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SOP for Microbiology Urine Screening

1. cccccceeceeeeeeeeeeeeeuueeeneues 5 6 PROCESSING PROCEDURE OLD SAMPLES cccccccececeeecseecesuueeeeuceeueeeeueaeeeaaeeenees 6 Te MAINTENANCE customs iii rico 6 8 QEPROGEDURE a de do da 7 9 PROCESSING PROCEDURE DIPPING AND ANALYSIS cooccccnccccnncccnnoccnonancnanccnnaccnnnancnnnos 7 10 PROCESSING PROCEDURE POST ANALYTICAL coccccnncnnnncnccnnccnnncncnnncnnnnanonancnonaninnno 8 11 RES WIGS eect Set ote ee ek e eo Ma i ate Me 8 12 TROUBLESHOOTINCG lt a a a a a e a 8 13 URINALYSIS USING DIPSTRIPS 0oocoononnncccccnncccnncncnncccnnnccnonanannncnnnnanonancnnncnconancnnnns 9 14 OTHER SOURCES OF ERROR USING DIPSTRIPS 0occcoccccnnccccnnccnnncncnnncnnnncnnonananonancnna canon 12 15 URINALYSIS FLOW CHART oooccccnccccnocccnncnconancnonononnancnonancnnancn nano nnnnnn narco aS e a a 12 Printed copies are uncontrolled unless there is an allocated Copy Number on page 1 Author K Halladay Checked by C Gouge Approved by N Roberts Page 2 of 14 RUH Bath NHS Trust Pathology Department STANDARD OPERATING PROCEDURE QMS SOP SP URI 11 5 Title Microbiology Urine Screening Effective date 05 08 2013 CLINICAL APPLICATION The purpose of this process is to offer a dipstick screening service testing for urinary tract infections and related abnormalities The dipstick analysis is NOT diagnostic and can only be used as a screening tool The parameters that are tested for using t
2. RUH Bath NHS Trust Pathology Department STANDARD OPERATING PROCEDURE QMS SOP SP URI 11 5 Title Microbiology Urine Screening Effective date 05 08 2013 COPY Summary of Significant Changes at this Revision Add maintenance procedure and not doing dipstick from urine collected into boric acid Purpose and Scope The purpose of this process is to offer a dipstick screening service testing for urinary tract infections and related abnormalities The dipstick analysis is NOT diagnostic and can only be used as a screening tool Items Required Definitions and Abbreviations Grade Qualifications Required Applicable to grades Band 2 and above Printed copies are uncontrolled unless there is an allocated Copy Number on page 1 Author K Halladay Checked by C Gouge Approved by N Roberts Page 1 of 14 RUH Bath NHS Trust Pathology Department STANDARD OPERATING PROCEDURE QMS SOP SP URI 11 5 Title Microbiology Urine Screening Effective date 05 08 2013 CONTENTS te CEINIGATZSAPPLIGATION cient ita la pde reel nd 3 2 PROCEDURAL SUMMARY FLOW CHART ccccccceccceecscceecseeeceseeuseeeeeeeueeseueeeaaeeenaues 4 3 THOSE SAMPLES THAT FALL INTO THE MUST CULTURE CATEGORY 0 5 4 PROCESSING PROCEDURE PRE ANALYTICAL OVERVIEW cccccccccceeecseeeeeeeeeeeeeeeeuaees 5 5 PROCESSING PROCEDURE CATHETER URINE SAMPLES
3. flow chart the samples are either referred for culture or indicative of an alternative diagnosis Printed copies are uncontrolled unless there is an allocated Copy Number on page 1 Author K Halladay Checked by C Gouge Approved by N Roberts Page 4 of 14 RUH Bath NHS Trust Pathology Department STANDARD OPERATING PROCEDURE QMS SOP SP URI 11 5 Title Microbiology Urine Screening Effective date 05 08 2013 3 THOSE SAMPLES THAT FALL INTO THE MUST CULTURE CATEGORY Those patient and sample catagories that are an exception to the use of screening via dipstick include All urgent and on call specimens which are referred to the urgent lab Children lt 10yrs old Pregnant women Neutropaenic patients Renal patients Pre operative urology patients Pre orthopaedic implant surgery Suprapubic aspirates Pyelonephritis Recurrent persistant symptoms Patients undergoing planned catheter change with a history of infection Patients with heart valve lesion septal defect patent ductus or prosthetic valve Lower urinary tract infection MRSA positive patients Self catheterisation Uro sepsis Microscopic haematuria Catheter samples clinically suggestive of UTI eg pyrexia abdo pain etc Male patients with haematuria 4 PROCESSING PROCEDURE Pre analytical overview 4 1 All samples for Urine M C amp S Microscopy Culture and Sensitivity are sent to pathology using a relevant pathology
4. 1 5 Title Microbiology Urine Screening Effective date 05 08 2013 9 8 After 30 seconds the strip holder will de drawn into the analyser for final analysis 9 9 Once the analysis is complete the URYXXON will bleep and generate a print out of the results 9 10 Wipe the strip holder with a tissue between tests 10 PROCESSING PROCEDURE Post Analytical 10 1 Once the results have printed out remove and discard the strip and wipe the strip holder with a tissue to remove excess urine 10 2 IF the sample is NEGATIVE no further action is required 10 3 IF the sample is POSITIVE for either Leucocytes or Nitrites follow the Urinalysis flow chart for advice on further action 10 4 IF the patient is male and is POSITIVE for blood follow the Urinalysis flow chart for advice on further action 10 5 IF the sample is POSITIVE for any of the other parameters refer to urinalysis interpretation sheet 10 6 The URYXXON is now ready for the next test strip 11 RESULTS All samples referred to pathology will be reported on Ultra in the usual way A note of the dipstick result must be entered in the patients notes 12 TROUBLESHOOTING Common errors Printed copies are uncontrolled unless there is an allocated Copy Number on page 1 Author K Halladay Checked by C Gouge Approved by N Roberts Page 8 of 14 RUH Bath NHS Trust Pathology Department STANDARD OPERATING PROCEDURE QMS SOP SP URI 11 5 Title Mic
