Western Lab Urologic Skeletal Systems Week 6 Flashcards
- Urology Lab Tests includes
1. Urinalysis (UA) BUN/serum creatinine Estimated GFR Creatinine clearance Serum electrolytes
- Which major indications require urinalysis (UA)?
- Diagnostic test in patients with:
a. abdominal or back pain
b. dysuria
c. hematuria
d. urinary frequency
Routine monitoring
a. Chronic renal disease
b. Metabolic disease
Pregnant and pre-surgical patients admitted to hospital
- UA looking for:
3. Appearance and color Odor pH (fresh specimen) Protein Glucose (should be none) Specify gravity Leukocyte esterase (WBC esterase) Nitrites Ketones Billirubin/Urobillinogen
- Microscopic UA is looking for:
4. Crystal (none) Casts: Hyaline casts, Cellular casts (none) WBC (few) RBC (less than 2)
- in an UA, what are the common measures in evaluating KI functions?
5.
- Most common measures are plasma concentrations of:
a. urea (BUN)
b. Creatinine - But these tests are abnormal only after 60% of total kidney function is lost.
- Not useful in detecting early kidney failure.
- More accurate measure:
a. Glomerular Filtration Rate (GFR)
b. Approximated by creatinine clearance
- UA, evaluating KI functions: Blood Urea Nitrogen (BUN). Explanation
6.
- Normal serum BUN is 2.0 to 8.5 mmol/L
- Increased serum levels (azotemia) indicate decreased kidney function.
- The liver produces urea as a waste product of the protein digestion.
- Urea is then excreted by the kidneys.
- BUN affected by diet and hormones, so it is not as good an indicator of renal function as serum creatinine levels.
- BUN increases in kidney disease, high protein diet, and after administration of steroids.
- BUN decreases in starvation, pregnancy and in persons on a low protein diet
- Basic facts of Serum Creatinine
- Produced at a fairly constant rate (a good indicator of KI function)
- Not affected by diet or hormone level (best KI function test)
- Waste product of muscle metabolism
- Serum creatinine rises when KI function is impaired
- Define Glomerular Filtration Rate (GFR) and how it is measured?
Glomerular filtration rate (GFR) is the best overall index of kidney function. Normal GFR varies according to age, sex, and body size, and declines with age.
Online calculators available. http://www.nephron.com/MDRD_GFR.cgi
- Volume of fluid filtered from the glomerular capillaries into the Bowman’s capsules per unit time.
Ideally measured by any chemical that:
a. Has a steady level in the blood
b. is freely filtered
c. Not reabsorbed by the kidneys
d. Not secreted by the kidneys
e. The concentration of this chemical in the blood is therefore directly related to the rate of glomerular filtration
f. The closest to this ideal chemical is creatinine.
- What is serum electrolytes?
Note: Serum values of electrolytes Cations (positive charge) Normal Range(mmol/L) Sodium 133 - 145 Potassium 3.3 – 5.1 Anions (negative charge) Chloride 98 - 111 Bicarbonate 24 - 31
9. 1. Electrolytes are substances that become ions (electrically charged particles) in solution and acquire the capacity to conduct electricity. 2. The balance of electrolytes is essential for normal function of cells and organs 3. Electrolyte balance affects: a. Hydration b. Acid-base balance c. Osmotic pressures d. Nerve and muscle function 3. Important in transport of substances into and out of cells 4. Most common serum electrolytes: Sodium Na⁺ Potassium K⁺ Chloride Cl⁻ Bicarbonate HCO3−
- Imbalances of Sodium/Chloride disorders
10. 1 Hypernatremia Inadequate fluid intake Increased sodium intake Diaphoresis Inadequate ADH(diabetes insipidus) Some drugs Hypertonic fluids/tube feedings Major burns 2. Hyponatremia Prolonged diuretic therapy Excessive sweating (diaphoresis) Gastrointestinal losses Insufficient Na intake Laxatives Administration of hypotonic fluids Compulsive water drinking Alcoholism Addison disease
- Imbalances of Potassium disorders
- Hypokalemia<3.3 mmol/L
Diarrhea, vomiting
Severe diaphoresis
Diuretics, laxatives
Inadequate dietary intake
Excess insulin
Stress
Steroid medications
Hepatic disease
Acute alcoholism
Transient shift of potassium into cells, as in Alkalosis - Hyperkalemia>5.1 mmol/L
Decrease K⁺ excretion
a. Renal failure
b. Oliguria
Excessive intake
Medications
Hyponatremia
Excessive use of salt substitutes!
Transient shift of potassium out of cells, as in Acidosis
Widespread cell damage, burns, trauma
- Basic facts on Bicarbonate (CO2 Content)
HCO3−
12.
Normal range 21–31 mmol/L
Acts as buffer to maintain normal pH in blood and body fluids
Also released by pancreas to neutralize acidic chyme entering duodenum from stomach.
HCO3- levels are increased in metabolic alkalosis (persistent vomiting, nasogastric suction).
HCO3- levels are decreased in metabolic acidosis (ketoacidosis of DM, shock, renal failure)
- What are the skeletal System lab tests
13. Serum calcium Serum uric acid Rheumatoid factor test (RF) Vitamin D
- Basic facts on serum calcium
14.
Normal Total serum calcium level is 2.18 to 2.58 mmol/L
Normal Ionized or free calcium level is 1.15-1.35mmol/L
Most abundant mineral in the body
More than 99% of the body’s calcium is located in the skeletal system
Regulated by the parathyroid gland hormone which:
a. Helps with calcium retention and phosphate excretion through the kidneys
b. Promotes calcium absorption in the intestines
c. Helps mobilize calcium from the bone
Important in coagulation and muscle contraction
Transmission of nerve impulses
Intracellular calcium - contraction of muscles
Extracellular calcium - blood clotting
Tooth and bone formation
Normal heart rhythm
- Basic facts on ionized calcium vs total calcium
15.
Normal Findings Ionized or Free Calcium:
Total serum calcium level varies with serum albumin level
Serum albumin is a protein which binds calcium
Biologic effects of calcium depend on ionized calcium, not total calcium
Ionized calcium is independent of albumin level
Therefore, measure ionized or free calcium if:
a. serum albumin is abnormal
b. calcium level is normal but a calcium disorder is suspected