|BIOCHEMISTRY AND IMMUNOLOGY||CLINICAL PATHOLOGY|
|HISTOPATHOLOGY / CYTOLOGY||MICROBIOLOGY|
PATIENT PREPARATION AND INSTRUCTIONS FOR VARIOUS LABORATORY INVESTIGATIONS
The following instructions are to be followed for specified investigations. If the patient preparation is inappropriate it may significantly affect the performance of the examination or the interpretation of results.
A. ROUTINE CLINICAL BIOCHEMISTRY:
FBS (Fasting Blood Sugar) : Overnight fasting.
ESR (Erythrocyte Sedimentation Rate) : Overnight fasting
TFT (Thyroid Function Test) : Overnight fasting
PPBS (Post Prandial Blood Sugar) : 1 hr 45 min after finishing meals.
URIC ACID : Overnight fasting
LIPID PROFILE : 10 to 12 hours fasting and alcohol abstinence on the evening prior to test
DRUG ASSAY : Patient to come after at least 8 hours of taking the medicine.
B. PREPARATION FOR GLUCOSE TOLERANCE TEST(OGTT):
i. FOR ADULTS (MALES & NON PREGNANT FEMALES)
Patient should be on normal carbohydrate diet, abstain from drugs and undue exercise 3 days prior to the test. Patient should be fasting for 10-12 hrs for the test preferably overnight.
After the fasting sample is collected the patient is given 75 gm of glucose dissolved in 150-200 ml of water for drinking within 5-7 minutes. Blood and urine samples are collected after 30 min, 60 min, 90 min and 120 min of glucose intake.
ii. OTHER VARIANTS OF GTT (AS PER THE PROTOCOLS REQUESTED BY THE CLINICIANS)
(a) With 75 gm of glucose and samples during fasting and after 1hr and 2hrs of glucose intake.
(b) With 75 gm of glucose and samples during fasting and after 2hrs of glucose intake.
iii. FOR GESTATIONAL DIABETES: (AS PER THE PROTOCOLS REQUESTED BY THE CLINICIANS)
(c) With 75 gm of glucose and samples during fasting and after 1hr and 2hrs of glucose intake.
(d) With 100 gm of glucose and samples during fasting and after 1hr, 2hrs and 3 hrs of glucose intake.
iv. OGTT IN CHILDREN.
GTT is rarely done in children. After collection of baseline fasting samples glucose is given as per the weight of the patient (1.75g/kg), up to a maximum of 75 gm. Glucose is dissolved in 100-150 ml of water and the patient has to the patient it within 5-7 minutes. Blood and urine sample is collected after 2 hrs of glucose intake.
C. PREPARATION FOR GLUCOSE CHALLENGE TEST:
This test is done during pregnancy and this test can be done without regard to time of day or time of last meal. 50 gm of glucose dissolved in 150-200 ml of water is given to the patient to drink within 5-7 minutes. Blood sample is collected 1 hr after glucose intake.
D. CLINICAL PATHOLOGY:
URINE FOR PREGNANCY TEST- First morning sample is preferred.
STOOL FOR OCCULT BLOOD- Should avoid Non vegetarian diet,hard tooth brushing and ingestion of asprin like drugs for atleast three days prior to the test. Sample should be brought to the lab at the earliest.
SEMEN ANALYSIS-Patient to abstain from sexual intercourse for at least 3 days. It is collected by masturbation in a clean wide mouth screw capped container.
Testosterone (Free/Total): Sample to be drawn in the morning hours.
Cortisol: Morning samples are collected at 8 am and evening samples are collected at 4 pm. Time should be noted for monitoring.
i.ROUTINE URINE EXAMINATION
Routine urine examination reveals the presence or absence of certain substances like glucose, proteins, ketones, nitrites, bilirubin which could be an indication of certain diseases like diabetes mellitus, jaundice, infection etc Routine examination is done by directly visualizing urine under the microscope.
URINE COLLECTION TECHNIQUE FOR MALES
Wash the hands with soap and water.Clean the genital area with soap and water, dry with tissue, open the cap of the sterile container (avoid touching inside of container), void into toilet for few seconds and without stopping the urine flow collect the sample (Minimum 5ml) in the container. Stopping the flow increases the risk of contaminated sample. Make sure that urine stream does not touch the fingers. Cap tightly and avoid touching inside the container .Submit the container to the lab as soon as possible.
