Skill 304Dr.Mohammad Marie

Lecture \ 4

Samples

Learning objectivesTo know what is the meaning of blood

culture.To recognize types of urine samples .To learn procedure of urine specimen

collection.To learn procedure of sputum specimen

collection.To learn some information about fecal

specimen collection.

Blood culture

Blood cultureBlood culture : is a microbiological

culture of blood. It is employed to detect infections that are spreading through the bloodstream (such as bacteremia or  septicemia amongst others). This is possible because the bloodstream is usually a sterile environment.

N.B : blood does not have a normal microbial flora .

Blood cultureWhenever possible blood should be collected

before antimicrobial treatment has started .1- when the patient has recurring fever collect

the blood as the temperature begins to rise .2- for other patients collect the blood as soon

as possible after receiving the request .* To increase the chance of isolating a

pathogen it is usually recommended that at least two specimens are collected at different times.

Urine collectionUn timed urine sample (random) ( single

sample )Timed urine sample ( 24 H sample )First Morning SpecimenMidstream Clean Catch SpecimenCatheter Collection SpecimenPediatric Specimen

Urine collection1- Random SpecimenThis 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 microscopic analysis, although it is not the specimen of choice for either of these tests.

Random specimens can sometimes give an inaccurate view of a patient's health if the specimen is too diluted and analytic values are artificially lowered.

Urine collectionAs the name implies, the

random specimen can be collected at any time. Although there are no specific guidelines for how the collection should be conducted, avoiding the introduction of contaminants into the specimen is recommended. This requires explicit instructions to patients so that they do not touch the inside of the cup or cup lid.

Urine collection2- Timed Collection SpecimenAmong the most commonly performed tests

requiring timed specimens are those measuring creatinine, urine urea nitrogen, glucose, sodium, potassium that are affected by diurnal variations.

A timed specimen is collected to measure the concentration of these substances in urine over a specified length of time .

Urine collection1- You should collect every drop of urine during

each 24-hour period. It does not matter how much or little urine is passed each time, as long as every drop is collected.

2- Begin the urine collection in the morning after you wake up, after you have emptied your bladder for the first time.

3- Urinate (empty the bladder) for the first time and flush it down the toilet. Note the exact time (e.g, 5:00 AM). You will begin the urine collection at this time.

Urine collection4- Collect every drop of urine during the day and

night in an empty collection bottle. Store the bottle at room temperature or in the refrigerator.

5- If you need to have a bowel movement, any urine passed with the bowel movement should be collected.

6- Finish by collecting the first urine passed the next morning, adding it to the collection bottle. This should be within ten minutes before or after the time of the first morning void on the first day (which was flushed). In this example, you would try to void between 4:50 and 5:10 on the second day.

Urine collectionIt is not recommended that the

patient void directly into the 24 hour collection container due to the preservative acid content inside the container.

The patient is encouraged to void into a separate (beaker style collection with pour spout ) cup and pour the contents into the 24 hour collection container during the collection process.

Urine collection3-First Morning SpecimenThis is the specimen of choice for urinalysis

and microscopic analysis, since the urine is generally more concentrated (due to the length of time the urine is allowed to remain in the bladder) .

Also called an 8-hour specimen, the first morning specimen is collected when the patient first wakes up in the morning, having emptied the bladder before going to sleep.

Urine collection4- Midstream Clean Catch SpecimenThis is the preferred type of specimen for culture

and sensitivity testing because of the reduced incidence of cellular and microbial contamination.

Patients are required to first cleanse the urethral area with soap . The patient should then void the first portion of the urine stream into the toilet. These first steps significantly reduce the opportunities for contaminants to enter into the urine stream. The urine midstream is then collected into a clean container . This method of collection can be conducted at any time of day or night.

Urine collection

Urine collection5- Catheter Collection

SpecimenThis assisted procedure

is conducted when a patient is bedridden or cannot urinate independently. The healthcare provider inserts a Foley’s catheter into the bladder through the urethra to collect the urine specimen.

Urine collection6- Pediatric SpecimenFor infants and small

children, a special urine collection bag is adhered to the skin surrounding the urethral area. Once the collection is completed, the urine is poured into a collection cup or transferred directly into an evacuated tube with a transfer straw.

sputumMaterial required is From the lower

respiratory tract expectorated by deep coughing .

Sputum specimen collection can be either self-expectorated or mechanically obtained.

Sputum samples should be collected in the morning before breakfast if possible , because sputum collects during the night.

PROCEDURE1- Wash hands thoroughly 2- Assemble necessary equipment.3- Confirm the patient’s identity using two

patient identifiers.4- Tell the patient that : * you will collect a specimen of sputum (not

saliva) and explain the procedure. * The cup is very clean. So Don’t open it

until you are ready to use it.

PROCEDURE5- Instruct the patient to sit in a chair or at the

edge of the bed. If the patient cannot sit up place him in high Fowler’s position.

* Place the head of the bed at 30° for semi-Fowler's, 45° to 60° for Fowler's, and 90° for high Fowler's

PROCEDURE6- Ask the patient to rinse his/ her mouth with

water (avoid mouthwash solution or toothpaste).

7- Tell patient to cough deeply and expectorate directly into the specimen container. Ask the patient to produce at least 15ml of sputum.

PROCEDURE8- Cap the container and if necessary, clean its

exterior.

Sputum collectionPurpose :For the detection of the causative agent of

pneumonia or tuberculosis .Examples of common causative agents of bacterial

pneumonia:Streptococcus pneumoniae,Haemophilus influenzae,Staphylococcus aureus,Klebsiella pneumoniae,Escherichia coli, andPseudomonas aeruginosa.

Fecal Collect the stool in a dry, clean, leak-proof container.Make sure no urine, water, soil or other material gets

in the container.Insure that the specimen containers are sealed well. 

Reinforce with parafilm or other suitable material.Insert the container in a plastic bag.Certain drugs and compounds will render the stool

specimens unsatisfactory for examination.  The specimens should be collected before these substances are administered, or collection must be delayed until after the effects have passed.

Thank you