BLOOD culture

1. COLLECTION OF
BLOOD FOR
CULTURING

2. What is a Blood
Culture?
• Ablood culture is a
laboratory test inwhich
blood is injected into
bottles with culture
media to determine
whether
microorganisms have
invaded the patient’s
bloodstream.

3. Need for Blood
Culture?
No microbiological test is more essential
to the clinician than the blood culture.
The finding of pathogenic microorganisms
in apatient’s bloodstream is of great
importance in terms of diagnosis,
prognosis,and therapy.”

4. Blood Culture
• Blood culture is a
microbiological culture of
blood. It is employed to
detect infections thatare
spreading through the
bloodstream (such as
bacteremia, septicemia
amongst others). Thisis
possible becausethe
bloodstream is usually a
sterile environment

5. GREEN TOP- ADULT AEROBIC
ORANGE TOP - ADULT ANAEROBIC
YELLOWTOP – PEDIATRIC

6. Blood culturing most
important and life saving
Investigation
Needs optimal Methods for
Diagnosis of Blood Borne
Pathogens

7. Blood Collection
• Aseptic collection
procedure iscritical
Amount ofblood
– 1:10ratio of blood to
broth
– Younger than 10years –
1ml of blood for every
year of life
– Over 10years –20 ml

8. Blood Collection
• Frequency of Collection
– Depends if bacteremiais
transient, intermediate
or continuous
– Number of cultures
collected are usually
inversely related to the
type of bacteremia
– Usually x3 from different
body sites

9. Blood Culture Methods
• Conventional Broth Systems
–One aerobic bottle and one
anaerobic bottle per blood
collection
–Aerobic broth contains soybean
casein digest broth, Tryptic or
trypticase soy broth, Brucella agar
or Columbia broth base
–Anaerobic broth is usually the same
as aerobic with addition of 0.5%

10. Venipuncture
• Venipuncture is the processof obtaining
intravenous accessfor the purpose of
intravenous therapy or obtaining asample of
venous blood. Thisprocedure is performed by
medical laboratory scientists, medical
practitioners, some EMT
s,paramedics
phlebotomists and other nursing staff.
Venipuncture is one of the most routinely
performed invasive procedures and is carried
out for two reasons, to obtain blood for
diagnostic purposes or to monitor levels of
blood components (Lavery&Ingram 2005).

11. Phlebotomy
Definition
• phle·boto·my (fli)
noun the act or
practice of
bloodletting as a
therapeutic
measure
• Phlebotomy from Greek
words, phlebo, relates
to veins, tomy, relates
to cutting.
• Opening avein to
collect blood

12. LABELING THE
SAMPLE
– Properly labelled sample is essential sothat
the results of the test match the patient. The
key elements in labelling are:
• Patient's surname, first andmiddle.
• Patient's IDnumber.
• Both of the above MUSTmatch the same
on the requisition form.
• Date, time and initials of thephlebotomist
must be on the label of eachtube.

13. Principles for
Collection
• Gloveswill be worn in accordance withstandard
precautions.
• •Appropriate verification of the patient's
identity, by means of an armband or areaspecific
procedure, will occur before the specimen
collection.
• •Cultures shouldbe drawn before
administration of antibiotics, if
possible.???
• Blood cultures should not be drawn from
lines, but should be drawnviavenipuncture.

14. What Materials We need
• Chlorhexidine swabs(1-2 packages)
• Alcohol swabs
• Blood culture bottles (2 bottles perset)
• 2 syringes (adult: 20 cc, paediatric: 5cc)
• 2 needles (adult: 22 gauge or preferably larger
butterfly
or standard needle; pediatric: 25 or 23 gauge
butterfly or standard needle)
• Gloves (sterile &nonsterile)
• Tourniquet
• Sterile gauzepad
• Adhesive strip or tape
• Self-sticking patient labels
• Plastic zip lock specimenbags

15. The requisitions form should be
completely filled out, and the requisition
must indicate the tests ordered.
15

16. Self
Protection
A few ways to make sure your
role in the collection process
is carried out with
efficiency, orderliness and safety

