Blood Culture in Sepsis

1. Blood Culture in Sepsis Prof. MD. Ahmet Başustaoğlu Girne American University Faculty of Health Sciences Kyrenia/Northern Cyprus

2. Anand Kumar, et. All., Chest 2009; 136;1237-1248;

4. Each hour of delay in initiation of effective antimicrobials can increase mortality rates by 7.6%.

7. Sepsis: The medical syndrome Hours to Days % Mortality *Rangel-Frausta, 1995 JAMA 273:117-23

8. Standards and Guidelines • WHO guidelines on drawing blood: best practices in phlebotomy • Blood Culture Ordering and Collection Guidelines Vanderbilt University Medical Center • Johns Hopkins Medical Microbiology Specimen Collection Guidelines • Principles and Procedures for Blood Cultures; Approved Guideline M47-A CLSI (Clinical Laboratories Standards Institude) • Cumitech 1C; Blood Cultures, ASM (American Society for Microbiology)

9. Key Points from CLSI 47-A and Cumitech 1C • Timing of drawing blood cultures • Skin disinfection • Volume of blood to inoculate • Number of blood culture sets • How long to incubate bottles?

10. Gram Positive Staphylococcus aureus Viridans Streptococci Streptococcus pneumoniae Streptococcus pyogenes Enterococcusfaecalis Clostridiumperfringens Anaerobic streptococci Yeasts Candida albicansand otherCandida spp. Other yeastse.g. Cryptococcus neoformans, Histoplasmacapsulatum Gram Negative Salmonella typhi Other Salmonella serovars Brucella spp. Haemophilus influenzae Pseudomonas aeruginosa Acinetobacter spp. Klebsiella spp. Escherichia coli Proteus spp. Bacteroides fragilis Neisseria meningitidis Common organisms associated with sepsis

11. American Journal of Medicine September 2010

12. Blood Culture Indications • Fever (> 38°C) • Hypothermia (< 36°C) • Leukocytosis (> 10.000/µl) • Granulocytopenia (< 1.000/µl) • Hypotension • Regional infections: pneumonia, UTI, … • Renal failure • Immune deficiency CUMITECH Blood Cultures IV, ASM Press 2005 Mylotte and Tayara EJCMID 2000

13. “When is the best time to draw blood cultures on a patient with suspected sepsis?” After an influx of bacteria into the bloodstream there is a lag time of approximately 1 h, after which chillsoccur. Feverthen follows.Draw blood cultures as close as possible to the episode of chills or fever. Do NOT delay, as recovery of microorganisms diminishes with time after the fever spike.Blood Cultures Obtained Prior to Antibiotic Administration Chills Blood Cultures Temp BACTEREMIA LEVEL 30 60 0 Time (min)

14. MEDIA • Multiple nutritionally enriched broth-based culture media have been used successfully. • The most widely used medium is soybean-casein digest broth. Other media include brain heart infusion, supplemented peptone, Columbia, and brucella broths. • Medium formulations designed to enhance the detection of anaerobes, fungi, and mycobacteria are also marketed commercially • Some media with resin or charcoal to inaktivate the antibiotic.

16. Methods of Obtaining Blood for Culture • Venipuncture • Intravascular devices • Venipuncture remains the technique of choice for obtaining blood for culture • Blood cultures obtained from intravascular access devices are associated withgreater contamination rates than obtained by venipuncture through a properly prepared skin site • If needed to be obtained from intravenous linesand similar access devices, should be paired with another cultureof blood obtained by venipuncture to assist in interpretationin the event of a positive result.

