Term
What are the components of Chem-7/Basic Metabolic Panel/Serum Chemistry Panel?
What are the reference ranges of each component? |
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Definition
Na: 136-145 mEq/L
K: 3.5-5 mEq/L
Cl: 96-106 mEq/L
HCO3-: 22-26 mEq/L
BUN: 8-20 mg/dL
SCr: 0.7-1.5 mg/dL
SGlu: 70-110 mg/dL |
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Term
What does sodium abnormality generally indicate?
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Definition
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Term
| How to determine the water abnormality of the patient? |
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Definition
Serum osmolality = 2xNa + Glu/18 + BUN/2.8
Ref Range: 280-295 mOsm/kg H2O
Elevated: dehydration/hypernatremic
Low: hypervolemic/hyponatremic |
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Term
How is body sodium regulated?
How can we interpret such function? |
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Definition
Kidney regulates most of the body Na. Reabsorption takes place in the nephron.
FENa = (UNa/SNa x SCr/UCr) x 100
Ref range: 1-2%
>2%: renal tubular damage, excretes more
<1%: prerenal dysfunction, retain more |
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Term
| List some of the causes of sodium/water abnormality. |
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Definition
Syndrome of Inappropriate Antidiuretic Hormone
Diabetes Insipidus
Hyponatremia: SSRI, carbamazepine, cyclophosphamide
Hypernatremia: Lithium, foscarnet, demeclocycline |
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Term
| How to interpret potassium abnormality? |
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Definition
Hyperkalemia: renal failure, K+ sparing diuretics, ACE-inhibitors. Results in arrhythmia, bradycardia, hypotension.
Hypokalemia: water loss due to diarrhea, N/V, loop diuretics, amphotericin B. Results in arrhythmia, muscle cramps/weakness, widening of QRS interval. |
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Term
| How to interpret chloride abnormality? |
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Definition
Acid-base disorders and fluid imbalance.
Hypochloremia: vomiting, diarrhea, GI suction, diuresis
Hyperchloremia: NSAID, corticosteroid, acetazolamide |
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Term
| How to interpret bicarbonate abnormality? |
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Definition
Acid-base disorders. Affected by carbonic anhydrase inhibitors, antacids
Anion Gap = Na - (Cl + HCO3-), Ref range: 3-11 mEq/L, determines causes of metabolic acidosis. Normal and elevated gap acidosis. The latter is caused by MUDPILES. |
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Term
| How to interpret values of BUN? |
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Definition
| Urea undergoes filtration and reabsorption. Azotemia is caused by acute renal failure, dehydration, GI bleed, postrenal obstruction. Serum BUN level is affected by renal function, hydration status, intravascular volume, protein breakdown. |
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Term
| How to interpret values of creatinine? |
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Definition
Product of muscle breakdown. Undergoes filtration and secretion. Affected by diseases, protein, muscle mass, drugs.
Cimetidine, trimethoprim, spironolactone, triamterene inhibit tubular secretion. Aminoglycosides, amphotericin B, vancomycin are nephrotoxic. |
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Term
| What is creatinine clearance? |
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Definition
Estimate of renal function.
CrCl = [(140-age) x kg]/(SCr x 72), Ref range: 90-140 mL/min.
If >= IBW but < 120% IBW, use IBW. If < IBW, use actual body weight. If > 120% IBW, use adjusted body weight. |
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Term
| How to interpret glucose values? |
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Definition
| Affected by diabetes mellitus, impaired fasting glucose, drugs. Corticosteroids, atypical antipsychotics, thiazide and loop diuretics, beta blockers. |
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Term
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Definition
| Average glucose level after 3 months. Ref range: 4-6%. Long term assessment of glucose control. Correlation to mean daily blood glucose levels, 7% = 170 mg/dL, 8% = 205 mg/dL, 9% = 240 mg/dL |
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Term
| How to interpret calcium levels? |
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Definition
| Total calcium = [(4-albumin) x 0.8 mg/dL] + Cameasured, Ref range: 8.5-10.8 mg/dL. Free/ionized: 4.6-5.2 mg/dL. |
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Term
| What are the symptoms of calcium abnormality? What are the factors affecting serum calcium levels? |
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Definition
Hypocalcemia: seizures, fatigue, memory loss, hallucinations. Hypercalcemia: GI disturbances, lethargy, psychosis, calcifications.
