Interpretation of Laboratory Values

Transcription

1 Interpretation of Laboratory Values Konrad J. Dias PT, DPT, CCS Overview Electrolyte imbalances Renal Function Tests Complete Blood Count Coagulation Profile Fluid imbalance Sodium Electrolyte Imbalances Potassium Calcium Magnesium 1

2 Sodium Normal serum level: meq/l Sodium imbalance Hyponatremia: Na <135 meq/l Hypernatremia: Na >145 meq/l Hyponatremia Renal disease, excessive sweating, CHF, SIADH Increased body water relative to sodium. Headaches, restlessness, anxiety, convulsions Muscle weakness and twitching, lethargy, nausea Hypernatremia Diabetes insipidus, diarrhea, dehydration, sodium bicarbonate and sodium chloride administration Increased sodium compared to body water Circulatory congestion: pitting edema, increased weight gain, pulmonary edema Lethargy, restlessness, flushed skin 2

3 Potassium Normal serum level: meq/l Potassium imbalance Hypokalemia Hyperkalemia Hypokalemia Diarrhea, vomiting, polyuria, diuretic therapy, medications like corticosteroid therapy. Muscle weakness and fatigue, leg cramps Postural hypotension, dizziness Arrhythmias and ECG abnormalities with flat T- waves, prolonged QT-interval, depressed STsegment Irritability, confusion, depression Hyperkalemia Renal failure, potassium-conserving diuretics, Addison s disease Muscle weakness Initial tachycardia and later bradycardia ECG changes with tall, peaked T-waves, prolonged PR-interval and QRS-duration 3

4 Calcium Normal serum level: 9-11 mg/dl Parathyroid hormone Secreted from parathyroid gland Target sites: kidneys, small intestine, bone Function: raise blood calcium levels Hypocalcemia Hypercalcemia Hypocalcaemia hypoparathyroidism Muscle cramps, tetany spasms Parasthesias Anxiety, irritability, depression Arrhythmias and hypotension Hypercalcemia hyperparathyroidism Decreased muscle tone, weakness, bone pain, pathological fractures Drowsiness, lethargy, headaches, irritability and confusion Heart blocks, cardiac arrest, hypertension 4

5 Magnesium Normal mg/dl Important in patients with Ventricular Tachycardia Renal Function Test BUN: blood urea nitrogen End product of protein and amino acid metabolism Normal level: 6-30 mg/dl Inc level indicative of dec renal function, inc protein intake, acute infection, or inc muscle catabolism Renal Function Test Creatinine Reference range: mg/dl Inc levels indicative of dec kidney function 5

6 Complete Blood Count (CBC) RBC count WBC count Hematocrit Hemoglobin Platelet count RBC Count Normal values Males: million/μl Females: million/μl Interpretation Important to assess with blood loss, anemia, polycythemia Increased: polycythemia vera, dehydration Decreased: anemia, leukemia, hemorrhage, and fluid overload WBC Count Normal values: 4,500-11,000 Interpretation Important to assess with infection, inflammation, bone marrow disease Monitor response to radiation or chemotherapy Increased: leukemia, infection Decreased: bone marrow suppression 6

7 WBC Differential Neutrophils: % Lymphocytes: % Monocytes: 3 7 % Eosinophils: 1 3 % Basophils: % Hematocrit Definition: %age of RBC s in blood Normal values Males: % Females: % Interpretation Assess with blood loss and fluid balance Increased: polycythemia, dehydration Decreased: anemia, blood loss, hemodilution Hemoglobin Normal values Males: g / 100 ml Females: g / 100 ml Interpretation Assess with anemia, blood loss, bone marrow suppression Increased: polycythemia, dehydration Decreased: anemia, hemorrhage, fluid overload 7

8 Hemoglobin and Hematocrit Blood volume and Composition Red Blood Cells (Hemoglobin) Pertinent laboratory values Hemoglobin Hematocrit Note: Each gram of hemoglobin/ 100 ml of blood carries 1.34 ml of oxygen Platelets Normal value: 150, ,000 μl Interpretation Assess with thrombocytopenia Increased: polycythemia vera, splenectomy, malignancy Decreased: anemia, hemolysis, splenomegaly, radiation or chemotherapy Exercise contraindicated with platelet < 20,000; use caution 20,000 30,000 8

9 Coagulation Profile Prothrombin time / international normalized ratio (PT / INR) Examines extrinsic and common clotting factors I, II, V, VII, and X Normal values PT: seconds INR goal: for warfarin (coumadin) INR: 2 3 for DVT, PE, valvular heart disease, tissue heart valve replacement, Atrial fibrillation INR: for MI, recurrent systemic emboli while on warfarin, mechanical prosthetic heart valve replacement Other Important Lab Values Blood Glucose Troponins BNP Hypovolemia Fluid volume deficit Vomiting, diarrhea, blood loss, uncontrolled DM, fever Weakness, tachycardia, hypotension, dizziness, thirst, confusion, cramps Assess hematocrit, BUN, sodium 9

10 Fluid volume excess Hypervolemia Renal failure, CHF, blood transfusions SOB, hypertension, bounding pulse Assess hematocrit, BUN, and sodium levels 10