Specimen Collection: BLOOD Flashcards
Types of specimen
Feces
Anaerobic sample
Blood
Urine
Tissue biopsy
Sputum
Swab
Test selection
Microscopy
Culture
Serologic
Genetic
This is done to identify antimicrobial drugs that will be best used to control or kill the organisms.
All the information gathered through the tests will be utilized by the clinician to come up with the ideal treatment regimen for the patient.
antimicrobial susceptibility testing
GENERAL SPECIMEN COLLECTION GUIDELINES
Obtain specimen before treatment;
Collect material from the appropriate site and avoid contamination.
Obtain material during the acute stage of the illness and ensure correct timing of specimen collection;
Collect using sterile collection method;
Collect sufficient quantity.
LABEL:
Patient’s full name
Identification number of the patient
the type of specimen
date and time of collection
Collector’s signature
Incorrect Labelling
• Label too high (on cap)
• Label too low (started on bottom)
• Labels exposed to adverse conditions: heat, cold, moisture
• Two labels should not share the same tube
• Double label cover epic label completely
• Twisted label
• Label upside down - Accession number belongs under cap
• Folded/ bubbled label
• Wrong color tube for test requested
SPEICMEN TRANSPORT GUIDELINES
All specimen must be sent to the laboratory on the day of collection with as little delay as possible.
Bacteria are vulnerable to delay in processing
DELAY IN TRANSPORT AND PROCESSING
Refrigeration
Ex: URINE ->
refrigerate (24 hrs)
DELAY IN TRANSPORT AND PROCESSING
Maintain viability of bacteria and slows down all 3 processes
Transport Medium
Transport media
Slows down: 3
• Growing process
• Reproducing process
• Dying process
TRANSPORT OF SPECIMEN (REFERRAL TESTING)
• Volume
• Packing
• Paperworks
TRANSPORT OF SPECIMEN (REFERRAL TESTING)
• Volume: must not exceed______
Bacteria and fungi ->_______
40 mL
tubed solid media
TRANSPORT OF SPECIMEN (REFERRAL TESTING)
• Packing: leak-proof, tightly sealed containers with________
DOH Manual on ______of Laboratory Specimen for Referral
______Dangerous Goods Shipping
Guidelines
Biohazard label
Packaging & Transport
IATA’s
TRANSPORT OF SPECIMEN (REFERRAL TESTING)
Paperworks: ______that are enclosed in the container, identified and marked properly
itemized content
IATA- DOH TPS
Patient specimens or culture isolates must be______ before being shipped.
The material is placed into a primary receptacle that must be watertight.
______material is placed around the primary receptacle, and it is then placed into a secondary container that is also watertight.
The secondary package is sealed and placed into a sturdy outer container constructed of______.
Specific instructions must be followed for labeling the container as “________.” Specimens that are shipped by air require specific labeling and shipping documents.
