Lab interpretation Flashcards
When is WBC elevated
- Chronic inflammatory disease
- infection
- chronic myelogenous leukemia
- Acute myelogenous leukemia
Cells that has given up all nuclear material except for remain iron; carries oxygen by virtue of its conficguration and Hb content
RBCs
What is the normal ration of Hb/ Hematocrit?
1: 3
- Hemoglobin is oxygen carrying pigment of erythrocytes
- Hematocrit (HCT) is a concentration of RBC’s
- males values > female values
What causes elevated HCT?
Primary: Polycythemia (overproduction of HCT)
Secondary:
1. Chronic lung disease (COPD)
2. High altitude living
3. Smoking
4. Extreme physical exercise
5. Hemoconcentration: (dehydration) Burns, Vomiting, Dehydration
What decreases Hgb/HCT?
- Hemorrhage**: Trauma, GI cancer, Peptic ulcer, Excessive menstruation, etc
- Decreased production of erythrocytes: Iron deficient microcytic anemia, Macrocytic anemia, Ethnic genetic variants
- Destruction of erythrocytes: Anemia of chronic disease (Cancer, TB, RA), Malaria, Hypersplenism, Sickle cell, Hypothyroidism, Renal insufficiency, Chronic infection; *always rule out Fe deficiency
Primary response to bleeding; Maintains homeostasis, Plugs microscopic pores
Platelets
- Vit K important
A substance that develops an electrical charge when dissolved in water; Under the control of regulatory centers in renal, thyroid, parathyroid and pituitary systems
Electrolytes
- Serum levels of electrolytes are a reflection of total body values
When do most abnormalities occur with Na and K? What is the most common clinical manifestation of hypokalemia?
- when patients are on diuretics
- leg cramps
What can cause hyperchloremia?
- Certain drugs including: carbonic anhydrase inhibitors (used to treat glaucoma), Acetazolamide, Ammonium chloride, Androgens, Cortisone, Estrogen, Guanethidine, Methyldopa, NSAIDs
- Dehydration
- Metabolic acidosis
- Respiratory alkalosis
What can cause hypochloremia?
- Addison’s disease
- Burns
- Certain kidney disorders
- Congestive heart failure
- Excessive sweating
- Metabolic alkalosis
- Overhydration
- SIADH
- Vomiting
- medications: Aldosterone, Bicarbonates, Certain diuretics, Triamterene
What is the cause of acutely low CO2? Chronic low?
–Acutely low = diabetic ketoacidosis
–Chronic low = chronic renal failure
When do BUN levels increase?
- Dehydration
- Renal failure
- Absorption of blood in the “gut”
Indication of renal function; Reflects amount of body muscle mass
Plasma and Urnie Creatinine (Cr)
- normal .5-1.4
What does a doubling of normal creatinine levels indicate?
50% reduction of kidney function
- normal .5-1.4
- new drugs can cause damage, so these levels are watched
What causes elevated serum creatinine levels?
- Dehydration
- Diabetic nephropathy
- Eclampsia (a condition of pregnancy that includes seizures)
- Glomerulonephritis
- Kidney failure
- Muscular dystrophy
- Preclampsia (pregnancy-induced hypertension)
- Pyelonephritis
- Reduced kidney blood flow (shock, congestive heart failure)
10 . Rhabdomyolysis - Urinary tract obstruction
What causes decreased serum creatinine levels?
- Muscular dystrophy (late stage)
2. Myasthenia gravis
What are some things to note of using NSAIDs?
- GI upset
- Renal deterioration - Use sparingly in the elderly
- Contraindicated in renal failure patients
What is the goal value of HgbA1C, which reflects a 3 month average for diabetic patients?
<7.5
What causes hyperuricemia?
- Gout
- Renal falure
- uric acid = breakdown or byproduct of purine metabolism
What controls Ca serum levels?
Parathyroids
- ca released by bone
What causes hypercalcemia?
- Malignancy: Primary bone tumor, Metastatic bone disease, Ectopic parathyroid syndrome (Lung cancer)
- Hyperparathyroidism: Primary = too much secretion causing bone deterioration, Secondary = renal failure, Females>Males 2:1, Bone demineralization
What are the liver function tests?
