M1 Specimen Processing Flashcards
What category of items are required to assess specimen acceptability?
- Description, e.g., site or source? ie. right leg; type? ie. swab
- Preparation & collection: LIM Shared Health
- Number; type; volume
- Container
- Clinical History
- Time of Collection
How many specimens per requisition should there be?
One specimen per requisition.
What are the first three specimen processing steps?
- Specimen arrives
- Time stamped
- Requisition versus sample is checked to see if they match and its priority.
Once the sample is considered valid (matching checked, etc.) what are the next three specimen processing steps?
- Labeling of sample, plates, and slides (as applicable).
- Accession in computer: # + barcode assigned
- Specimen placed in fridge if needed
What are the remaining last three specimen processing steps?
- Pre-treatment (Centrifuge, elution, etc.)
- Planting and incubation.
- Reading and reporting gram stains.
For general prioritizing guidelines what specimens are critical and need a gram stain STAT in 1 hour?
- Blood cultures (to the blood machine asap),
- CSF (always STAT)
- Sterile fluids
What specimens are typically unpreserved?
- Wounds drainage,
- stool,
- Sputum,
- Urine (if they go to the fridge they can wait, no gram stain)
What specimens are preserved?
- Stool (ova and parasites),
- Swabs in transport media (TM) - Gram stain STAT 4 hours for some
- Some organisms might need special treatment (gonococci)
Will another sample from the same patient, same site, same day be accepted in the micro lab?
No, more than 1 sample from same site/day is rejected.
Are leaking specimens a cause for rejection (what could be the exception)?
Yes, Leaking specimens are rejected (excludes irreplaceable sterile fluid samples: TBD with doctor)
Are samples submitted in preservatives a cause for rejection (what could be the exception)?
Yes, Samples submitted in preservative and/or wrong preservative are rejected (excludes formalin for parasites, boric acid for urine)
Why are fluid samples submitted in a syringe not accepted in the micro lab?
Fluids in a syringe are a safety concern and therefore are rejected.
Why might a sample for testing anaerobes be rejected?
Request for anaerobes from inappropriate sites
Can you list some of the etiological agents the Dr. is to notify the lab if they are suspected in the sample?
All physicians are required to notify lab if they suspect the following etiological agents in specimens to be sent to the laboratory:
- Bacillus anthracis,
- Bordetella pertussis,
- Brucella spp.,
- Francisella tularensis,
- Burkholderia pseudomallei,
- Yersinia pestis, and
- dimorphic fungus like Blastomyces dermatitidis, Coccidioides immitis, Histoplasma capsulatum, Paracoccidioides brasiliensis.
What containers are accepted in the micro lab?
Containers are to be sterile and appropriate for specimen.
Non-sterile or inappropriate containers are rejected.
What are the procedures to follow when a specimen is rejected? What about records?
*Notify physician/nurse.
*Request new specimen
*Call physician or charge nurse to obtain clarifying info
*Inform physician or charge nurse of problem and suggest solution
*Accession sample and hold specimen-labeled as UNACCEPTABLE
All records pertaining to lack of acceptability must be maintained.
What is done before planting a specimen?
Macroscopic observations are made and recorded: eg. bloody, purulent, etc.
Can a specimen be processed if it has inadequate volume supplied?
No specimens with inadequate volume are rejected.
What can happen if a sample is not brought to the lab in a timely manner?
Delay in transport or transported inappropriately (no refrigeration) are cause for rejection.
Where must all specimens be planted and why?
All specimens must be planted in a Biosafety cabinet to
- protect the worker from aerosol exposure
- the sample from environmental contamination and
- the environment.
What PPE are required when working at a biosafety cabinet?
Staff working in a biosafety cabinet must wear:
1. Gown and
2. Gloves
The gloves must be removed when exiting the biosafety cabinet or when the gloves become soiled or lose their integrity.
All standard precautions procedures apply when handling patient samples and sharps policies are also enforced.
What is the media checked for prior to planting?
- Examine plates for expiration and contamination before inoculation
- All media prepared in Microbiology is labelled with expiration date and name
What do you label the media with and how?