5. a as set down on the results sheet then the analyser must be taken out of action and the failure reported immediately to pathology on the numbers provided Acceptance Criteria results for QC should fall within the limits as indicated on the QC results sheets provided as given by the manufacture 9 PROCESSING PROCEDURE Dipping and Analysis 9 1 QC needs to be run on a daily basis Remove QC from fridge and allow to warm for 15 minutes 9 2 Record QC results on sheet provided 9 3 Ensure the URYXXON is switched on in sleep mode the screen remains blank to wake it up just touch the screen 9 4 Invert the urine gently 9 5 Remove lid and immerse the strip so that all the tests are covered 9 6 Quickly remove the stick blot off the excess urine and place on the strip holder N B As soon as the test strips come into contact with the urine the reaction starts There should be as little delay in placing the strip on the strip holder as possible to avoid false results 9 7 As soon as the strip is placed on the strip holder the URYXXON will detect it and begin the analysis A count down bar will display on screen to show the progress of the reaction Printed copies are uncontrolled unless there is an allocated Copy Number on page 1 Author K Halladay Checked by C Gouge Approved by N Roberts Page 7 of 14 RUH Bath NHS Trust Pathology Department STANDARD OPERATING PROCEDURE QMS SOP SP URI 1
6. ent symptoms despite empiric therapy Pregnant women Male with symptoms suggestive of a UTI YES Pre operative urology patients Pre orthopaedic implant surgery Male with haematuria Please ensure that the indication for the urine test is clearly marked on the request form NO YES HES Is the patient systemically unwell Is the patient catheterised HIGH LOW Clinical Assessment What is the probability of lower urinary tract infection e g Frequency dysuria haematuria Positive Nitrite or Leukocyte Negative Positive Nitrite or Leukocyte Negative Esterase Result Esterase Result Positive either or both test positive Positive either or both test positive Negative both tests negative Negative both tests negative Supports Diagnosis Consider Empirical Therapy Excludes UTI No need to senda sample UTI Possible Send sample to microbiology Consider Alternative Diagnosis Send sample to microbiology and consider empirical therapy Send sample for culture Send sample for culture Do Not Send sample for culture unless patient due for re catheterisation and has either a history of catheter associated urinary tract infection following catheter change or a heart valve lesion septal defect patent ductus or prosthetic valve Printed copies are uncontrolled unless there is an allocated Copy Number on page 1 Author K Halladay Checked b
7. f tests depends on the prevalence of the disease in the population tested and the N LE tests are best interpreted after making an assessment of the likelihood of UTI in the patient to be tested please refer to attached flow chart In a typical population of patients presenting with symptoms where UTI enters the differential diagnosis the prevalence of UTI is about 20 In those with a high gt 50 clinical probability of UTI symptoms or signs referable to the urinary tract such as frequency dysuria loin pain tenderness gross haematuria and a positive N LE test either or both positive the post test probability of infection is in the region of 90 Printed copies are uncontrolled unless there is an allocated Copy Number on page 1 Author K Halladay Checked by C Gouge Approved by N Roberts Page 9 of 14 RUH Bath NHS Trust Pathology Department STANDARD OPERATING PROCEDURE QMS SOP SP URI 11 5 Title Microbiology Urine Screening Effective date 05 08 2013 Those without these characteristics have a low clinical probability lt 50 of UTI and if the N LE tests are both negative the post test probability of infection is lt 5 13 3 Glucose Detects urine glucose gt 200 mg L 1 1 mmol L The test is not diagnostic for diabetes mellitus and should not be used for this purpose A negative result does NOT exclude DM A fasting blood glucose should be measured for diagnosing DM refer to WHO g
