Pre analytical in lab testing

Slides on medical laboratory testing process and pre-analytical factors that might contribute to laboratory errors and sample rejection, and how to prevent it.

1. Pre Analytical Factors & Rejection – T he dark side in laboratory testing Dr Normila Abd Hadi Department of Pathology & Transfusion Hospital Kuala Krai

2. Table content Medical errors and errors within laboratory total testing process Impact of sample rejection Pre analytical variables in laboratory total testing process Common sample issues Ways to minimize pre-analytical errors Conclusion

3. Medical Errors The complexity of the current healthcare environment has increased the potential of medical errors. Statistics by the Institute of Medicine (IOM):- Hospital-based errors is 8th leading cause of death in US Medical errors contribute to >1 million injuries and approximately 44k - 98k deaths in hospital annually These errors results in 2.4 milion extra days of hospitalization thus increase hospital costs. A study of medical errors published in the New England Journal of Medicine: 11% of patients recieved potential harmful care 46% of patients did not recieved the recommended care

4. Laboratory service & testing Laboratory services are the backbone of the modern healthcare sector. Laboratory testing provides essential information used by physicians. An estimated 60-70% of medical decisions are based on laboratory test results. (Regan M & Forsman R, 2006) Lab tests are increasingly important position in the diagnostic process in monitoring the effect of therapy in monitoring health of the individual

5. Laboratory Total Testing Process Total testing process starts and end with patient Laboratory Total Testing Process A series of activities, starting with the clinical question in the clinician's mind, leading to test selection, sample collection, transport to the laboratory, analysis, reporting back to the clinician, and final interpretation and decision making by the clinician

6. Laboratory Total Testing Process Any error occurred in any phase can cause rejection Laboratory Total Testing Process

7. Laboratory Errors Hammerling J.A, 2011 “a ny defect from ordering of tests to reporting of results and appropriately interpreting and reacting on this”’ (Hawkins R., 2012)

8. Review of lab errors by processing phase R eference Preanalytical % Analytical % P ostanalytical % Goldschmidt and Lent 53.0 23.0 24.0 Nutting et al. 55.6 13.3 30.0 Plebani and Carraro 68.2 13.3 18.5 Stahl et al. 75.0 16.0 9.0

9. Examples Primary rejection

10. Examples Secondary rejection

11. Impacts of rejection Patients Delayed diagnosis and treatment Misdiagnosed and inappropriate treatment Increased risks to patients safety Discomfort and stress imposed on patient Prolonged hospital stay and increase cost of health care Sol F. Green “The cost of poor blood specimen quality and errors in preanalytical processes” Clinical Biochemistry 2013 Liyun Cao Et Al. “Causes and Impact of specimen rejection in a clinical chemistry laboratory” Clinica Chimica Acta 2016

12. Medical outcome as a result of laboratory errors Sol Green “Improving the preanalytical process: The focus on specimen quality” Data management and Biostatictics Journal 2008

13. Impacts of rejection Laboratory Prolonged turn around time Extra work – communicate between clinicians and lab personal Extra expenditure/cost for recollection and retesting and reanalysis. re-venipuncture Cost – syringe, tube, form Reagent use Sol F. Green “The cost of poor blood specimen quality and errors in preanalytical processes” Clinical Biochemistry 2013 Liyun Cao Et Al. “Causes and Impact of specimen rejection in a clinical chemistry laboratory” Clinica Chimica Acta 2016

14. IMPACT OF SPECIMEN REJECTION AND RECOLLECTION Recollection added an average of 108 min to turnaround time of the test The total cost of specimen recollection and reanalysis was around $ 43,210 USD Liyun Cao et al, “Causes and impact of specimen rejection in a clinical chemistry laboratory” Clinica Chimica Acta 2016

15. The pre - analytical phase The most error-prone part of laboratory testing due to its complexity due to presence of many steps that occur outside as well as inside the laboratory most of the errors occur outside the lab

16. Source of PRE ANALYTICAL variation in laboratory analysis Physiological/biological factor Beyond control of phlebotomist/lab staff Technical/pre-analytical factor Within control of phlebotomist/lab worker

17. P hysiological and biological factors

18. Technical/pre analytical factors Within control of phlebotomist/lab staff These may be divided into two broad categories Category Variables Sample collection Pt identification and sampling Phlebotomy technique Sample volume Collection tube Sample handling Storage Agitation, centrifugation Transport conditions Delays in transport to the lab for processing

19. Root causes of Pre-analytical variables The most frequently encountered causes of pre-analytical errors are: hemolysis incorrect patient identification insufficient sample volume, and clotted specimens (Salvago et. al J Eval Clin Pract 2008 )

20. Sample collection - Incorrect p atient identification Most important steps in venipuncture procedure . Incorrect patient identification prior to sample collection is one of the major & most dangerous source of pre-analytical error. This can result in may be fatal if an acute haemolytic transfusion reaction occured . delayed diagnosis additional lab testing treatment of a patient for the wrong medical condition

21. ...Incorrect patient identification Outpatients : to be asked of full name. This is verified with the information on the request form Inpatients : check identification band to verify name and hospital identification number match to the order Young or mentally incompetent patient : need to ask patient’s parent, relative or nurses in-charge to identify him/her

22. Best practice: Draw and label the specimen at the bedside Do not label tube prior to venipuncture The outpatient must not be dismissed before labelling is complete Make sure the information on the request form and sample are tally ...Incorrect patient identification