URINE COLLECTION TECHNIQUES FOR FEMALES
Wash the hands with soap and water. Clean the genital area with soap and water, dry with tissue, open the cap of the sterile container (avoid touching inside of container), void into toilet for few seconds and without stopping the urine flow collect the sample in the sterile container as stopping the flow increases the risk of contaminated sample. Make sure that urine stream does not touch the fingers. Cap tightly and avoid touching inside the container. Submit the container to lab as soon as possible.
URINE COLLECTION TECHNIQUES FOR CHILDREN
If a child is toilet trained then a mid stream sample is collected in a similar fashion as in case of adults. In case of infants genital & private area is cleaned and child is encouraged to drink oral fluids and subsequently urine sample is collected by the parents/ attendants in a similar fashion.
Blood in urine could indicate infection, stones etc. Pus cells could indicate infection. Casts could indicate real disease. Crystals like oxalate, urate etc. are seen following high dietary intake of food rich in these minerals.
ii URINE CULTURE AND SENSITIVITY
Urine culture is done to isolate bacteria causing infection in urinary system. We take 2 days for culture and sensitivity For urine culture, the urine is plated on culture plate which provide nutrition for the bacteria to grow. After overnight incubation bacteria grow on the media and then are replated on media on which different antibiotic discs are put and again after overnight incubation we see which antibiotics are able to prevent the growth of the bacteria.
Morning sample of urine is the ideal sample for culture, but a sample can be collected at any time of the day after proper cleaning and washing the area with soap and water to prevent bacteria from the surrounding areas from entering the urine or this will give you erroneous result.
Remove the lid from the collection container. Be careful not to touch the inside of the lid or the inside of the container.Hold the collection container with your fingers on the outside of the container.Do not touch the rim of the container.Begin urinating. After the urine has passed for several seconds, put the container in the urine stream and collect the urine.When the container is full, remove it from the urine stream and finish urinating in the toilet.Put the lid back on the container.
Urine sample should be brought to the lab as soon as possible (within 1-2 hours of collection) as the urine provides an excellent source of nutrition to the bacteria present and the bacteria multiply and will give a wrong result when tested after a longer time interval In case there is a delay the sample can be placed inside the refrigerator (not freezer)
The patient is instructed not to eat or drink anything for at least an hour before sample collection. A sterile cotton swab used to collect a throat swab. The patient is asked to protrude the tongue and elevate the uvula. A tongue depressor is used to collect samples from children. The swab is rubbed with rotation over one tonsillar area, then the arch of the soft palate and uvula, the other tonsillar area and finally the posterior pharynx.The swab should be replaced in its tube.
Sputum should be collected in a disposable, wide mouthed, screw capped sterile (in case of culture) plastic container. It should be collected before any antibiotic therapy is begun. First morning sample of sputum is collected. The patient is instructed to forcefully expectorate the sputum into the container, avoiding spilling over the rim. It is tightly screw capped. The specimen is delivered to the laboratory as quickly as possible, preferably within 2 hours.
v. PUS OR EXUDATE:
This should be submitted in a sterile screw-capped bottle. Swabs should be loaded well with the material. Two swabs should preferably be collected, one for microscopy and the other for culture.
G.COLLECTION OF BODY FLUIDS
i. C.S.F. SAMPLE CSF Sample collected by referring physician; should reach lab within 30
min preferably & latest by 1 hour.
ii. OTHER BODY FLUIDS are collected by the in house doctors or from the referring doctors.
iii. PAP SMEARS/VAGINAL SWAB & FNAC are collected by the doctors with assistance of technicians.
H FINE NEEDLE ASPIRATION
A fine needle aspiration (FNA) is a procedure that helps provide information about the cause of a lump or mass.A pathologist uses a very thin needle to remove cells from the lump. This needle is thinner than those used to draw blood. The sample is sent to the lab to be looked at under a microscope.Most people do not have any pain during this procedure. A local anesthetic (a drug that numbs an area of your body) is not commonly used because it can be more uncomfortable than the procedure. After the FNA, the site is covered with a bandage and you can return to your normal activities.
The side effects in some patients at the site are mild pain for 1 to 2 days, bruising, hematoma (clotted or partially clotted blood under the skin, usually caused by a broken blood vessel)