8. he Medi Test Combi 8 dipsticks include blood protein nitrites ketones glucose pH specific gravity and leucocytes The screening procedure for referral for culture will be based upon the presence of either leucocytes leucocytes esterase and or nitrite or the presence of blood in male patients and the clinical findings Urine Dipstick can not be done on urine samples collected into boric aid collection pots a plain urine is required Printed copies are uncontrolled unless there is an allocated Copy Number on page 1 Author K Halladay Checked by C Gouge Approved by N Roberts Page 3 of 14 RUH Bath NHS Trust Pathology Department STANDARD OPERATING PROCEDURE QMS SOP SP URI 1 1 5 Title Microbiology Urine Screening Effective date 05 08 2013 2 PROCEDURAL SUMMARY FLOW CHART The specimens are taken by the patient on instruction from a Doctor Taking note of the dipstick exceptions list samples are either tested or referred direct for culture All samples positive for Leucocytes and or Nitrites are sent to the lab accompanied with an ICE request or a blue microbiology form Those samples where some or all of the other tests are positive may not be of a microbiological aetiology and may require further investigation Those samples from male patients that show positive for blood may result from a microbiological aetiology and may require further investigation Following the Urinalysis
9. ng removed the strip holder the two sensors require cleaning by wiping with a sterile cotton tipped applicator dampened with distilled water 3 After cleaning the strip holder should be put back into its transport mechanism carefully The rectangular notches of transport mechanism and stick retainer must be placed on top of each other 4 Record on the QC Maintenance log for the appropriate instrument Periodic maintenance 1 Wipe off urine residues from the strip holder with a tissue after each measurement This prevents crustification and drying of urine residues 2 The instrument housing maybe wiped with a cloth using warm water with detergent or with a clini wipe 3 Record on the QC Maintenance log for the appropriate instrument For further details refer to User manual Printed copies are uncontrolled unless there is an allocated Copy Number on page 1 Author K Halladay Checked by C Gouge Approved by N Roberts Page 6 of 14 RUH Bath NHS Trust Pathology Department STANDARD OPERATING PROCEDURE QMS SOP SP URI 11 5 Title Microbiology Urine Screening Effective date 05 08 2013 8 QC PROCEDURE All URYXXON analysers must pass the QC prior to analysis There are two QC levels QC 1 Negative amp QC 2 Positive Each level must be tested at the beginning of each day on all analysers and the results recorded on the relevant QC chart for each analyser If any of the QC fail the criteri
10. request through ICE where available or on a microbiology form 4 2 All sample will be reviewed and processed with reference to the must culture exceptions list URGENT sample being processed in the Hot Lab 5 PROCESSING PROCEDURE Catheter Urine Samples Those CSU samples that do not fall into the must culture category and do not show clinical details suggesting UTI will be requested and reported as below Sample not processed for urine dipstick Printed copies are uncontrolled unless there is an allocated Copy Number on page 1 Author K Halladay Checked by C Gouge Approved by N Roberts Page 5 of 14 RUH Bath NHS Trust Pathology Department STANDARD OPERATING PROCEDURE QMS SOP SP URI 11 5 Title Microbiology Urine Screening Effective date 05 08 2013 Culture of Catheter urine is rarely indicated No relevant clinical details given on request form so specimen NOT processed Please discuss if clinical concerned 6 PROCESSING PROCEDURE Old Samples All urine samples should be processed on day of collection Samples that fall outside this time frame will still be tested and a comment entered indicating that the sample was received more than two days after collection 7 MAINTENANCE Daily Maintenance 1 The strip holder can be removed from its transport mechanism and cleaned with water Make sure the instrument is turned off before removing the test slide 2 Havi
11. robiology Urine Screening Effective date 05 08 2013 If an error is encountered first repeat the test with a new dipstick If the error persists switch the analyser off then on again If the analyser does not detect the strip in the black holder wipe the sensors with a damp cotton bud Refer all problems to one of the contact names in pathology from the sheet provided 13 URINALYSIS USING DIPSTRIPS 13 1 NITRITES Detects a product of bacterial metabolism this test is specific for the presence of bacteria but not very sensitive not all bacteria produce nitrites Testing of old urine specimens may result in false positives due to the proliferation of scanty perineal flora with time 13 2 Leucocyte Esterase LE Detects the presence of polymorphonuclear leucocytes involved in the inflammatory response This test is sensitive but not very specific eg leucocytes may have been picked up from elsewhere in the genitourinary tract due to an infection inflammation from other causes eg catheterisation or stones or from other conditions such as analgesic nephropathy or tumours Used in combination the nitrite and leucocyte esterase N LE tests are helpful for the assessment of patients with suspected UTI and have been evaluated for predicting UTI in a variety of inpatient outpatient and general practice populations where they have been found to have a sensitivity and specificity equivalent to microscopy The performance o
