**2.6 Sample size**

Fisher's formula for determining sample size was used. This is:

$$\mathbf{N} = \frac{\mathbf{Z}\mathbf{2}\mathbf{P}\mathbf{q}}{\mathbf{d}\mathbf{2}}$$

n= number of sample size p= prevalence of the problem =0.06% q= 1-P z= 95% confidence interval =1.96 d= level of precision =0.05 n= 86.7=87

However since this was a pilot study, sample size of approximately 50% of above (that is 50) was used.

The Prevalence of Renal Osteodystrophy in

**2.8.1 X-ray machine – Watson RO1** 

This is a standard machine with good resolution quality.

**MATERIAL AND METHODS** 

**2.8.2 Ultrasound machine** 

**2.9 Serum phosphate estimation** 

Ammonium molybdate -7nM Sulphuric acid – 1.7N Iron (11) Sulphate -8Mm

The composition of the reagent is a follows:

1. Three test tubes were labeled as: Blank –BL

minutes at room temperature (20-250C).

Inorganic phosphate (mg/dl) = SA O.D 4

O.D = Optic Density

To all 3 test tubes were added 3.0ml of the reagent.

**2.8 Apparatus** 

positions.

good resolution.

Subbarow reagent.

**2.9.1 Principle** 

**2.9.2 Technique** 

formula.

Chronic Renal Failure Patients in Urban Niger Delta of Nigeria 51

The procedure was carried out by an experienced radiographer using the posterior- anterior

Sonoace 1500 (Medison) 3.5 MHz sector probe was used. This is a standard machine with

This was done using Fiske-Subbarow method. This is a colorimetric method using Fiske-

The phosphate ion reacts with Molybdate to produce Phosphomolybdate, which is finally

Standard –ST Sample -SA 2. 0.1ml of patient's blood sample was added to SA. 0.1ml of standard was added to ST.

3. The content of each of the test tubes were mixed properly and allowed to stand for 10

5. The concentration of inorganic phosphate in patient sample was calculated using the

ST O.D 

4. Reading was done using a spectrophotometer set at 650nM wavelength.

Normal value of serum phosphate was taken as 2.4- 4.5 mg/dl.

The film was read and reported by an experienced consultant Radiologist.

Renal ultrasound scan was carried out by an experience Sonographer

reduced to a molybdenum blue, which is photo metrically measured.

A total of 115 patients were screened by:

Taking of a detailed history and physical examination at the initial contact with the patients with view to determining whether the patients had features suggestive of CRF and also whether patients met the inclusion criteria. Those with obvious exclusion criteria were dropped from the study at this level. This resulted in the exclusion of 55 subjects.

Twenty-four hours urine was collected and used for estimation of creatinine clearance and 24hours urinary calcium. On the morning of the test (8.00am), patients emptied their bladder and discarded the urine. Subsequently, urine passed was put into a clean container until 8.00am the next day. At the end of the urine collection, 5mls of blood was collected from the patients for estimation of serum creatinine. The creatinine clearance was calculated by using the formula: UV/P, where V is the urine flow rate (mls/min). Normal values of creatinine clearance was taken as 105-150mls/min while 24 hours urinary calcium was taken as 100-300 mg/dl. Where it was necessary radiograph of the chest and lumbo-sacral spines were carried out to rule out metastatic bone lesion. An abdominal ultrasonographic scan was carried out. After these evaluations a total of 52 subjects were studied having met the inclusion criteria.
