Diagnostic Investigation of Lower Back and Abdominal Pain

Case study 2:

A 35 year old patient showed the symptoms of pain in his lower back and abdomen. For investigation of the reason behind the pain urine was collected after a span of 24 hours along with the other blood tests. The serum creatinine level of patient was estimated to be 150 umol/l with an urinary concentration of 7.5mmol/l and the volume of total urine was 2.15 litres.

Interpretation:

The creatinine clearance rate can be calculated with the formula (Sandilands, et al, 2013):

U (urinary concentration) x V (volume of urine) = creatine clearance rate P (plasma concentration)

Therefore, the eGFR rate for 24 hours:

eGFR for 24 hours:

2150mL (Volume of urine in 24 hours) / 1440min (minutes in 24 hours) = 1.493055556 mL/min

7500 µmol/L x 1.493055556 mL/min = 24-hour creatine clearance rate 150 µmol/L

7500 µmol/L x 1.493055556 mL/min = 74.6527778mL/min/1.73m2 150 µmol/L

eGFR for 17 hours:

2150mL (volume of urine in 24 hours) / 1020min (minutes in 17 hours) = 2.107843137mL/min

7500 µmol/L x 2.107843137mL/min = 17-hour clearance rate 150 µmol/L

7500 µmol/L x 2.107843137mL/min = 105.3921569 mL/min/1.73m2 150 µmol/L

The normal reference range of the creatinine level in the serum is 60 to 110 micromoles per litre (μmol/L) for normal male adults. The patient had shown higher level of serum creatinine of 150 umol/l which indicated about the condition of chronic kidney disease (CKD). The eGFR level lies between 100–110 mL/min/1.73m2 for a normal adult (age 30 -39 years) and if the level is below it indicates about damaged functioning of the kidney. The value of GFR tends to decrease with the increasing age of the people without indicating about the kidney disease (Levey, et al, 2002). But the patient showed the GFR value for 24 hours to be 74 which indicated mild damaged state of the kidney which was in the progressing state. The normal urine production for an adult lies in the range of 1-2 litres so the patient showed normal output of urine. The result of the GFR rate has to be correlated with the level of protein in the urine especially albuminuria (the level >300 mg day−1) which is a classification marker of the kidney damage or CKD progression (Viswanathan, et al, 2011). The 24 hour collection method is considered to be the gold standard for the quantification of urinary protein but the inconvenience of patient may acts as barriers and can result in incomplete collection or inaccurate measurement of proteinuria (Price, 2005). The condition of CKD is often associated with mortality because of kidney failure in the future or association with other cardiovascular problems (Coresh, et al, 2005). Further necessary investigation of the kidney with ultrasound or CT scan may be suggested to know about the size (large or too small) of kidney. This may also help to identify the condition of kidney stone or tumour or any structural problems of kidney or urinary tract (Astor, et al, 2011).

Moreover, in case of diabetic neuropathy the most preferred first line test for investigating the condition of proteinuria is the urinary albumin – creatinine ratio (ACR) as it is considered to be one of the most of sensitive, standardised and quantitative method for the measurement of loss of protein. Though the case study did not reveal any report about the presence of condition diabetic neuropathy (Price, et al, 2005).

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References:

Levey, A.S., Coresh, J., Bolton, K., Culleton, B., Harvey, K.S., Ikizler, T.A., Johnson, C.A., Kausz, A., Kimmel, P.L., Kusek, J. and Levin, A., 2002. K/DOQI clinical practice guidelines for chronic kidney disease: evaluation, classification, and stratification. American Journal of Kidney Diseases, 39(2 SUPPL. 1).

Viswanathan, G. and Upadhyay, A., 2011. Assessment of proteinuria. Advances in chronic kidney disease, 18(4), pp.243-248.

Price, C.P., Newall, R.G. and Boyd, J.C., 2005. Use of protein: creatinine ratio measurements on random urine samples for prediction of significant proteinuria: a systematic review. Clinical chemistry, 51(9), pp.1577-1586.

Coresh, J., Byrd-Holt, D., Astor, B.C., Briggs, J.P., Eggers, P.W., Lacher, D.A. and Hostetter, T.H., 2005. Chronic kidney disease awareness, prevalence, and trends among US adults, 1999 to 2000. Journal of the American Society of Nephrology, 16(1), pp.180-188.

Astor, B.C., Matsushita, K., Gansevoort, R.T., Van Der Velde, M., Woodward, M., Levey, A.S., De Jong, P.E., Coresh, J. and Chronic Kidney Disease Prognosis Consortium, 2011. Lower estimated glomerular filtration rate and higher albuminuria are associated with mortality and end-stage renal disease. A collaborative meta-analysis of kidney disease population cohorts. Kidney international, 79(12), pp.1331-1340.

Sandilands, E.A., Dhaun, N., Dear, J.W. and Webb, D.J., 2013. Measurement of renal function in patients with chronic kidney disease. British journal of clinical pharmacology, 76(4), pp.504-515.