Patient SafetyPreanalytical PhaseVladimir PalickaCharles University Hradec Kralove, Czech RepublicInternational Symposium Patient Safety, Prague, April 12, 2013
Preanalytical PhaseThe Weakest Point in Quality ManagementInternational Symposium Patient Safety, Prague, April 12, 2013
The value of laboratory testing for diagnostics and therapyQuantitativeat minimum 80-90 % of all objective data are results of laboratory or other complementary departmentsQualitativehigh quality information only are of value, the others are dangerous
To err is human:building a safer health systemKohn LT, Corrigan JM, Donaldson MSNational Academy Press, Washington, DC, 2000
Errors in medicine
10-20 % of errors negatively influence health care quality> 3 % of errors are of direct influence on patient safetythe more tests, the more errors
Laboratory error
A defect occurring at any part of the laboratory cycle, from ordering tests to reporting results and appropriately interpreting and reacting to these
ISO/PDTS 22367
negative/risky trends for quality
Consolidation pre-analytical phase
Decentralization (POCT) analytical quality
Outsourcing pre- and post-analytical
Downsizing, shortages total quality
positive trends for quality Integration of automatization and informaticsimproved process control
Standard Operation Proceduresreduction of errors in all phases
Improved contact with clinicianspre- and post-analytical phase
Errors in laboratory medicineanalyticsapprox 15 % (7-13%)
preanalyticsapprox 62 % (46 68%)
postanalyticsapprox 23 % (18 45%)
Total Testing Process Improvementprevalence of errors was reduced byautomationimproved laboratory technologyassay standardizationinformaticsbut mostly in analytical part !
Most common reasons of pre-analytical errorsHaemolysisMisidentificationSampling error (wrong tube, inappropriate amount of the sample)ClottingSample and/or request missingWrong patient preparation
Preanalytical errorsRetrospective analysis2001-20054.715.132 samples in 105 labsThe most common reason for sample rejectionMissing sample (37.5%)Haemolysis (29.3%)(serum 38.6%, plasma 68.4%)Alsina J: CCLM 2008, 46: 849
preanalytical errorsmisidentificationwrong samplingpumping with fistwet skintourniquet timesample mixing (inverting)time for transport and centrifugation
Detection of inappropriatenessVisual inspection of lipaemic, icteric and/or haemolysed samples is
highly unreliable
and should be replaced by automated systems (serum indices)
Haemolysisupper reference limit for free Hbplasma 20 mg/lserum 50 mg/lVisible haemolysis after centrifugationfree Hb > 300 mg/l = 18.8 mmol/l(approximately 0.5% of Ery are lysed)
Haemolysis - reasonsin vivo in vitroUp to 2% samples are haemolysedAt minimum 50 possible reasonsinherited-acquired haemolytic anaemiahaemoglobinopathiasHELLP syndromedrugs, infectionartificial heart valvestransfusion of incompatible blood
Haemolysis common reasonsin vivo in vitroWet skin at sampling siteThin needle (usually < 21 G)Difficult venipuctureFragile veinsVacuum in tube is too highWrong amount of blood for the amount of additive (anticoagulant)
Haemolysis - reasonsInappropriate shaking the sampleTemperature discomfortHigh centrifugation forceLong centrifugationTo early centrifugationLate serum/plasma separationWrong separation barrierRe-centrifugation of gel-tubesPneumatic sample transporting
HaemolysisThe most common reasons of the wrong samples
Frequency40 70% of all rejected samples(5-times more than any other reason)
Haemolysis according deptLippi G, CCLM 47: 616, 2009
Haemolysisincreased concentration/activity:AST, ALT, CK, LDH, lipasecreatinine, urea, Fe, Mg, P, Kdecreased concentration/activity: ALP, GGTAlb, bilirubin, Cl, G, NaSpecial care: newborn bilirubin !!
HaemolysisImmunoassayFalse negative troponin TFalse increase of troponin IFalse increase of PSANegative bias: testosterone, cortisol, FPIAImpossibility to measure:insulin, glukagon, CT, PTH, ACTH, gastrin
In the case of haemolysis
Correction of result(s)Release of results with flags and commentsInformation of ward and new-sample request
In the case of haemolysis
Result correctionMethods with known interference (nm) rejectedRelease unaffected results, onlyPotassium results corrected by recalculation
Should we correct the results ?Haemolysis: potassiumLinear correlationShould we use the index or measured concentration ?different analyzers different indexesdifferent calculation of corrected K =K measured (Hb mmol/l x 5.2)K measured (Hb mmol/l x 10)Bland-Altman: uncertainty 0.4 mmol/l
In the case of haemolysisResult correctionMethods with known interference (nm) rejectedRelease unaffected results, onlyPotassium results corrected by recalculationincorrect, error is too big !intravascular haemolysis ?
