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Three Part Question

[in patients presenting with loin pain] [ is haematuria a sensitive sign] [ for diagnosing urinary calculi] ?

Clinical Scenario

A 30 year old male attended the Emergency Department with complaints of loin pain on the right side. Urinalysis was performed which came back as negative for haematuria. The SHO questioned whether that was enough to discard the diagnosis of a calculus as he knew that a percentage of patients are indeed diagnosed with urinary calculi despite having no haematuria.

Search Strategy

Medline/ ovid 1966- june week 4 2005
Embase 1980 -2005 week 27
Pubmed
[exp Kidney Diseases/ or exp Hematuria/ or loin pain.mp. or exp Kidney/ or exp Back Pain/] OR [flank pain.mp. or exp Kidney Diseases/ or exp Flank Pain/ or exp Bacterial Infections/ or exp Pyelonephritis/] OR [exp Urinary Calculi/ or exp Kidney Diseases/ or exp Kidney Calculi/ or exp Colic/ or renal colic.mp.] AND [exp Kidney Diseases/ or exp Hematuria/ or haematuria.mp.] AND [calculi.mp. or exp URETERAL CALCULI/ or exp CALCULI/ or exp URINARY CALCULI/ or exp KIDNEY CALCULI/] AND [silent stones. mp.]
limit 7 to (full text and humans and english language)

Search Outcome

1 papers found ovid
2 papers found embase
5 papers found pubmed
3 additional papers found
8 papers relevent, all used

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
N.P Buchholz, F. Abbas, M. Afzal, R. Khan, I.Rizvi, J. Talati 2003 Pakistan	Patients in Karachi hospital undergoing kidney screening techniques.	Screening study: 201 consecutive patients at the hospital underwent kidney screening whilest undergoing abdominal ultrasound. all patients did not have a history or symptoms of urolithiasis.	number of patients with silent kidney stones	3% of subjects had silent stones, most in the left kidney. multiple stones and stones of considerable size went unnoticed.	Pakistan has a high incidence of renal calculi therefore the results may not be generalised to other countries.
N. L Bishop 1980 UK	Patients attending Addenbrooke's hospital for urography and haematuria testing	Diagnostic Study: prospective study of 50 consecutive patients for emergency urography, supervised by a radiologist. The first available sample of urine was tested using Hemastix and then sent for microscopy.	sensitivity of haematuria,number of patients without haematuria but positive for a calculus	haematuria was present in 44 out of 50 patients. The 5 with negative tests had normal contrast films. Out of 50 patients 1 patient with negative haematuria on Hemastix had a calculi on radiology. 11 patients had haematuria with normal IVU	The study does not represent a random survey of patients with urinary calculi explaining the high haematuria figure. Also the Hemastix test is less sensitive in the presence of high urinary ascorbic acid levels and high specific gravity- levels which were not measured.
R. Boyd, A.J Gray 1996 UK	Patients attending the ED in 3 months from Aug to Oct 1994 with provisional diagnosis of acute ureteric colic	Diagnostic study:60 consecutive patients underwent urinalysis with BoeringerMannheim dipsticks before admission.	sensitivity of urinalysis for haematuria	sensitivity for positive urinalysis 100% specificity 32%. PPV haematuria on dipstick 64% (50% to 80%) NPV 100% (59% to 100%)	The study does not take in to account factors affecting haematuria levels e.g. ascorbic acid levels, peroxidases and contamination.
H.S Teh, M.B.K Lin, T.K Khoo 2001 Singapore	Patients ranging from 18 to 80 years old attending the ED with flank pain in Feb 1998	Diagnostic study: 110 patients attending the ED for emergency IVU, the case notes and urinalysis results were traced and reviewed for 98 patients.	accuracy of urinalysis	25 out of 98 patients had negative urine microscopy. 73 out of 98 patients had positive urinalysis for haematuria. urinalysis sensitivity 90.9% specificity 33.8%	Only 98 out of 110 patients' urinalysis results were documented. Also false positive results may have been due to the urine sample being left for too long before analysis. The results would also differ if the patient had a UTI or was menstruating.
S.B Ooi, N.W Kour, A. Mahadev 1998 Singapore	Patients presenting to the ED with symptoms suggestive of renal or ureteric colic	Diagnostic study: prospective study of 122 patients who gave a urine sample for dipstick and microscopy for the detection of haematuria.	the sensitivity of dipstick to detect haematuria	haematuria was found in 62 of the 65 patients with urinary calculi hence urine dipstick detected haematuria in 95.4% of patients (95% CI: 87.1% to 100%) microscopy detected haematuria in 70.8% of patients ( 95% CI: 58.2% to 92.6%)	4.6% of patients did not have haematuria on dipstick therefore would probably be declined for IVU even though a calculus may well still be present.
O. Eray, M.S Cubuk, C. Otkay, S. Yilmaz, Y. Crete, F.F Ersoy 2002 Turkey	Patients presenting to the ED during the daytime over a 1 year period.	Prospective diagnostic study- to see the value of urinalysis in 138 patients with renal colic presenting to the ED. Sensitivity and specificity was calculated using the Chi-Squared test	sensitivity of urinalysis	sensitivity 69% specificity 27%	34 patients were lost to follow up. Also confirmation of the passage of a stone was obtained over the telephone- patients may have missed small stones being passed. The study does not mention the control of factors affecting urinalysis e.g. time taken to analyse the sample and contamination.
P. Bove, D. Kaplan, N. Dalrymple, A.T Rosenfield, M. Verga, K. Anderson, R.C Smith 1999	267 patients with acute flank pain suspected for renal colic were referred from the Emergency Department for unenhanced helical CT from February 1994 to January 1995.	Review- medical records of 267 consecutive patients with acute flank pain referred for unenhanced helical CT. Microscopic and dipstick urinalysis data were obtained in 195 patients	number of patients with haematuria and calculi. sensitivity and specificity of haematuria and urinalysis	Out of 183 patients with dipstick urinalysis 91 (50%) did and 92 (50%) did not have ureterolithiasis on CT. sensitivity of haematuria for ureterolithiasis was only 81%. Similar results were demonstrated with dipstick urinalysis. 26% of patients without hematuria and suspected renal colic proved to have ureterolithiasis. 40% of patients with haematuria and suspected renal colic did not have calculi.	The study is is retrospective. A prospective analysis in which CT and haematuria testing are obtained in all patients presenting with acute flank pain is more ideal.
S.M Press, A.D Smith 1995 New York USA	Patients with acute urinary lithiasis presenting to the ED with flank pain from Jan 1991 to December 1992	Retrospective review of the records of 140 patients who underwent urinalysis, urine microscopy and IVU	incidence of negative haematuria and urinary calculi	14.5% incidence of negative haematuria with positive IVU. urinalysis sensitivity 85.5% specificity 42.6%. urinalysis+dipstix sensitiviy 94.5% specificity 35.2%. difference between 14.5% urinalysis and 5.5% urinalysis+dipstix was statistically significant P=0.031 using McNemars test.	109 patients out of 140 used, only 67 had a acute urinary lithiasis. What constitutes significant haematuria is unclear and variable from one institute to the next and is down to the laboratory technicians discretion. there was also selection bias- only patients with a strong history of acute urinary stones were offered IVU and hence urinalysis. those with a weak history may have included patients with negative urinalysis and dipstix for haematuria and flank pain.

