SPECIMEN COLLECTION AND TRANSPORT

SPECIMEN COLLECTION AND TRANSPORT: Specimen collection and handling are among the most critical considerations in patient care because any results the laboratory generates are directly dependent on the quality of the specimen and its condition on arrival in the laboratory. Specimens submitted for microbiological testing require proper handling from the time of collection through all stages of transport, storage, and processing. Issues common to all clinical specimens submitted for microbiological testing include not only proper identification but also collection techniques that maximize recovery of microbial pathogens contamination. For specimens such as sputum and urine, the relative proportions of microorganisms present in vivo must be preserved, or culture results may be misleading. If specimens are handled properly, culture results are easier to interpret, patient care is improved, and costs are potentially decreased. Although most guidelines for specimen handling remain unchanged, a recent emphasis has been placed on modifying traditional practices to decrease or eliminate unnecessary work, increase laboratory efficiency, and make microbiological testing more cost effective. 

When collecting specimens for microbiological analysis, the health worker should think about these questions:

“In what ways can I prevent extraneous microorganisms from contaminating this sample?”

“What can I do to prevent myself from becoming infected while I collect this sample?”

SPECIMEN COLLECTION

Patient results are only as good as the specimen collected. The integrity of the sample must be preserved and requirements for collection and handling must be followed. It is critical that adequate volumes are collected on each patient and the patient preparation is adhered to follow test requirements such as fasting.

• Microorganisms are living organisms and must be provided with conditions that permit their survival but do not permit their multiplication.

• If microorganisms are allowed to multiply after their collection, the culture results will not reflect the true disease state.
• Transport media

NURSES EDUCATION TO THE PATIENT IN SPECIMEN COLLECTION

Prior to taking any sample, the nurse should inform the patient about the test(s) to be performed and the preparation for the test. You should:

1. define and explain the test
2. state the specific purpose of the test
3. explain the procedure
4. discuss test preparation, procedure, and posttest care
5. selection of suitable supplies
6. Precise and correct sample identification
7. Prompt transfer of specimen to the lab.

PRINCIPLES OF SPECIMEN COLLECTION AND TRANSPORT

• The health worker must strictly follow the directions in collecting and transporting laboratory specimens.
• Use universal precautions for collecting and handling all specimens.
• Whenever possible, collect all culture specimens prior to administration of any anti-microbial agents.
• Avoid contamination with normal flora.
• Swabs are convenient but inferior to tissue and fluid. Tissue and fluid are essential for fungal and mycobacterial culture.
• All Specimens must be appropriately labeled with two patient identifiers. Identifiers include patient name, birthdate, ward name and/or hospital number. The requisition will include the patient’s name, hospital number, hospital service, date and time of collection, Specimen type and tests requested. A requisition needs to accompany each different specimen.
• Deliver all specimens to the laboratory as soon as possible after collection. Specimens for bacterial culture should be transported at room temperature. If transport is delayed the following specimens should be refrigerated: urines (within 30 min), stool (within 1hr)
• Specimens for viral culture must be transported to the laboratory immediately on ice.
• Transport the specimen directly after collection or by courier.
• Specimens should be in tightly sealed, leak proof containers and transported in

sealable, leak-proof plastic bags. Specimens for TB should be double bagged. Specimens should not be externally contaminated. Specimens grossly contaminated or compromised may be rejected.

• If anaerobic culture is requested, make certain to use proper anaerobic collection containers.

PROCEDURES INVOLVED IN THE COLLECTION OF VARIOUS  LABORATORY SPECIMENS.

SPECIMEN FINGER PRICK PUNCTURE

• Skin punctures are performed when small quantities of capillary blood are needed for analysis or when the client has poor veins.
• Capillary puncture is also commonly performed for blood glucose analysis. The common sites for capillary puncture are the Finger tips.

EQUIPMENT NEEDED

• Collection tubes.
• Antiseptic.
• Sterile cotton wool swabs.
• Sterile lancet.
• Nonsterile gloves.
• Hand towel or absorbent pad.
• Slides.

IMPLEMENTATION

• Wash hands, to reduce transmission of microorganisms.
• Check clients identification band if appropriate to ensure correct client
• Explain procedure to client to allay anxiety and encourages cooperation.
• Prepare supplies and place in easy reach to ensure efficiency
• Open sterile packages.
• Label specimen collection tubes.

• Apply gloves to decrease health care provider’s exposure to blood borne organisms.
• Select site: lateral aspect of fingertips in adults or children to avoid damage to nerve endings and calloused areas of the skin. Place hand towel or absorbent pad under the extremities to prevents soiling the bed linen.