12. t is not specific for any particular cause of renal dysfunction A positive test must be followed up with appropriate laboratory investigations e g microscopy renal function tests etc False negative may occur if there is a lot of ascorbic acid vitamin C in the urine e g patient on supplements False positive may occur as a result of contamination of the sample with menstrual blood flow or external injury to the urethral tract Printed copies are uncontrolled unless there is an allocated Copy Number on page 1 Author K Halladay Checked by C Gouge Approved by N Roberts Page 11 of 14 RUH Bath NHS Trust Pathology Department STANDARD OPERATING PROCEDURE QMS SOP SP URI 11 5 Title Microbiology Urine Screening Effective date 05 08 2013 See below 14 Other Sources of error using dipstrips Problem May cause Solution Dipsticks out of False results due to Discard strips and repeat the date or altered reagent activity test with a new vial of test strips inappropriately stored Reading strip False results Repeat test reading the results after too short at the appropriate time i e 60 or too long a 120 seconds for leucocytes 30 time interval 60 seconds for everything else NB different makes of dipsticks will have different reaction times Inappropriate False results due to Collect a fresh specimen using specimen pot residues of disinfec
13. tant appropriate specimen pot and or sampling and detergents and or sampling vessel and re vessel test Old sample False results Collect a fresh urine sample and test within 2 hours of collection Test strip pot Wrong results Ensure that the arrows on the held the wrong test strip are aligned to those on way round when the label before comparing to comparing test the colour scale strip to reference colour fields Highly coloured May mask the Be aware that test field colour urine e g colouration of test fields changes may be affected when medical dyes or giving false positive or interpreting results beetroot false negative results pigments Various drugs Falsely high or low Be aware of any medications results that the patient is taking and their effect on urine dipstick testing 15 Urinalysis Flow Chart Printed copies are uncontrolled unless there is an allocated Copy Number on page 1 Author K Halladay Checked by C Gouge Approved by N Roberts Page 12 of 14 RUH Bath NHS Trust Pathology Department STANDARD OPERATING PROCEDURE QMS SOP SP URI 11 5 Title Microbiology Urine Screening Effective date 05 08 2013 Does this urine sample need to be sent to microbiology for culture Is the patient in the complicated group of patients Children lt 10y old Neutropenic patients Renal patients Suprapubic aspirates Pyelonephritis Recurrent persist
14. uidelines False negative may occur in a very old urine or if there is a lot of ascorbic acid vitamin C in the urine e g patient is on supplements 13 4 Protein Detects urine protein gt 300 mg L 13 5 pH Detects how acidic or alkaline the urine is Usual pH value is 5 6 on a freshly passed sample A very alkaline urine pH gt 9 0 may be associated with a urinary tract infection However a high pH value may also indicate that the sample is old or has not been stored properly and is therefore unsuitable for other tests on the dipstick Some tests on the dipstick strip may give false results if the pH of the urine is too high e g protein 13 6 Ketones Detects urine ketones gt 100 mg L Useful in rapid assessment of possible diabetic ketoacidosis a positive result gives strong evidence that the patient has DKA However the test is NOT diagnostic and a laboratory blood glucose must be urgently performed as well False positive may occur if urine has a very low pH 13 7 Blood Detects haemoglobin or erythrocytes in urine gt 5 erythrocytes ul Printed copies are uncontrolled unless there is an allocated Copy Number on page 1 Author K Halladay Checked by C Gouge Approved by N Roberts Page 10 of 14 RUH Bath NHS Trust Pathology Department STANDARD OPERATING PROCEDURE QMS SOP SP URI 11 5 Title Microbiology Urine Screening Effective date 05 08 2013 A positive tes
15. y C Gouge Approved by N Roberts Page 13 of 14 RUH Bath NHS Trust Pathology Department STANDARD OPERATING PROCEDURE QMS SOP SP URI 11 5 Title Microbiology Urine Screening Effective date 05 08 2013 Copy number Location held GU Medicine Children s Ward Children s Outpatients Diabetic Centre ED Minors Urology oja RO PO Printed copies are uncontrolled unless there is an allocated Copy Number on page 1 Author K Halladay Checked by C Gouge Approved by N Roberts Page 14 of 14

SOP for Microbiology Urine Screening

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