17. Skin Disinfection • A positive blood culture represents • Cause of infection • Contamination • Failure to adequately cleaning of the skinincreases the risk that microbial flora ofthe skin, will contaminate the blood culture. • Health care workers who obtain blood culturesare often in a hurry, do not understandthe importance of antiseptic preparationcontact time. Cumitech; Blood Cultures, ASM

18. Skin Disinfection • Povidone-iodine • 2% Tincture of iodine, • 0,2% Chloride peroxide, • 5% Chlorhexidine gluconate • Tincture of iodine, chloride peroxide, and chlorhexidine gluconate are superior to povidone-iodine preparations • Tincture of iodine and chlorhexidine gluconate are probably equivalent • Chlorhexidine gluconate is recommended for older infants, children, and adults • 30 seconds to 1.5 - 2 min of contact time • Chlorhexidine preparations have the advantage of being both colorless and less irritating to skin.

19. Blood-to-Broth Ratio • Human blood contains substances capable of inhibiting microbial growth. • Diluting blood in culture broth reduces the concentrations of these inhibitory substances and concentrations of any antimicrobial agents that may be administered to patients. • Studies that have addressed the blood-to-broth ratio have recommended 5- to 10-fold dilution • Dilutions less than 1:5 may result in reduced yield

20. Methods of Obtaining Blood for Culture • “two-needle” method • “single-needle” method • “transfer set” or “a double-ended needle” method • Higher contamination rates with the single-needle method (3.7%) compared with the two-needle method (2.0%), • the higher rates are tolerated in order to reduce the risk of occupational needle-stick injuries

21. Methods of Obtaining Blood for Culture • Using a transfer set or a double-ended needle, • Low contamination risk • Low blood-borne pathogen risk • Taking the proper amount of blood

22. Blood Culture At least 2 blood culture sets should be drawn in critically ill patients with suspected sepsis Catheter-drawn blood cultures Catheter-drawn blood cultures are equally likely to be truly positive (associated with sepsis), but more likely to be colonized (J Clin Microbiol 38:3393, 2001.) Both drawn through vein PPV of 98% One drawn through catheter and other though vein PPV of 96% Both drawn from catheter PPV 0f 50% Study of positive coagulase negative Staphylococcus cultures and sepsis (Clin Infect Dis. 39:333, 2004.)

23. Use of Anearobic blood culture bottles; • When one aerobic andone anaerobic bottle was used, a significantly increased yield of some agents was demonstrated; • Streptococci, Staphylococci,Enterococci • Enterobacteriaceae, Anaerobes • In a study by Akyar et al. (Acıbadem University) out of all the positive cultures; • 172 (%24.3) was only in anerobic bottles, • 310 (%43.7) was only in aerobic bottles, • 227 (%32) was both aerobic and anerobic bottles

24. “The patient is already on antibiotics, would resin-based media help to recover the organism?” • Approximately 28-62% of patients are already on antibiotics when the first blood culture is obtained!!! • In patients overall, resin media are superior to media without resins • The difference is greatest in those patients already on antibiotics…and too many patients are on antibiotics when blood cultures are obtained! • Therefore, best practice would be to use resin media routinely!

25. Checklist for Blood Cultures beforeLeaving the Patient’s Bedside As with all specimens submitted to the laboratory, blood culture vials should be labeled with the appropriate identification information showing • date and time of collection, • the identification of the patient (barcode), • All bottles or tubes and requisitions are labeled with collector’s employee name, number, or code. • The specific site of collection (which vein, which arm, etc.) is recorded for each set of bottles or tubes obtained • Examples of such a code are as follows: • AL, arterial line; • DIALL, dialysis catheter left; and • MEDL, mediport left

26. Transport to the Laboratory and Handling andMoving within the Laboratory • Timing. Blood should be transported as quickly as possible to the laboratory, preferably within 2 h, and should be placed into the incubator as quickly as possible. • Temperature. Blood culture should never be refrigerated or allowed to cool. Keeping the bottles warm (no warmer than 37°C) is preferable to leaving them at room temperature. • Safety for transport. Blood culture bottles should be carried in some sort of container that will protect them from dropping and from knocking against each other.

