SAMPLE COLLECTION, HANDLING AND PROCESSING

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SAMPLE COLLECTION, HANDLING AND PROCESSING
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Doctor initiates the order by writing it in the
patients chart
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Samples are drawn and possibly kept in the
ward/OPD until there are enough to call for
movement to the lab
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Nurse or ward attendant will transport the
samples together with order forms to the
laboratory. Accidents do occur and there is
potential for severe confusion.
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Specimens are batched for processing and some
samples may actually be kept till the following
morning
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When the laboratory results are ready, they are
sent for registration and subsequent filing in
the cabinet
Ah! I don tire. They no fit bring all results at
once sef. When they are ready I will register all
results at once
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Nurse or lab attendant will transport the results
back to the ward. Again, there is the potential
for mix-ups.
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AIM
OUTLINE PROCEDURES FOR COLLECTION, HANDLING AND
PROCESSING SAMPLES FOR LABORATORY INVESTIGATIONS
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SCOPE

• 1. SAMPLES FOR RAPID HIV TESTING
• 2. SAMPLES FOR CD4 COUNT
• 3. SPUTUM SAMPLES FOR AFB EXAMINATION

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POSSIBLE SAMPLES FOR HIV RAPID TESTS
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POSSIBLE SAMPLES FOR HIV RAPID TEST

• 1. SERUM
• 2. PLASMA
• 3. WHOLE BLOOD
• 4. SALIVA
• 5. URINE

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BLOOD COLLECTION

• 1. VENIPUNCTURE (CEPHALIC, MEDIAN CUBITAL,
  MEDIAN BASILICA)
• 2. FINGERSTICK/FINGER PRICK

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POINTS TO NOTE IN SAMPLE COLLECTION
1. BLOOD SHOULD BE COLLECTED ASEPTICALLY TO
AVOID LYSIS 2. FOR WHOLE BLOOD AND PLASMA
SPECIMENS, EDTA CONTAINERS MUST BE USED 3. FOR
SERUM SPECIMEN, USE PLAIN AND DRY CONTAINERS
ALLOW SAMPLE TO CLOT, RETRACT BEFORE SPINNING TO
RECOVER THE SERUM
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POINTS TO NOTE CONTD
4. SERUM AND PLASMA SAMPLES SHOULD BE STORED
AT 2-80C IF THE TEST IS TO BE RUN WITHIN 7 DAYS
OTHERWISE FREEZE AT 200C. AVOID FREQUENT
THAWING 5. DO NOT FREEZE WHOLE BLOOD STORE AT
2-80C IF TEST IS TO BE CARRIED OUT WITHIN 7 DAYS
OF COLLECTION 6. FINGER STICK COLLECTION SHOULD
BE TESTED IMMEDIATELY
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SAMPLE FOR CD4 CELL COUNT
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DEFINITION

• CD4 CELLS ARE ALSO KNOWN AS T4 CELLS AND T-helper
  CELLS
• CD4 CELLS ARE THE CELLS THAT HIV SELECTIVELY
  INFECTS
• THE NUMBER OF CD4 CELLS IN BLOOD CIRCULATION
  THEREFORE INDICATES THE STAGE OF HIV INFECTION
• MOST AIDS PATIENTS HAVE CD4 CELL COUNTS OF LESS
  THAN 200 PER ML OF BLOOD

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BLOOD FOR CD4 COUNT

• 1. SPECIMENS MUST BE COLLECTED IN EDTA WITH A
  RATIO OF 1.0 1.5 mg EDTA PER ML OF WHOLE BLOOD
• 2. DO NOT REFRIGERATE SAMPLES FOR CD4 COUNT
• 3. SPECIMENS COLLECTED IN ACD MAY RESULT IN
  LEUKOCYTES PHAGOCYTOSING THE LATEX SPHERES

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BLOOD FOR CD4 COUNT CONTD

• 4. SPECIMENS FOR CD4 CELL COUNTS ARE TO BE KEPT
  BETWEEN 20-250C AND MUST BE TESTED WITHIN 6 HOURS
  OF COLLECTION
• 5. REJECT SAMPLES WITH EVIDENCE OF HAEMOLYSIS
  OR CLOTTING
• 6. PRIOR TO TESTING, SAMPLE SHOULD BE MIXED
  THOROUGHLY BY GENTLE TILTING AND ROTATING

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SPUTUM SAMPLES FOR AFB EXAMINATION
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SPUTUM
SPUTUM EXAMINATION IS DONE TO STUDY BRONCHIAL
AND PULMONARY SECRETIONS.
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CHARACTERISTICS OF GOOD SPUTUM
1. PURULENT 2. MUCOPURULENT 3. MUCOID NOTE
REJECT SALIVARY SAMPLES AND ADVISE THE PATIENT TO
EXPECTORATE FROM THE LOWER RESPIRATORY TRACT
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SPUTUM

• SPUTUM IS COLLECTED IN A WIDE-MOUTH OPEN
  CONTAINER
• SPUTUM MUST BE DISTINCT FROM SALIVA

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W.H.O. GUIDELINES FOR SPUTUM COLLECTION