- AST / SGOT
- ALT / SGPT
- Alk Phos
- Bilirubin
- Albumin
- PT / INR
What causes elevated SGOT/ SGPT (transaminases)?
Liverinfiltration, inflammation
- Cell destruction releases transaminases:
1. Tumor – primary vs metastatic
2. Infection – mono, hep A, B, C
3. Autoimune – primary bilary cirrhosis/ Crohn’s disease
4. Iatrogenic: Glucophage/ metformin, Excessive tylenol, Sulfa/ Septra
4. Alcohol
What increases prothrombin time (PT)?
- Bile duct obstruction
- Cirrhosis
- Hepatitis
- Malabsorption
- Vitamin K deficiency
- Coumadin (warfarin) therapy
- concerning if prothrombin time is > 2.5 times ref range
- intern’l normalized ration (INR) > 2-3
What patient population should be cautious with the use of acetaminophen?
Pts with liver disease
Pituitary releases TSH which stimulates the thyroid to release _______ which in turn circulates regionally and has a _____ feedback on the pituitary
thyroxine / T4; inhibitory
- thyroid regulates body’s metabolism and co-reg glucose levels/ homeostasis
What sx are seen in elevated TSH/ Decreases T4 (hypothyroidism) ?
- Vague fatigue, forgetfulness (early)
- Mild sensitivity to cold (early)
- Mild weight gain (early)
- Proximal muscle weakness
- Carpal tunnel syndrome
- Compartment syndrome
- Women > Men, 4:1
- Peak incidence - 30 to 60 yo
What sx are seen in decreased TSH/ elevated T4 (hyperthyroidism)?
- HTN
- Tachycardia
- Hyper-reflexia
- Lid lag- when the person is asked to slowly look down, there is a delay in initiation of movement of the upper lid downwards, such that the eyelid looks like it is ‘being left behind’
- Tremor
- Weight loss
- Sweating
What elevates creatine phosophokinase (CPK)
- CPK released with injury to muscle
1. Striated muscle - Trauma, Rhabdomyolysis, Severe muscle exertion, Polymyositis, Muscular dystrophy (CPK MM)
2. Cardiac - MI, Myocarditis (CPK MB)
3. Iatrogenic - Statin drugs (I.e. mevacor)
Measures the distance in mm that RBC’s fall per hour
Erythrocyte Sedimentation Rate (ESR)
- Usually settle slowly
- If they aggregate due to plasma proteins (I.e. fibrinogen) they settle rapidly
- Gradual, mild increase with age is acceptable
- By itself is almost meaningless
What conditions is ESR sensitive and specific for diagnosing and monitoring?
- Temporal arteritis
- Polymyalgia rheumatica
- Endocarditis (93% sensitive)
- can be useful in: Detecting occult disease, Confirming diagnosis, and Differential diagnosis
What elevates ESR?
- Infection
- Inflammatory disease
- Acute arthropathy
- Chronic arthritis
- Tissue necrosis
- Chronic renal failure
- Ulcerative colitis
- Anemia
- Hypothyroid
- Hyperthyroid
- Malignant neoplasm
A globulin that in the presence of calcium ions precipitates the c-substance of pneumoccocal cells; An abnormal protein that appears in the blood in the acute stages of various inflammatory disorders, but is undetectable in the blood of healthy individuals; Progressive increases correlate with increases in inflammation; May also be used to track therapeutic response to medications
C-reactive protein (CRP)
What elevates CRP levels?
- Bacterial infections
- Active rheumatic fever
- Wound infection
- Kidney and bone marrow transplant rejections
- Inflammatory bowel disease
- SLE
- Inflammatory arthritides
- TB
- Blood transfusion
- Acute myocardial infarction
What is the only marker to help support the diagnosis of ankylosing spondylitis
HLA-B27
Non-specific rheumatologic marker used in conjunction w/ history and physical to make a diagnosis; Associated with lupus, mixed connective tissue disease, JRA and scleroderma
Antinuclear antibody (ANA) - (+) ANA doesn’t mean lupus, - False (+): unusually low titer, women