27. Rejection Criteria • Staff who receive blood cultures in the laboratory should check the bottles and requisitions carefully to detect a number of problems or errors; • Depending on laboratory and hospital guidelines, specimens with improper labeling may need to be rejected • Bottles with no labels are usually rejected at all times • Patient identification data on the culture bottles and requisition must match, and mismatched specimens may have to be rejected • Whenever rejection is being considered, the physician and/or nursing unit must be notified immediately so they can recollect the samples or discuss the options with a laboratory director or supervisor.

28. Length of Incubation of Blood Cultures • In routine circumstances, using automated continuousmonitoring systems, blood cultures need not beincubated for longer than 5 days • For laboratories using manual blood culturesystems, 7 days should be sufficient. • 99.5% ofnonendocarditis BSIs and 100% of endocarditisepisodes were detected within 5 days of incubation • Extended incubation periods recommended in the past for Brucella, Capnocytophaga, Campylobacter spp. and the HACEK group (Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella spp.) are not necessary for the new continious monitoring systems.

29. BLOOD CULTURE AEROBIC ANAEROBIC TELEPHONE REPORT GRAM STAINING GRAM STAINING CHOCOLATE AGAR McCONKEY AGAR BLOOD AGAR BLOOD AGAR ID+ADT • Arecent study has shown that a telephone report of apositive blood culture with Gram stain results has agreater influence on antimicrobial therapy.

30. Interpretation of Culture Results • Time to detection of positive cultures • Most positive cultures detected in first 48 hours of incubation • S. aureus detected in <24 hours; other staph >24 hours • Culture routinely held 5-7 days • Spectrum of organisms recovered in blood cultures • 10-15% of cultures typically positive • Most common isolates are: CNS, S. aureus, E. coli, Enterococcus, Klebsiella, S. pneumoniae • Significant vs. contaminated culture • Most isolates of S. aureus, S. pneumoniae, ß-hemolytic streptococci, Enterococcus, Enterobacteriaceae, Ps. aeruginosa, gram-neg. anaerobes, and yeasts are significant • Most isolates of CNS, Corynebacterium, Proprionibacterium, and Bacillus are insignificant • Significant isolates of CNS are typically associated with a contaminated line or other foreign body.

31. Reasons for Negative BC in Sepsis Patients • Infection is contained locally • Host defenses are containing the infection at the 1°site • Poor timing of collection • A potential issue with intermittent bacteremias • Too low blood volume collected • A frequent issue • Patient on antibiotics • An increasingly important issue • Not loaded on time • An increasingly important issue

32. Contaminants versus Pathogens • Some organisms more associated with colonization E.g. coagulase negative staphylococci, diphtheroids • Others are always / mostly pathogenic E.g. E.coli, MRSA, Pseudomonas spp., Acinetobacter spp., Legionella, Shigella, Listeria • But most fall in between so: • Consider the body site • Look to see if there are multiple specimenswith same organism • Look at the gram stain …….

33. False-Positive Blood Cultures (“Contaminants”) Contamination is“a single culture positive for coagulase-negative staphylococci or coryneform gram-positive rods orMicrococcus or Propionibacterium, or a single bottlewith Bacillus species, not anthracis.” These isolates are also perfectly capableof causing serious infections, catheter-associated septicemia. Differentiating “contaminants”from true pathogens is extremely difficult,especially because the same species can easily be found in either situation. Obviously, this can be accomplished most effectively bypaying strict attention to the process of skin antisepsis,venipuncture, and specimen transfer to blood culture bottles. Contamination True pathogen

34. What is an “acceptable” blood culture contamination rate*? Berkeris LG, JA Toworek, MK Walsh, PN Valenstein. Trends in Blood Culture Contamination. Arch Pathol Lab Med 129:1222-1294, 2005

35. How to calculate the contamination rate; • Should we calculate it? • Yes • What parameters should we use to calculate it? • The ratio of positive results • Rate of real positivity • Rate of contamination • How should we calculate? • A LOW CONTAMINATION RATE ATTRIBUTES TO THE SUCCESS OF NURSES • Contaminated isolates • Total number of blood cultures

