5 - POCT Flashcards
What is Point of Care Testing (POCT)
Clinical testing is done at the patient’s side (point of patient care) rather than in the clinical laboratory.
Not a replace for clinical testing but a supplement
Testing done in the emergency rooms, critical care units, clinics and nursing homes
Most frequent test is Glucose
Other tests blood gas analysis, coagulation tests and common chemistry tests such as for electrolytes and cardiac enzymes
Training
Point of care testing may be performed by nurses, RPN’s , laboratory technicians and laboratory technologists.
Formal training in preventive maintenance and quality control procedures is required for the personnel who perform point of care testing.
A training program that includes proper specimen collection, instrument operation and calibration and a strictly enforced quality control program is essential for laboratory results that are reliable reproducible and accurate.
Fasting Specimens (FBS)
- The patients eat or drink nothing other than water for a 8 to 12 hours prior to having their blood drawn.
- Common test are cholesterol, triglycerides and glucose determinations.
- phlebotomist’s responsibility
• CDA new recommendation for OGTT
: that anyone with a risk factor for diabetes and a fasting plasma glucose level between 5.7 and 6.9 mmol/L should be considered for an oral 2 hr glucose tolerance test
• OGTT can be in conjunction with hemoglobin A1C levels
• A1C – optimal glycemic control (usually ≤ 7%)
Oral Glucose Tolerance Test (OGTT) used for?
• Used to diagnose carbohydrate metabolism disorders such as diabetes mellitus (lack of insulin) and hypoglycemia(low blood sugar).
• The Canadian Diabetes Association’s 2003 clinical
practice guidelines for diabetes mellitus——-
fasting plasma glucose test 7.0 mmol/L or more
Test Procedure OGTT
• The fasting patient is given a standard amount of glucose (75g -100g for adults) to drink within 5 minutes.
- Blood and urine samples are then taken at periodic intervals to determine how long it takes the patient to metabolize the glucose.
- The length of the test may vary from 2 to 6 hours.
- The phlebotomist responsibility
- The patient fast for the 12 hours
- The patient may not smoke or chew gum during the fasting period because digestion may be stimulated and interfere with the test results.
- They should eat a balanced diet that contains at least 150 to 200 grams of carbohydrate per day for 3 days before the test. Fruits, breads, cereals, grains, rice, crackers, and starchy vegetables such as potatoes, beans, and corn are good sources of carbohydrate.
- The test begins with the collection of a fasting blood specimen and a urine sample.
- Some patients may vomit after drinking the glucose drink. Notify the physician and ask whether to continue the test.
- Timing for specimen collection begins as soon as the glucose solution is consumed.
- A blood specimen and a urine specimen are collected at 30 minutes and then at hourly intervals for the remainder of the test.
- All specimens should be labeled as to the time they were drawn and their order in the test.
Therapeutic Drug Monitoring.
- Measures the amount of a particular medication in the patient’s bloodstream (dependent on age, age, metabolic rate, kidney function etc)
- Used to determine the optimal dose of a medication for a patient.
- Two blood samples are needed (trough and peak levels.)
- The trough level is the least amount of the medication found in the blood just prior to administration of the net dose of medication.
- The peak level occurs when the largest amount of the medication is found in the bloodstream. The drawing time of the peak level varies with the type of medication.
- cortisol and iron is affected by the time of day
Trace Metals
- Tested for trace metals such as arsenic or lead.
* The blood must be collected in a royal blue stoppered metal free tube. (no anticoagulant)
Alcohol Levels
- When drawing for alcohol testing, use a disinfectant solution other that alcohol.
- Solutions such as zephrin chloride, soap or hydrogen peroxide are acceptable.
- Do not use Betadine, iodine swabs or chlorohexadine because these contain alcohol.
- Care must also be taken with these specimens because the results are often needed for legal reasons.
WHO CAN ORDER A TEST
The health professionals currently authorized include:
• Doctors
• Dentists
• Nurses (extended class) – nurse practitioners
• Midwives
PROTOCOL FOR REPEAT COLLECTIONS
- NSQ
- Hemolysis
- Sample taken in wrong container
- Incorrect patient
- Sample needed to verify and confirm test result
WHAT DO YOU DO IF THE SAMPLE CANNOT BE PROCESSED IMMEDIATELY
Storage temperature is specified as room temperature (15 - 30°C), refrigerated (2 to 10°C) or frozen (-20°C or colder).
What is the difference between a MLT and MLA/T
A medical laboratory technologist (MLT) is a regulated health professional in Ontario, as defined by the Medical Laboratory Technology Act, 1991. Medical laboratory assistants and medical laboratory technicians are not regulated in Ontario.