triple packaged
Absorbent
fiberboard
Hazardous Material
Triple Package System
Watertight Primary Receptacle
Glass, Metal, or Plastic*
Watertight Secondary Packaging
List of Contents
Rigid Outer Packaging
made of glass tubes/metal tubes/ mostly plastic (safer)
there should be an absorbent packing material (especially for liquids) that should keep the tubes from shaking around
Inner Container/Primary Receptacle
Placed in a second packaging that would contain the Itemized List of Contents
Inserted into a rigid cardboard that has an Infectious Substance Label, Shipping name, shipper’s name and Identification, data or information, UN number/UN package certification mark
Watertight Secondary Packaging
SHIPPING LABELS
WHAT’S PRESENT:
Information from the sender
Information for the receiver
Package and content
Laboratory & contact number
UN Number is present
‘Infectious substance’ sticker
Infectious substance’ sticker
If the infectious substance is_______, UN2814 is the number
If the infectious substance contains a biologically______ organism, it belongs to Biological Substance Category B, UN3373
known or identified
unknown
Respiratory
Gastrointestinal
Blood Culture
Urine
Fungal
Mycobacterial
Chlamydia
1 hr
Anaerobic DT
30mins
Wound, skin & soft tissue DT
30mins
CSE and Other fluids DT
Immediately
Certain bacteira, such as _____ and _____ are very susceptible to drying and changes in temperature
Neissera and Haemophilus
CRITERIA FOR SPECIMEN REJECTION
- Unlabelled specimen
- Incorrectly labelled specimens (Mismatch Specimen and Form)
- Specimen sent in wrong container; Inappropriate container; Wrong preservative for test
- Broken Leaking container; Spilt sample
- Insufficient sample volume (Volume not to the mark) e.g Citrated blood
- Specimen received in syringe
- Contaminated sample or Contaminated request form
REJECTED SPECIMEN: ANAEROBIC CULTURE
- Gastric washings
- Voided urine
- Stool
- Oropharyngeal samples
- Sputum
- Swabs of ileostomy or colostomy sites
- Superficial skin specimen
UNIVERSAL PRECAUTIONS
General rule:
Treat any specimen as infectious
Appropriate barriers (PPE)
Gloves
Lab coat
Masks
Goggles
Impermeable gowns or aprons
CLINICAL SPECIMEN
• Blood
• respiratory tract (upper, lower)
• Urine
• Cerebrospinal fluid
• Gastrointestinal Tract
• Genital Tract
• Wound & Abscess
Blood culture purpose
Confirm the infectious etiology
Identify the etiologic agent
Guide antimicrobial therapy
BLOOD CULTURE -> determines (3)
• Aims to grow pathogenic microorganisms for diagnosis of above-mentioned diseases
bacteremia, fungemia & septicemia
FACTORS THAT AFFECT RECOVERY OF ETIOLOGIC AGENT IN THE BLOOD
Specimen Collection
Culture Medium
Incubation Requirement
Volume of blood is critical; yield affects isolation of the infectious agent - collect more than_____, minimum is_____ for adults (2 containers)
10mL
20mL
Temperature for incubation
35-37C
Frequent blood culture contaminants but also true pathogens:
• Coagulase-negative staphylococci
• viridans Streptococci
• Corynebacteria A
• Bacillus species
• Propionibacterium species
VOLUME OF BLOOD
• 1 set=
2 tubes
Aerobic & anaerobic
Adult
One set in one arm, the other in another arm, last set is from the leg vein
The more blood volume to be examined, the greater chances for you to be able to isolate organisms
20-60 mL (adult)
(pediatric patient)
(neonates)
(1 month - 2 years old)
(children below 10 years old)
5-10 mL
1-2 mL
2-3 mL
3-5 mL
NUMBER OF BLOOD CULTURE SETS
Collect______ sets of bottles (aerobic + anaerobic) for each septic episode
If culture is negative after _____ incubation and patient is still
potentially septic without an identified source
Collect______additional sets of bottles (aerobic + anaerobic)
If culture is negative after 24 h incubation…….
2 to 3
24-48 h
2 to 3
Repeat protocol if necessary
Prolong incubation
Investigate non-microbial etiology
= watch out for the times where the
patient’s temperature would spike up, this is a telltale sign that the organisms or are in their generation time period
Septic episode
= it could be viral.
Viral organisms do not respond very well on culture media used for bacteria.
They do not just grow on any environment.
Investigate non-microbial etiology
= sometimes, there are organisms that would be present after 21 days of incubation; if not, call and inform the physician, and ask if they could repeat process for the third time around (2-3 sets per septic episode)
Prolong incubation
If there’s one tube that turns out to be positive, what should we do?
• If the pathogenic organism identified in that bottle is
Listeria, Staphylococcus, Brucella, Haemophilus or Enterobacteriaceae…
This is a probable bloodstream infection
If there’s one tube that turns out to be positive, what should we do?