36. False-Positive Blood Cultures (“Contaminants”) • If, a potential contaminant is recovered fromone or both bottles and without a second blood culturefor comparison, interpretation of the clinical relevanceof that positive culture is impossible. • Physiciansmay be forced to initiate treatment for practicaland legal reasons ifsusceptibilities are reported by the laboratory. • Therefore, the evaluation of an isolate with lowvirulence potential recovered from a single blood cultureset (one or both bottles) should be limited to theextent to which phenotypically similar but medicallyimportant organisms can be safely excluded from the identification. • Routine susceptibility testing is not necessary for suspectedcontaminants, but all isolates should be saved sothat additional studies can be performed if an identicalorganism is recovered from a subsequent bloodculture from the same patient. • At that point, full identification of both isolates along with susceptibility testing should be initiated.

37. QUALITY CONTROL / QUALITY ASSURANCE • CLIA and the Clinical and Laboratory StandardsInstitute (CLSI; formerly NCCLS) both state thatcommercially produced blood culture media do notrequire additional in-laboratory QC testing beyondvisual inspection if the manufacturer follows CLSI guidelines. • Users should, however, keep accuraterecords of lot numbers, dates received andexpired, and the product inserts certifying the proper QC by the manufacturer. • Blood culture accessioning, processing, incubating,and all the activities that occur within the laboratoryfor identification of isolates, susceptibility testing,and results formatting are activities for which QCparameters should be measured and monitored

38. EVALUATION OF BLOOD CULTURE PRACTICES: USE OF EPICENTER DATA Ahmet Başustaoğlu1, Serap Süzük2, İpek Mumcuoğlu3, Z. Ceren Karahan4, Dilara Öğünç5, İlknur Kaleli6, Şenol Kurşun3, Ebru Evren4, Betil Özhak Baysal5, Melek Demir6, Nermin Hamurcu7 Patrick Murray8 • Girne American University, Girne, Northern Cyprus • MOH. Public Health Agency of Turkey, Ankara, Turkey • Ankara Numune Training and Research Hospital, Ankara,Turkey • Ankara Uni. Faculty of Medicine İbni Sina Training and Research Hosp., Ankara, Turkey • Akdeniz Uni. Faculty of Medicine , Antalya, Turkey • Pamukkale Uni. Hospital, Denizli, Turkey • BD Diagnostic Systems , Istanbul, Turkey • BD Diagnostic Systems , Maryland , ABD.

39. EVALUATION OF BLOOD CULTURE APPLICATIONS BY EPICENTER DATA

40. The aim of the study : To use the data obtained from proper blood culture practices for; • Demonstrating of the traceability of the data via the statistical analysis program of the EpiCenter operating system • Revealing the efficacy of proper blood culture practices on correct diagnosis through the data obtained and offer areas for improvement within this process • Raising awareness about the use of this program.

44. Important points that arouse upon the analysis of EpiCenter data; Preanalytical phase: • Data requested on EpiCenter that can support hospital quality systems/practices such as • the name of the clinic, • the name of the requesting physican • the name of the person that collected the sample, • the patient’s room number which are important with respect to monitoring hospital infections and epidemiology have not been entered into the HIS and not transferred to the system. • Times of sample collection for blood culture were mostly not entered into the HIS and/or not written on the request form and consequently were not transferred to the EpiCenter database.

46. Adopting of appropriate sample collection techniques through necessary trainings ensures drop in contamination rate for blood cultures and increases the chance of obtaining correct results. . • Contamination rates for the hospitals that were included in this study were (6,2- 8,9%), • The reasons behind not being able to calculate contamination rates were ; • the site of blood collection was not specified, • more than one vial/set was not taken, • mistakes in the interpretation of the isolated agent were made • there was a lack of clinic-laboratory cooperation • Awareness should be raised in hospitals of the importance of monitoring these rates

47. Number of bottle/set loaded to the device and rate of positivity

49. Loading times

50. Unloading times