- Label media with accession number and date. Do not obscure the name and expiration date
Does it matter what order you inoculate the media (e.g. plates) in and why?
Yes, arrange labeled plates in order from least to most selective
- Inoculate least inhibitory first to prevent carryover of inhibitory substances ie. most routine aerobic culture BA→ CA → Mac
Is the method of inoculation the same for all specimen types?
No.
Method of inoculation varies depending on the specimen source and type. They may include use of a loop, syringe, swab or transfer pipette.
What are four purposes of documenting work in the micro lab?
Records serve 4 purposes
1. They document what has occurred without recourse to memory (they provide a paper audit trail).
2. They serve as a point of reference for developing facts regarding an incident.
3. They aid in the recognition of trends and resolution of problems.
4. They establish the credibility of the laboratory.
“If it is isn’t documented, it hasn’t been done”
How long are records typically kept in the micro lab?
Records are kept for at least 2 years (instrument record for the life of the instrument)
Safety and Personnel – 5 years min.
What types of information must the microbiology lab requisition contain? How many can you list?
- Examination request- aerobic culture, anaerobic, TB, mycology, C. difficile toxin, etc.
- Specimen – source = anatomical body, eg. throat; type = swab, aspirate
- Clinical information/history- pneumonia, pain x 2 weeks, prenatal
- Collection time and date
- Antimicrobial therapy- history
- Patient info: “Patient demographics”-PHIN number, name, address (depends), medical
Insurance #, age, gender - Physician Info: Pager /Phone/Fax, Address
- Ward / station/ clinic
What is done with Critical “PANIC VALUES” in the microbiology lab?
- Certain report results in microbiology must be phoned immediately.
- The date and time of the phone call must be documented on the report.
- These results include the detection of clinical important microorganisms that require immediate action by the physician, hospital personnel and/or governmental agencies. (This may differ from province to province).
Are organisms seen in CSF and sterile fluids critical “panic values”?
Yes, critical are:
1.Organisms seen in CSF (original Gram)
2. Organisms seen in sterile fluids (original Gram)
3. Positive CSF antigen detection for pneumococci, Streptococcus agalactiae, Neisseria meningitidis, and Haemophilus influenzae (now rare)
4. Positive blood cultures, CSF cultures, or other sterile sites.
Is Cryptococcus spp. critical? How found?
Yes, if
* Positive India Ink preparations (stain used for Cryptococcus spp.)
* Positive Cryptococcal antigen detection
Then it is a panic value
Is a Positive AFB (acid fast bacilli) smear critical??
Yes
What organisms if isolated are considered critical “panic values”?
In general:
- Enteric pathogens
- Risk level III organism
- S.pyogenes (Necrotizing fasciitis)
- Organisms reportable to Public Health
- Multi-resistant organisms
- Isolation of Streptococcus pyogenes or S. aureus in necrotizing fasciitis
- Isolation of Mycobacterium tuberculosis
- Isolation of Salmonella spp., Shigella spp., E. coli 0157, Campylobacter.
Isolation of pathogenic Neisseria spp.
What occurs if antimicrobial resistance is discovered?
Antimicrobial Resistant Organism (MRSA, VRE, etc.) are considered critical “panic values”.
Why must you avoid the edge of the plate when inoculating?
Avoid inoculating the edge of the plate. Specimen will ‘run’ along the entire circumference.
What new practice may labs used to avoid order of inoculation being important?
Many labs are using broth to extract specimen from swabs and then using pipettes to plate the sample so as a result order is not as important as previously when a swab was used to inoculate.
How are plates oriented when incubating?
Incubate plates appropriately- lid side down! (Atmosphere * Temp. * Time)
What are some general guidelines for incubation temperatures/environment for different types of organisms (mycology cultures, general culture, aerobes, anaerobic, respiratory and capnophiles and campylobacter)?
- 30oC –used for mycology culture incubation-parafilm plates
- 35oC-used for general culture incubation
o ambient air for aerobes
o Anaerobic atmosphere for anaerobes (Anaerobic jar/chambers)
o 5% CO2 for respiratory and capnophiles - 42oC-used for Campylobacter cultures – placed in jars with campy gas pack
