The preanalytical phase is an important component of laboratory medicine. Preanalytical phase a continuous challenge for laboratory. Errors in clinical laboratories or errors in laboratory. Preanalytical phase is nowadays recognized as the most vulnerable part of the total testing process. Table 2 provisional guidance for testing of pharmacological effects on coagulation. Most errors in laboratory test results occur in the preanalytical phase. Donald s young published in 1997 in washington dc by aacc press.
The contribution of laboratory services to patient care plays a key role within the health system. Preanalytical, analytical, and postanalytical phases of. These generally affect the composition of the body fluid before analysis. The preanalytical phase of the testing process has an important effect on the reliability of patients laboratory results and consequently, on the quality of patient care and on patient safety.
Oct 11, 2012 various types of errors that we, as clinical biochemists, encounter in the laboratory are classified as preanalytical, analytical, and postanalytical, depending upon the time of presentation. Documentation of statistical analysis or method validation before put into use and. Preanalytical variables in coagulation testing thieme connect. Reducing preanalytical laboratory sample errors through educational and technological interventions rosa lillo 1, maria salinas 1, maite lopezgarrigos 1, yurena naranjosantana 1, mercedes gutierrez 1, maria dolores marin 1, manuel miralles 1, joaquin uris 2 1 clinical laboratory department, university hospital of san juan, alicante, spain. There are some variables that can cause errors in the preanalytical phase of the laboratory testing. Jul 01, 2016 preanalytical variation includes all the steps that occur from test ordering until right before sample analysis. Postanalytical phase quality assurance for laboratory. Preanalytical variables and their influence on the quality of. Mario plebani department of laboratory medicine, university hospital of padova and center of biomedical research, castelfranco veneto, italy abstract laboratory testing is a highly complex process and, although laboratory services are relatively safe, they. The effects of analytical bias on medical and econom. Preanalytic variables in laboratory testing laboratory. Advancement in instrumental technology and automation have simplified work in terms of analytical quality in laboratory diagnostics and improved the quality of test results. Some of the preanalytical variables such as specimen variables can be. Effects of preanalytical variables on clinical laboratory tests, 3rd edition 9781594250682.
The laboratory staff should aware of all these variables to reduce the errors. The total testing process consists of three separate phasesthe preanalytic, the analytic, and the postanalytic. With the increasing number in laboratory tests per patients, the burden of phlebotomy increased. Defined as errors which occur when non analytical factors change the conc. Most mistakes often occur before the samples are analysed. The serum sample looks reddish effects of haemolysis 80. Module 5 postanalytical phase of laboratory testing once an accurate test result is obtained the lab must report the result in a timely manner by. The preanalytical phase involves specimen collection, acquisition by the laboratory, labeling and coding, and preparation for analysis. Food ingestion is a significant source of preanalytical variability. Effects of preanalytical variables on clinical laboratory. In this lesson, sources of errors for the preanalytic and postanalytic phases of the total testing process are discussed, along with possible solutions. Pre analytical errors have a major impact on diagnostic accuracy of laboratory results.
Quality indicators to detect preanalytical errors in laboratory testing. Preanalytical variables and their influence on the quality of laboratory results author sheshadri narayanan 1, walter g. Diagnosis, laboratory standards handbooks handbooks effects of preanalytical variables on clinical laboratory tests edited by donald s. The quantity of errors in the postanalytical phase makes it the second most affected in the ttp as previously stated. Preanalytical errors in laboratory their consequences and measures to reduce them. Examples of preanalytic variables affecting mainly clinical chemistry, hematology, and coagulation tests are discussed. Reducing preanalytical errors whitehat communications. All the samples received in the hematology laboratory of dayanand medical college and hospital, ludhiana, india over a period of one year july 20july 2014 were included in the study and preanalytical variables like clotted samples, quantity not sufficient, wrong sample, without label, wrong label were studied. There have been tremendous work and established quality control criteria for analytical phase of testing but. Preanalytical variables and their influence on the quality. Preanalytical variables and factors that interfere with. It includes specimen collection, handling and processing variables. It starts and ends with the patient remember that the laboratory testing process begins and ends with patient care all laboratory tests must be interpreted in light of the clinical situation although lab testing may yield unexpected results that are critical in guiding further patient evaluation. A companion reference to effects of drugs on clinical laboratory tests, effects of disease on clinical laboratory tests, and effects of herbs and natural products on clinical laboratory tests, this new edition completes the background information of what you need to know to interpret clinical laboratory test values.
Better control of these variables will improve the total. The optimal sample volume needed for laboratory tests has been. Preanalytical variables and their influence on the quality of laboratory results article pdf available in laboratoriumsmedizin 265 april 2001 with 932 reads how we measure reads. A retrospective analysis of the results obtained from the clinical chemistry laboratory for errors in the preanalytical phase has been carried out to summarize data regarding the frequency of the main factors affecting the preanalytical quality of results. Only registered clinical laboratory scientists are employed in our cap college of american pathologistsinspected lab.
