Basic examination of urine Formation Ultrafiltrate of blood Average daily output o 1200 to 1500 ml/day 600cc/day still considered normal o 170,000 filtered plasma/day o 18L glomerular filtrate reduced to 1-2L o 20 – 25 % of total blood volume Parts of nephron o Glomerulus o Bowman's capsule Cortical nephron and ? PCT and DCT located in the cortex Glomerulus: only type of capillary that can filter; 2 arterioles (afferent and efferent) o Compared to normal capillary: 1 venule and 1 arteriole Composition of urine Organic: Urea (50%), creatinine, uric acid Inorganic: Chloride, sodium, potassium o Traces: calcium, phosphate Water:99% Amino acids, peptides Formed elements:sediments o Cells: RBC, epithelial, WBC o Casts (UNIQUE TO URINE) o Crystals o Mucus, bacteria Mucus threads Yeast, sperm cell URINE VOLUME Normal: 600-2000 ml/day Night: >400ml Factors that influence volume: o State of hydration o ADH secretion: caffeine: inhibit ADH o Excretion of dissolved solids Glucose, salts Anuria: complete cessation of urine flow o Decreased renal blood flow o Severe renal failure Oliguria: decreased normal daily urine output (< 30 ml/hr) o Vomiting, diarrhea, perspiration, severe burns, hydronephorsis o Refer o Renal: vascular d/o, AGN, ATN, CGN, CRF, glomerulus, tubules or both are affected Polyuria: increase in daily urine volume o More than 2L in 24 hrs o DM- excess glucose requires water for excretion,( osmolarity: excrete a lot of concentrated urine) o Diabetes Insipidus-decrease in secretion of ADH, (diluted urine) o caffeine, alcohol Nocturia: increase in nocturnal urine output o DM o More than 500cc at night Types of urine specimens Random: routine screening (most frequent) o ease of collection o anytime o prob: menstruation, hormonal evaluation First morning: o Ideal screening specimen o Concentrated specimen o Pregnancy test- false negative results (random urine is not concentrated) o Orthostatic proteinuria: happends when patient stands at prolonged standing due to pressure on thee renal vein which increases the GFR Upon waking up: collect 1 st Let patient walk: collect 2 nd Positive if first is negative and 2 nd is positive Fasting specimen (2 nd morning) o Glucose monitoring (ideal specimen) FOR INSULIN THERAPY for diabetics Why not first: will no tell the efficiency of insulin therapy due to its high concentration CLIN PATH FINALS: BASIC EXAMINATION OF URINE-DR. AYOCHOK (ROVZ) Page 1-2 ND SEMESTER
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Basic examination of urineFormation
Ultrafiltrate of blood Average daily output
o 1200 to 1500 ml/day 600cc/day still considered normal
o 170,000 filtered plasma/dayo 18L glomerular filtrate reduced to 1-2Lo 20 – 25 % of total blood volume
Parts of nephrono Glomeruluso Bowman's capsule
Cortical nephron and ? PCT and DCT located in the cortex Glomerulus: only type of capillary that can filter; 2 arterioles
(afferent and efferent)o Compared to normal capillary: 1 venule and 1
arteriole
Composition of urineOrganic:
Urea (50%), creatinine, uric acid
Inorganic: Chloride, sodium, potassium
o Traces: calcium, phosphate Water:99% Amino acids, peptides Formed elements:sediments
o Cells: RBC, epithelial, WBCo Casts (UNIQUE TO URINE)o Crystalso Mucus, bacteria
For difficulty of voiding Sterile specimen and no contamination
Midstream clean catch: incorporated in a random and 1st morning urine
o Bacterial cultureo Safer, less traumatic method
C L I N P A T H F I N A L S : B A S I C E X A M I N A T I O N O F U R I N E - D R . A Y O C H O K ( R O V Z ) Page 1-2ND SEMESTER
Suprapubic aspirationo Most sterileo Bacterial cultureo Cytologic examination (ideal)o For tumors of UB: has a low yield specimeno Biopsy still superior
Three-glass collectiono Prostatic infection: evaluation for prostatitis
Compare 1st and 3rd specimen (10x the amount of bacteria compared to 1st)
o 1st urine, midstream, massage prostate, remaining urine
o Interpretation 1st: if + for WBC 2nd: control 3rd: if + for bacteria = Prostatitis (negative
control and in either 1 & 3 (+) UTI?
IF all are positive: recollect thru 3 glass 4 glass also for prostatitis
Pathologic causes of turbid urine:o Red blood cells: not from menstrual bloodo White blood cellso Bacteria, yeasto Abnormal crystals: tyrosine and eosine?o Lymph fluid:Pyuriao Lipids: Lipiduriao Malignant cells
SPECIFIC GRAVITY Normal: 1.015 to 1.035
o Urea, NaCl, Sulfate, Phosphate (major components of urine)
o Proportion of dissolved solid components to total of specimen
Evaluation of renal concentrating ability Isosthenuria: 1.010
o Same with initial filtrate Hyposthenuric: < 1.010: DI, PN, GN