17. Steps 1 – 3, Check, Explain,
Wash
• 1.Identify the patient
• 2.Explain the
procedure to the
patient.
• 3.Washhands with
soapand water with
friction for 15seconds
or usealcohol based
hand rub

18. Materials
• Chlorhexidine swabs(1-2 packages)
• Alcohol swabs
• Blood culture bottles (2 bottles perset)
• 2 syringes (adult: 20 cc, paediatric: 5cc)
• 2 needles (adult: 22 gauge or preferably larger
butterfly or standard needle; pediatric: 25 or 23
gauge butterfly or standard needle)
• Gloves(sterile &nonsterile)
• Tourniquet
• Sterile gauzepad
• Adhesive strip or tape
• Self-sticking patient labels
• Plastic zip lock specimenbags

19. . Barrier protection for the
phlebotomist consists of the
latex gloves.
Dr.T
.V
.RaoMD 19

20. Obtaining Blood
• Locate the vein
• Prep kit
– Alcohol 5 sec.Dry 30-60 sec( resource poor conditions)
– Ideal to collect with alcohol swabscontaining2%Chlorhexidine
and 70%isopropyl alcohol
• Removecaps,clean with alcohol
• Put on gloves
• Without palpating, draw 20 ml and put10
in anaerobic and 10 in aerobicbottle
• Disposeof syringe in sharpscontainer

21. Method of Blood
Collection
• Aminimum of 10 ml of blood is taken
through venipuncture and injected
into two or more "blood bottles"
with specific media foraerobic and
anaerobic organisms.
• Theblood is collected using clean
technique. Thisrequires that both
the tops of the culture bottles and
the venipuncture site of the
patient are cleaned prior to
collection with alcohol swabs
containing 2%Chlorhexidine and
70%isopropyl alcohol.
21

22. Preparation of Cap before
Injecting Blood
• Prep the rubber
capof the blood
culture bottles
with an alcohol
pad in acircular
motion. Allow
the alcohol to
dry.

23. Inject the Blood…..
• Inject the blood
into theSelected
Media
• Gently rotate the
bottles to mix
the blood & the
broth (do not
shake
vigorously).
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24. Follow the universal precautions
when disposing Needle
• Disposeof
needle in sharps
container and
dispose of other
waste in proper
container

25. Label the tubes, checking the requisition for theproper
identification.

26. Give the all possible
Medical Information
• Patient’s name
• • Hospital number (Patient ID)
• • Patient’s location (room and bed #)
• • Date and time of collection
• • Collector’s initials
• • Site of venipuncture
• • Or other information asper facility
• Include you Mobile Contact No –A
vital information canbe delivered
any time

27. Document the Medical
Records
• Document the
following in the
medical record:
• –Date & time
specimen obtained
• –Site of specimen
collection
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28. Frequency of Collection
• Frequency of Collection
– Depends if bacteremia is
transient, intermediate or
continuous
– Number of cultures
collected are usually
inversely related to the
type of bacteremia
– Usually x3 from different
body sites

29. Second Set
• If 2 or more sets
of blood cultures
have been
ordered, obtain
the second set in
the samemanner
asthe
first, makinga
new venipuncture
at adifferent site.

30. Newer Blood Culture Methods
• Newer Blood Culture Systems
– Biphasic Broth-Slide System
• Agar “paddles” attached to top of bottle
• Closed system
– Continuous Monitoring Blood Culture Systems
• BacTec – measures 14CO2
• BacTec 9000 Series – measures CO2
• ESP – measures consumption of gases
• BacT-Alert – measures change in pH

31. The Contaminated Blood
Culture
• If the skin is not adequately cleansed before
drawing blood for culture, bacteria on the skin
will be injected into the bottle,producing afalse
positive blood culture
• It is difficult for the physician to determine
whether the bacteria growing in the blood
culture is areal pathogen causing bloodstream
infection or whether bacteria on the skin have
contaminated the culture. This canlead to
excessuseof antibiotics and prolongation of
hospital stay.