Due to their impact on the quality of results of laboratory testing, preanalytical errors have been included within the greatest challenges to the laboratory professionals, during the last 20 years 1,2. Advances in instrument technology and automation have simplified tasks in laboratory diagnostics and improved the quality of test results. By identifying all preservatives compatible for each test, many tests can be conducted from one 4hour collection. These variables are patient variables age, gender, diet, medication, body mass etc. Errors in clinical laboratories or errors in laboratory medicine. Pdf preanalytical phase in clinical chemistry laboratory. Although the laboratory approximately spends only up to 10% of the total hospital budget, it delivers almost 70% of the diagnostic information per patient. Many preanalytical variables may affect the results of routine coagulation. According to bd and clsi clinical and laboratory standards institute, formerly nccls, following is the correct order of draw during venipuncture will help to ensure accurate test results.
Three phases of laboratory testing analytical phase analyzers and equipments calibration thank you. Preanalytical variables account for 5075% of the errors with laboratory. Recognition of preanalytical variables causing changes in laboratory results every laboratory should have a strategy for recognizing preanalytical errors. Many factors other than disease influence the results of chemistry tests. Making sense of conflicting priorities in the laboratory. Preanalytical, analytical, and postanalytical phases of testing the preanalytic testing phase occurs first in the laboratory process. Reducing preanalytical laboratory sample errors through. The challenge to todays laboratory managers and phlebotomy supervisors is to continually teach and enforce sound blood collection and. Preanalytical phase an overview sciencedirect topics.
Effects of preanalytical variables on clinical laboratory tests. Three phases of laboratory testing by shane richel esterban. The impact of preanalytical variables on sample quality in. The interpretation of clinical laboratory test results michael schaer, dvm, diplomate acvim, acvecc university of florida, college of veterinary medicine with the advent of modern medical technology, the availability of hematological and serum biochemical data to the veterinary practitioner has become commonplace. Lab results lead to clinical action 7080% of all clinical decisions regarding patient care are based on lab results coag samples are especially susceptible sample collection initiates clotting pt and ptt are complex enzymatic reactions 1. Preanalytical errors in laboratory their consequences and. Apr 02, 2014 test precautions, introduction, pre analytical phase,clinical laboratory science. Preanalytical variableserrors are often unknown testing personnel. Effects of preanalytical variables on clinical laboratory tests, 3rd. The analytical phase involves the actual running of the test, while the postanalytical. The potential to affect assays and proposed verification and validation. Preanalytical errors in laboratory their consequences. Test precautions, introduction, pre analytical phase. Preanalytical errors and their impact on tests in clinical laboratory practice pakistan journal of medical research, 2012 january march 29 phlebotomy practices should be adopted by all health care workers.
Preanalytical errors and their impact on tests in clinical laboratory practice. Various types of errors that we, as clinical biochemists, encounter in the laboratory are classified as preanalytical, analytical, and postanalytical, depending upon the time of presentation. The national committee for clinical laboratory standard in the usa update their guidelines on various aspects of preanalytical variables. Information and translations of preanalytical in the most comprehensive dictionary definitions resource on the web. Our laboratory information system lis shows previous results on patient blood tests, no matter what saint lukes health system slhs entity last tested the patient. Effects of preanalytical variables on clinical laboratory tests, american journal of clinical pathology, volume 101, issue 4, 1 april 1994, pages 549.
Feb 15, 2014 preanalytical errors contd order of draw. Under the broad umbrella of the preanalytical phase can be included specimen collection, handling and processing variables, physiological variables such as the effect of lifestyle, age, gender, pregnancy and menstruation and endogenous variables such as drugs and circulating antibodies. Preanalytical variablespreanalytical variables tapeshwar yadav lecturer bmlt, dnhe, m. Weve often heard the opinion that the quality control of laboratory testing isnt the biggest problem were facing. Learn phlebotomy exam chapter 9 preanalytical with free interactive flashcards. Preanalytical errors and their impact on tests in clinical laboratory. Most errors affecting laboratory test results occur in the preanalytical phase, primarily because of the difficulty in achieving standardized procedures for sample collection. The resource centre contains an introduction to preanalytical variables and updated materials on the latest preanalytical guidelines, preanalytical flow charts, literature, in focus and useful links. In general, for testing 20 analytes in clinical chemistry, 3 to 4 ml of whole.