Parathyroid hormone, vitamin D, diet, serum phosphate |
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Term
| How to interpret magnesium levels? |
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Definition
| Ref range: 1.5-2.2 mEq/L. Symptoms of hypomagnesemia include disorientation, prolonged QT interval, muscle fasciculation. Caused by diarrhea, alcoholism, diuretics, pancreatitis. Symptoms of hypermagnesemia include bradycardia, sweating, GI complaints. Caused by supplementation and renal failure. |
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Term
| How do you interpret phosphate level? |
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Definition
| Ref range: 2.6-4.5 mg/dL. Hypophosphatemia causes muscle weakness, cardiac and respiratory failure. Affected by PTH, serum calcium levels, renal function, vitamin D, dietary |
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Term
| How to interpret WBC values? |
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Definition
| Ref range: 4.4-11.3 x 103 cells/mm3. Consists of granulocytes (neutrophils, basophils, eosinophils), lymphocytes, and monocytes. Infections and corticosteroids, prednisone, and hydrocortisone increase WBCs. |
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Term
| How to interpret neutrophil values? |
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Definition
| Ref range: 45-73%. Elevated in infections. Neutropenia = <1500 cells/mm3. Absolute neutrophil count (ANC) = WBC x (% Neutrophils + % Bands). If ANC < 500, pt is susceptible to infections. Ref range of Bands: 3-5%. |
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Term
| How to interpret eosinophil values? |
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Definition
| Ref range: 0-4%. Parasitic infections, hypersensitivity reactions, autoimmune diseases cause elevated levels. |
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Term
| How to interpret basophil values? |
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Definition
| Ref range: 0-1%. Chronic inflammation, leukemia, hypersensitivity reactions cause elevated levels. |
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Term
| How to interpret lymphocyte values? |
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Definition
| Ref range: 20-40%. Including T cells, B cells, and natural killer cells. Viral infections, fungal infections, mononucleosis, syphilis, lymphomas cause elevated levels. |
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Term
| How to interpret monocyte values? |
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Definition
| Ref range: 2-8%. Mature into macrophages. Disseminated TB, endocarditis, recovery from a bacterial infection cause elevated levels. |
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Term
| How to interpret red blood cell levels? |
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Definition
| For males, ref range: 4.5-5.9 x 106 cells/mcL. For females, ref range: 4.1-5.1 x 106 cells/mcL. Anemia is caused by chronic disease, iron deficiency, B12 deficiency, blood loss. Polycythemia is caused by COPD, pregnancy, smokers, athletes, high elevations. |
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Term
| How to interpret reticulocyte count? |
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Definition
| Used clinically instead of RBC count. Ref range: 0.5-2.5%. Blood loss and hemolysis cause elevated levels. Bone marrow suppression causes decreased levels. |
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Term
| How to interpret hemoglobin levels? |
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Definition
| For males, ref range: 14-17.5 g/dL. For females, ref range: 12.3-15.3 g/dL. Polycythemia and chronic hypoxia cause elevated levels. Anemia, acute bleeding, dilutional effect decrease levels. |
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Term
| How to interpret hematocrit? |
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Definition
| Percentage of erythrocytes in a given volume of blood. For males, ref range: 42-50%. For females, ref range: 36-45%. Generally it is 3 x hemoglobin level. |
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Term
| What are the components of complete blood count? |
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Definition
WBC: granulocytes (neutrophil, eosinophil, basophil), lymphocytes, monocytes
RBC: reticulocyte count, MCV, MCH, MCHC, RDW
Hemoglobin
Hematocrit
Platelets |
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Term
| How to interpret mean corpuscular volume? |
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Definition
| Estimated average volume/size of RBCs. Ref range: 80-96 fL/cell. If MCV > 99, macrocytic anemia due to folate/B12 deficiency. If MCV = 81-99, normocytic anemia due to blood loss. If MCV < = 80, microcytic anemia due to iron deficiency. |
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Term
| How to interpret mean corpuscular hemoglobin? |
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Definition
| Amount of hemoglobin per red blood cell. Ref range: 27.5-33.2 pg/cell. Low MCH may be caused by Fe deficiency, hypochromic. High MCH may be caused by folate deficiency. |
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Term
| How to interpret mean corpuscular hemoglobin concentration? |
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Definition
| Hgb/Hct. Ref range: 33.4-35.5 g/dL. Low in Fe deficiency anemia. |
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Term
| How to interpret red cell distribution width? |
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Definition
| Indicates variation in size of RBCs/degree of Anisocytosis. Ref range: 11.5-14.5%. High in early iron deficiency anemia. |
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Term
| What are the components of urinalysis? |
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Definition
| Color, specific gravity, pH, cells, casts, crystals, protein, urobilinogen |
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Term
| How to interpret urine color? |
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Definition
Red/orange: myoglobin, hemoglobin, drugs, food
Blue/green: pseudomonas/proteus, drugs
Brown/black: myoglobin, bile pigments, drugs, liver dysfunction |
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Term
| How to interpret specific gravity? |
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Definition
| Ref range: 1.010-1.025. Na is the largest contributor. Low in chronic renal failure or diabetes insipidus. High in excess antidiuretic hormone or dehydration. |
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Term
| How to interpret urine pH? |
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Definition
| Ref range: 4.5-8. pH < 5: drugs, food, metabolic acidosis. pH > 9: drugs, vegetarianism, metabolic alkalosis, UTI with proteus, renal rubular acidosis |
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Term
| How to interpret cells in urine? |
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Definition
Large numbers may indicate a UTI.
RBC ref range: 1-3/HPF. Glomerulonephritis, pyelonephritis, renal infarction, stone elevates RBC.WBC ref range: 0-2/HPF, >5 suggests infection or inflammation.Tubular epithelial cells ref rage: 0-1/HPF, contaminant. Acute tubular necrosis and nephritic syndrome elevate. |
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Term
| How to interpret urine casts? |
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Definition
Ref range: 0-few.
Hyaline
Cellular (WBC, RBC, epithelial)
Granular
Waxy
Broad |
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Term
| How to interpret urine crystals? |
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Definition
| Phosphate or uric acid. Common in UTIs caused by Proteus. |
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Term
| How to interpret urine protein? |
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Definition
| Ref range: zero to trace. <0.5 g/day: HTN, exercise, fever, tubular damage. 0.5-3 g/day: HF, DM, multiple myeloma, glomerulonephritis. >3 g/day: lupus nephritis, severe diabetic nephropathy, amyloidosis |
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Term
| How to interpret urobilinogen? |
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Definition
| Ref range: zero to trace. Elevated urobilinogen is caused by hemolytic anemia, HF with liver congestion, cirrhosis, alkaline and dark urine, early hepatocellular damage. Decreased urobilinogen is caused by total biliary obstruction |
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