CO2 Absorbents

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CO2 Absorbents
2013-11-09 20:35:10
Anesthesia Exam

Exam 2
Show Answers:

  1. What is the end product of cellular metabolism?
  2. How is CO2 removed from the body?
    CO2 is transported by the blood to the alveoli where it is excreted by the body thru ventilation.
  3. The average CO2 production is around:
    ___L/hr in an adult.
    • 4ml/kg/min
    • ~14L/h
  4. The activator of soda lime is ____ or ____.
    NaOH or KOH
  5. What are added as hardeners to make up soda lime?
    Silica and Kieselguhr
  6. What color is Sodasorb (such as ethyl violet) when it is fresh (not used)?? What about when it is exhausted?

    purple when exhausted.
  7. What is the purpose of the CO2 absorber??
    it makes rebreathing possible, thus conserving gases and volatile agents, decreases OR pollution and avoids hazards of CO2 rebreathing.
  8. What causes the change in color of the granules present in soda lime?
    the change in PH changes the colors of the granules
  9. Small pellets/granules provide ______ surface areas in comparison to larger pellets.  Smaller pellets/granules ______ resistance.  They also ____ caking.
    • greater surface areas (which  means they can absorb more)
    • increase resistance
    • increase caking
  10. The size of absorbents are measured by _____ _____.
    mesh number.
  11. What is the size of all absorbent granules? What does this mean?
    4-8 mesh, meaning they will pass thru screens with 4-8 holes per linear inch
  12. Which size pellets are generally used in CO2 absorbers?
    large and small for best CO2 reabsorption results!
  13. High alkali absorbents contain high amounts of ____ or _____.  These substances can react to form ___ ____.
    KOH or NaOH

    They can react to form carbon monoxide
  14. Alkali free agents contain _____.

    • These agents are very expensive.
  15. How does exhaustion of granules without color change occur?
    channeling or inactivation of indicator along the canister walls by UV light can cause exhaustion without color change.
  16. Hardening agents are added to CO2 absorbents for what purpose?
    to reduce the amount of dust formed..

    this dust is caustic and irritant--its a strong base.
  17. What can be used to prevent dust from the CO2 absorber from reaching the patient?
    a filter can be added to the inspiratory side of the system to prevent dust from reaching the patient.
  18. What is an HME?
    • a humidification device, it is not a filter
    • keeps patients from drying out
  19. What is the purpose of filters in the breathing system???
    to filter dust and bacteria.
  20. When should you check your CO2 absorber???
    at the end of each case and several times throughout the day.... the granules can be inactivated when not in use... make sure to label and date when you change your canisters
  21. Sevoflurane is unstable in soda lime... it produces ______ __.
    Compound A
  22. What patients should you not use sevoflurane with???
    Renal insufficiency-- if the patient is in the hospital for acute complications.

    If renal disease its okay to use bc these patients are prolly on dialysis**
  23. It is not recommended to use Sevoflurane at FGF less than ??
  24. Desflurane produces ????
    What causes it to occur more often??
    • Cabron Monoxide
    • happen more in Baralyme than Soda Lime

    it occurs more often if the absorbent is dry...therefore you want to make sure to turn off the o2 at the end of cases, at the end of the day, and use low flows (keeps granules moist)
  25. What are the positives of using Lithum hydroxide line as an absorbent??
    • 1.  Does not produce carbon monoxide.
    • 2.  Does not produce Compound A.
    • 3.  Undergoes a permanent color change.
    • 4.  Generates less heat than Soda Lime.
    • 5.  Comparable in price to Soda Lime.
  26. What is the catalyst of Lithium hydroxide lime (litholyme)?
  27. What color was baralyme before use and at exhaustion???
    colorless or pink and changed to blue-gray
  28. What are some signs of CO2 exhaustion???
    • 1. increased end tidal CO2
    • 2. increased bleeding at surgical site
    • 3. signs of SNS activation -- flushed, cardiac irregularities, sweating
    • 4. r. acidosis
    • 5. hyperpnea
    • Last signs---dysrhythmias and a rise (later a fall) in HR AND BP

    *** dark or cherry red blood is not an indicator of CO2 exhaustion...
  29. Where should the fresh canister be place when changing out CO2 canisters??
    Put the fresh canister on the bottom.  Promote the bottom canister to the top.
  30. When you change the canisters you should ALWAYS remember to do what two things???
    • 1. always remove the plastic
    • 2. recheck for circuit leaks
  31. Soda lime is composed of what percentages of the following:
    CaOH _____
    • 80
    • 4
    • 1
    • 15
  32. Can  you change your canisters mid case??
    NO!!! increase your FGF to ensure CO2 levels are decreased.

    • change FGF to 1-2 x minute ventilation
    • or >5L/min
  33. You don't have to memorize the chemistry behind soda lime.. but what two things should you know???
    The reaction involves heat and it is a neutralization reaction between an acid (CO2) and a base (the absorbers).
  34. What is the predominant component of Soda lime??
    Calcium Hydroxide
  35. What are the final products of reactions with Soda Lime??
    • 1. Calcium Carbonate
    • 2. Regenerated NaOH and KOH (these are the catalyst or activators)

    catalyst--is a substance that increases the rate of a chemical reaction without itself undergoing any change...therefore KOH and NaOH is a final product of the reaction
  36. What is ethylene violent in the Soda Lime granules??
    the pH sensitive indicator

    Turns purple in response to increase levels of H ions
  37. CO2 absorbers absorb approx. ___ of its weight in CO2.
  38. ____gm of CO2 absorbers will absorb approximately ___ L of CO2.
    • 100 gm
    • 26 L
  39. How does used gas flow thru the CO2 absorber?? What about fresh gas??
    • used gas flows downward
    • fresh gas flows upward

    ***therefore, the top absorber changes color first.
  40. What are some safety measures to remember with CO2 absorbers???
    • 1. don't sniff
    • 2. don't shake
    • 3. wear gloves
    • 4. wash hands
    • 5. its a strong base!! so be careful!!
    • 6. make sure to take plastic off canister