Pdf preanalytical variables and their influence on the. Quality in the preanalytical phase of laboratory activity can be assured by implementing a quality system that complies with the iso 15189. Mayo clinic laboratories is approved as a provider of continuing education programs in the clinical laboratory. Pre analy tical phase in clinical chemistry laboratory sohini sengupta neogi, 1 mohit mehndiratt a, 2 stuti gupta, 2 dinesh puri 2 department of 1 bioc hemistry, sir gangaram hospital, delhi and. In particular, this international standard, specifically developed for medical laboratories, takes into account both quality issues and the competence needed to deliver a state of theart.
Like all clinical testing, molecular genetics involves several steps. Clinical biochemistry preanalytical aspects of laboratory. Preanalytical variables and the impact on quality test results. Preanalytical variables in poct and their impact on test results. Preanalytical variables in coagulation testing and. Each laboratory should have a quality manual addressing preanalytical variables and device measures to recognize and control these crucial components of laboratory quality. For everyone involved in patient care and using or performing laboratory tests.
Preanalytical variables and the impact on quality test results author. Preanalytical errors are quite frequent in the area of pointofcare testing poct. Three phases of laboratory testing by shane richel. As with the preanalytic phase, the errors of the postanalytical can occur either inside or outside of the laboratory. The preanalytical phase is an important component of laboratory medicine 1,2,3, 4. Effects of preanalytical variables on clinical laboratory tests ghent. Article id 1200107 preanalytical phase preanalytical. Clinical decisions based on laboratory test values are correctly made only when the. Effects of preanalytical variables on clinical laboratory tests young, donald s. Preanalytical variation in clinical laboratory testing. Preanalytical variation includes all the steps that occur from test ordering until right before sample analysis. Using an electronic process allowing for acceptable results to be transmitted electronically via an interface between the analyzer and lab information systemlis and then via another interface between the lis and the electronic medical. This section contains a list of preanalytical guidelines associated with the preanalytical phase in laboratory medicine to help you improve the efficiency and effectiveness of healthcare testing. Lipemic samples lipemic samples are often seen following collection after heavy meals or the due to pre existing metabolic.
Test precautions, introduction, pre analytical phase,clinical laboratory science. Critical preexamination variables in the hemostasis laboratory and their quality indicators. Identification of the types of preanalytical errors in the. Preanalytical variables account for 3275% of laboratory errors, and encompass the time from. The impact of preanalytical variables on the quality of laboratory results. These factors may be preanalytical, analytical and postanalytical. Preanalytical and postanalytical qc often these papers play a zerosum game, emphasizing pre and postanalytical quality while diminishing the importance of analytical quality. While the likelihood of variation in any of the three phases is not negligible, the vast majority of laboratory variation emerges from the many factors affecting laboratory specimens prior to testing. This webinar will provide background on commonly performed coagulation screening tests but also discuss the impact of preanalytical variables on these tests. First of all, poct testing is usually performed by clinical staff i. This site aims to raise awareness in the laboratory and medical community, and improve the safety and efficiency of laboratory services by controlling preanalytical variables to more effectively manage clinical outcomes. Effects of preanalytical variables on clinical laboratory tests, 2nd edn. By continuing to use our website, you are agreeing to our use of cookies.
Preanalytical variables are variables associated with the patient, sample collection and sample handling. Effects of preanalytical variables on clinical laboratory tests, american journal of clinical pathology, volume 101, issue 4, 1 april 1994, pages 549, we use cookies to enhance your experience on our website. Sometime people quote a statistic that 40% of the errors in the laboratory are preanalytical, 40% are postanalytical, and only 20% are analytical. Effects of drugs on clinical laboratory tests d s young. This effect varies based on the analyte and the time between meal ingestion and blood collection. If any of the preanalytical variables are not properly adhered to, incorrect or uninterpretable results are reported resulting in possible adverse patient consequences or delays in treatment. Quality assurance of the preanalytical phase complying with. Admittedly, given the comprehensive range of subject. The accuracy and reliability of a laboratory result depend on the quality of each phase. Preanalytical variableserrors are often unknown to testing. In addition, the authors provide a glossary as well as a separate list of analytes containing the available data on reference intervals, biological halflife times, stability and influence and interference factors. Preanalytical errors and their impact on tests in clinical. Pdf preanalytical variables and their influence on the quality of.
This phase may include specimen handling issues that occur even prior to the time the specimen is received in the laboratory. Preanalytical variables account for 3275% of laboratory errors, and encompass the time from when thetest is ordered by the physician until the sample is ready for analysis. Guder 2 1 department of pathology, new york medical college metropolitan hospital center, new york, ny, 10029, u. Choose from 500 different sets of phlebotomy exam chapter 9 preanalytical flashcards on quizlet. Several studies have documented that most of the errors in the clinical laboratory occur in the pre analytical phase accounting up to 80% 2,4,6, 8, 9. Preanalytical variables and factors that interfere with the.
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