SOME LABORATORY PROCEDURES

UNSUITABLE SAMPLE

• 
  Unlabeled or incorrectly labeled samples or specimens
• 
  The container of stool is full
• 
  Sputum sample contaminated with food particles or other substances
• 
  Insufficient samples such as urine and blood

Actions we can take

• 
  Inform the ward sister to send a repeat sample
• 
  If the sample is insufficient, clotted, contaminated or heamolysed inform the ward sister immediately for a repeat sample and document in the repeat sample register
• 
  If it is an OPD patient, try to contact the patient and explain the problem to the patient
• 
  If the OPD sample is insufficient or unsuitable on receiving, ask for a repeat sample before registering

Patient preparation for different laboratory test

• 
  Fasting blood sugar
  Ask the patient to fast for 8 hours
• Post parandial blood sugarCollect blood 2 hours from the time of taking food
• Post glucose blood sugarPatient is ask to come after 8 hours fasting, 50grams of glucose is given orally and blood is collected after 2 hours
• 
  Oral Glucose Tolerance TestAsk the patient to fast 8 hours
  Ask the patient to bring 100 grams glucose packet and a lemon
  Patient is asked to collect a fasting urine sample and blood is collected
  Patient is given 75 grams of glucose
  Take 3 more blood sample.
  Instruct the patient to collect a urine sample with each blood sample
• 
  Lipid profileInstruct the patient to come for blood collection after 13 hours fasting
• 
  

Urine collection for routine test

The container need not to be sterile but
should be free from detergents and other impurities.
Minimum of 10ml should be collected.
For urinary porphobilinogen urine sample should be collected in a dark bottle
Collection of stool for routine test
The container for specimen collection need not be sterile
It should be a clean, leak proof, disinfectant free, wide mouthed.
The faeces specimen should not be contaminated with urine
Instruct the patient to collect a very little amount of stool.( 1 – 2 grams )

MANTOUX TEST


Materials required1.Spirit swab
2.Dry swab
3.Tuberculin PPD ( 10TU/0.1ml ), make sure that it comes to room temperature before administering and check the expiry date.
4.Tuberculin syringe

PROCEDURE

• The preferred site for the test is the flexor dorsal surface of the forearm about 4 inches below the elbow join
• Clean the chosen site by using 70% alcohol or spirit and allow to dry
• The stopper of the PPD vial is cleaned with spirit or 70% alcohol
• 0.1ml of the Tuberculin PPD solution is drawn into the sterile tuberculin syringe fitted with a short 26 – gauge needle
• Insert the needle-point with the bevelled side upwards so that the needle opening is visible
• Stretch the skin between finger and thumb
• Hold the needle almost parallel to the skin
• PPD is injected intradermally by inserting the tip of the needle into the most superficial layers of the skin with needle bevel pointing upwards
• As the solution is injected a pale white bleb, 6 – 10 mm in diameter will rise at the needle point

NOTE

• If significant part of the dose leaks from the injection site, the result should be repeated immediately at another site, 5 cms away from the first site
• Instruct the patient not to scratch the area and not to apply any lotion or cosmetics
• Instruct the patient to come to the laboratory for result of the Mantoux test which should be read at 40 – 72 hours after the injection