Bacteriological Examination of Urine.

The urine culture remains a standart procedure for diagnosing urinary tract infections. A test of the antimicrobial sensitivity of identified organisms is usually ordered. Newer methods help identify positive specimens more accurately and rapidly.

The patient is told that the detection of the urinary tract infection and that proper collection is necessary for useful results. The nurse ensures that patient has a sterile container, is aware that only the outside of the container is to be touched, and that the container should be held in such a way that it does not contact legs, genitalia, or clothing. The patient is instructed in proper cleansing techniques.

Specimens for urine culture may also be collected through catheterization or directly from an indwelling catheter. The first voided morning specimen is preferred because bacterial counts are highest at this time.

A colony count of less than 50,000 bacterial units/ml of urine is not significant, and a count of 50,000 to 100,000 is inconclusive. A count of 100,000 is considered a positive culture and is indicative of pyelonephritis if accompanied by fever and flank pain.

A positive culture that is accompanied by dysuria, frequency and urgency is indicative of cystitis.

A positive culture that is not accompanied by symptoms may indicate contamination of the specimen during collection or chronic low-grade pyelonephitis.

The presence of more than two organisms or of vaginal or skin organisms is suggestive of contamination.

 

The Examples of Analyses:

URINALYSIS

Color - red		Microscopy of urine sediment:
Reaction - acid		Squamous epithelium -  5-10 in f.v.
Protein - 0,066 g/L		Leucocytes - 20-30 in f.v.
Specific gravity - 1018		Erythrocytes - 50-60 in f.v.,unaltered
Glucose -		Casts:
Transparance - cloudiness		Hyaline -
Bilirubin -		Granular -
Urobilin -		Salt - urates much
Aceton -		Mucus -
		Bacteria -
		Renal epithelium -

   

Conclusion: presence of macrohematuria (red color and unaltered erythrocytes), much urates, cloudiness urine are typical for renal colic.

 

 

NECHIPORENKO'S METHOD is used to count erythrocytes, leucocytes and casts in 1 ml of urine for differential diagnosis between pyelonephritis and glomerulonephritis. The main advantage of this method is that an average sample of urine is taken for analysis and the presence of pus from the sex organs is excluded thus.

In norm: erythrocytes count is to 1 x 10⁶/L;

           leucocytes count is to 4 x 10⁶/L;

                    hyaline casts count is to 0,25 x 10⁶/L.

The amouth of leucocytes increases in pyelonephritis; the amount of erythrocytes and casts increases in glomerulonephritis.

 

 

NECHIPORENKO'S

Leucocytes 14,0 x 10^6 л

Erythrocytes 2,0 x 10^6 л

Conclusion: increased leucocytes count indicates pyelonephritis.

 

 

ZIMNITSKY'S TESTS assess the concentration and excreted functions of the kidney by specific gravity and amount of the excreted urine. The main advantage of this method is that the renal function is tested without interfering with the normal life of the patient. The patient collects his urine at 3-hour intervals (8 portions during 24 hours). He begins to collect the urine from 9 o'clock in the morning and finishes at 6 o'clock in the morning the next day.

Excreted Function. The volume of each portion of the urine determined. It is necessary to compare daily diuresis with amount of taken liquid.

The normal daily amount of urine (daily diuresis) excreted by an adult varies from 1000 to 2000 ml. A normal individual should eliminate about 75-80% of the taken liquid during a day.

The daily amount of urine below taken liquid is observed in patient with edema (negative diuresis).

The amount of urine, both total daily volume and volume of each voiding, depends on a number of factors: fluid intake, fluid losses from other routes, fever, environmental temperature, age (a child excretes proportionately more than an adult), ingestion of a high-protein diet (which produces more urine), or diuretic drugs.

The daily amount of urine over 2000 ml (polyuria) is observed in person who takes much liquid (physiologically or in diabetes mellitus), during resolution of edema and after taken diuretics, in early stage of chronic pyelonephritis, renal failure.

The daily amount of urine below 500 ml (olyguria) may be of patient with kidney diseases (renal insufficiency) and unrenal diseases (vomitus, diarrhoea, limited intake of liquid, after hemorrhage, heart failure, pyrexia).

The volumes of daily and night urine are compared and a conclusion is derived concerning daily (the first 4 portions) and nocturnal (the next 4 portions) diuresis. Normally the daily diuresis exceeds the nocturnal one in 2-3 times. Nocturnal diuresis (nocturia) prevails in renal insufficiency to indicate longer work of the kidneys because of their impaired functional capacity.

Oliguria accompanied with nocturia is typical for heart failure.