POCT PART 2

• Point-of-Care Testing (POCT)


  Also known as alternate site testing (AST) or ancillary, bedside, or near-patient testing
• POCT


  • Development of small, portable, and often handheld testing devices
• POCT


  • Convenience to the patient
  • Short turnaround time (TAT)
• POCT operation


  1. Quality Control

  2. Maintenance Procedures

  3. Meets the requirements of CLIA and OSHA
• Waived Tests


  Does not require quality checks in the level of moderately complex tests
• Quality Control (QC)


  1. External liquid control be performed only by the manufacturer's instructions

  2. Electronic QCs (ECQs) - detect problems with the specimen and internal checks
• Coagulation Monitoring by POCT

  • Activated Clotting Time (ACT)
  • Prothrombin Time/INR
  • Activated Partial Thromboplastin Time (APTT/PTT)
  • Platelet function
  • Bleeding Time
• Activated Clotting Time (ACT)

  Analyzes activity of intrinsic coagulation factors, used to monitor heparin therapy
• Prothrombin Time/INR


  • Monitor warfarin (Coumadin) therapy
  • INR = (PT patient/PT normal)ISI
  • ISI = International Sensitivity Index (manufacturer reagent)
• Activated Partial Thromboplastin Time (APTT/PTT)

  Screen bleeding disorders prior to surgery, clotting disorders, clotting factor deficiencies (extrinsic), and monitor low-dose heparin therapy
• Platelet Function


  • Determine patient's response to medication before open heart surgery or cardiac catheterization
  • Prevent excessive bleeding or blood clots
• Bleeding Time


  • The time required for blood to stop flowing from a standardized puncture on the inner surface of the forearm
  • Detects platelet function disorders and capillary integrity problems
  • Prone to sources of error
• Arterial Blood Gases measured by POCT

  • pH
  • Partial pressure of carbon dioxide (PCO2)
  • Oxygen saturation (SO2)
  • Partial pressure of oxygen (PO2)
• pH


  • Potential hydrogen, acidity/alkalinity of a solution, indicates metabolic and respiratory status
  • Normal range 7.35 - 7.45
• PCO2


  • Measures the pressure exerted by dissolved CO2 in the plasma and is proportional to the PCO2 in the alveoli
  • Abnormal increase: hypoventilation
  • Abnormal decrease: hyperventilation
• PO2


  • Measure the pressure exerted by dissolved O2 in the blood plasma and indicates the ability of the lungs to diffuse O2 through the alveoli into the blood
  • Used to evaluate the effectiveness of O2 therapy
• SO2


  • Measure of the percentage of hemoglobin binding sites occupied by oxygen in the blood stream
  • Oxygenation status
  • Normal is around 98%
  • Below 90% - hypoxemia and cyanosis
• Electrolytes


  • Sodium (Na+)
  • Potassium (K+)
  • Chloride (Cl-)
  • Bicarbonate (HCO3-)
  • Ionized Calcium (iCa2+)
• Sodium


  • The most plentiful electrolyte in the blood
  • Plays a major role in maintaining osmotic pressure and acid–base balance and in transmitting nerve impulses
  • Hyponatremia, Hypernatremia
• Potassium


  • Plays a major role in nerve conduction, muscle function, acid–base balance, and osmotic pressure
  • Hypokalemia, Hyperkalemia
• Chloride


  Responsible for maintaining cellular integrity by influencing osmotic pressure and both acid–base and water balance
• Bicarbonate


  Role in transporting carbon dioxide (CO2) to the lungs and in regulating blood pH
• Ionized Calcium


  • 45% of the calcium in the blood
  • Critical functions as muscular contraction, cardiac function, transmission of nerve impulses, and blood clotting
• Multiple-Test-Panel Monitoring by POCT

  • BUN, glucose, lactate, hemoglobin and potassium
• Cardiac Troponin T and I


  • Proteins specific to heart muscle
  • Blood levels begin to rise within 4 hours of the onset of myocardial damage and may stay elevated for up to 14 days (TnT)
  • Levels rise within 3 to 6 hours and return to normal in 5 to 10 days (TnI)
  • Used to diagnose Acute Myocardial Infarction (AMI)
• Other Tests Performed by POCT

  • Lipid Testing (Cholesterol, Triglyceride, LDL, HDL, ALT)
  • B-type Natriuretic Peptide (BNP)
  • C-Reactive Protein (CRP)
  • Glucose
  • Glycemic Index Control
  • Glycosylated Hemoglobin
  • Hematocrit
  • Hemoglobin
  • Lactate
  • Occult Blood (Guaiac) in stool
  • Pregnancy Testing
  • Skin Tests
  • Strep Testing
  • Urinalysis