemia � Decreased with anemia and blood loss Decreased with anemia and blood loss � Monocytes: Bacterial infections, protozoan Monocytes: Bacterial infections, protozoan infections, ulcerative colitis infections, ulcerative colitis � Hemoglobin: ~12 Hemoglobin: ~12- -16 g/dl (lower in women, 16 g/dl (lower in women, higher in men) higher in men) � Neutophils: Bacterial infection, Neutophils: Bacterial infection, noninfectious tissue damage, metabolic noninfectious tissue damage, metabolic � Does not acurately reflect acute bleeding Does not acurately reflect acute bleeding disorders disorders because plasma and RBC lost at same rate because plasma and RBC lost at same rate 3

7/24/2010 Coagulation Studies Coagulation Studies Causes of Positive Values on UA Causes of Positive Values on UA � Collect in blue top tube Collect in blue top tube � Bilirubin: Jaundice, hepatitis, fecal Bilirubin: Jaundice, hepatitis, fecal contamination of sample contamination of sample � PT: 11.5 PT: 11.5- -13.5 second 13.5 second � Blood: Stones, BPH, infection, Foley cath Blood: Stones, BPH, infection, Foley cath � INR: 0.8 INR: 0.8- -1.4 1.4 � Glucose: DM, pancreatitis, steroids Glucose: DM, pancreatitis, steroids � Higher with mechanical heart valves or Higher with mechanical heart valves or history of thromboembolitic disease or atrial history of thromboembolitic disease or atrial � Ketones: Starvation, high fat diet, diabetic Ketones: Starvation, high fat diet, diabetic fibrillation fibrillation ketoacidosis, vomiting, diarrhea, asprin ketoacidosis, vomiting, diarrhea, asprin overdose overdose � INR is now the standard measure reported INR is now the standard measure reported Causes of Positive Values on UA Causes of Positive Values on UA Questions? Questions? � Leukoesterase: UTI Leukoesterase: UTI – Leukoesterase plus nitrates: 75% of UTI Leukoesterase plus nitrates: 75% of UTI – Neither LE or nitrates: 92% not UTI Neither LE or nitrates: 92% not UTI � Protein: Renal failure, CHF Protein: Renal failure, CHF P P i i R R l f il l f il CHF CHF 4