In the case of haemolysis
b) Release of results with flags and commentsMany types of commentsWrong decision is quite commonCredibility of lab decreasesExtreme situations?
In the case of haemolysis
c) Information of ward and new-sample requestNonconformity notificationLaboratory book and hospital rulesQuick reaction is necessaryNew sample request
In the case of haemolytic sample
Information to wardConsultationNew sample request
To err is humanbuilding a safer health systemKohn LT, Corrigan JM, Donaldson MSNational Academy Press, Washington, DC, 2000
To err is humanto delay is deadlyConsumer Reports HealthSafe Patient Project.org
Patient Identification Errors
EQA - PAPAAustralia, New Zealand12-year period59 participating laboratories3.9 million specimensPAPA incident rate: 1.22 %most significant incidentPatient or Sample Identification !
Quality System RequirementsISO 15189:2007SOPsJCI: at least two patient identifiersBraceletsbar-codesRFID (radiofrequency identifier devices)automated systems
The most common systemPatient WardsWrist-bands, electronic order, bar-code sticksLaboratoryData terminalHand-held bare code scannerPortable label printersoftware
systems for patient identificationbarcodes
Bar codesHistory: local grocery, 1948Patent was applied for 1949Patent issued 1952Today: more that 2 dozen different linear bar code symbologiesMost frequent used: Code 128, Code 39Error rate expected 1:400.000 1.800.000
Most common sources of errors
Printing defect in the barcodeSuboptimal barcode orientationLack of error detectionScanner resolutionSasavage N: Clin.Lab.News, 2011, Jan
Errors in bar code technologyMore often in POCTMore often on wristband than on paperTake care about printer headsThick black lineTurn the label stock by 90oSnyder ML, Clin.Chem. 2010, 56:1554
Sasavage N: Clin.Lab.News, 2011, Jan
Sasavage N: Clin.Lab.News, 2011, Jan
Sasavage N: Clin.Lab.News, 2011, Jan
Errors in bar code technologyMore often in POCTMore often on wristband than on paperTake care about printer headsThick black lineTurn the label stock by 90oQuality programCleaning and bar code verifier useSnyder ML, Clin.Chem. 2010, 56:1554
systems for patient identificationbarcodesradio frequency identification (RFID)biometricsmagnetic stripesoptical character recognitionsmart cardsvoice recognition
causes of patient misidentificationidentical names
China example60 in-patient sampledin 32 of them (53 percent)common full name shared with 1 101 other patients attending the same hospital (Hong Kong)
Lee AC: Int.J.Health Care Qual.Assur.Inc.Leadersh.Health Serv., 2005:18/1:15
Astion M: Clin.Lab.News 20110,Jan
causes of patient misidentificationidentical nameswristband problemsCAP: 2.6 % errors(missing wristband, ID, illegible, incorrect)
wristband errorsJoin Commission on AccreditationCAP Q-Probesmean wristband error rates5.4 8.4 %after the introduction of QIM< 1.0 %
wristband errors4-years study464 bed public hospitalbar-coded wristbandstotal wristband error rates 10.6-16.5%training sessionstotal wristband error rates 0.4-1.5%
Dhatt GS: CCLM 2001, 49/5: ??
wristband errors2 hospitals in Sweden (230+152 beds)295 nurses/phlebotomistsquestionnaireundesirable practice9.6% not asking name and ID17% not checking identity79% not checking wristband during ID43% using health care card for IDWallin O: Scand.J.Caring Sci. 2010, 24/3: 581
Patient Identification Errorsdifferences between type of labstransfusion medicine 0.05 %clinical chemistry up to 1 %most common reasonsmalpractice (low interest), low adherence to QSRhigh workflowwrong technique
What about relabelingVery strict policyBlood and urine rarely will be candidatesSometimes indicated for irreplaceable specimens(cerebrospinal fluid, bone marrow, surgical)The risk of recollection is greater than a risk for relabelingSOPAstion M: Clin.Lab.News 20110,Jan
home mesageidentification mistakes are not easily detectableno immediate harm or signalmany steps no personal responsibilitymostly not systematicnot considered as the big problemfear of blamehuman factor involved
home mesagepatient identification is common duty of clinicians, phlebotomists and clinical chemiststechnical equipment is necessary(but must be under the control)ISO, SOP, EQA are extremely importanteducation and enthusiasm of people is the corner stone
home mesagebefore any test we should be sure whom are we testing !
Patient safetyand proper careis the target !