I m proving Patient Care w ith better Blood Gas Preanalytics By - PowerPoint PPT Presentation

I m proving Patient Care w ith better Blood Gas Preanalytics By Anne Skurup, Clinical and Scientific Affairs Manager, Radiom eter Medical Aps, Denm ark 22/ 09/ 2017

Agenda  I mpact on patient care  Needle-stick and safety  Patient I D  Bias on results due to sampling device  Sample contamination  I mportance of mixing  Resources for how to:  Get into the details  Troubleshooting  Skill test

Learning Objectives  Review the reasons why careful attention to the preanalytical phase helps to avoid risk to patients  I dentify the steps for healthcare provider to help avoid preanalytical errors  Discuss how preanalytical errors can effect patient results and how these errors can be avoided

The preanalytical phase of arterial blood gas sam pling Preanalytical errors are said “Several aspects of blood pH and to be the reason for up to gas analysis are unique among 6 2 % of all errors in clinical and laboratory laboratory m edicine [ 1 ] . determinations, and, at the same time, no other test results have Error rate more immediate impact on patient care” [ 2] 6 2 % Preanalytical phase CLSI 1 5 % Analytical phase 2 3 % Post- analytical phase 1. Carraro P et al . Errors in a stat laboratory: Types and frequencies 10 years later. Clin Chem 2007; 53,7: 1338-42. 2. CLSI. Blood Gas and pH Analysis and Related Measurements; Approved Guideline – Second Edition. CLSI Document C46-A2. Wayne, PA: Clinical and Laboratory Standards Institute: 2009. 3. www.clsi.org.

Preanalytical quality m anagem ent w orks!  Examples:  “Introduction of recommendations regarding proper blood collection enabled a decrease in the ratio of hyperkalemic samples from 16% to < 5% [ 1] ”  “Impact of the implementation on the process after modification of the preanalytical process… the bias for hemoglobin concentration was drastically reduced…−2 [−10; 5] g/L instead of −19 [− 64; 27] g/ L [ 2] ” 1. Ciepiela O et al. Pseudohyperkalemia in capillary whole-blood samples – an occasional error or a significant problem in a pediatric hospital? Clin Chem Lab Med 2017; 26; 55(8): e159-e162 2. Auvet A, Preanalytical conditions of point-of-care testing in the intensive care unit are decisive for analysis reliability. Ann. Intensive Care 2016; 6: 57

Question A  How often do you have clots in a blood gas sample?  Answers: A. Several times a day B. Once a week C. Once a month D. Never E. Don’t know/ is not registered

Question B  For how long do you mix the sample before analysis?  Answers: A. 3 minutes B. 2 minutes C. 1 minute D. < 1 minute E. Operator decides on sample-by-sample basis F. I s not mixed before analysis G. Don’t know

W ill it im pact patient care?  Which results are you to trust? p O 2 100 mmHg p O 2 90 mmHg c tHb c tHb p CO 2 41 mmHg p CO 2 42 mmHg 10.0 g/ dL 7.2 g/ dL s O 2 98 % s O 2 97.4 % c K + 4.1 mmol/ L c K + 3.4 mmol/ L c Ca 2+ c Ca 2+ c Na + 141 mmol/ L c Na + 147 mmol/ L 1.15 mmol/ L 1.08 mmol/ L c Cl - 100 mmol/ L c Cl - 110 mmol/ L

Operator Safety  Consider:  Use a safety device that limits contact with patient blood  Use a protection device for the safe removal of needles  Ensure procedure for operator safety is established and followed

Operator Safety  Needle-stick injury and unwanted contact with patient blood are daily risks for operators taking blood gas samples.  From the literature[ 1] :  “A total of 10,441 percutaneous injuries were reported from 1998 to 2002”  “7 % occurred in ICUs/ CCUs, ORs (29 % ) and EDs (9 % )” 1. From: Perry J, Jagger J. Reducing sharps injury risk in intensive care www.acutecaretesting.org Jun 2005

Needle-stick injury  Can be caused by:  Unavailability of sampling safety devices for operators  Lack of dedicated procedure for operator safety  Procedures for safety not followed  Can lead to:  Operator concern over own safety  Needle-stick injury  Infection by blood-borne pathogens

Patient and sam ple I D  Consider:  Use at least two patient identifiers [ 2]  Make sure the arterial syringe has a patient ID label attached or  Use a prebarcoded arterial syringe  Always enter a patient ID into the analyzer before analysis  Use barcode readers

Patient and sam ple I D  I ncorrect or missing patient and sample I Ds are some of the most frequent – and critical – preanalytical errors [ 1] . 1. Kahn SE. Specimen mislabeling: A significant and costly cause of potentially serious medical errors. www.acutecarestesting.org Apr 2005