23. Actual time of collection The concentration of many analytes fluctuates over 24 hours These includes cortisol, hemoglobin, potassium, sodium, renin and aldosterone Test Subjected to diurnal variation Acid phosphatases* ACTH Cortisol (& other adrenal steroid) Growth hormone Insulin Parathyroid hormone Renin/aldosterone TSH* Testosterone* *higher in afternoon and evening All others higher in the morning Test affected by meals LDH Phosphate* Potassium* Sodium TG Urine pH Glucose Growth hormone Insulin Ionized calcium *lowest after meal; all others higher Sample collection – Sampling time

24. Best sites for venipuncture are superficial veins of the upper limb Median cubital vein Cephalic vein Basilic vein Sample collection – Sampling site

25. Inappropriate site include Arm on side of mastectomy Oedematous areas Hematomas Damaged veins ( eg. Thromboses, non-elastic veins) Scarred areas Arms with fistulas or vascular grafts Site above IV cannula** Common prob: NaCl drip  ↑ Na & Cl (other analytes ±↓) …Sampling site

26. Tourniquet applications Aim for max application time of 1 minute to avoid localised stasis with haemoconcentration increased Alb, T. protein & protein-bound analytes ( e.g Calcium, Tbili , Chol, iron) Inappropriately narrow gauge needle  leading to clotting & haemolysis of sample Allow alcohol to dry before sample collection  leading to haemolysis Sample collection – Phlebotomy technique

27. …Phlebotomy technique Order of draw To avoid contamination of anticoagulant  erroneous results Follow specific recommended ‘order of draw’ Blood culture tube ↓ Coagulation tube(light blue) ↓ Serum tube ↓ ↓ Heparin tube ↓ EDTA ↓ Glycolytic inhibitor- glucose

28. …Phlebotomy technique EDTA contamination

29. …Phlebotomy technique Appropriate volume Appropriate blood to additive ratio needs to be maintained by allowing tubes to fill with blood until the flow stops (vacuum exhausted)

30. Correct volume of blood drawn Crucial in ensure sufficient sample for analysis Also to avoid under filling or over filling volume impact Insufficient sample is one of commonest cause for rejected sample

31. Fill volume impact Under filling Over filling Can lead to excessive concentration of heparin Can interfere with some tests results ( eg. Reduced values for ionised calcium & Magnesium) In gel tube, under filling will increase gel-to-specimen area ratio, which increase adsorption of some analytes to gel Dilution of additive Inadequate anticoagulation, leading to formation of micro clots in plasma which can affect instrument performance

32. Mixing of tubes Inappropriate mixing may cause clotting and cannot processed for FBC testing Clotting may produce false leucopenia , low RBC count & hematocrit Micro-clots interfere with instrument performance Leading to downtime  delay processing and test reporting …Phlebotomy technique

33. Delays of >6 hours between collection and processing of INR or PT samples can cause significant changes in results ( i.e >10%) Delayed transportation to the lab affects some test result E.g : K, AST, ALT etc Improper preservation e.g ice or not  ACTH, ammonia, lactate etc Sample handling

34. Common sample issues

35. Haemolysis of sample Haemolysis - breakage of the RBC’s membrane, causing release of Hb and other internal components into the surrounding fluid Test affected: K, LDH, AST, bHCG, CK, coagulation test, iron, digoxin Degree of haemolysis….

36. Haemolysis of sample Haemolysis can occur from two sources In-vivo haemolysis Due to pathological conditions such as AIHA or transfusion reaction In-vitro haemolysis Can occur due to improper sample collection, processing or transport

37. Hemolysis- during specimen collection

38. Hemolysis - during specimen processing, handling and transportation

39. Reducing the cause of pre-analytical error Quality control Identify and monitor possible causes of pre-analytical errors QA Programs should include monitoring the sample collection process Good practice Understand the current practice vs hospital procedures and best practice Training and education programs Support staff by providing clear and effective training Tracking the cost of poor quality and errors in preanalytical procsses : proven steps labs can use to boost patient outcomes, a lecture by Sol F. Green, BD Preanalytical Systems

40. Ways to minimize pre-analytical errors Comprehensive and standardized training programs reaching a wide range of staffs – HO, SN, MO on : SOP Specific competency assessment Academic seminars to inform impacts of pre-analytical errors on patient diagnoses and and therapy Sol F. Green “The cost of poor blood specimen quality and errors in preanalytical processes” Clinical Biochemistry 2013 Liyun Cao Et Al. “Causes and Impact of specimen rejection in a clinical chemistry laboratory” Clinica Chimica Acta 2016

41. Conclusion Health provider relies on laboratory test results for management of the patients. The lab responsible to provide accurate and reliable test results. The accuracy of test results depend greatly on the quality of the specimens sent to the lab

42. Take home message Fill up request form completely – INCLUDING DATE & TIME of collection Make sure correct sample for correct pt Make sure correct tube container Make sure appropriate sample volume Practice correct order of draw to avoid contamination Any doubt, call lab for enquiry

43. References Regan M, Forsman R. The impact of the laboratory on disease management, Dis Manag . 2006 Apr;9(2):122-30. Robert Hawkins, M.D., Managing the Pre- and Post-analytical Phases of the Total Testing Process, Ann Lab Med 2012;32:5-16. Hammerling J. A., A Review of Medical Errors in Laboratory Diagnostic and Where We Are Today, LABMEDICINE; Vol. 43, No. 2; 2012 Sintayehu A. et al., Errors in the Total testing Process in the Clinical Chemistry Laboratory at the University of Gondar Hospital, Euthopia J Health Sci; Vol. 28, No. 2; 2018