CTVS ICU

1. Collection of Samples in
ICU
Dr. Dharmraj Singh
SR Cardiac Surgical Intensive Care

2. Index
• Introduction
• Sample collection
• Responsibility of clinical staff
• Task to be completed before & after analysis
• Guidelines for specimen collection
• Standard precautions

3. Questions
• Are you suspecting an Infection ?
• Which tests are your priority ?
• When to collect the specimen ?
• How to collect the specimen ?
• Am I choosing the correct container ?
• Why to send the specimens promptly if not what I should do ?

4. Types of samples
Non-infective
• Blood- HB, PLC etc
• Serum- LFT, RFT, Electrolyte
etc
• Plasma- drugs
• Urine- Routine
Infective
• Blood-eg. Malaria
• Serum- eg. Dengue, HIV, HBsAg,
HCV
• Plasma-
• Respiratory- eg. Sputum,Tracheal
aspirate, BAL etc
• Body fluids- pleural, peritoneal etc
• Wound/Exudate-

5. Non-infective samples

6. Before analysis
• Requisition form
• Preparation of a patient & containers
• Collection of sample
• Labelling of sample
• Preparation of samples for transport
• Transport of sample to laboratory
• Documentation

7. Anticoagulant or preservative for blood
Three types of specimen containers are used
• Plain tube (No anticoagulant) – all estimations on serum
• Fluoride tube – for estimation of Glucose level
• Oxalate tube for estimation of fibrinogen level
Anticoagulated specimen containers are prepared and issued by
the laboratory.

8. Vacutainers

9. Vacutainer Chemical Use
SST (serum
separator tube)
spray-coated silica and a
polymer gel
Serum determinations in chemistry (LFT,
RFT,)
PST (plasma
separator tube)
spray-coated lithium
heparin and a gel
Plasma determinations in chemistry
EDTA spray-coated K2EDTA
Tubes
Whole blood hematology(CBC)
determinations and immunohematology
testing (Cyclosporine,Trop-T, HbA1C)
Serum spray-coated silica Serum determination in chemistry,
serology, and immunology(Electrolyte)
Heparin spray-coated with either
lithium heparin or
sodium heparin
Plasma determination in chemistry(pH,
pCO2, pO2, etc)
Citrate 3.2% buffered sodium
citrate solution
Routine coagulation studies(PT,APTT,
INR, D-Dimer, Fibrinogen)
Glucose Fluoride tube (glycolytic
inhibitor)
Glucose determination in plasma

10. Requisition form
1. This is a duty of the clinician looking after the patient. Other
category of staff are not authorized to fill requisition form.
2. It should be completely filled in his/her own
handwriting.(Name, age, sex, ward, specimen type, date,
clinical reasons for request, drug therapy)
3. Patient registration no.(UHID) should be accurate.
4. Generate barcode
5. It should be duly signed, indicating the designation of the
clinician.

11. contd…
5. The requesting clinician name should be written legibly,
under the signature.
6. The name of the requested test/s should be clearly written.
7. The requesting clinician may write the telephone extension
(or a contact number) for abnormal results to be rung
through.
8. Omission of destination (Ward No.) will result in loss of
report.

12. Requisition form

13. Order of drawing
• This is important - so that additives in one tube will not contaminate specimen
in subsequent tubes
1. Non Additive tube
2. Coagulation tube
3. Additive tube
• If using syringes minimize clotting by filling additive tubes before non additive
• Before collection of sample ascertain that you know everything about the
sample collection
• Confirm from laboratory how much volume, what tube, procedure, timing etc.

14. Blood collection
• Venipuncture- vein
• Arterial puncture- artery
• Skin puncture- capillary blood from the tip of the finger (or sole of the
babies )
• Venipuncture should be performed by a clinician, a trained nurse or a
trained blood-collector (phlebotomist).
• Arterial puncture can only be performed by an experienced clinician.
• Skin puncture may be performed by any of the above or even the
patient himself after training.
• Blood collection is done as an aseptic procedure.

15. When & how to get Serum & Plasma
 Serum sample
• blood collected without any
anti-coagulant and centrifuged
• clear supernatant fluid devoid
of any fibrin products
 Plain tube
• Most enzymes,
• Biochemical, LFT,KFT,
• Sr. Electrolytes.
• Serological: Dengue,CMV, HIV,
HBsAg, HCV
• CRP, PCT, Digoxin, CK-MB
 Plasma sample
• blood collected & mixed with
anticoagulant and centrifuged
• clear supernatant fluid with
thrombosis inhibited. Most
satisfactory sample. No
changes occur in blood
 Heparinized tube
• pH, pO2,pCO2, HCO3, NH4,
Hematology, Plasma cortisol

16. Therapeutic drug monitoring
• Measurement of drugs and /or their breakdown products at timed
intervals to maintain a relatively constant concentration of the
medication in the blood.
• Take a blood sample just before the next dose. Otherwise, mention
time of collection.
• Some of the monitored drugs tend to have a narrow “therapeutic
index” which is a ratio between the toxic and therapeutic (effective)
dose of medication.
• Cardiac drugs (digoxin), antibiotics (aminoglycosides, vancomycin),
antiepileptics (valproic acid), bronchodilators(theophylline),
immunosppressants (cyclosporine, tacrolimus), etc.

