Best Practices in Blood Cultures: Effective QA

1. Best Practices in Blood Cultures: Effective QA Michael Mitchell, MD, F(CAP) Department of Hospital Laboratories, UMass Memorial Medical Center Worcester, MA

2. Introduction and Overview • Review issues related to bacteremia and fungemia • Review general principles of QA monitors • QA monitors for routine blood cultures • Data analysis • Responses and interventions

3. Bacteremia and Fungemia

4. Significant Bacteremia • Bugs in > Bugs out • Endovascular vs. extra-vascular infection • Bacteremia may be continuous or intermittent • “Organism load” (cfu/mL) is low

5. Clinical Implications • Bacteremic infections are increasing • Bacteremic infection result in high morbidity and mortality • Isolates are more likely to be resistant • Bacteremic infection may cause metastatic, localized complications

6. Risk Factors • Pathogen virulence factors • Host underlying medical conditions • Nosocomial factors

7. Impact of True Positive Cultures • Provides therapeutic and prognostic insight • Informs a general approach to care • Antimicrobials • Critical care interventions • Investigation of sources

8. Impact of True Positive Cultures • Provides a pathogen for further testing • Another indicator of prognosis • Susceptibility testing • Testing for specific virulence factor • Stocked organisms

9. Impact of Contaminated Cultures • Costs to Patient • Additional testing • Unneeded antimicrobial therapy • Additional LOS • Complications of the above!

10. Impact of Contaminated Cultures • Costs to the Institution • $10 to $40 thousand dollars per episode of care! • Patient safety and satisfaction • Public Reporting

11. Quality assurance: general issues

12. Quality Monitors • PROCESS • Analytical • Pre-analytical • Post-analytical • DATA → INFORMATION

13. What is Monitored and ReportedWill Improve…

14. Effective QA Programs • Harmonize Lab’s and Institution’s QA activities • Choose Indicators that reflect quality • Choose Indicators for a assessment of all aspects of analytical process • Engage stakeholders

15. Effective QA Monitor Data • Measurable, reliable and objective • Collection must be achievable • Interpretable and informative • Allow for relevant stratification • Actionable

16. Developing Effective Monitors • Define critical elements in process • Determine informative data • Determine how data will be analyzed • Determine potential “interventions” • Collectable over time; analyze effects of interventions • Determine “Life Cycle”?

17. Microbiologists and Hospital QA • Access to patient-specific and cumulative data • Comfortable with computer databases and analytical tools • Insight into pre-, post- and analytical aspects of quality • Experience working in multi-disciplinary teams • Use of Standards is standard

18. Choose indicators wisely Objective data Easily captured Informative analysis (insight into problems) Subject to intervention Don’t choose too many!

19. Specific QA monitors for blood cultures

20. Resources • CLSI document M-47A: Principles and Procedures for Blood Cultures; Approved Guideline • Cumitech 1C Blood Cultures IV • Various publications (See Reference pages below) • Local process analysis—Ishikawa diagram

21. M-47A Quality Components • Pre-Analytical • Patient Evaluation • Test Selection and Ordering • Sample Collection and Inoculation • Sample Transport • Sample Receipt and Initial Processing

22. M-47A Quality Components • Analytical • Platforms and procedures for detection • Identification of Isolates • Susceptibility testing protocols • Verification of results • Interpretation of results

23. M-47A Quality Components • Post-Analytical • Reporting • Record Management • Consultation

24. UMMMC Quality Monitors • True Positive and Contamination Rates • Single Bottle Cultures • Single Culture Evaluations • Clinically Uninformative Cultures • Stratification by Location • Harmonize with CR-BSI Activities

25. UMMMC Blood Culture QA Initiative • Laboratory • Microbiology, Information Services, Phlebotomy, Quality Management • Critical Care Operations • Infection Control • Patient Safety/Quality Management

26. NPR Report • Lab# • MR# • Patient name • Date and time of collection • Location of collection • Requesting MD • Culture results

27. Activities Related to Blood Culture Quality Review External Benchmarks Provide Educational Resources On-site visits to Units Stress critical aspects for Quality Quarterly monitoring and reporting

28. Specificity Avoid collection through lines. Sterilize of each “barrier” crossed Collection of multiple independent cultures; Avoid excessive cultures Recognize of probable contaminants

29. Skin Decontamination M47 discusses several methods for effective skin decontamination: • Tincture of iodine or chlorhexidine gluconate • 30 second abrasive scrub

30. Specificity: Number of Cultures per Evaluation The risk of a patient having a contaminated blood culture increases arithmetically with the number of cultures obtained.

31. The Cost of Contaminated Blood Culture is High Increased LOS Increased antibiotic treatment Increased numbers of laboratory tests Complications of above

32. Sensitivity: Volume of blood inoculated You have to get bugs in the broth to get a positive blood culture! Typical bacteremia 1 cfu/mL + log10. Linear increased detection as inoculum increases.

33. Sensitivity How do we get volume? Volume of blood per bottle Number of bottles per culture Number of cultures per evaluation

34. Culture Timing Back-to-back cultures may be collected. Wait 48 to 72 hours before repeating evaluation with additional blood cultures. Consider other sources of infection or diagnostic techniques.

35. Prior Probability of Bacteremia or Fungemia CLSI Recommendation: For patients with low prior probability of bacteremia or fungemia, surveillance cultures or extensive test of cure assessments are not recommended.

36. Evaluation Recommendation • Each blood culture: • Collect 20 mL by venipuncture for each culture • Inoculate 10mL of blood each into an aerobic and an anaerobic bottle • Immediately collect a second, independent blood culture

37. If you think about doing a blood culture,DO TWO

38. Inoculum Volume for Adults

39. Data analysis

40. Paper is sooo Last Milenium • Reports • Relevant Fields • Unformated text file • Importable into data management program

41. Blood Culture QA Data Lab # Patient Name Patient MR# Patient Age Collection Date Collection Time Collection Location Submitting MD Aerobic Bottle Result Anaerobic Bottle Result Interpretation (TP, FP)

42. Interpretation of Positive Cultures • Species isolated • Other co-isolated organisms • Isolation of the organism from other independent blood cultures or infected sites

43. Blood Culture Pairs Label bottles so that those from a single collection can be accurately paired Never submit bottles from different collections as a single culture

44. Questionable Positive

45. COLLECTED 1-1 2-2 STERILE CONTAM 2-1 1-2 SUBMITTED CONTAM CONTAM

46. How Have We Done?

47. Performance Over Time

48. Performance Over Time