• 1. SPECIMENS FOR AFB EXAMINATION SHOULD BE
  COLLECTED WHEN THE PATIENT REPORTS AT THE LAB FOR
  SPECIMEN CONTAINERS
• 2. TELL THE PATIENT TO EXPECTORATE ANOTHER
  SAMPLE THE FOLLOWING MORNING BEFORE COMING TO THE
  HOSPITAL
• 3. ON RECEIVING THE SECOND SPECIMEN AT THE
  LABORATORY THE PATIENT SHOULD BE ASKED TO
  EXPECTORATE THE THIRD AND LAST SPECIMEN

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GENERAL PRECAUTIONS FOR COLLECTION OF LABORATORY
SAMPLES

• 1. ALL SPECIMENS FROM PATIENTS SHOULD BE
  CONSIDERED INFECTIOUS
• 2. WEAR APPROPRIATE PROTECTIVE BARRIERS FOR THE
  LABORATORY PROCEDURE
• 3. SYRINGES SHOULD NOT BE RECAPPED WITH
  NEEDLES
• 4. SAMPLES MUST BE PROCESSED AS SOON AS
  POSSIBLE

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GENERAL PRECAUTIONS FOR COLLECTION OF LABORATORY
SAMPLES

• 5. ALL SPECIMENS MUST BE ACCOMPANIED BY A
  CORRECTLY FILLED ORDER FORM, CONTAINING THE
  RELEVANT DATA
• 6. ALL SPECIMENS MUST BE WELL LABELLED
• 7. INFORMATION ON THE SPECIMEN CONTAINER MUST
  AGREE WITH THAT OF THE ORDER FORM
• 8. EACH SAMPLE MUST BE REGISTERED AT THE
  LABORATORY RECEPTION AND BE GIVEN A CODE NUMBER,
  PRIOR TO PROCESSING

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GENERAL PRECAUTIONS FOR COLLECTION OF LABORATORY
SAMPLES

• 9. ALL SAMPLES MUST BE PROCESSED IN LINE WITH
  SOP DESIGNED FOR THE TEST
• 10. RESULTS MUST BE RECORDED IMMEDIATELY
• 11. IN-PATIENTS RESULTS MUST BE DESPATCHED
  IMMEDIATELY AND OUTPATIENTS RESULTS KEPT IN A
  CABINET VERY WELL SECURED
• 12. NEVER LEAVE RESULTS REGISTER ON TABLE WHEN
  NOT IN USE

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Flowchart of Specimen Ordering, Testing and
Results Reporting Process
Ward/OPD
Laboratory
Maid/Cleaner or Patient Attendant
Specimens are batched for processing and results
are placed in pigeon holes grouped by ward
Doctor fills in the request forms and then
directs the nurses either to collect the samples
or send patient to the lab
Results are collected from the lab in batches,
stored at the nursing station, and periodically
distributed to patients on the ward
Nursing Station
Maid/Cleaner or Patient Attendant
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CONCLUSION
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Why laboratory record-keeping and Good Laboratory
Practices are so vital
Two days passed without results from the
laboratory. Nobody bothered to ask for the
results since the condition of the patient seemed
to have improved slightly. On the night of July
20, 2005 at 11 pm, Pam started convulsing again.
This surprised his mother since he had seemed
fine earlier that day. She rushed to the night
nurse who alerted the clinician on call. After 10
minutes he came to Pams bed and asked for the
chart to review his medications. He noted that
the patient was being treated for malaria, but he
could not see the results of all the samples that
were taken on the day of admission. An
initiative to inquire for the patients results
from the lab was made immediately but due to a
faulty phone extension in the lab, communication
proved futile. He later went to the laboratory
himself to check for the results. Flipping
through all the recently documented results in
the laboratory logbook, he managed to find the
results for the CSF which were negative for
meningitis. However, no results for malaria
could be found. Worse still, the sample itself
could not be traced. It might be necessary to
wait for Captain Jonathan who handled the sample
and unfortunately he was the orderly officer for
the day. He would not be available until the
following morning after submitting his report.
Therefore the doctor told the mother that the
patient would continue with the current
medication and everything concerning the lab
results would be sorted out the following
morning. He gave slow intravenous diazepam to
arrest the convulsions.   During the morning
report the doctor on call reported all the cases
emphasizing the case of Pam Bulus noting that the
results for malaria could not be traced. This
invited echoes from many of the clinicians in the
room that the laboratory department had been
misplacing and delaying release of results. Since
the results for this patient were not available,
then the alternative was to take another sample
although this procedure is a painful one that no
patient would want to experience more than once.
The doctor on duty that morning told Pams mother
that he needed to collect another blood sample
from her son because the previous sample was
somehow misplaced. She did not take this news
well. Regardless, the doctor continued. He
filled another request form this time adding a
request for Widal test and urgent PCV. Two
minutes after this collection, the patient
convulsed again and suddenly became unconscious.
The mother started weeping while blaming the
doctor who had just collected yet another blood
sample from her son. She believed that her son
did not have enough blood but the doctors were
still collecting more.   By the afternoon the
results were known. Pam had a slightly raised
titer from the Widal test, and also malaria
parasite in the blood film. The plan was to
modify treatment to cover for suspected case of
chloroquine-resistant malaria. However, the
condition of the child kept on deteriorating
until on the third day when a confirmed diagnosis
of cerebral malaria was made. However it was too
late because Pam passed away on that same day.
The hospital has killed my son, could be heard
from the mother who had now lost control and was
crying aloud.
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THANK YOU