17. Arterial blood sample
• Patient on mechanical ventilation
• Radial, brachial, femoral
• Radial artery is preferred site
• Allen test should be performed

18. Hemolysis of sample
• Contact with water
• Excessive heat or cold
• Rigorous mechanical injury ( thin gauge )
• Prolonged storage
• Hemolyzed samples will give erroneous results

19. Prevention of hemolysis
• Equipment used to collect : absolutely dry
• Minimum constriction of limb
• Use correct gauge
• Collect slowly and steadily
• Remove needle and put immediately into the bulb
• Easier if collection in Vacutainer

20. Labeling of sample
The label should contain the following information :-
• Name of patient – Age /Sex –
• Registration (UHID / CR.) No. -
• Ward No./Bed No./Dept.-
• Date of collection - Time of collection –
• Name/s of test/s

21. Preparation for transport to the
laboratory
• The nursing officer should prepare the specimens for dispatch to the
laboratory.
• The samples should be placed in rows in an empty box of injection vials
or in a tube rack issued by the laboratory.
• The relevant specimen forms too should be kept in the same order as
the samples and clipped together.
• Samples should be kept properly
• Leaky samples should be discarded (not accepted)
• 24-hour urine collections should be sent separately, preferably
wrapped in a polythene cover, after entering the exact times on the
label (start and finish).

22. Transport to the laboratory
• Send without delay.
• Whole blood may be kept at room temperature for about 2 hours.
• If there is a longer delay, the serum or plasma should be separated
from the cells and stored in a refrigerator at 4°C.
• Certain molecules are heat labile and need to be kept in a constant cold
chain eg. Parathyroid hormone (PTH), ammonia, & blood gases.
• The sample should be kept in melting ice and delivered to the
laboratory rapidly (within 10 minutes).
• The blood collector should communicate with the laboratory for
instructions on these special tests.

23. Documentation
• The nursing staff should maintain a record of all the
specimens sent to the laboratory and verify the receipt of
reports.
• The staff should cancel unwanted / inappropriate tests by
phone as early as possible eg. Death, serum cortisol

24. Task to be completed after analysis
1. Collection of report from the laboratory
2. Scrutinization of report by the clinician and appropriate
action
3. Filling of report in patient’s record
4. Maintenance of records
5. Patient's personal record of investigations given at
discharge (including negative results)

25. Standard precautions
1. Hand washing & antisepsis (hand hygiene)
2. Use of personal protective equipment
3. Appropriate handling of patients care equipment
4. Prevention of needle-stick/sharp injuries
5. Environmental cleaning & spills-management
6. Appropriate handling of waste

26. Infectious samples

27. Key points
• Assure absolute indication
• Selection of representative specimen
• Proper requisition
• Additional information
• Discuss for specific test before collecting specimens
• Standard precautions

28. General rules for specimen includes
• Should be representative of the infectious process
• Sufficient material
• Avoid contamination.
• Oral secretion, Foleys tip are considered inappropriate.
• Avoid improper transport and leaking container.
• Send to the laboratory and examined immediately

29. contd…
• Collected before using antimicrobial agents Or atleast the
second day of antibiotics.
• Proper requisitions- name, age and gender, ward and bed
number, physician name, anatomic culture site, date and
time of specimen collection, signature of person obtaining
specimen, antimicrobials, if any, clinical diagnosis, test
requested.
• Proper filling up of requisition form

30. Blood culture
• There are adult and pediatric culture bottles.
• Always check the date of manufacture on the lid.
• Consume the bottle within 7 to 10 days of preparation.
• Keep the bottle at room temperature half an hour before
adding the specimen.
• Disinfect venipuncture site with alcohol, iodine (wait for at
least 1 min) or chlorhexidine.
• Do not again palpate the vein.

31. contd…
• Culture bottle medium should be at room temperature, add
1 to 5 ml (ped)/ 5-10 ml (adult) of blood, dilution should be 1
:10 (The lid of the bottle may need disinfection with same
disinfectant.
• Do not refrigerate after inoculation, should be incubated at
37oC.
• Infective endocarditis requires 3 blood culture.