Comment(s)

The majority of patients with a urinary calculus have a positive urinalysis test for haematuria. However a small percentage of patients are negative for haematuria but go on to have a calculus. Severe ureteric obstruction can exist without haematuria being present. Around 3% of patients have 'silent stones' which are found by accident on routine tests or investigtaions for other medical problems

Clinical Bottom Line

Urinalysis itself is not a specific test,however the presence of haematuria is a useful sign for the presence of a calculus which would then need further investigation.

References

1. N.P Buchholz, F. Abbas, M. Afzal, R. Khan, I.Rizvi, J. Talati The prevelence of silent kidney stones--an utrasonic screening study. Journal of the Pakistan Medical Association Jan 2003; 53(1): 24-5
2. N. L Bishop The influence of emergency urography and haematuria on the diagnosis of ureteric colic Clinical Radiology 1980; 31:605-610
3. R. Boyd, A.J Gray Role of plain radiograph and urinalysis in acute ureteric colic J Accid Emerg Med 1996;13:390-391
4. H.S Teh, M.B.K Lin, T.K Khoo Flank pain: is intravenous urogram necessary? Singapore Medical Journal 2001;42(9): 425-427
5. S.B Ooi, N.W Kour, A. Mahadev Haematuria in the diagnosis of urinary calculi Ann Acad Med Singapore Jul 1998;27(4):606
6. O. Eray, M.S Cubuk, C. Otkay, S. Yilmaz, Y. Crete, F.F Ersoy The efficacy of urinalysis, plain films and spiral ct in ED patients with suspected renal colic Am J Emerg Med Mar 2003;21(2):152-4
7. P. Bove, D. Kaplan, N. Dalrymple, A.T Rosenfield, M. Verga, K. Anderson, R.C Smith Re-examining the value of haematuria testing in patients with acute flank pain Journal of Urology 1999 Sep; 162(3 pt 1):685-7.
8. S.M Press, A.D Smith Incidence of negative haematuria in patients with acute urinay lithiasis, presenting to the emergency room with flank pain. Urology 1995; 45:753-7