ABG analyzer.txt

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ABG analyzer.txt
2012-02-04 03:16:41
Quiz ABG analyzer

Quiz for ABG analyzer
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  1. What are the measurements that are directly obtained?
    pH, PCO2, PO2
  2. What are the measurements that are indirectly obtained?
    HCO3, BE, Hb saturation, and correction for Temp.
  3. What are the six components of the gas analyzer?
    operator interface, measuring chamber w/ three electrode system, Calibrating gas tanks, Reagent containers, Waste container, and results display/storgae/transmittal system.
  4. What does the Sanz electrode measure?
  5. What does the Stowe-Severinghaus electrode measure?
  6. What does the clark electrode measure?
  7. Consists of two electrodes(1/2cells); a measureing and a reference electrode. ? When two solutions of different pH values are separated by a hydrogen ion (H+) permeable glass membrane, a potential difference develops that can be measured as a voltage change across the membrane.
  8. is an electrode that supplies a constant reference voltage and is usually composed of mercury-mercurous chloride (calomel), housed in a compartment filled with potassium chloride (KCl) solution
    reference half-cell (part of the Sanz)
  9. is the Sanz electrode, usually composed of a silver-silver chloride substance imbedded within a 6.840 phosphate buffer solution inside the chamber.
    measuring half-cell
  10. measures carbon dioxide tensions by allowing the CO2 gas to undergo a chemical reaction that produces hydrogen ions.? This electrode is essentially a pH electrode exposed to a electrolyte solution that is in equilibrium with the sample through a carbon dioxide-permeable membrane. The hydrogen ions produced from the chemical reaction cause a difference in potential that is measured by the half-cells.
    Stowe-Severinghaus electrode
  11. What are the measureing half-cells made up of in the Stowe-Severinghaus electrode?
    silver-silver chloride
  12. is a polarographic device that measures oxygen tensions by oxidation/reduction reactions, a chemical process that generates measurable electrical currents.The electrode is bathed in an electrolyte solution with an oxygen-permeable, polypropylene membrane covering the cathode tip. ? An external polarizing voltage of approximately -0.6 V is applied to the cathode and is required to minimize the interference of other gases that can also be reduced and to maximize oxygen reduction.
    Clark electrode
  13. The polarographic electrode of the clark electrode consists of?
    platinum cathode and Silver andoe connected by a KCL bridge.
  14. Complications of the electrode include: permeablity of the electrode caused by damage or protein build up, use of an incorrect buffer will alter readings.
    Sanz Electrode
  15. Complications of this electrode include: problems w/ the membrane or glass, can be worn or cracked, protein build up, use of wrong buffer, allowing the bicarbonate solution to dry will all corrupt the data.
    Stowe-Severinghaus electrode
  16. Complications from this electrode have to do with: Worn membranes, Protein build up on membrane, Cracked electrode, Loss of or incorrect electrolyte solution, there is a blood gas factor, which is as the oxygen in the sample is consumed it is not replenished from the blood and the oxygen reading is reduced about 2% to 6%, Other gases such as nitrous oxide and halothane can alter readings by increasing the production of peroxide ions
    Clark electrode
  17. Evaluation of the adequacy of ventilation, acid base, oxygenation, O2 capcity of blood. Need to evaluate the responmce of theraputic intervention, mechanical intervention, and diagnostic evaluation of O2 therapy and exercise.
  18. An improper fuctioning analyzer, the performance had not been validated by quality control or proficiency testing, sample with preanalytical errors, contamination, improper anticoagulation, improper storage or handling, incomplete requisition the precludes adequate interpretation, and an inadequately labled sample.
  19. Infection of specimen handler from blood, inappropriate patient mediacl treatment, based on an improperly analyzed sample, analysis of unacceptable sample, or incorrect reporting of sample are what when dealing with gas analyzers?
    Hazards and possible complications
  20. What should you monitor before running a sample?
    No air bubbles, assurance that a coninuous sample is aspirated into analyzer, all electrodes are covered by sample, 8-hr quality control and calibration has been done, and assurance the sample was labled properly.
  21. is an evaluation of services provided and the results achieved as compared with accepted standards
    Quality assurance
  22. What are the four parts of quality aeeurance?
    Recordkeeping, Performance validation, preventative maintanance and function checks, and automated calibration.
  23. is an adjustment of the electronic response to a single standard. This should be accomplished before each sample analysis or every 30 min. (Some newer machines are constantly calibrating.)
    One point calibration or balance
  24. One point calibration is the balance point and uses a near normal pH buffer (around XXXX), a PCO2 gas concentration of YYY* and a PO2 gas concentration of ZZZZ* is generally used.
    XXXX = 7.384 YYYY=5% ZZZZ=12-20%
  25. adjusts the electronic responses to 2 standards. This should be accomplished every 2 to 8 hours (usually done every 4) and after electrode maintenance and repair measures.
    Two-Point calibration
  26. The slope point, for two point calibration uses a pH buffer of XXXX, PCO2 of YYYYY* and a PO2 gas concentration of ZZZZ.
    XXX=6.840 YYYY=10% ZZZZ=0%
  27. To determine the expected calibration readings for the PO2 and PCO2 systems, Dalton�s law of partial pressures must be applied. What is it?
    (PB � 47 mm Hg) x % gas concentration
  28. What is the standard deviation range used in determining the presence of analytical error
    +/- 2 SD ranges
  29. The reference materials are manufactured by the blood gas instrument manufacturers, The majority of these materials are aqueous solutions of a known pH with known partial pressures of dissolved gases, Most companies manufacture three levels, ensuring that the instruments is tested over a wide physiological range of values, Some employ tonometry- the rapid equilibration of known gas samples with whole blood samples are all apart of?
    Quality control methods
  30. takes blood gas analysis from the specialized laboratory to the patient�s bedside, This reduces turnaround time, which should improve care and lower costs, Individual cartridges are used at patient bedside and the cartridges are introduced into a portable analyzer for readout, The cartridge system requires no operator oversight because it is self-calibrating and disposable after a single use, The cartridges are single use and disposed of after use is all apart of?
    Point of care testing
  31. hemoximetry, It is a laboratory analytical procedure requiring invasive sampling of arterial blood
  32. are spectrophotometers that simultaneously analyze four hemoglobin moieties: Oxyhemoglobin (O2Hb), Reduced hemoglobin (RHb), Carboxyhemoglobin (COHb) or (HbCO), and Methemoglobin (metHb)
  33. What are the four hemoglobins measured by the co-oximeter?
    O2Hb, COHb, matHb, and RHb (HHb).
  34. Know the parts of the Stowe. electrode?
  35. Know the parts to the Clark electrode.
  36. Know the parts of the Sanz electrode.
  37. When a diluted, hemolyzed sample is introduced, an absorbance reading is obtained at each wavelength, Each concentration is obtained by calculation using this information. The total hemoglobin is the sum of the four calculated concentrations. The percentage concentration values are then derived for O2Hb, COHb, metHb, and RHb, a light source, a series of lenses, filters, mirrors that focus the light beam, a cuvette or sample chamber, a monochromator that isolates the wavelengths of interest using filters or gratings, and photodiode detectors that emit electrons in proportion to the amount of light that strike their surfaces, The emitted electrons (current) are fed to a circuit whose output is proportional to the relative absorbance of the sample. What is this the pricippal operation of?