32. Bactec aerobic
pediatrics
Bactec aerobic
adult Bactec fungal
BLOODCULTURE
BOTTLES
Adult Pediatrics

33. BACTEC Automated blood culture
system
• utilizes fluorescent technology
• Microorganisms metabolize nutrients in the culture medium, releasing
CO2 into the medium.
• Dye in the sensor at the bottom of the culture bottles
will react with CO2
• modulates the amount of light that is absorbed by a fluorescent
material in the sensor
• photo detectors measure the level of fluorescence, which corresponds
to the amount of CO2 released by the organisms
• interpreted by the system according to preprogramed positivity
algorithms

34. IV catheter in view of CRBSI
• Central venous catheter, peripheral, arterial etc.- Clean skin
around catheter with alcohol.
• Aseptically remove and clip 5 cm distal tip into a sterile
container.
• Transport directly to prevent drying or store at 40C for upto
24 hrs.
• Do not add into a liquid broth. Send a parallel blood culture

35. Sterile fluids
• CSF, Peritoneal, pleural, etc.
• Collect under aseptic precautions.
• Do not refrigerate.
• Transport as early as possible.
• If laboratory closed – can be added to broth medium or add
to pediatric blood culture vial.

36. Respiratory specimens
• Collect sputum under direct supervision [EARLY MORNING].
• 24hr collection should be discouraged .
• Sterile wide mouth screw capped container used for
collection.
• Transport at room temperature <2 hours or store at 40C for
upto 24 hrs.
• Induced sputum by hypertonic saline inhalation. Check for
salivary contamination.

37. contd…
• Diagnosis ofVAP may be made by Proximal airway sampling
(ETA) or Distal airway sampling (BAL , mini BAL etc).
• Quantitative cultures are done as colonization of upper
respiratory tract is common.
• BAL or tracheal aspirate is done when, no sputum is
produced , no clear predominance of a potential pathogen on
culture or a poor response to antibiotics chosen on the basis
of the results obtained from expectorated sputum.

38. contd…
• Always use a sterile wide mouth screw capped container.
• Transport at room temperature <2 hours or store at 40C for
upto 24 hrs .
• May need quantitative culture if non-bronchoscopic
collection
• Prevent excessive dilution of specimen with saline in case of
ET aspirate.

39. Upper respiratory samples
• Nasopharyngeal Swab
• (Nasal Swab + Oropharyngeal/Throat Swab)
• Nasopharyngeal wash (<5yrs)

40. Swab for respiratory viruses
• Avoid cotton and calcium alginate swabs with wooden
sticks
• Ideally use Dacron/Rayon swabs or Flocked Swabs
with plastic shafts

41. Viral transport
media issued from
Virology lab

42. Nasal swab
Respiratory viruses
• Accepted for influenza when combined with throat
swab
• Insert a sterile swab into the nose until resistance is met
• Rotate the swab a few times against the nasal mucosa
• Repeat the process using the same swab on the other
side

43. Nasopharyngeal swab

44. contd…

45. Lower Respiratory Samples
• Types
1. Sputum
2. Endotracheal Aspirate
3. Mini BAL
4. BAL

46. Sputum
• Container specifications:
• 30-50ml capacity
• Transparent
• Wide mouth
• Leak proof with screw cap
• Walls allow easy labeling
• Single use

47. contd…
• Early morning specimen is preferred
• Gargle with water immediately before obtaining the
sputum
• Healthcare professional should ensure his/her own
safety
• Deliver the specimen to the laboratory as quickly as
possible
• If delay >2hrs, refrigerate and notify the lab

48. Induced sputum
• Ideally should be done in Negative pressure room with an
exhaust
• Rinse the patient's mouth thoroughly with water
• Bronchodilator inhalation
• Let the patient inhale approximately 20-30 ml of hypertonic
saline/till he/she starts coughing
• Discard the 1st sample and collect the subsequent samples

49. Endotracheal aspirate
• Suction of ET tube secretions
• Suction catheter tip for culture should be discouraged

50. Mini BAL
• A sheathed catheter is advanced till resistance is met
• Saline is instilled and then aspirated, catheter
withdrawn with the outer sheath
• Blind procedure
• Yield is better than ET Aspirate
• Lesser chances of contamination

51. Urine
• Mid-stream voided urine- Instruct patient properly.
• Transport- can be kept at room temp for half an hour,
refrigerate up to 4 hours, discard if more delay. 1.8% boric
powder preserves for upto 24 hours.
• Indwelling catheter- Disinfect catheter collection tube with
70% alcohol. Use sterile needle and syringe to collect
specimen.
• SUPRAPUBIC ASPIRATE is treated on sterile fluid.

52. Urine collection from Urobag

53. Suction port for sample
collection

54. Urobag with collection port

55. Wounds/ Exudates
• Be specific in the identification of the wound site.
• For open lesions remove the superficial flora using saline.
• For dry encrusted lesions culture not recommended.
• Specimen of choice must be taken from the margin of the
lesion.
• Swabs are not very useful specimen
• Do not submit in formalin.

56. Wounds/ Exudates
• If specimen is collected with swabs, 2 swabs must submitted-
1 for Culture, and 1 for Gram stain

57. Stool
• Parasite and ova, culture, toxin for Clostridium difficile.
• In case of diarrhea

58. References
1. Hospital infection control (ICMR)
2. WHO guideline on drawing blood

59. Thank you