If viridans streptococci or coagulase-negative staphylococci and consistent with clinical setting (e-g-Indwelling catheter, prosthetic heart valve, immunocompromised patient)….
Probable bloodstream infection
If there’s one tube that turns out to be positive, what should we do?
If normal skin flora is positive ONLY for Propionibacterium, corynebacterium, Bacillus, coagulase-negative Staphylococci….
Probable contamination
What to do after if….
This is a probable bloodstream infection
Probable bloodstream infection
Probable contamination
- Repeat collection / repeat procedure
- Consider non-infecitous etiology
- Investigate viral etiology or non-culturable microorganism
SAMPLES FOR REJECTION
• Clotted specimens
• Specimens collected using only alcohol as antiseptic
• For adults: less than 20 mL of blood sample
BLOOD TO BROTH RATIO
• Recommended:____
• dilute the antibacterial & inhibitory substances in the blood
• Commercial Continuously Monitoring Blood Culture System may use smaller blood to broth ratio of less than____
1:10 ratio
1:5
CULTURE MEDIA
Glucose broth
Bile broth
Trypticase soy broth
Brain heart infusion broth
Thioglycollate broth
Columbia or Brucella broth
o Ideal for endocarditis
Glucose broth
Ideal for samples for patients with enteric fever
Bile broth
NOT for samples that may contain
Neisseria and Streptococcus pneumoniae
Use BHI instead
Trypticase Soy Broth
Multipurpose broth
For anaerobes
Brain Heart Infusion broth
Thioglycollate broth
Anticoagulant, anti-phagocytic and anti-complementary action
Neutralizes bactericidal effect of serum
Inactivates certain antimicrobial agents
Sodium Polvathenol Sulfonate [SPS] (0.025 to 0.03%)
EXAMPLES OF ANTIMICROBIAL AGENTS THAT CAN BE INACTIVATED RATHER BY SPS
Gentamicin
Kanamycin
Streptomycin
Polymyxin B
Downside to SPS
• Quite toxic to certain fastidious organisms like
Neisseria, Mycoplasma, Peptostreptococcus, Streptobacillus moniliformis
Use_______- used to inactive penicillin
1-2% gelatin or penicillinase
Subculture on BAP (Blood Agar Plate) & CA (Chocolate Agar Plate): after _____hours, 3rd /5th /7th day
Usually incubated on____
enhanced atmosphere
14-17 hrs.
carbon dioxide
Incubation
______days is sufficient
Not more than____ days; _____ = contamination
3-5
7
> 5 days
7 DAYS INCUBATION IS USEFUL FOR
Fungemia
Bacteremia (HACEK group, Brucella, Legionella)
Mycobacterial culture
> 4 weeks
Manual Examination of bacterial growth
Turbidity
Hemolysis
Gas production
Pellicle formation or discrete colonies
COMMERCIALLY DEVELOPED SYSTEM
Biphasic Septicheck System
Oxoid Signal Broth Displacement System
Has an agar slant attached to the broth containing bottle
Allows the subculturing to be done in a closed system-we don’t need to open the container to subculture the agar.
Simply tilt the bottle to allow the broth to flow on the surface of the agar to allow the organism on the broth to grow on the culture media
Biphasic Septicheck System
Comes with a cylindrical signal device that’s attached to the main bottle with a long needle extending to the surface of the broth.
Closed system as well
Oxoid Signal Broth Displacement System
Automated Detection System
BACTEC 9240/ 9120/ 9050
BAC T/Alert
TREK ESP culture system
• Alerts when the culture is positive
• You can process a lot at one time
Gram stain & subculture follows
Automated detection system
CONTINUOUS MONITORING SYSTEMS
ADVANTAGES
•
•
•
Decrease the laboratory work
Decrease the pseudo bacteremia due to decrease in sampling and handling
Increase in the speed of detection and rate of recovery
DISADVANTAGES OF CONTINUOUS
MONITORING SYSTEMS
Requires an instrument
Limited selection of medium
Expensive