• Cleanse punctures site with an antiseptic and allow to dry to reduce skin bacteria
• With nondominant hand, apply gentle milking pressure above or around the puncture site, do not touch puncture site. This increases blood to puncture site and maintain asepsis. Wipe off the first drop of blood with sterile gauge, allow the blood to flow freely. First drop may contain a large amount of serous fluid, which could affect results. Pressure at the puncture site can cause hemolysis
• Collect the blood into tube, and Apply pressure to the puncture site with a sterile gauze to control bleeding.

• Place contaminated articles into a sharps container to reduce risk for needle stick injuries.
• Remove gloves, wash hands to reduce transmission of microorganisms.
• Document in the file the date, time and type of sample taken.

COLLECTING BLOOD SAMPLE USING A TOURNIQUET

• Apply tourniquet, clean area, prick the vein and if blood is coming out you are in the vein. Draw the amount needed for the ordered test and release the tourniquet.

• Apply pressure with a dry swab after withdrawing the needle to prevent bleeding from the punctured site.

• Observe and leave the patient comfortably.
• Dispose the equipment safely into a sharps box.

URINE SPECIMEN

Urine specimen remains an important tool for clinical diagnosis. A correct urine result is influenced by the collection method, timing and handling. The laboratory test ordered determines the type of container to be used for collecting a specimen.

TYPES OF COLLECTION

Laboratory urine specimens are classified by the type of collection conducted or by the collection procedure used to obtain the specimen.

RANDOM SPECIMEN

This is the specimen most commonly sent to the laboratory for analysis, primarily because it is the easiest to obtain and is readily available. This specimen is usually submitted for urinalysis and microscopy analysis.

FIRST MORNING SPECIMEN

This is the specimen of choice for urinalysis and microscopic analysis, since the urine is generally more concentrated due to the length of time urine is allowed to remain in the bladder and, therefore, contains relatively higher levels of cellular elements and analytes such as protein, if present. It is Also called an 8hour urine specimen.

NOTE: any urine that is voided from the bladder during the eight hour collection period is pooled and refrigerated, so that a true 8hour specimen is obtained.

MIDSTREAM CLEAN CATCH SPECIMEN

This is the preferred type of specimen for culture and sensitivity testing because of the reduced incidence of cellular and microbial contamination. The patient should then void the first portion of the urine out. The urine midstream is then collected into a clean container, (any excess urine should be voided into the toilet). This method of collection can be conducted at any time of day or night.

CATHETER COLLECTION SPECIMEN.

This assisted procedure is conducted when a patient is bedridden or cannot urinate independently. The healthcare provider inserts a Foley catheter into the bladder through the urethra to collect the urine specimen. Specimen may as well be collected through an existing Foley catheter.

DEEP SPECIMEN COLLECTION

• Specimens for wound, lesion, abscess, drainage, effusions, exudates, boils, incisions or ulcerations are best collected by aspirating with a syringe and needle.
• Using aseptic technique, clean the area in and over the lesions with sterile saline and sterile gauze prior to collection.
• Debride skin lesions, removing the crust and any purulent exudates with the moistened gauze.

• Since delay and exposure to oxygen can kill these organisms, prompt receipt in the laboratory is paramount.
• Best results are obtained for cultures when specimen is collected from the area closest to the normal tissue after removal of debris the dried pus.

STOOL SPECIMEN

• Collect stool specimens in containers provided by the laboratory. Specimen should be well covered and labeled.
• For culture only or both culture and parasite examination the specimen must be returned to the laboratory within one hour of collection.
• If more than one specimen has been ordered they should be collected on alternate days for best results.

COMMON BLOOD COLLECTION TUBES AND LARORATORY USES

The evacuated tube system for blood collection in use for various laboratory tests consists of tubes of various sizes, with color coded tops indicating tube contents. Most blood collection tubes contain an additive that either accelerates clotting of the blood (clot activator) or prevents the blood from clotting (anticoagulant).

SPECIMEN TRANSPORT CONTAINERS

Specimen or sample transport containers are ideal for holding and storing a variety of laboratory equipment and samples, including:

• Clinical and Phlebotony samples
• Blood bags and/or tissue/organ samples
• Public Health samples
• Laboratory instruments

CULTURE MEDIA

A microbiological culture medium is a substance that encourages the growth, support, and survival of microorganisms. Culture media contains nutrients, growth promoting factors, energy sources, minerals, metals, and gelling agents. Culture media can be liquid, solid or semi-solid.

TYPES OF CULTURE MEDIA

• All-purpose or nutritive – This supports growth of a wide variety of bacteria but does not support fastidious bacteria.
• Selective -This type supports growth of one type of organism while inhibiting growth of others.
• Differential – contains chemicals or dyes that alter the appearance of certain bacterial types; used in biochemical testing
• Enriched-contains complex organic materials that certain fastidious species must have in order to multiply; blood agar, needed for the growth of Streptococcus pyogenes, is made by adding sterile sheep blood to an all-purpose medium used to cultivate pathogens.