Patient and sam ple I D  From the literature [ 1] :  “Average specimen mislabeling 250/ month  Key staff determined average total cost per mislabeling incident is USD 500  The annual cost: 3000 × USD 500 = USD 1.5 million  Excludes any "downstream" medicolegal or liability costs”  “Bedside barcode labeling system… … reported to reduce specimen labeling errors by 41 % “. 1. Kahn SE. Specimen mislabeling: A significant and costly cause of potentially serious medical errors. www.acutecarestesting.org Apr 2005

Patient and sam ple I D  Errors can be caused by:  Lack of patient identification and/ or sample labeling  Transcription errors due to manual data entry  Lack of a procedure for identifying patient and samples  Errors can lead to:  Noncompliance  Misdiagnosis  Incorrect treatment of a patient  Need for resampling  Lost billing opportunities

W hat preanalytical error?  Same sample  A: Correct  B: WI TH preanalytical error A B c Ca2 + 1 .1 5 m m ol/ L c Ca2 + 1 .0 8 m m ol/ L

Heparin induced bias  Bias on electrolytes m ay be caused by:  Use of heparin that is not formulated to reduce bias on electrolytes

Heparin induced bias  Some facts:  Clots in the sample may interfere with the analyzer and produce inaccurate values [ 1]  Anticoagulation is needed to reduce the clotting of the sample  Heparin is the only anticoagulant that is recommended for blood gas analysis [ 2] 1: Siggaard-Andersen O, Thode J, Wandrup J. The concentration of free calcium ions in the blood plasma “ionized calcium”. In: Siggaard-Andersen O, ed. Blood pH, carbon dioxide, oxygen and calcium-ion. 1 ed. Copenhagen: Private Press, 1981: 163-90. 2. Clinical and Laboratory Standards Institute (CLSI). Blood Gas and pH Analysis and Related Measurements; Approved Guidelines. NCCLS Document C46-A2. (ISBN 1- 56238-694-4). Clinical and Laboratory Standards Institute, 940 West Valley Road, Suite 1400, Wayne, Pennsylvania 19087-1898, USA. 2009

Poll responses  How often do you have clots in a blood gas sample?

Heparin  The higher heparin concentration, the better anticoagulation  “10 IU/ mL may not eliminate clotting and 150 IU/ mL may also not be enough” [ 1]  “When below 200 IU/ mL there is no effect on the blood gases but on electrolytes” [ 2]  In 1960 the conventional heparin concentration adopted was 40 IU/ mL [ 3] 1. NCCLS. Blood Gas and pH Analysis and Related Measurements; Approved Guideline. NCCLS document C46-A [ ISBN 1-56238-444-9] . NCCLS, 940 West Valley Road, Suite 1400, Wayne, Pennsylvania 19087-1898, USA 2001. Summary of Comments and Working Group Responses. C46-P: Blood Gas pH Analysis and Related Measurements; Proposed Guideline. Comment 8 to section 4.2.5. 2. Siggaard-Andersen O. Sampling and storing of blood for determination of acid-base status. Scand J Clin Lab Invest 1961; 13: 196-204. 3. Higgins C. The use of heparin in preparing samples for blood gas analysis. www.acutecaretesting.org Apr 2007.

Heparin  Heparin binds positively charged ions Bias on iCa using non-balanced heparin I U/ m L Bias on c Ca 2 + [ 1 ,2 ] Heparin 15 -0.03 50 -0.15 100 -0.19  Avoided by using electrolyte-balanced heparin 1. Toffaletti J. Use of novel preparations of heparin to eliminate interference in ionised calcium measurements: Have all the problems been solved? Clin Chem 1994; 40,4: 508-09. 2. Sachs C et al . Preanalytical errors in ionized calcium measurements induced by the use of liquid heparin. Ann Clin Biochem 1991; 28: 167-73.

The choice of device m akes a difference “Taken together, two out of the three syringes tested here introduced a clinically significant negative bias” [ 1] A B C A B C A B C A B C 1. van Berkel M et al . Electrolyte-balanced heparin in blood gas syringes can introduce a significant bias in the measurement of positively charged electrolytes. Clin Chem Lab Med 2011; 49,2: 249-52.

CLSI and heparin induced bias  CLSI C46-A2:  5.2.1. “..special preparations of heparin are available, which virtually eliminate the interference form heparin binding of these electrolytes.”  5.2.1. “The ideal collection device for arterial blood sampling is… .containing a small amount of anticoagulant such as lyophilized heparin”  5.2.5: “Although a low concentration of ordinary heparin will reduce the error, it will not eliminate it, and the special heparin preparations discussed above (balanced or dispersed) are preferable”

W hat preanalytical error?  Same sample  A: Correct  B: WI TH preanalytical error A B p O 2 1 0 0 m m Hg p O 2 9 0 m m Hg p CO 2 4 1 m m Hg p CO 2 4 1 .5 m m Hg s O 2 9 8 % s O 2 9 7 .4 %